On Jan 16, 2025, at 6:37?AM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:

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Lately, my go-to for setting C2 has been setting my IC-7610 to 5645 and setting it to CW. I listen to the note on CW and reverse CW. I can also see the carrier on the spectrum display but the correct frequency is there when the beat notes are the same on CW and CW-R. Much better than trying for zero beat in SSB.?

Setting the carrier null is easy using a scope.?

I’ve not found a really good way of setting the filter match than using the method in the manual, so you will be messing with the balance adjustment and C2 no matter what.?

BTW, it’s easier as well to use a scope to watch the amplitude of the transmitted signal, if you otherwise prefer using the by the book method.?

73,

Steve Wedge, W1ES

Time flies like an arrow. Fruit flies like a banana.

Sent from for iOS

On Thu, Jan 16, 2025 at 02:29, Richard Knoppow via groups.io <1oldlens1@...> wrote:

If the carrier balance adjustment does nothing something is
seriously wrong. Go over the carrier balance adjustment on P,15 of the
handbook. The balance control should show an definite null. It is more
common that a good null can not be achieved than that the modulator can
not be unbalanced but in either case something is wrong. When working
properly the balanced modulator has a very good null, you really need to
set it using a receiver lightly coupled to the output. C-6 will affect
the null but usually in making it impossible to get a null.
Go over the adjustments again and see what you find. I am disturbed
that the original problem may not have been a bad filter but whatever is
causing this to happen.
A story: when I first got my T4XB I could not null the carrier.
After I got Garry's discs I found the wiring in the photographs didn't
look write. I asked Garry and he confirmed that what was in mine was not
correct, although it looked factory. In fact, the circuit is quite
sensitive to stray capacitance. With the wires as they were the
modulator could not be balanced. I moved them and got the correct deep
null. So, look for something out of place. You should be able to get a
substantial amount of carrier by unbalancing the pot. Actually, you need
it for alignment.
On 1/15/2025 10:28 PM, Tony Sokol via groups.io wrote:
> ?Hi Gang,
> I thought I’d update my progress on the T4XB filter issue that I brought up just before Christmas. I found that I had the mate for the blue USB filter I had mounted years ago. Mounting the new filter which is on the bottom was exciting. Now they match pretty well. I was not able to match them per the manual though. You are told to unbalance the balanced modulator by turning the pot fully CCW. This did nothing so I didn’t have a carrier feeding the filters to balance. Rather than detuning the coil possibly opening another can of worms, I simply went to transceive mode and tuned C2 till they “birdied in”. Then I went back and forth between upper and lower sideband listening to myself. Not only did it sound good but the transmitter oscillator ended up on 5.645008. Close enough. The acid test will come when I check in with the Friday evening gang. Hopefully they will not tell me my shorts are way too tight. ?
> Thank you for all the help and suggestions.
>

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

You're referring to the 5-10 section, correct? Injection Crystal Oscillator adjustment. Thanks for the tip about using a scope instead of the VTVM, that worked much better for me. I was pretty close with the VTVM but got a better adjustment with the scope. So that is correct now and 29.1 is working (but weak signals on the CAL). But using my signal generator at 29.4 MHZ I'm getting an S9 which is the same signal I'm getting on my Flex Radio at that freq so I think the 29.1 band is working OK, there's just no signals out there to listen to on SSB, I do hear an FM signal at 29.620 which sounds like garbage of course on the Drake.?

So? Anything else I should check before ordering a Xtal?

73, Dave KD5FX

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On Jan 16, 2025, at 12:24 PM, Dave KD5FX via groups.io <land.dave@...> wrote:

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You're referring to the 5-10 section, correct? Injection Crystal Oscillator adjustment. Thanks for the tip about using a scope instead of the VTVM, that worked much better for me. I was pretty close with the VTVM but got a better adjustment with the scope. So that is correct now and 29.1 is working (but weak signals on the CAL). But using my signal generator at 29.4 MHZ I'm getting an S9 which is the same signal I'm getting on my Flex Radio at that freq so I think the 29.1 band is working OK, there's just no signals out there to listen to on SSB, I do hear an FM signal at 29.620 which sounds like garbage of course on the Drake.?

So? Anything else I should check before ordering a Xtal?

73, Dave KD5FX

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I just picked up this TR-4C a couple of weeks ago and I'm going through it, everything is working fine except both the 28.0 and 28.5 bands do not work. I receive nothing and can't hear the CAL oscillator either. The 29.1 band is working OK but signals are weak. I thought it might be the Xtals so I swapped them around to see what happened. I put the 28.0 Xtal in the 29.1 band position and got nothing, same with the 28.5 Xtal. Then I put the 29.1 Xtal in the 28.0 band position and a tiny bit of signal by peaking the RF Tune but no CAL heard. When I put the 29.1 in 28.5 I got a little band noise I could peak but no CAL signal. I did check all the tubes and they are good.?

So? Does that sound like two bad Xtals or is something else bad?

Thanks in advance & 73, Dave KD5FX

?

