Re: R4C Sherwood audio mod questions
Hi Rob,
?
Thank you for posting these six files.
?
Chuck
|
Re: T-4XC Sideband adjustments?
BTW, the one with the long shaft is for balancing the carrier, along with the 10-turn pot.? These three adjustments are in the same patch of real estate.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:50 PM, Steve Wedge, W1ES <w1es@...> wrote:
the one with the slot.? If you are on frequency, you may have a bad crystal filter.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:47 PM, Ed KG5UN via groups.io <maikranze@...> wrote:
Carrier oscillator is on freq. Sorry but I still dont know where C-6 is. Is it the big silver looking thing with a slot for a screw driver or the taller looking thing against the back of the chassis with the slug sticking out of it?
On Thu, Jan 2, 2025 at 4:41?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Check that your carrier oscillator is at 5645 kHz. C6 is the ceramic trimmer on top of the chassis, right-rear corner area.
If your CO is on-frequency, you could have a bad filter. Rare, but it happens.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:09 PM, Ed KG5UN via <maikranze= [email protected]> wrote:
My T-4XC sounds decent on LSB but very tinny and pinched on USB. How do I adjust this? I saw a reference to adjusting C-6 but I can not find a C-6. Where is it?
Thanks, Ed KG5UN
|
Re: T-4XC Sideband adjustments?
I turn it and it just spins and spins. doesnt?seem to change anything. Ed
On Thu, Jan 2, 2025 at 4:50?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: the one with the slot.? If you are on frequency, you may have a bad crystal filter.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:47 PM, Ed KG5UN via <maikranze= [email protected]> wrote:
Carrier oscillator is on freq. Sorry but I still dont know where C-6 is. Is it the big silver looking thing with a slot for a screw driver or the taller looking thing against the back of the chassis with the slug sticking out of it?
On Thu, Jan 2, 2025 at 4:41?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Check that your carrier oscillator is at 5645 kHz. C6 is the ceramic trimmer on top of the chassis, right-rear corner area.
If your CO is on-frequency, you could have a bad filter. Rare, but it happens.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:09 PM, Ed KG5UN via <maikranze= [email protected]> wrote:
My T-4XC sounds decent on LSB but very tinny and pinched on USB. How do I adjust this? I saw a reference to adjusting C-6 but I can not find a C-6. Where is it?
Thanks, Ed KG5UN
|
Re: T-4XC Sideband adjustments?
the one with the slot.? If you are on frequency, you may have a bad crystal filter.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:47 PM, Ed KG5UN via groups.io <maikranze@...> wrote:
Carrier oscillator is on freq. Sorry but I still dont know where C-6 is. Is it the big silver looking thing with a slot for a screw driver or the taller looking thing against the back of the chassis with the slug sticking out of it?
On Thu, Jan 2, 2025 at 4:41?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Check that your carrier oscillator is at 5645 kHz. C6 is the ceramic trimmer on top of the chassis, right-rear corner area.
If your CO is on-frequency, you could have a bad filter. Rare, but it happens.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:09 PM, Ed KG5UN via <maikranze= [email protected]> wrote:
My T-4XC sounds decent on LSB but very tinny and pinched on USB. How do I adjust this? I saw a reference to adjusting C-6 but I can not find a C-6. Where is it?
Thanks, Ed KG5UN
|
Re: T-4XC Sideband adjustments?
Carrier oscillator is on freq. Sorry but I still dont?know where C-6 is. Is it the big silver looking thing with a slot for a screw driver?or the taller looking thing against the back of the chassis?with the slug sticking out of it?
On Thu, Jan 2, 2025 at 4:41?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Check that your carrier oscillator is at 5645 kHz.? C6 is the ceramic trimmer on top of the chassis, right-rear corner area.
If your CO is on-frequency, you could have a bad filter.? Rare, but it happens.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:09 PM, Ed KG5UN via <maikranze= [email protected]> wrote:
My T-4XC sounds decent on LSB but very tinny and pinched on USB. How do I adjust this? I saw a reference to adjusting C-6 but I can not find a C-6. Where is it?
Thanks, Ed KG5UN
|
Re: T-4XC has a "condition"
OK guys,
?
Here is an observation. I just cleaned the power connection and decided to check the bias again. All knobs turned to ¡°0¡±. Now, on the RF tune I see a ¡°0¡± in the 10 meter section.
At this point I can get the bias to the tick mark. Now I see another ¡°0¡± in the 160 meter range. The lowest bias setting here is .3 amps
?
With the bias set now the tune procedure is closer to what I see on videos and I get a grid dip. But for normal operation all knobs are fully CW.
?
Dean
?
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Show quoted text
From: [email protected] <[email protected]>
On Behalf Of VE7PS via groups.io
Sent: Thursday, January 2, 2025 1:06 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] T-4XC has a "condition"
?
