|
Hi Tommy, ? I suspect the track overheated by someone tuning while at full power and running a hight SWR. I presume you do have full power control and can turn it down? ? KR ? Andrew ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Tommy Wooten via groups.io
Sent: 13 February 2025 01:26
To: [email protected]
Subject: Re: [ic7000] IC7000 no HF Transmit? 
GREAT NEWS!!!? I found the problem and resolved it. The problem was an open circuit on one side of L305 output transformer.? The open circuit was caused by a manufacturing flaw (quality control). I removed L305 to inspect it and possibly replace if necessary.? I have attached a photo of the issue.? There is missing board trace material on one of the input legs as compared to the other leg. To repair this, I soldered a small piece of copper foil in this area.? I then reinstalled the transformer, reset the bias currents.? Voila!!!? Tx is now working. ?100W out as designed, power meter, ALC and SWR meter are working.? Fantastic.? I also made a 59 contact on 20 meters. This is a very strange find.? I don't know much about the history of this radio, but how could this radio have ever?worked?? To me this is a blatant quality control issue at ICOM.? Oh well, I now have a working IC7000 at a great price. I want to thank all those who pushed me to track down the issue.? Especially Andrew who suggested replacing L305 in the beginning. Thank you, thank you, thank you ? ? I appreciate all the instructions and advice from Andrew, JD and James. ? It has been a few days since I last did any testing. ? So far, I have found nothing that is causing the output power to be so low. ? I did go back and check the DRIVER/FINAL IDLING CURRENT as defined in section 4-4 of the service manual.? The idle current is set to 2.5A for the driver and HF-1 and HF-2.? Then I checked the voltage at the base of each PA transistor.? I observed the following: What can cause these to be different? ? I do see that the output signal at each drain is not a clean sign wave. ?(See attached). Then, the combined signal at the output of transformer L305 seems to show two out of phase signals. ? I have done a little more troubleshooting around the LPF final filter section.? I unplugged the cable from the main board to the PA.? I set the freq to 14.2 MHz.? I separated the output of L305 transformer and injected a 14.2 signal into C327 and looked at ant1 with a scope.? When I pushed tx the signal is seen at a reduced level at ant1.? I also saw the signal reduce at the input when tx is activated.? The signal level was 7 volts and is reduced to 3.5 volts when tx is activated. I also saw 0 ohm resistance of the tx path of the RL801 at tx.? I also saw 0 ohms resistance inward side of C327 and C972 at tx. I just chose 14.2 but all the filter paths are similar. Please provide comments and suggestions. 20% high does not sound too bad!!
It is when they drop low and you lose 90% will be the issue.
73
Andrew
?Get BlueMail for Android ?
On 30 Jan 2025, 20:28, at 20:28, "Tommy Wooten via " <kf4rwg=[email protected]> wrote:
>JD
>I think Andrew suggested that capacitors may be the issue.? There are
>two
>large smt capacitors in the filter section after the PA section.? I
>removed
>these and measured them.? The result is as follows:
>C327 = 942 nF
>C972 = 811 nF
>
>These are rated at 680 nF and measure 20 to 30% high in value.
>
>I will check other caps in the path before the driver.
>
>Any thoughts?
>
>Tommy
>
>
>
>
>On Wed, Jan 29, 2025 at 1:02?PM J.D. Barron via
><jeter.d.barron=
>[email protected]> wrote:
>
>> RL801 may not be making good contact. You can check the levels with
>your
>> scope. I would use SSB and whistle in the Mike for tracing to keep
>the
>> power dissipation low.
>>
>> On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via
><jeter.d.barron=
>> [email protected]> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> [email protected]> wrote:
>>>
>> JD
>>>>
>>>> I was able to access each of the relay leads from the top side of
>the PA
>>>> board.? I found that each relay had the 14VR supplied at the relay
>coil.
>>>> The voltage is 10.5V and falls to 9.2V when tx is activated.? I
>verified
>>>> that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when
>activated
>>>> by the appropriate band selection.? PHT8 at RL801 acted same when
>tx is
>>>> activated.
>>>> All gnd readings were 130mV except RL941 read 363mV as an
>observation.
>>>> All relays seem to click appropriately when each band was selected.
>>>> I cannot access IC981 since it is on the bottom side of PA.? But
>from
>>>> the info above it indicates it is working correctly.
>>>>
>>>> This does not explain why I was able to see 6W at the output of
>L305 but
>>>> I see negligible power when it passes through the filters.? There
>must be a
>>>> short or open in path.
>>>>
>>>> No smoking gun yet!
>>>>
>>>> I won’t stop until I find the issue or tear something up.
>>>>
>>>> Thanks
>>>> Tommy
>>>>
>>>> On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via
>>>> <jeter.d.barron=[email protected]> wrote:
>>>>
>>>>>
>>>>> (PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2)
>(changes
>>>>> from orange to blue and out through (A). to
>>>>> (PA 3) the bandpass filters. There are a pair of relays that have
>to be
>>>>> energized for each frequency band. The input relays are controlled
>by L1 -
>>>>> L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from
>IC981.
>>>>> (Powered by 3R3V)
>>>>>
>>>>> 14 VR provides the operating voltage for these relays and the
>output
>>>>> relays. (At this point I have to say I have not looked long enough
>and hard
>>>>> enough to understand how the output relays are activated but they
>must be.)
>>>>> as each band is selected by L1 - L7 going low.
>>>>> VR14 comes from RL701 output through L981 and resistors R1002 (150
>ohm)
>>>>> and 1003 (180 ohm) (paralleled). This line also provides power to
>RL801
>>>>> which would also stop the RF power from getting to the bandpass
>filters
>>>>> HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would
>cause
>>>>> this problem as well. One of the anti-flyback diodes shorted could
>take out
>>>>> these resistors
>>>>>
>>>>> I think that as each L1 - L7 goes low that low is transferred via
>the
>>>>> blue line to the normally closed contact on the relay below to
>ground on
>>>>> the unenergized relay (I think).
>>>>>
>>>>> I would verify that the VR14 voltage is present first and then -
>if
>>>>> present
>>>>>
>>>>> I would look for the L1 - L7 signals being pulled low by Q980 -
>Q987.
>>>>> end then If switching I would look to
>>>>> The outputs on IC981.
>>>>>
>>>>> I believe you will find the problem in this area as you are
>drawing
>>>>> current indicating power being produced (unless the current is not
>in the
>>>>> 1-3 Amp range in SSB no modulation idling current).
>>>>>
>>>>> Since the power is not going through L961 the FOR / REV (SWR)
>>>>> transformer and being read by IC060 (JFOR) the RF drive is going
>to the
>>>>> point of current limit and cannot be adjusted in any carrier mode
>with the
>>>>> power adjustment.
>>>>>
>>>>> Just my best guess without making some measurements, but this is
>where
>>>>> I would start.
>>>>>
>>>>> Good luck and best regards.
>>>>>
>>>>>? JD
>>>>> KE4MD
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>
>>
>
>
>
|
Nice work Tommy!
?
It’s so gratifying to fix this stuff even after all these years.
?
My wife still asks why I don’t send the radio off for repair, I do know a guy close by that services these. I explained again, that fixing anything yourself
is the reward.
Give it the old college try!
?
73-
W1JCW
John
?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]>
On Behalf Of Tommy Wooten via groups.io
Sent: Wednesday, February 12, 2025 7:26 PM
To: [email protected]
Subject: Re: [ic7000] IC7000 no HF Transmit
?
GREAT NEWS!!!? I found the problem and resolved it.
The problem was an open circuit on one side of L305 output transformer.? The open circuit was caused by a manufacturing flaw (quality control).
I removed L305 to inspect it and possibly replace if necessary.? I have attached a photo of the issue.? There is missing board trace material on one of the input legs as compared to the other leg.
To repair this, I soldered a small piece of copper foil in this area.? I then reinstalled the transformer, reset the bias currents.? Voila!!!? Tx is now working. ?100W out as designed, power meter, ALC and SWR meter are working.? Fantastic.?
I also made a 59 contact on 20 meters.