If the carrier balance adjustment does nothing something is
seriously wrong. Go over the carrier balance adjustment on P,15 of the
handbook. The balance control should show an definite null. It is more
common that a good null can not be achieved than that the modulator can
not be unbalanced but in either case something is wrong. When working
properly the balanced modulator has a very good null, you really need to
set it using a receiver lightly coupled to the output. C-6 will affect
the null but usually in making it impossible to get a null.
Go over the adjustments again and see what you find. I am disturbed
that the original problem may not have been a bad filter but whatever is
causing this to happen.
A story: when I first got my T4XB I could not null the carrier.
After I got Garry's discs I found the wiring in the photographs didn't
look write. I asked Garry and he confirmed that what was in mine was not
correct, although it looked factory. In fact, the circuit is quite
sensitive to stray capacitance. With the wires as they were the
modulator could not be balanced. I moved them and got the correct deep
null. So, look for something out of place. You should be able to get a
substantial amount of carrier by unbalancing the pot. Actually, you need
it for alignment.
On 1/15/2025 10:28 PM, Tony Sokol via groups.io wrote:
> ?Hi Gang,
> I thought I’d update my progress on the T4XB filter issue that I brought up just before Christmas. I found that I had the mate for the blue USB filter I had mounted years ago. Mounting the new filter which is on the bottom was exciting. Now they match pretty well. I was not able to match them per the manual though. You are told to unbalance the balanced modulator by turning the pot fully CCW. This did nothing so I didn’t have a carrier feeding the filters to balance. Rather than detuning the coil possibly opening another can of worms, I simply went to transceive mode and tuned C2 till they “birdied in”. Then I went back and forth between upper and lower sideband listening to myself. Not only did it sound good but the transmitter oscillator ended up on 5.645008. Close enough. The acid test will come when I check in with the Friday evening gang. Hopefully they will not tell me my shorts are way too tight. ?
> Thank you for all the help and suggestions.
>

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

?Hi Gang,
I thought I’d update my progress on the T4XB filter issue that I brought up just before Christmas. I found that I had the mate for the blue USB filter I had mounted years ago. Mounting the new filter which is on the bottom was exciting. Now they match pretty well. I was not able to match them per the manual though. You are told to unbalance the balanced modulator by turning the pot fully CCW. This did nothing so I didn’t have a carrier feeding the filters to balance. Rather than detuning the coil possibly opening another can of worms, I simply went to transceive mode and tuned C2 till they “birdied in”. Then I went back and forth between upper and lower sideband listening to myself. Not only did it sound good but the transmitter oscillator ended up on 5.645008. Close enough. The acid test will come when I check in with the Friday evening gang. Hopefully they will not tell me my shorts are way too tight. ?
Thank you for all the help and suggestions.

On Dec 22, 2024, at 6:45?PM, Richard Knoppow via groups.io <1oldlens1@...> wrote:
? Good idea, Merry Christmas and Happy New Year to all.

On 12/22/2024 2:53 PM, Tony Sokol via groups.io wrote:

I did essentially the same thing to keep from loading down the circuit. I’ll report on the progress but for the next couple of weeks my priorities are going in another direction.
Everyone have a very Merry Christmas and a safe and Happy New Year.
Tony - W9JXN

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

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Clint, is the CD for sale? ?Bob NZ5A

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I have all the QST’s from the beginning to 1980 on CD.? I also have all the 73’s in digital as well.? At one point, I had a lot of QST, Radio Electronics and Popular Electronics and others that I had to get rid of as they were taking too much room up.? I offered them to a school library and they accepted them, and then threw them out!? These magazines, especially QST, taught me just about everything I know.

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Clint, VE3CMQ

On Jan 14, 2025, at 9:49?AM, Clint VE3CMQ <ve6cmm@...> wrote:

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I have all the QST’s from the beginning to 1980 on CD.? I also have all the 73’s in digital as well.? At one point, I had a lot of QST, Radio Electronics and Popular Electronics and others that I had to get rid of as they were taking too much room up.? I offered them to a school library and they accepted them, and then threw them out!? These magazines, especially QST, taught me just about everything I know.

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Clint, VE3CMQ

Thank you for the information Steve. I think I'm going to try to find someone that knows what they are doing to check, fix and align this R4B, it's such a nice receiver!?

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Any recommendations for a good Drake tech from anyone out there, will be much appreciate. As I see a few of the "go to" Drake techs seem to have stopped their operation.? ??

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Thanks again, Steve. 73

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Dale, KD5UVV

Hello all, I hope I can explain this correctly. I have a R4B and sometimes when I turn the radio on to the STBY position, the S-meter reflects all the way over to around the 40 decibel mark on the meter. Then when moved to the ON position, I get full volume and normal deflection of the S meter as to the incoming signal.?

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But sometimes, (and it's starting to happen more often now), when I turn the radio on to the STBY position. The meter will only go to the mid section (around S-9) and when put in the ON position, the receive volume is low and the S-meter barely moves. Stays around 1 to 3 S-units on the meter and seems to respond in a very "tight" way by movement.?

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Any idea what this could be? Or what is the cause? Thanks in advance! 73

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Dale, KD5UVV??

Hi Jerry,
The 6V6 was a popular tube to use as a power oscillator, the first transmitter I owned was built using a 6V6 driving an 807 to near-novice power levels.? Back then (1970) power was calculated by output but by Plate V*A, so I really do not know how much output that transmitter actually had, having been built by a 14 year old...likely not much, but some of the power definitely went into harmonics.
My favorite band was 15M and a favorite local TV channel was Ch.3, WTIC in Hartford, CT.? When I'd operate in the early evening, the phone would begin ringing and my parents would yell to the basement: "Stop screwing up the neighbor's TV reception!"? About this time I received a pink slip from an FCC monitoring station saying my emissions were observed on 63 MHz in Boston, MA and to desist in transmitting on that frequency.
I spent my hard-earned TV and Radio repair money on a Drake TV-CB-LP filter which was all I could afford, but it did the trick and mollified my neighbors.
Exciting times in the basement ham shack!
Cheers & 73,
Howie / WA4PSC

Hi I am Looking for a VOX 2-pin cable for an L-4b to T-X4b.

I know there are RCA connector mods but I'd like to keep them original.

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TIA,

de Larry, W6YH

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