Barry...indeed, check for correct idling current with zero
drive. Adjust it using the bias control on the AC-4 power supply.? You are aiming for about 70 mA (the "tick mark").
Also.....practice tuning up into a known good 50 Ohm load rated at 150w or better with known good cables first.?
Dump the "tuner" for now.? I would put a wattmeter inline to the 50 ohm load if you have one,?rather than trying to use the internal relative output meter.? That way there are fewer buttons to "mess" with until you are comfortable with the tune-up process.
And if you are pinning the ammeter...STOP right away, as something is wrong!? Back off the drive and try again.
?
How have you set your bias. That¡¯s the first step. Pinned to the right is not a condition you want to be in for long so I would suggest not tuning up until you figure it out.? I would verify
that you have appropriate and steady bias current first.
On Thursday, January 2, 2025 at 10:01:40 AM CST, Dean N2TNN via
<n2tnn=[email protected]> wrote:
I have a T-4XC in great condition but is not acting normal. It puts out 110 watts, sounds great on CW and cooperates with my straight key. Unknown about the
SSB side because I never used it.
This is difficult to express because I don't really know what I am talking about so here goes. Tuning the rig on different bands takes forever to get it right.
I have watched videos and it looks easy. I follow the instructions in the manual and it never is the same.
All controls are set CCW. I then turn up the gain control slowly, maybe 1/4 the way and the needle pins to the right. Once it is pinned I can never get it to
dip when I adjust the plate knob.
So what I do next is to fool with the controls to get max power out with the lowest SWR on the tuner. With the load knob adjusted for output the needle is still
pinned. When I push it in the needle moves down to about .300
Also, after tuning up with the "tune" setting I go to CW and when I key down I have to fine tune all the settings again.
I really like this rig and want to use it but something is not right. Any suggestions?
|
Re: Replacing T4XC Finals?
Film resistors will work fine. Use the same coils.
The final tubes should be 6JB6's
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 3:30 PM, Jay W6CJ via groups.io <lastradioman@...> wrote:
I looked into the PA I damaged when a faulty key put the radio in transmit: - One of the parasitic choke leads popped out of the resistor.
- One of the 1-watt cathode resistors is cracked and both read higher than 15 ohms.
- No more than 75mA when tuning.
I'm thinking of replacing the 6GE5s; both cathode resistors with 2-watt film resistors; both parasitic chokes; possibly replacing the 12BY7 driver tube.
Appreciate any expert advice on where else to check and what else to replace.
Thanks & 73 Jay W6CJ
|
Re: T-4XC Sideband adjustments?
Check that your carrier oscillator is at 5645 kHz.? C6 is the ceramic trimmer on top of the chassis, right-rear corner area.
If your CO is on-frequency, you could have a bad filter.? Rare, but it happens.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 5:09 PM, Ed KG5UN via groups.io <maikranze@...> wrote:
My T-4XC sounds decent on LSB but very tinny and pinched on USB. How do I adjust this? I saw a reference to adjusting C-6 but I can not find a C-6. Where is it?
Thanks, Ed KG5UN
|
My TR7A still has the annoying feature of not going to no signal.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, January 2nd, 2025 at 4:48 PM, Gary Follett via groups.io <xntrick1948@...> wrote:
Later TR7¡¯s did not suffer this problem. It seems the pot was changed to one which got to zero ohms before the click.?
Gary
W0DVN On Jan 2, 2025, at 3:44?PM, Rob Sherwood via groups.io <rob@...> wrote:
The R-4C has the same problem. It may go clear back to my original R-4. ?Rob, NC0B-----Original Message-----From:?[email protected]?[mailto:[email protected]] On Behalf Of jerry-KF6VBSent: Thursday, January 02, 2025 11:15 AMTo:?[email protected]Cc: Jim Shorney via?Subject: [DRAKE-RADIO] TR7 AudioOne minor audio annoyance with the TR7 - the volume control doesn't go?all the way to zero.Instead of a tradition voltage divider pot, they do something with the?AGC. ?So to getthe thing to quiet down, I also turn down the RF gain.?????????????????- Jerry, KF6VBOn 2025-01-01 08:06, Jim Shorney via groups.io wrote:FWIW the TR7 uses an LM380. It works pretty well.
On Wed, 1 Jan 2025 10:45:24 -0500
"Mike Bryce via groups.io" <prosolar@...> wrote:
FYI¡ I designed an audio amp board for the R4C that used a LM380.?
Worked great and had plenty of humph to drive the MS4 speaker to room?
filling volume
--
73
-Jim
NU0C
|
Re: Replacing T4XC Finals?