This is a very strange find.? I don't know much about the history of this radio, but how could this radio have ever?worked?? To me this is a blatant quality control issue at ICOM.? Oh well, I now have a working IC7000 at a great price.
I want to thank all those who pushed me to track down the issue.? Especially Andrew who suggested replacing L305 in the beginning.
Thank you, thank you, thank you
?
?
I appreciate all the instructions and advice from Andrew, JD and James. ?
It has been a few days since I last did any testing. ? So far, I have found nothing that is causing the output power to be so low. ?
I did go back and check the DRIVER/FINAL IDLING CURRENT as defined in section 4-4 of the service manual.? The idle current is set to 2.5A for the driver and HF-1 and HF-2.? Then I checked the voltage at the base of each PA transistor.?
I observed the following:
What can cause these to be different? ?
I do see that the output signal at each drain is not a clean sign wave. ?(See attached). Then, the combined signal at the output of transformer L305 seems to show two out of phase signals.
?
I have done a little more troubleshooting around the LPF final filter section.? I unplugged the cable from the main board to the PA.? I set the freq to 14.2 MHz.? I separated the output of L305 transformer and injected a 14.2 signal into
C327 and looked at ant1 with a scope.? When I pushed tx the signal is seen at a reduced level at ant1.? I also saw the signal reduce at the input when tx is activated.? The signal level was 7 volts and is reduced to 3.5 volts when tx is activated.
I also saw 0 ohm resistance of the tx path of the RL801 at tx.? I also saw 0 ohms resistance inward side of C327 and C972 at tx.
I just chose 14.2 but all the filter paths are similar.
Please provide comments and suggestions.
20% high does not sound too bad!!
It is when they drop low and you lose 90% will be the issue.
73
Andrew
?Get BlueMail for Android
?
On 30 Jan 2025, 20:28, at 20:28, "Tommy Wooten via " <kf4rwg=[email protected]> wrote:
>JD
>I think Andrew suggested that capacitors may be the issue.? There are
>two
>large smt capacitors in the filter section after the PA section.? I
>removed
>these and measured them.? The result is as follows:
>C327 = 942 nF
>C972 = 811 nF
>
>These are rated at 680 nF and measure 20 to 30% high in value.
>
>I will check other caps in the path before the driver.
>
>Any thoughts?
>
>Tommy
>
>
>
>
>On Wed, Jan 29, 2025 at 1:02?PM J.D. Barron via
><jeter.d.barron=
>[email protected]> wrote:
>
>> RL801 may not be making good contact. You can check the levels with
>your
>> scope. I would use SSB and whistle in the Mike for tracing to keep
>the
>> power dissipation low.
>>
>> On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via
><jeter.d.barron=
>> [email protected]> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via
<kf4rwg=
>>> [email protected]> wrote:
>>>
>> JD
>>>>
>>>> I was able to access each of the relay leads from the top side of
>the PA
>>>> board.? I found that each relay had the 14VR supplied at the relay
>coil.
>>>> The voltage is 10.5V and falls to 9.2V when tx is activated.? I
>verified
>>>> that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when
>activated
>>>> by the appropriate band selection.? PHT8 at RL801 acted same when
>tx is
>>>> activated.
>>>> All gnd readings were 130mV except RL941 read 363mV as an
>observation.
>>>> All relays seem to click appropriately when each band was selected.
>>>> I cannot access IC981 since it is on the bottom side of PA.? But
>from
>>>> the info above it indicates it is working correctly.
>>>>
>>>> This does not explain why I was able to see 6W at the output of
>L305 but
>>>> I see negligible power when it passes through the filters.? There
>must be a
>>>> short or open in path.
>>>>
>>>> No smoking gun yet!
>>>>
>>>> I won’t stop until I find the issue or tear something up.
>>>>
>>>> Thanks
>>>> Tommy
>>>>
>>>> On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via
>>>> <jeter.d.barron=[email protected]> wrote:
>>>>
>>>>>
>>>>> (PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2)
>(changes
>>>>> from orange to blue and out through (A). to
>>>>> (PA 3) the bandpass filters. There are a pair of relays that have
>to be
>>>>> energized for each frequency band. The input relays are controlled
>by L1 -
>>>>> L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from
>IC981.
>>>>> (Powered by 3R3V)
>>>>>
>>>>> 14 VR provides the operating voltage for these relays and the
>output
>>>>> relays. (At this point I have to say I have not looked long enough
>and hard
>>>>> enough to understand how the output relays are activated but they
>must be.)
>>>>> as each band is selected by L1 - L7 going low.
>>>>> VR14 comes from RL701 output through L981 and resistors R1002 (150
>ohm)
>>>>> and 1003 (180 ohm) (paralleled). This line also provides power to
>RL801
>>>>> which would also stop the RF power from getting to the bandpass
>filters
>>>>> HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would
>cause
>>>>> this problem as well. One of the anti-flyback diodes shorted could
>take out
>>>>> these resistors
>>>>>
>>>>> I think that as each L1 - L7 goes low that low is transferred via
>the
>>>>> blue line to the normally closed contact on the relay below to
>ground on
>>>>> the unenergized relay (I think).
>>>>>
>>>>> I would verify that the VR14 voltage is present first and then -
>if
>>>>> present
>>>>>
>>>>> I would look for the L1 - L7 signals being pulled low by Q980 -
>Q987.
>>>>> end then If switching I would look to
>>>>> The outputs on IC981.
>>>>>
>>>>> I believe you will find the problem in this area as you are
>drawing
>>>>> current indicating power being produced (unless the current is not
>in the
>>>>> 1-3 Amp range in SSB no modulation idling current).
>>>>>
>>>>> Since the power is not going through L961 the FOR / REV (SWR)
>>>>> transformer and being read by IC060 (JFOR) the RF drive is going
>to the
>>>>> point of current limit and cannot be adjusted in any carrier mode
>with the
>>>>> power adjustment.
>>>>>
>>>>> Just my best guess without making some measurements, but this is
>where
>>>>> I would start.
>>>>>
>>>>> Good luck and best regards.
>>>>>
>>>>>? JD
>>>>> KE4MD
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>
>>
>
>
>
|
 GREAT NEWS!!!? I found the problem and resolved it.
The problem was an open circuit on one side of L305 output transformer.? The open circuit was caused by a manufacturing flaw (quality control). I removed L305 to inspect it and possibly replace if necessary.? I have attached a photo of the issue.? There is missing board trace material on one of the input legs as compared to the other leg.
To repair this, I soldered a small piece of copper foil in this area.? I then reinstalled the transformer, reset the bias currents.? Voila!!!? Tx is now working. ?100W out as designed, power meter, ALC and SWR meter are working.? Fantastic.? I also made a 59 contact on 20 meters.
This is a very strange find.? I don't know much about the history of this radio, but how could this radio have ever?worked?? To me this is a blatant quality control issue at ICOM.? Oh well, I now have a working IC7000 at a great price.
I want to thank all those who pushed me to track down the issue.? Especially Andrew who suggested replacing L305 in the beginning.
Thank you, thank you, thank you
Tommy KF4RWG
I appreciate all the instructions and advice from Andrew, JD and James. ?
It has been a few days since I last did any testing. ? So far, I have found nothing that is causing the output power to be so low. ?
I did go back and check the DRIVER/FINAL IDLING CURRENT as defined in section 4-4 of the service manual.? The idle current is set to 2.5A for the driver and HF-1 and HF-2.? Then I checked the voltage at the base of each PA transistor.? I observed the following:
Q301 = 4.3V Q302 = 2.4 V
What can cause these to be different? ? I do see that the output signal at each drain is not a clean sign wave. ?(See attached). Then, the combined signal at the output of transformer L305 seems to show two out of phase signals.
Any suggestions?
Thanks again Tommy KF4RWG I have done a little more troubleshooting around the LPF final filter section.? I unplugged the cable from the main board to the PA.? I set the freq to 14.2 MHz.? I separated the output of L305 transformer and injected a 14.2 signal into C327 and looked at ant1 with a scope.? When I pushed tx the signal is seen at a reduced level at ant1.? I also saw the signal reduce at the input when tx is activated.? The signal level was 7 volts and is reduced to 3.5 volts when tx is activated.
