|
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
|
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
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.
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? ?
(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=
gmail.com@groups.io> 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=
gmail.com@groups.io> wrote:
Take a good look at RL801
On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via groups.io <kf4rwg=
gmail.com@groups.io> 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
|
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=gmail.com@groups.io> 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=
>gmail.com@groups.io> 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=
>> gmail.com@groups.io> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> gmail.com@groups.io> 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=gmail.com@groups.io> 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=gmail.com@groups.io> 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=
>gmail.com@groups.io> 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=
>> gmail.com@groups.io> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> gmail.com@groups.io> 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=gmail.com@groups.io> 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=gmail.com@groups.io> 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=
>gmail.com@groups.io> 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=
>> gmail.com@groups.io> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> gmail.com@groups.io> 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=gmail.com@groups.io> 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=gmail.com@groups.io> 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=
>gmail.com@groups.io> 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=
>> gmail.com@groups.io> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> gmail.com@groups.io> 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=gmail.com@groups.io> 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: ic7000@groups.io <ic7000@groups.io>
On Behalf Of Tommy Wooten via groups.io
Sent: Wednesday, February 12, 2025 7:26 PM
To: ic7000@groups.io
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=gmail.com@groups.io> 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=
>gmail.com@groups.io> 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=
>> gmail.com@groups.io> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via
<kf4rwg=
>>> gmail.com@groups.io> 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=gmail.com@groups.io> 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
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>
>>
>
>
>
|
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: ic7000@groups.io <ic7000@groups.io> On Behalf Of Tommy Wooten via groups.io
Sent: 13 February 2025 01:26
To: ic7000@groups.io
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=gmail.com@groups.io> 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=
>gmail.com@groups.io> 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=
>> gmail.com@groups.io> wrote:
>>
>>> Take a good look at RL801
>>>
>>> On Wed, Jan 29, 2025, 11:06?AM Tommy Wooten via <kf4rwg=
>>> gmail.com@groups.io> 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=gmail.com@groups.io> 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
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>
>>
>
>
>
|
Andrew Lenton