Peter, Oops... I meant 6JB6A's.?? The NOS 6JB6A tubes I see for sale are never listed as "matched pair".... is that going to be a problem? Thanks for the screen resistor advice. 73 Jay W6CJ
Jay:
Couple of things....
Suspect you made an error about the final tubes.? 6GE5's wouldn't fit as they are 12 pin tubes, with the Plate on pin 7 instead of plate cap like the original tube, a 6JB6.? Perhaps you meant 6GJ5?? I believe some have used those in the T4X(any) transmitters.
It's not unusual to see the original cathode resistors up around 17-18 ohms by the time, and they still work fine, but seeing as you will be replacing the cracked one?I would do both for sure.? My "change 'em out" threshold?is usually about 17.2 ohms.
Check the screen resistors while you are in there as well. Again, common to see the original 68 ohm resistors drifted up around 75 ohms or thereabouts.? Higher than that and they get swapped out for new ones.
Good luck.
73 Peter VE7PS
I looked into the PA I damaged when a faulty key put the radio in transmit: - One of the parasitic choke leads popped out of the resistor.
- One of the 1-watt cathode resistors is cracked and both read higher than 15 ohms.
- No more than 75mA when tuning.
I'm thinking of replacing the 6GE5s; both cathode resistors with 2-watt film resistors; both parasitic chokes; possibly replacing the 12BY7 driver tube.
Appreciate any expert advice on where else to check and what else to replace.
Thanks & 73 Jay W6CJ
|
T-4XC Sideband adjustments?
My T-4XC sounds decent on LSB but very?tinny and pinched on USB.? How do I adjust this? I saw a reference to adjusting C-6 but I can not find a C-6. Where is it??
Thanks, Ed KG5UN
|
I don't actually know but suspect they are the same. Pillow stuffing would work OK and is likely cheaper. Anything sold for audio seems to become expensive.
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Show quoted text
On 1/2/2025 1:56 PM, Stan Gammons via groups.io wrote: I've wondered if the Acousta-Stuf? Polyfil is the same as the Poly-Fil pillow stuffing one can buy at Walmart?
73
Stan
KM4HQE
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
I've wondered if the Acousta-Stuf? Polyfil is the same as the
Poly-Fil pillow stuffing one can buy at Walmart?
73
Stan
KM4HQE
On 1/2/25 13:52, Joe - W7RKN via
groups.io wrote:
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Yup¡One
and the same, albeit a wee (sic)
bit cheaper at your store
Joe
¨C W7RKN
?
?
Is
this the same product?
|
Rob ¡ª I read somewhere that the last version of the SE-3, with the addition of the "AR" switch on the front panel, involved only the addition of the switch and a 100k resistor.? Can you please confirm that's correct and if so, explain where the 100k resistor
is connected?? ?
Thanks, and happy new year!
Regards,
Art Delibert, KB3FJO
|
Later TR7¡¯s did not suffer this problem. It seems the pot was changed to one which got to zero ohms before the click.?
Gary
W0DVN
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Show quoted text
On Jan 2, 2025, at 3:44?PM, Rob Sherwood via groups.io <rob@...> wrote:
The R-4C has the same problem. It may go clear back to my original R-4. ?Rob, NC0B-----Original Message-----From:?[email protected]?[mailto:[email protected]] On Behalf Of jerry-KF6VBSent: Thursday, January 02, 2025 11:15 AMTo:?[email protected]Cc: Jim Shorney via?Subject: [DRAKE-RADIO] TR7 AudioOne minor audio annoyance with the TR7 - the volume control doesn't go?all the way to zero.Instead of a tradition voltage divider pot, they do something with the?AGC. ?So to getthe thing to quiet down, I also turn down the RF gain.?????????????????- Jerry, KF6VBOn 2025-01-01 08:06, Jim Shorney via groups.io wrote:FWIW the TR7 uses an LM380. It works pretty well.
On Wed, 1 Jan 2025 10:45:24 -0500
"Mike Bryce via groups.io" <prosolar@...> wrote:
FYI¡ I designed an audio amp board for the R4C that used a LM380.?
Worked great and had plenty of humph to drive the MS4 speaker to room?
filling volume
--
73
-Jim
NU0C
|
Re: Replacing T4XC Finals?
Jay:
Couple of things....
Suspect you made an error about the final tubes.? 6GE5's wouldn't fit as they are 12 pin tubes, with the Plate on pin 7 instead of plate cap like the original tube, a 6JB6.? Perhaps you meant 6GJ5?? I believe some have used those in the T4X(any) transmitters.
It's not unusual to see the original cathode resistors up around 17-18 ohms by the time, and they still work fine, but seeing as you will be replacing the cracked one?I would do both for sure.? My "change 'em out" threshold?is usually about 17.2 ohms.