I also saw 0 ohm resistance of the tx path of the RL801 at tx.? I also saw 0 ohms resistance inward side of C327 and C972 at tx.
I just chose 14.2 but all the filter paths are similar.
Please provide comments and suggestions.
Thanks Tommy
20% high does not sound too bad!!
It is when they drop low and you lose 90% will be the issue.
73
Andrew
?Get BlueMail for Android ?
On 30 Jan 2025, 20:28, at 20:28, "Tommy Wooten via " <kf4rwg=[email protected]> wrote:
>JD
>I think Andrew suggested that capacitors may be the issue.? There are
>two
>large smt capacitors in the filter section after the PA section.? I
>removed
>these and measured them.? The result is as follows:
>C327 = 942 nF
>C972 = 811 nF
>
>These are rated at 680 nF and measure 20 to 30% high in value.
>
>I will check other caps in the path before the driver.
>
>Any thoughts?
>
>Tommy
>
>
>
>
>On Wed, Jan 29, 2025 at 1:02?PM J.D. Barron via
><jeter.d.barron=
>[email protected]> wrote:
>
>> RL801 may not be making good contact. You can check the levels with
>your
>> scope. I would use SSB and whistle in the Mike for tracing to keep
>the
>> power dissipation low.
>>
>> On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via
><jeter.d.barron=
>> [email protected]> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> [email protected]> wrote:
>>>
>> JD
>>>>
>>>> I was able to access each of the relay leads from the top side of
>the PA
>>>> board.? I found that each relay had the 14VR supplied at the relay
>coil.
>>>> The voltage is 10.5V and falls to 9.2V when tx is activated.? I
>verified
>>>> that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when
>activated
>>>> by the appropriate band selection.? PHT8 at RL801 acted same when
>tx is
>>>> activated.
>>>> All gnd readings were 130mV except RL941 read 363mV as an
>observation.
>>>> All relays seem to click appropriately when each band was selected.
>>>> I cannot access IC981 since it is on the bottom side of PA.? But
>from
>>>> the info above it indicates it is working correctly.
>>>>
>>>> This does not explain why I was able to see 6W at the output of
>L305 but
>>>> I see negligible power when it passes through the filters.? There
>must be a
>>>> short or open in path.
>>>>
>>>> No smoking gun yet!
>>>>
>>>> I won’t stop until I find the issue or tear something up.
>>>>
>>>> Thanks
>>>> Tommy
>>>>
>>>> On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via
>>>> <jeter.d.barron=[email protected]> wrote:
>>>>
>>>>>
>>>>> (PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2)
>(changes
>>>>> from orange to blue and out through (A). to
>>>>> (PA 3) the bandpass filters. There are a pair of relays that have
>to be
>>>>> energized for each frequency band. The input relays are controlled
>by L1 -
>>>>> L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from
>IC981.
>>>>> (Powered by 3R3V)
>>>>>
>>>>> 14 VR provides the operating voltage for these relays and the
>output
>>>>> relays. (At this point I have to say I have not looked long enough
>and hard
>>>>> enough to understand how the output relays are activated but they
>must be.)
>>>>> as each band is selected by L1 - L7 going low.
>>>>> VR14 comes from RL701 output through L981 and resistors R1002 (150
>ohm)
>>>>> and 1003 (180 ohm) (paralleled). This line also provides power to
>RL801
>>>>> which would also stop the RF power from getting to the bandpass
>filters
>>>>> HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would
>cause
>>>>> this problem as well. One of the anti-flyback diodes shorted could
>take out
>>>>> these resistors
>>>>>
>>>>> I think that as each L1 - L7 goes low that low is transferred via
>the
>>>>> blue line to the normally closed contact on the relay below to
>ground on
>>>>> the unenergized relay (I think).
>>>>>
>>>>> I would verify that the VR14 voltage is present first and then -
>if
>>>>> present
>>>>>
>>>>> I would look for the L1 - L7 signals being pulled low by Q980 -
>Q987.
>>>>> end then If switching I would look to
>>>>> The outputs on IC981.
>>>>>
>>>>> I believe you will find the problem in this area as you are
>drawing
>>>>> current indicating power being produced (unless the current is not
>in the
>>>>> 1-3 Amp range in SSB no modulation idling current).
>>>>>
>>>>> Since the power is not going through L961 the FOR / REV (SWR)
>>>>> transformer and being read by IC060 (JFOR) the RF drive is going
>to the
>>>>> point of current limit and cannot be adjusted in any carrier mode
>with the
>>>>> power adjustment.
>>>>>
>>>>> Just my best guess without making some measurements, but this is
>where
>>>>> I would start.
>>>>>
>>>>> Good luck and best regards.
>>>>>
>>>>>? JD
>>>>> KE4MD
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>
>>
>
>
>
|
I appreciate all the instructions and advice from Andrew, JD and James. ?
It has been a few days since I last did any testing. ? So far, I have found nothing that is causing the output power to be so low. ?
I did go back and check the DRIVER/FINAL IDLING CURRENT as defined in section 4-4 of the service manual.? The idle current is set to 2.5A for the driver and HF-1 and HF-2.? Then I checked the voltage at the base of each PA transistor.? I observed the following:
Q301 = 4.3V Q302 = 2.4 V
What can cause these to be different? ? I do see that the output signal at each drain is not a clean sign wave. ?(See attached). Then, the combined signal at the output of transformer L305 seems to show two out of phase signals.
Any suggestions?
Thanks again Tommy KF4RWG I have done a little more troubleshooting around the LPF final filter section.? I unplugged the cable from the main board to the PA.? I set the freq to 14.2 MHz.? I separated the output of L305 transformer and injected a 14.2 signal into C327 and looked at ant1 with a scope.? When I pushed tx the signal is seen at a reduced level at ant1.? I also saw the signal reduce at the input when tx is activated.? The signal level was 7 volts and is reduced to 3.5 volts when tx is activated.
I also saw 0 ohm resistance of the tx path of the RL801 at tx.? I also saw 0 ohms resistance inward side of C327 and C972 at tx.
I just chose 14.2 but all the filter paths are similar.
Please provide comments and suggestions.
Thanks Tommy
20% high does not sound too bad!!
It is when they drop low and you lose 90% will be the issue.
73
Andrew
?Get BlueMail for Android ?
On 30 Jan 2025, 20:28, at 20:28, "Tommy Wooten via " <kf4rwg=[email protected]> wrote:
>JD
>I think Andrew suggested that capacitors may be the issue.? There are
>two
>large smt capacitors in the filter section after the PA section.? I
>removed
>these and measured them.? The result is as follows:
>C327 = 942 nF
>C972 = 811 nF
>
>These are rated at 680 nF and measure 20 to 30% high in value.
>
>I will check other caps in the path before the driver.
>
>Any thoughts?
>
>Tommy
>
>
>
>
>On Wed, Jan 29, 2025 at 1:02?PM J.D. Barron via
><jeter.d.barron=
>[email protected]> wrote:
>
>> RL801 may not be making good contact. You can check the levels with
>your
>> scope. I would use SSB and whistle in the Mike for tracing to keep
>the
>> power dissipation low.
>>
>> On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via
><jeter.d.barron=
>> [email protected]> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> [email protected]> wrote:
>>>
>> JD
>>>>
>>>> I was able to access each of the relay leads from the top side of
>the PA
>>>> board.? I found that each relay had the 14VR supplied at the relay
>coil.
>>>> The voltage is 10.5V and falls to 9.2V when tx is activated.? I
>verified
>>>> that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when
>activated
>>>> by the appropriate band selection.? PHT8 at RL801 acted same when
>tx is
>>>> activated.
>>>> All gnd readings were 130mV except RL941 read 363mV as an
>observation.
>>>> All relays seem to click appropriately when each band was selected.
>>>> I cannot access IC981 since it is on the bottom side of PA.? But
>from
>>>> the info above it indicates it is working correctly.
>>>>
>>>> This does not explain why I was able to see 6W at the output of
>L305 but
>>>> I see negligible power when it passes through the filters.? There
>must be a
>>>> short or open in path.
>>>>
>>>> No smoking gun yet!
>>>>
>>>> I won’t stop until I find the issue or tear something up.
>>>>
>>>> Thanks
>>>> Tommy
>>>>
>>>> On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via
>>>> <jeter.d.barron=[email protected]> wrote:
>>>>
>>>>>
>>>>> (PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2)
>(changes
>>>>> from orange to blue and out through (A). to
>>>>> (PA 3) the bandpass filters. There are a pair of relays that have
>to be
>>>>> energized for each frequency band. The input relays are controlled
>by L1 -
>>>>> L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from
>IC981.
>>>>> (Powered by 3R3V)
>>>>>
>>>>> 14 VR provides the operating voltage for these relays and the
>output
>>>>> relays. (At this point I have to say I have not looked long enough
>and hard
>>>>> enough to understand how the output relays are activated but they
>must be.)
>>>>> as each band is selected by L1 - L7 going low.
>>>>> VR14 comes from RL701 output through L981 and resistors R1002 (150
>ohm)
>>>>> and 1003 (180 ohm) (paralleled). This line also provides power to
>RL801
>>>>> which would also stop the RF power from getting to the bandpass
>filters
>>>>> HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would
>cause
>>>>> this problem as well. One of the anti-flyback diodes shorted could
>take out
>>>>> these resistors
>>>>>
>>>>> I think that as each L1 - L7 goes low that low is transferred via
>the
>>>>> blue line to the normally closed contact on the relay below to
>ground on
>>>>> the unenergized relay (I think).
>>>>>
>>>>> I would verify that the VR14 voltage is present first and then -
>if
>>>>> present
>>>>>
>>>>> I would look for the L1 - L7 signals being pulled low by Q980 -
>Q987.
>>>>> end then If switching I would look to
>>>>> The outputs on IC981.
>>>>>
>>>>> I believe you will find the problem in this area as you are
>drawing
>>>>> current indicating power being produced (unless the current is not
>in the
>>>>> 1-3 Amp range in SSB no modulation idling current).
>>>>>
>>>>> Since the power is not going through L961 the FOR / REV (SWR)
>>>>> transformer and being read by IC060 (JFOR) the RF drive is going
>to the
>>>>> point of current limit and cannot be adjusted in any carrier mode
>with the
>>>>> power adjustment.
>>>>>
>>>>> Just my best guess without making some measurements, but this is
>where
>>>>> I would start.
>>>>>
>>>>> Good luck and best regards.
>>>>>
>>>>>? JD
>>>>> KE4MD
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>
>>
>
>
>
|
I appreciate all the instructions and advice from Andrew, JD and James. ?
It has been a few days since I last did any testing. ? So far, I have found nothing that is causing the output power to be so low. ?
I did go back and check the DRIVER/FINAL IDLING CURRENT as defined in section 4-4 of the service manual.? The idle current is set to 2.5A for the driver and HF-1 and HF-2.? Then I checked the voltage at the base of each PA transistor.? I observed the following:
Q301 = 4.3V Q302 = 2.4 V
What can cause these to be different? ? I do see that the output signal at each drain is not a clean sign wave. ?(See attached). Then, the combined signal at the output of transformer L305 seems to show two out of phase signals.
Any suggestions?
Thanks again Tommy KF4RWG
I have done a little more troubleshooting around the LPF final filter section.? I unplugged the cable from the main board to the PA.? I set the freq to 14.2 MHz.? I separated the output of L305 transformer and injected a 14.2 signal into C327 and looked at ant1 with a scope.? When I pushed tx the signal is seen at a reduced level at ant1.? I also saw the signal reduce at the input when tx is activated.? The signal level was 7 volts and is reduced to 3.5 volts when tx is activated.
I also saw 0 ohm resistance of the tx path of the RL801 at tx.? I also saw 0 ohms resistance inward side of C327 and C972 at tx.
I just chose 14.2 but all the filter paths are similar.
Please provide comments and suggestions.
Thanks Tommy
20% high does not sound too bad!!
It is when they drop low and you lose 90% will be the issue.
73
Andrew
?Get BlueMail for Android ?
On 30 Jan 2025, 20:28, at 20:28, "Tommy Wooten via " <kf4rwg=[email protected]> wrote:
>JD
>I think Andrew suggested that capacitors may be the issue.? There are
>two
>large smt capacitors in the filter section after the PA section.? I
>removed
>these and measured them.? The result is as follows:
>C327 = 942 nF
>C972 = 811 nF
>
>These are rated at 680 nF and measure 20 to 30% high in value.
>
>I will check other caps in the path before the driver.
>
>Any thoughts?
>
>Tommy
>
>
>
>
>On Wed, Jan 29, 2025 at 1:02?PM J.D. Barron via
><jeter.d.barron=
>[email protected]> wrote:
>
>> RL801 may not be making good contact. You can check the levels with
>your
>> scope. I would use SSB and whistle in the Mike for tracing to keep
>the
>> power dissipation low.
>>
>> On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via
><jeter.d.barron=
>> [email protected]> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> [email protected]> wrote:
>>>
>> JD
>>>>
>>>> I was able to access each of the relay leads from the top side of
>the PA
>>>> board.? I found that each relay had the 14VR supplied at the relay
>coil.
>>>> The voltage is 10.5V and falls to 9.2V when tx is activated.? I
>verified
>>>> that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when
>activated
>>>> by the appropriate band selection.? PHT8 at RL801 acted same when
>tx is
>>>> activated.
>>>> All gnd readings were 130mV except RL941 read 363mV as an
>observation.
>>>> All relays seem to click appropriately when each band was selected.
>>>> I cannot access IC981 since it is on the bottom side of PA.? But
>from
>>>> the info above it indicates it is working correctly.
>>>>
>>>> This does not explain why I was able to see 6W at the output of
>L305 but
>>>> I see negligible power when it passes through the filters.? There
>must be a
>>>> short or open in path.
>>>>
>>>> No smoking gun yet!
>>>>
>>>> I won’t stop until I find the issue or tear something up.
>>>>
>>>> Thanks
>>>> Tommy
>>>>
>>>> On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via
>>>> <jeter.d.barron=[email protected]> wrote:
>>>>
>>>>>
>>>>> (PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2)
>(changes
>>>>> from orange to blue and out through (A). to
>>>>> (PA 3) the bandpass filters. There are a pair of relays that have
>to be
>>>>> energized for each frequency band. The input relays are controlled
>by L1 -
>>>>> L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from
>IC981.
>>>>> (Powered by 3R3V)
>>>>>
>>>>> 14 VR provides the operating voltage for these relays and the
>output
>>>>> relays. (At this point I have to say I have not looked long enough
>and hard
>>>>> enough to understand how the output relays are activated but they
>must be.)
>>>>> as each band is selected by L1 - L7 going low.
>>>>> VR14 comes from RL701 output through L981 and resistors R1002 (150
>ohm)
>>>>> and 1003 (180 ohm) (paralleled). This line also provides power to
>RL801
>>>>> which would also stop the RF power from getting to the bandpass
>filters
>>>>> HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would
>cause
>>>>> this problem as well. One of the anti-flyback diodes shorted could
>take out
>>>>> these resistors
>>>>>
>>>>> I think that as each L1 - L7 goes low that low is transferred via
>the
>>>>> blue line to the normally closed contact on the relay below to
>ground on
>>>>> the unenergized relay (I think).
>>>>>
>>>>> I would verify that the VR14 voltage is present first and then -
>if
>>>>> present
>>>>>
>>>>> I would look for the L1 - L7 signals being pulled low by Q980 -
>Q987.
>>>>> end then If switching I would look to
>>>>> The outputs on IC981.
>>>>>
>>>>> I believe you will find the problem in this area as you are
>drawing
>>>>> current indicating power being produced (unless the current is not
>in the
>>>>> 1-3 Amp range in SSB no modulation idling current).
>>>>>
>>>>> Since the power is not going through L961 the FOR / REV (SWR)
>>>>> transformer and being read by IC060 (JFOR) the RF drive is going
>to the
>>>>> point of current limit and cannot be adjusted in any carrier mode
>with the
>>>>> power adjustment.