Check the screen resistors while you are in there as well. Again, common to see the original 68 ohm resistors drifted up around 75 ohms or thereabouts.? Higher than that and they get swapped out for new ones.
Good luck.
73 Peter VE7PS
I looked into the PA I damaged when a faulty key put the radio in transmit: - One of the parasitic choke leads popped out of the resistor.
- One of the 1-watt cathode resistors is cracked and both read higher than 15 ohms.
- No more than 75mA when tuning.
I'm thinking of replacing the 6GE5s; both cathode resistors with 2-watt film resistors; both parasitic chokes; possibly replacing the 12BY7 driver tube.
Appreciate any expert advice on where else to check and what else to replace.
Thanks & 73 Jay W6CJ
|
The R-4C has the same problem. It may go clear back to my original R-4. Rob, NC0B
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of jerry-KF6VB Sent: Thursday, January 02, 2025 11:15 AM To: [email protected]Cc: Jim Shorney via groups.io Subject: [DRAKE-RADIO] TR7 Audio One minor audio annoyance with the TR7 - the volume control doesn't go all the way to zero. Instead of a tradition voltage divider pot, they do something with the AGC. So to get the thing to quiet down, I also turn down the RF gain. - Jerry, KF6VB On 2025-01-01 08:06, Jim Shorney via groups.io wrote: FWIW the TR7 uses an LM380. It works pretty well.
On Wed, 1 Jan 2025 10:45:24 -0500
"Mike Bryce via groups.io" <prosolar@...> wrote:
FYI¡ I designed an audio amp board for the R4C that used a LM380.
Worked great and had plenty of humph to drive the MS4 speaker to room
filling volume
--
73
-Jim
NU0C
|
Dave, I shipped an R4C (with PTO and other issues) to WB4HFN, who reported the NB was not repairable - parts availability.
Before shipping the R4C with the NB installed, I tried alignment from the R4C manual and not all of the 4NB adjustments were responsive.
Thanks & 73, Jay
Jay, I just took a look at the schematic and didn't see anything that would currently be unavailable except maybe the coils and possibly the socket for the blanker. What is specifically wrong with it? Is it physical damage or electrically not functioning?
?
Dave
|
Small lamp reference for Drake L7
Hello,
?
I am? looking for the part reference for the very small lamps used to display the buttons pushed state (Ep, Ig, STBY, OPR, ...).
?
Thanks you.
|
Re: T-4XC has a "condition"
Peter,
?
Thanks? for the reply. I always use an appropriate dummy load to initiate a tuning process. Once I establish max output I switch over to the antenna and re-tune and adjust.
The output is monitored on a cross needle power/ swr meter.
?
I also just adjusted the bias right on the tick mark.
?
I am going to check the connectors and deoxit to be sure.
?
73, Dean
?
?
?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]>
On Behalf Of VE7PS via groups.io
Sent: Thursday, January 2, 2025 1:06 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] T-4XC has a "condition"
?
Barry...indeed, check for correct idling current with zero
drive. Adjust it using the bias control on the AC-4 power supply.? You are aiming for about 70 mA (the "tick mark").
Also.....practice tuning up into a known good 50 Ohm load rated at 150w or better with known good cables first.?
Dump the "tuner" for now.? I would put a wattmeter inline to the 50 ohm load if you have one,?rather than trying to use the internal relative output meter.? That way there are fewer buttons to "mess" with until you are comfortable with the tune-up process.
And if you are pinning the ammeter...STOP right away, as something is wrong!? Back off the drive and try again.
?
How have you set your bias. That¡¯s the first step. Pinned to the right is not a condition you want to be in for long so I would suggest not tuning up until you figure it out.? I would verify
that you have appropriate and steady bias current first.
On Thursday, January 2, 2025 at 10:01:40 AM CST, Dean N2TNN via
<n2tnn=[email protected]> wrote:
I have a T-4XC in great condition but is not acting normal. It puts out 110 watts, sounds great on CW and cooperates with my straight key. Unknown about the
SSB side because I never used it.
This is difficult to express because I don't really know what I am talking about so here goes. Tuning the rig on different bands takes forever to get it right.
I have watched videos and it looks easy. I follow the instructions in the manual and it never is the same.
All controls are set CCW. I then turn up the gain control slowly, maybe 1/4 the way and the needle pins to the right. Once it is pinned I can never get it to
dip when I adjust the plate knob.
So what I do next is to fool with the controls to get max power out with the lowest SWR on the tuner. With the load knob adjusted for output the needle is still
pinned. When I push it in the needle moves down to about .300
Also, after tuning up with the "tune" setting I go to CW and when I key down I have to fine tune all the settings again.
I really like this rig and want to use it but something is not right. Any suggestions?
|
Ed KG5UN
Jay W6CJ
Rob Sherwood