>>>>>
>>>>> Just my best guess without making some measurements, but this is
>where
>>>>> I would start.
>>>>>
>>>>> Good luck and best regards.
>>>>>
>>>>>? JD
>>>>> KE4MD
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>
>>
>
>
>
|
I have done a little more troubleshooting around the LPF final filter section.? I unplugged the cable from the main board to the PA.? I set the freq to 14.2 MHz.? I separated the output of L305 transformer and injected a 14.2 signal into C327 and looked at ant1 with a scope.? When I pushed tx the signal is seen at a reduced level at ant1.? I also saw the signal reduce at the input when tx is activated.? The signal level was 7 volts and is reduced to 3.5 volts when tx is activated.
I also saw 0 ohm resistance of the tx path of the RL801 at tx.? I also saw 0 ohms resistance inward side of C327 and C972 at tx.
I just chose 14.2 but all the filter paths are similar.
Please provide comments and suggestions.
Thanks Tommy
20% high does not sound too bad!!
It is when they drop low and you lose 90% will be the issue.
73
Andrew
?Get BlueMail for Android ?
On 30 Jan 2025, 20:28, at 20:28, "Tommy Wooten via " <kf4rwg=[email protected]> wrote:
>JD
>I think Andrew suggested that capacitors may be the issue.? There are
>two
>large smt capacitors in the filter section after the PA section.? I
>removed
>these and measured them.? The result is as follows:
>C327 = 942 nF
>C972 = 811 nF
>
>These are rated at 680 nF and measure 20 to 30% high in value.
>
>I will check other caps in the path before the driver.
>
>Any thoughts?
>
>Tommy
>
>
>
>
>On Wed, Jan 29, 2025 at 1:02?PM J.D. Barron via
><jeter.d.barron=
>[email protected]> wrote:
>
>> RL801 may not be making good contact. You can check the levels with
>your
>> scope. I would use SSB and whistle in the Mike for tracing to keep
>the
>> power dissipation low.
>>
>> On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via
><jeter.d.barron=
>> [email protected]> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> [email protected]> wrote:
>>>
>> JD
>>>>
>>>> I was able to access each of the relay leads from the top side of
>the PA
>>>> board.? I found that each relay had the 14VR supplied at the relay
>coil.
>>>> The voltage is 10.5V and falls to 9.2V when tx is activated.? I
>verified
>>>> that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when
>activated
>>>> by the appropriate band selection.? PHT8 at RL801 acted same when
>tx is
>>>> activated.
>>>> All gnd readings were 130mV except RL941 read 363mV as an
>observation.
>>>> All relays seem to click appropriately when each band was selected.
>>>> I cannot access IC981 since it is on the bottom side of PA.? But
>from
>>>> the info above it indicates it is working correctly.
>>>>
>>>> This does not explain why I was able to see 6W at the output of
>L305 but
>>>> I see negligible power when it passes through the filters.? There
>must be a
>>>> short or open in path.
>>>>
>>>> No smoking gun yet!
>>>>
>>>> I won’t stop until I find the issue or tear something up.
>>>>
>>>> Thanks
>>>> Tommy
>>>>
>>>> On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via
>>>> <jeter.d.barron=[email protected]> wrote:
>>>>
>>>>>
>>>>> (PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2)
>(changes
>>>>> from orange to blue and out through (A). to
>>>>> (PA 3) the bandpass filters. There are a pair of relays that have
>to be
>>>>> energized for each frequency band. The input relays are controlled
>by L1 -
>>>>> L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from
>IC981.
>>>>> (Powered by 3R3V)
>>>>>
>>>>> 14 VR provides the operating voltage for these relays and the
>output
>>>>> relays. (At this point I have to say I have not looked long enough
>and hard
>>>>> enough to understand how the output relays are activated but they
>must be.)
>>>>> as each band is selected by L1 - L7 going low.
>>>>> VR14 comes from RL701 output through L981 and resistors R1002 (150
>ohm)
>>>>> and 1003 (180 ohm) (paralleled). This line also provides power to
>RL801
>>>>> which would also stop the RF power from getting to the bandpass
>filters
>>>>> HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would
>cause
>>>>> this problem as well. One of the anti-flyback diodes shorted could
>take out
>>>>> these resistors
>>>>>
>>>>> I think that as each L1 - L7 goes low that low is transferred via
>the
>>>>> blue line to the normally closed contact on the relay below to
>ground on
>>>>> the unenergized relay (I think).
>>>>>
>>>>> I would verify that the VR14 voltage is present first and then -
>if
>>>>> present
>>>>>
>>>>> I would look for the L1 - L7 signals being pulled low by Q980 -
>Q987.
>>>>> end then If switching I would look to
>>>>> The outputs on IC981.
>>>>>
>>>>> I believe you will find the problem in this area as you are
>drawing
>>>>> current indicating power being produced (unless the current is not
>in the
>>>>> 1-3 Amp range in SSB no modulation idling current).
>>>>>
>>>>> Since the power is not going through L961 the FOR / REV (SWR)
>>>>> transformer and being read by IC060 (JFOR) the RF drive is going
>to the
>>>>> point of current limit and cannot be adjusted in any carrier mode
>with the
>>>>> power adjustment.
>>>>>
>>>>> Just my best guess without making some measurements, but this is
>where
>>>>> I would start.
>>>>>
>>>>> Good luck and best regards.
>>>>>
>>>>>? JD
>>>>> KE4MD
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>
>>
>
>
>
|
20% high does not sound too bad!!
It is when they drop low and you lose 90% will be the issue.
73
Andrew
?Get BlueMail for Android ?
toggle quoted message
Show quoted text
On 30 Jan 2025, 20:28, at 20:28, "Tommy Wooten via groups.io" <kf4rwg@...> wrote: JD
I think Andrew suggested that capacitors may be the issue. There are
two
large smt capacitors in the filter section after the PA section. I
removed
these and measured them. The result is as follows:
C327 = 942 nF
C972 = 811 nF
These are rated at 680 nF and measure 20 to 30% high in value.
I will check other caps in the path before the driver.
Any thoughts?
Tommy
On Wed, Jan 29, 2025 at 1:02?PM J.D. Barron via groups.io
<jeter.d.barron=
[email protected]> wrote:
RL801 may not be making good contact. You can check the levels with your
scope. I would use SSB and whistle in the Mike for tracing to keep the
power dissipation low.
On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via groups.io <jeter.d.barron=
[email protected]> wrote:
Take a good look at RL801
On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via groups.io <kf4rwg=
[email protected]> wrote:
JD
I was able to access each of the relay leads from the top side of
the PA
board. I found that each relay had the 14VR supplied at the relay
coil.
The voltage is 10.5V and falls to 9.2V when tx is activated. I
verified
that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when
activated
by the appropriate band selection. PHT8 at RL801 acted same when
tx is
activated.
All gnd readings were 130mV except RL941 read 363mV as an
observation.
All relays seem to click appropriately when each band was selected.
I cannot access IC981 since it is on the bottom side of PA. But
from
the info above it indicates it is working correctly.
This does not explain why I was able to see 6W at the output of
L305 but
I see negligible power when it passes through the filters. There
must be a
short or open in path.
No smoking gun yet!
I won’t stop until I find the issue or tear something up.
Thanks
Tommy
On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via groups.io
<jeter.d.barron@...> wrote:
(PA 1) The RF comes from L305 through HF03 to RL-801 (PA 2)
(changes
from orange to blue and out through (A). to
(PA 3) the bandpass filters. There are a pair of relays that have
to be
energized for each frequency band. The input relays are controlled
by L1 -
L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from
IC981.
(Powered by 3R3V)
14 VR provides the operating voltage for these relays and the
output
relays. (At this point I have to say I have not looked long enough
and hard
enough to understand how the output relays are activated but they
must be.)
as each band is selected by L1 - L7 going low.
VR14 comes from RL701 output through L981 and resistors R1002 (150
ohm)
and 1003 (180 ohm) (paralleled). This line also provides power to
RL801
which would also stop the RF power from getting to the bandpass
filters
HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would
cause
this problem as well. One of the anti-flyback diodes shorted could
take out
these resistors
I think that as each L1 - L7 goes low that low is transferred via
the
blue line to the normally closed contact on the relay below to
ground on
the unenergized relay (I think).
I would verify that the VR14 voltage is present first and then -
if
present
I would look for the L1 - L7 signals being pulled low by Q980 -
Q987.
end then If switching I would look to
The outputs on IC981.
I believe you will find the problem in this area as you are
drawing
current indicating power being produced (unless the current is not
in the
1-3 Amp range in SSB no modulation idling current).
Since the power is not going through L961 the FOR / REV (SWR)
transformer and being read by IC060 (JFOR) the RF drive is going
to the
point of current limit and cannot be adjusted in any carrier mode
with the
power adjustment.
Just my best guess without making some measurements, but this is
where
I would start.
Good luck and best regards.
JD
KE4MD
|
JD I think Andrew suggested that capacitors may be the issue.? There are two large smt capacitors in the filter section after the PA section.? I removed these and measured them.? The result is as follows: C327 = 942 nF C972 = 811 nF
These are rated at 680 nF and measure 20 to 30% high in value. ?
I will check other caps in the path before the driver.
Any thoughts?
Tommy
On Wed, Jan 29, 2025 at 1:02?PM J.D. Barron via <jeter.d.barron= [email protected]> wrote: RL801 may not be making good contact. You can check the levels with your scope. I would use SSB and whistle in the Mike for tracing to keep the power dissipation low.
On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via <jeter.d.barron= [email protected]> wrote: Take a good look at RL801
JD
I was able to access each of the relay leads from the top side of the PA board.? I found that each relay had the 14VR supplied at the relay coil.? The voltage is 10.5V and falls to 9.2V when tx is activated.? I verified that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when activated by the appropriate band selection.? PHT8 at RL801 acted same when tx is activated. All gnd readings were 130mV except RL941 read 363mV as an observation. All relays seem to click appropriately when each band was selected. I cannot access IC981 since it is on the bottom side of PA.? But from the info above it indicates it is working correctly.
This does not explain why I was able to see 6W at the output of L305 but I see negligible power when it passes through the filters.? There must be a short or open in path.
No smoking gun yet!
I won’t stop until I find the issue or tear something up.
Thanks Tommy? On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via <jeter.d.barron= [email protected]> wrote: ?
(PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2) (changes from orange to blue and out through (A). to?
(PA 3) the bandpass filters. There are a pair of relays that have to be energized for each frequency band. The input relays are controlled by L1 - L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from IC981. (Powered by 3R3V)
?
14 VR provides the operating voltage for these relays and the output relays. (At this point I have to say I have not looked long enough and hard enough to understand how the output relays are activated but they must be.) as each band is selected by L1 - L7 going low.
VR14 comes from RL701 output through L981 and resistors R1002 (150 ohm) and 1003 (180 ohm) (paralleled). This line also provides power to RL801 which would also stop the RF power from getting to the bandpass filters HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would cause this problem as well. One of the anti-flyback diodes shorted could take out these resistors
?
I think that as each L1 - L7 goes low that low is transferred via the blue line to the normally closed contact on the relay below to ground on the unenergized relay (I think).
?
I would verify that the VR14 voltage is present first and then - if present
?
I would look for the L1 - L7 signals being pulled low by Q980 - Q987. end then If switching I would look to?
The outputs on IC981.
?
I believe you will find the problem in this area as you are drawing current indicating power being produced (unless the current is not in the 1-3 Amp range in SSB no modulation idling current).
?
Since the power is not going through L961 the FOR / REV (SWR) transformer and being read by IC060 (JFOR) the RF drive is going to the point of current limit and cannot be adjusted in any carrier mode with the power adjustment.
?
Just my best guess without making some measurements, but this is where I would start.
?
Good luck and best regards.
?
?JD
KE4MD
?
?
?
|
Steve Great info.? I will consider these measurements, especially the ALC section.
Thanks Tommy
Tommy,
This file in the Group's Files section shows RF levels at key points from the IF output to the Antenna output.? Typical ALC levels are also shown at the end:
?
?
Note that the RF levels were taken without the standard ground lead on the scope probe, but with a coiled spring ground finger that fits over the ground barrel near the tip of the probe.? Taking accurate RF measurements with a standard ground lead is futile!
?
Maybe this will help determine if the ALC output that controls the IF section gains is working.
?
Steve, W3AHL
|
Tommy,
This file in the Group's Files section shows RF levels at key points from the IF output to the Antenna output.? Typical ALC levels are also shown at the end:
?
?
Note that the RF levels were taken without the standard ground lead on the scope probe, but with a coiled spring ground finger that fits over the ground barrel near the tip of the probe.? Taking accurate RF measurements with a standard ground lead is futile!
?
Maybe this will help determine if the ALC output that controls the IF section gains is working.
?
Steve, W3AHL
|
RL801 may not be making good contact. You can check the levels with your scope. I would use SSB and whistle in the Mike for tracing to keep the power dissipation low.
On Wed, Jan 29, 2025, 11:51?AM J.D. Barron via <jeter.d.barron= [email protected]> wrote: Take a good look at RL801
JD
I was able to access each of the relay leads from the top side of the PA board.? I found that each relay had the 14VR supplied at the relay coil.? The voltage is 10.5V and falls to 9.2V when tx is activated.? I verified that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when activated by the appropriate band selection.? PHT8 at RL801 acted same when tx is activated. All gnd readings were 130mV except RL941 read 363mV as an observation. All relays seem to click appropriately when each band was selected. I cannot access IC981 since it is on the bottom side of PA.? But from the info above it indicates it is working correctly.
This does not explain why I was able to see 6W at the output of L305 but I see negligible power when it passes through the filters.? There must be a short or open in path.
No smoking gun yet!
I won’t stop until I find the issue or tear something up.
Thanks Tommy? On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via <jeter.d.barron= [email protected]> wrote: ?
(PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2) (changes from orange to blue and out through (A). to?
(PA 3) the bandpass filters. There are a pair of relays that have to be energized for each frequency band. The input relays are controlled by L1 - L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from IC981. (Powered by 3R3V)
?
14 VR provides the operating voltage for these relays and the output relays. (At this point I have to say I have not looked long enough and hard enough to understand how the output relays are activated but they must be.) as each band is selected by L1 - L7 going low.
VR14 comes from RL701 output through L981 and resistors R1002 (150 ohm) and 1003 (180 ohm) (paralleled). This line also provides power to RL801 which would also stop the RF power from getting to the bandpass filters HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would cause this problem as well. One of the anti-flyback diodes shorted could take out these resistors
?
I think that as each L1 - L7 goes low that low is transferred via the blue line to the normally closed contact on the relay below to ground on the unenergized relay (I think).
?
I would verify that the VR14 voltage is present first and then - if present
?
I would look for the L1 - L7 signals being pulled low by Q980 - Q987. end then If switching I would look to?
The outputs on IC981.
?
I believe you will find the problem in this area as you are drawing current indicating power being produced (unless the current is not in the 1-3 Amp range in SSB no modulation idling current).
?
Since the power is not going through L961 the FOR / REV (SWR) transformer and being read by IC060 (JFOR) the RF drive is going to the point of current limit and cannot be adjusted in any carrier mode with the power adjustment.
?
Just my best guess without making some measurements, but this is where I would start.
?
Good luck and best regards.
?
?JD
KE4MD
?
?
?
|
Take a good look at RL801
JD
I was able to access each of the relay leads from the top side of the PA board.? I found that each relay had the 14VR supplied at the relay coil.? The voltage is 10.5V and falls to 9.2V when tx is activated.? I verified that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when activated by the appropriate band selection.? PHT8 at RL801 acted same when tx is activated. All gnd readings were 130mV except RL941 read 363mV as an observation. All relays seem to click appropriately when each band was selected. I cannot access IC981 since it is on the bottom side of PA.? But from the info above it indicates it is working correctly.
This does not explain why I was able to see 6W at the output of L305 but I see negligible power when it passes through the filters.? There must be a short or open in path.
No smoking gun yet!
I won’t stop until I find the issue or tear something up.
Thanks Tommy? On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via <jeter.d.barron= [email protected]> wrote: ?
(PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2) (changes from orange to blue and out through (A). to?
(PA 3) the bandpass filters. There are a pair of relays that have to be energized for each frequency band. The input relays are controlled by L1 - L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from IC981. (Powered by 3R3V)
?
14 VR provides the operating voltage for these relays and the output relays. (At this point I have to say I have not looked long enough and hard enough to understand how the output relays are activated but they must be.) as each band is selected by L1 - L7 going low.
VR14 comes from RL701 output through L981 and resistors R1002 (150 ohm) and 1003 (180 ohm) (paralleled). This line also provides power to RL801 which would also stop the RF power from getting to the bandpass filters HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would cause this problem as well. One of the anti-flyback diodes shorted could take out these resistors
?
I think that as each L1 - L7 goes low that low is transferred via the blue line to the normally closed contact on the relay below to ground on the unenergized relay (I think).
?
I would verify that the VR14 voltage is present first and then - if present
?
I would look for the L1 - L7 signals being pulled low by Q980 - Q987. end then If switching I would look to?
The outputs on IC981.
?
I believe you will find the problem in this area as you are drawing current indicating power being produced (unless the current is not in the 1-3 Amp range in SSB no modulation idling current).
?
Since the power is not going through L961 the FOR / REV (SWR) transformer and being read by IC060 (JFOR) the RF drive is going to the point of current limit and cannot be adjusted in any carrier mode with the power adjustment.
?
Just my best guess without making some measurements, but this is where I would start.
?
Good luck and best regards.
?
?JD
KE4MD
?
?
?
|
JD
I was able to access each of the relay leads from the top side of the PA board.? I found that each relay had the 14VR supplied at the relay coil.? The voltage is 10.5V and falls to 9.2V when tx is activated.? I verified that L1 thru L7 leads were 10.5V and dropped to 130mV (gnd) when activated by the appropriate band selection.? PHT8 at RL801 acted same when tx is activated. All gnd readings were 130mV except RL941 read 363mV as an observation. All relays seem to click appropriately when each band was selected. I cannot access IC981 since it is on the bottom side of PA.? But from the info above it indicates it is working correctly.
This does not explain why I was able to see 6W at the output of L305 but I see negligible power when it passes through the filters.? There must be a short or open in path.
No smoking gun yet!
I won’t stop until I find the issue or tear something up.
Thanks Tommy?
On Tue, Jan 28, 2025 at 5:45?PM J.D. Barron via <jeter.d.barron= [email protected]> wrote: ?
(PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2) (changes from orange to blue and out through (A). to?
(PA 3) the bandpass filters. There are a pair of relays that have to be energized for each frequency band. The input relays are controlled by L1 - L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from IC981. (Powered by 3R3V)
?
14 VR provides the operating voltage for these relays and the output relays. (At this point I have to say I have not looked long enough and hard enough to understand how the output relays are activated but they must be.) as each band is selected by L1 - L7 going low.
VR14 comes from RL701 output through L981 and resistors R1002 (150 ohm) and 1003 (180 ohm) (paralleled). This line also provides power to RL801 which would also stop the RF power from getting to the bandpass filters HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would cause this problem as well. One of the anti-flyback diodes shorted could take out these resistors
?
I think that as each L1 - L7 goes low that low is transferred via the blue line to the normally closed contact on the relay below to ground on the unenergized relay (I think).
?
I would verify that the VR14 voltage is present first and then - if present
?
I would look for the L1 - L7 signals being pulled low by Q980 - Q987. end then If switching I would look to?
The outputs on IC981.
?
I believe you will find the problem in this area as you are drawing current indicating power being produced (unless the current is not in the 1-3 Amp range in SSB no modulation idling current).
?
Since the power is not going through L961 the FOR / REV (SWR) transformer and being read by IC060 (JFOR) the RF drive is going to the point of current limit and cannot be adjusted in any carrier mode with the power adjustment.
?
Just my best guess without making some measurements, but this is where I would start.
?
Good luck and best regards.
?
?JD
KE4MD
?
?
?
|
Very well said, Tommy has removed the PA transformer and resolder it top side, but he was still only getting low power, so does not make much sense
KR
Andrew
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On 28 Jan 2025, 22:45, at 22:45, "J.D. Barron via groups.io" <jeter.d.barron@...> wrote: (PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2) (changes
from orange to blue and out through (A). to
(PA 3) the bandpass filters. There are a pair of relays that have to be
energized for each frequency band. The input relays are controlled by
L1 - L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from
IC981. (Powered by 3R3V)
14 VR provides the operating voltage for these relays and the output
relays. (At this point I have to say I have not looked long enough and
hard enough to understand how the output relays are activated but they
must be.) as each band is selected by L1 - L7 going low.
VR14 comes from RL701 output through L981 and resistors R1002 (150 ohm)
and 1003 (180 ohm) (paralleled). This line also provides power to RL801
which would also stop the RF power from getting to the bandpass filters
HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would
cause this problem as well. One of the anti-flyback diodes shorted
could take out these resistors
I think that as each L1 - L7 goes low that low is transferred via the
blue line to the normally closed contact on the relay below to ground
on the unenergized relay (I think).
I would verify that the VR14 voltage is present first and then - if
present
I would look for the L1 - L7 signals being pulled low by Q980 - Q987.
end then If switching I would look to
The outputs on IC981.
I believe you will find the problem in this area as you are drawing
current indicating power being produced (unless the current is not in
the 1-3 Amp range in SSB no modulation idling current).
Since the power is not going through L961 the FOR / REV (SWR)
transformer and being read by IC060 (JFOR) the RF drive is going to the
point of current limit and cannot be adjusted in any carrier mode with
the power adjustment.
Just my best guess without making some measurements, but this is where
I would start.
Good luck and best regards.
JD
KE4MD
|
?
(PA 1) The RF comes from L305? through HF03 to RL-801 (PA 2) (changes from orange to blue and out through (A). to?
(PA 3) the bandpass filters. There are a pair of relays that have to be energized for each frequency band. The input relays are controlled by L1 - L7 (Bus line 3) from the (PA 3) Q980 - Q987 by the outputs from IC981. (Powered by 3R3V)
?
14 VR provides the operating voltage for these relays and the output relays. (At this point I have to say I have not looked long enough and hard enough to understand how the output relays are activated but they must be.) as each band is selected by L1 - L7 going low.
VR14 comes from RL701 output through L981 and resistors R1002 (150 ohm) and 1003 (180 ohm) (paralleled). This line also provides power to RL801 which would also stop the RF power from getting to the bandpass filters HF03 (Orange) to A (Blue). If R1002 and R1003 were open this would cause this problem as well. One of the anti-flyback diodes shorted could take out these resistors
?
I think that as each L1 - L7 goes low that low is transferred via the blue line to the normally closed contact on the relay below to ground on the unenergized relay (I think).
?
I would verify that the VR14 voltage is present first and then - if present
?
I would look for the L1 - L7 signals being pulled low by Q980 - Q987. end then If switching I would look to?
The outputs on IC981.
?
I believe you will find the problem in this area as you are drawing current indicating power being produced (unless the current is not in the 1-3 Amp range in SSB no modulation idling current).
?
Since the power is not going through L961 the FOR / REV (SWR) transformer and being read by IC060 (JFOR) the RF drive is going to the point of current limit and cannot be adjusted in any carrier mode with the power adjustment.
?
Just my best guess without making some measurements, but this is where I would start.
?
Good luck and best regards.
?
?JD
KE4MD
?
?
?
|
Ok it is a cap, I had this, a 390nf cap measured 50 of, and did attenuated lower frequencies.
Change a few caps
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On 28 Jan 2025, 22:00, at 22:00, "Tommy Wooten via groups.io" <kf4rwg@...> wrote: JD,
Thank you for the insight. I appreciate the response.
I agree with your comment that there may some kind of fault past the
L305
transformer. I have looked for broken traces in the path through to
the
ant1 connector. Finding a faulty relay may be difficult but I think
each
of the band paths are working since all of the receive bands are
working.
But I may not be understanding it correctly.
I have tried to limit transmit time where the current is high. I did
mention in a previous comment that the modulated supply current is
lowest
at 160M and highest at 50M.
I look forward to your evaluation of the circuit.
Thanks
Tommy KF4RWG
On Tue, Jan 28, 2025 at 3:47?PM J.D. Barron via groups.io
<jeter.d.barron=
[email protected]> wrote:
Tommy, Pay careful attention to what I am saying here.
If you key the radio RTTY, AM, FM, CW and you are drawing 20 amps AND if
you key the mike on SSB and you draw just a couple of amps you are
producing RF power.
Your radio is drawing power trying to get the feed back from the forward
power measurement circuit to satisfy the CPU power demand signal and
increasing the drive to the point where the IC current limit is limiting
the drive to limit the current draw to 20 amps.
If the radio in SSB is just drawing a few amps in SSB with no audio input
the current limit is not reached because the PA is just sitting there at
idle current.
You do have something keeping the RF power from getting as far as the
forward power sensing circuit and out of the antenna jack, perhaps a broken
trace, bad relay or a band pass filter out of kilter.
While I think that the transformer could be bad, I suspect that it is not
as they are pretty rugged.
It has been a while since I have had an IC-7000 on my bench, but I have
seen this kind of action from a number of radios and often it has been in
the transmitter bandpass filters and either relay drivers or PIN diodes
defective.
I will take time to revisit the prints for the IC-7000 and see if I can
offer some suggestions, but if I were you I think that I would start
checking the direct pathways through the circuits after the PA amplifiers.
The output transformer is at least carrying current to the PA from the 13.8
volts and probably the secondary is doing it's job as well. There could be
some shorted caps (or open for that matter) that are an issue or perhaps
one of the TR relays etc.
Just my opinion, but I have managed to be wrong before and I reserve that
option as well.
JD
KE4MD
|
Hi Tommy
Have you tried removing J101, drive to hf PA.
You can then put the radio into TX mode and check continuity of circuit after C327. You should be able to check circuit through the relay and onto the filter section?
James?
|
JD, Thank you for the insight.? I appreciate the response. I agree with your comment that there may some kind of fault past the L305 transformer.? I have looked for broken traces in the path through to the ant1 connector.? Finding a faulty relay may be difficult but I think each of the band paths are working since all of the receive bands are working.? But I may not be understanding it correctly.?
I have tried to limit transmit time where the current is high.? I did mention in a previous comment that the modulated supply current is lowest at 160M and highest at 50M.
I look forward to your evaluation of the circuit. ?
Thanks Tommy KF4RWG
On Tue, Jan 28, 2025 at 3:47?PM J.D. Barron via <jeter.d.barron= [email protected]> wrote: Tommy, Pay careful attention to what I am saying here.
If you key the radio RTTY, AM, FM, CW and you are drawing 20 amps AND if you key the mike on SSB and you draw just a couple of amps you are producing RF power.
Your radio is drawing power trying to get the feed back from the forward power measurement circuit to satisfy the CPU power demand signal and increasing the drive to the point where the IC current limit is limiting the drive to limit the current draw to 20 amps.
If the radio in SSB is just drawing a few amps in SSB with no audio input the current limit is not reached because the PA is just sitting there at idle current.?
You do have something keeping the RF power from getting as far as the forward power sensing circuit and out of the antenna jack, perhaps a broken trace, bad relay or a band pass filter out of kilter.?
While I think that the transformer could be bad, I suspect that it is not as they are pretty rugged.
It has been a while since I have had an IC-7000 on my bench, but I have seen this kind of action from a number of radios and often it has been in the transmitter bandpass filters and either relay drivers or PIN diodes defective.?
I will take time to revisit the prints for the IC-7000 and see if I? can offer some suggestions, but if I were you I think that I would start checking the direct pathways through the circuits after the PA amplifiers. The output transformer is at least carrying current to the PA from the 13.8 volts and probably the secondary is doing it's job as well. There could be some shorted caps (or open for that matter) that are an issue or perhaps one of the TR relays etc.?
Just my opinion, but I have managed to be wrong before and I reserve that option as well.
?
JD
KE4MD
|
Hi There is an path problem broken track or inductors or SC caps.
You need to to feed a DC in reflected path to drop the power to a few watts current no more than 3 amps, then signal trace
73
Andrew
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On 28 Jan 2025, 19:50, at 19:50, "Tommy Wooten via groups.io" <kf4rwg@...> wrote: Andrew
I am retired but sometimes household task take priority. I can discuss
radio things most afternoons.
I did measure the transformer output in CW mode at 28 MHz and saw 6+
watts
and 20amps.
I have found that my oscilloscope is old and not accurate, but is good
for
a relative measurement that shows the L305 input voltage is higher than
the
output. I also verified this with a VTVM.
I can’t argue that the L305 maybe bad, but is of robust construction
with
the secondary windings shielded coax. I did check continuity of the
primary to the secondary. Which shows a good open circuit.
I can’t explain why the 6 watts does not pass through the rx/tx relay
and
the HPFs.
Tommy
On Tue, Jan 28, 2025 at 3:48?AM Andrew Lenton via groups.io <a=
[email protected]> wrote:
Oh !!!
Well done how much current was it drawing when you were measuring 6 Watts,
now you can put a watt meter try FM or CW see if you get 100 Watts.
If the rig draws 20 Amp and you are only getting a few Watts, then the
transformer is faulty in some way.
Order a new transformer any way, then you can move with fault finding.
If you saw 6 Watts at the output of the transformer, then why was it
not
at the aerial socket?
73
Andrew
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On 27 Jan 2025, 23:27, at 23:27, "Tommy Wooten via groups.io" <kf4rwg=
[email protected]> wrote:
Andrew
I removed the PA board, separated the transformer and reinstalled the
board
so I could access the transformer output on the top side. See photo
attached.
Tommy
On Mon, Jan 27, 2025 at 5:42?PM Andrew Lenton via groups.io <a=
[email protected]> wrote:
Yes indeed,
CW or AM would be my preferred option, also you need a PEP Watt meter.
KR
Andrew
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On 27 Jan 2025, 22:35, at 22:35, "James Tiberius via groups.io"
<nono2212000@...> wrote:
In SSB mode current draw should be low until audio is being
modulated.
I would expect high current draw when using carrier modes
|
Here here 100%
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On 28 Jan 2025, 20:47, at 20:47, "J.D. Barron via groups.io" <jeter.d.barron@...> wrote: Tommy, Pay careful attention to what I am saying here.
If you key the radio RTTY, AM, FM, CW and you are drawing 20 amps AND
if you key the mike on SSB and you draw just a couple of amps you are
producing RF power.
Your radio is drawing power trying to get the feed back from the
forward power measurement circuit to satisfy the CPU power demand
signal and increasing the drive to the point where the IC current limit
is limiting the drive to limit the current draw to 20 amps.
If the radio in SSB is just drawing a few amps in SSB with no audio
input the current limit is not reached because the PA is just sitting
there at idle current.
You do have something keeping the RF power from getting as far as the
forward power sensing circuit and out of the antenna jack, perhaps a
broken trace, bad relay or a band pass filter out of kilter.
While I think that the transformer could be bad, I suspect that it is
not as they are pretty rugged.
It has been a while since I have had an IC-7000 on my bench, but I have
seen this kind of action from a number of radios and often it has been
in the transmitter bandpass filters and either relay drivers or PIN
diodes defective.
I will take time to revisit the prints for the IC-7000 and see if I?
can offer some suggestions, but if I were you I think that I would
start checking the direct pathways through the circuits after the PA
amplifiers. The output transformer is at least carrying current to the
PA from the 13.8 volts and probably the secondary is doing it's job as
well. There could be some shorted caps (or open for that matter) that
are an issue or perhaps one of the TR relays etc.
Just my opinion, but I have managed to be wrong before and I reserve
that option as well.
JD
KE4MD
|
Andrew Lenton
Steve W3AHL