SSB drift on a vintage Golden Eagle Mark III

[Dave239]

I just bought a Golden Eagle Mark III. I haven't had a chance to try it our yet but I hear these radios are poor Sideband radio's because they drift too much when transmitting. If It does is there a cure for this? A little advice from the guys with experience running tube radios would be appreciated. Thanks

 

[wavrider]

Siltronix model 90-3 vfo will help with the drift, or turn the radio on and let it get warm, 15 minutes or longer.
google is your friend to get info for the mark 3
Not a great SSB talker but it can be done
Pay a lot of attention to your mic setting for gain which is an under the cover adjustment.

Great AM talker worlds of audio and of course that browning ping, which can be eliminated on SSB by either changing the cap or increasing your squelch setting until the ping stops.

I prefer the siltronix 1011D or 1011C for SSB if you looking for a good tuber for SSB

 

[Dave239]

thanks for your quick response. I googled it and it said the Transmit is actually good except for the low output wattage, its the receive that's bad and the transmitter warbles if you try to hook external components on the VFO power supply of the radio. Ill look into the Siltronix 1011C and D thanks again

 

[wavrider]

1011c&d are drifters also, but there are some modern modifications that can be dome to improve stability, and if you are a devout SSB you can even purchase a VFO stabilizer to install in it.
Real radios glow in the dark

 

[w9cll]

My Yaesu drifts like crazy till its warm but if I use the second external VFO its fine. So I run on that VFO till the rig is warm.

 

[Road Squawker]

1011D(rifter)

 

[BBB]

The PAL brand VFO is claimed to be a bit more stable than the Siltronix, but with less bandwidth. Interestingly the PAL VFO on one of my Mark IIIs is a model "B-1" not listed here:

There are other modification$ that can be done including digital readout$, although I'm not ver$ed in them.

In my eyes, I have always seen the Mark III as more of an AM only rig.

 

[wavrider]

1011D(rifter)

like the Swans, just get on the band they will drift by.

My Swan 700CX I installed a VFO stabilizer, NO drift digital stability, $60 modification for rock solid frequency stability. Tapped off the LO tube with a digital display now I can see exactly what frequency I am on, $13 Chinese freq counter with programmable offsets.

Pair of 8950 tube finals, more power out than most modern HF rigs.

Now recap that old tuber with todays caps, more stable, better specs.
Replace old out of tolerance resistors with new resistors.

Give that old tuber a good alignment, 15 minutes to warm up and ops will ask you what type of outboard hi fi audio gear you are running.

Tube audio, often imitated never duplicated.

 

[ExitThirteen]

Which is why I am fired up to get my old 1011D functional again. I gotta put the VFO stabilization mod in, change out a coupe resistors, and get it talking!


~Cheers~

 

[wavrider]

http://www.eham.net/reviews/detail/7448

Review of stabilizer I installed in my Swan 700CX, Do not know if Phils is still producing this stabilizer,,

http://www.cumbriadesigns.co.uk/x-lock.htm

Friend of mine bought a couple of these kits installed them in His Swan and is working digital modes JT 65.




Those old tubers can be made rock solid enough to work digital modes.

 

[nomadradio]

Separate receiver and transmitter means separate causes for trouble with SSB transmit and recieve.

Warble on transmit is probably 45 year-old power-supply filter capacitors gone bad. They weren't meant to last more than 10 or 15 years, so it's a good bet more than one of them is failing. Causes the power-supply voltages to fall with modulation, making the frequency unstable. The transmitter has a 150-Volt zener diode that regulates the power feeding the crystals in the radio. Tends to make it fairly stable on crystals, until age catches up with the power supply. Modulation draws current from the power supply. Makes the voltage fall. That makes the frequency drift in step with the modulation.

The receiver's SSB performance is a whole 'nother bucket of worms. The tuning dial doesn't drift all that much once the band selector switch is thoroughly cleaned, along with the ground contact on the shaft of the capacitor attached to the tuning dial. 45 years of oxidation makes those connections unstable, along with the dial frequency.

Biggest worm in the bucket is with the SSB (only) receive tube V12, a 6BE6. What makes SSB receive different from AM is the need to put the carrier back into your signal. Turns those "honk-honk" noises you hear in a AM receiver back into understandable audio. This receive-side carrier comes from a crystal in EVERY other SSB receiver you have ever seen.

But Browning cheaped out. The two white ceramic trimmer capacitors C69 and C70 next to V12 are what control the receiver's internal receive-carrier frequency. Crystals for this frequency tend to be expensive, so they took the low road. You'll play the devil getting C69 and C70 to set a stable frequency. THOSE are where most of your SSB receiver drift comes from, rather than the dial.

Unless the dial oscillator is late for its 40-year tuneup. When a radio is this old, never assume you have only one problem.

And even if you restore it to like-new condition, it's not a terribly good SSB radio in the first place.

73

 

[Flatop]

I just bought a Golden Eagle Mark III. I haven't had a chance to try it our yet but I hear these radios are poor Sideband radio's because they drift too much when transmitting. If It does is there a cure for this? A little advice from the guys with experience running tube radios would be appreciated. Thanks

Again, I know this is old, but I fired up a MKIII the other day, and the transmitter is rock solid on frequency. I just spoke on it for 4 hrs, no drift whatsoever. Stations were commenting on how it did not drift without me mentioning it once. I have done nothing to this radio.
On top of that, its sideband performance is excellent. It is now my best sounding radio, or near to it, a close second at worst. And the benchmark is pretty high, I am not an AMer, pretty much SSB only. In fact, operators comment on the audio without me telling them what type of radio it is. They typically say 'that sounds good, really good. And loud.'
Now, several forums had me absolutely convinced that these radios will simply not perform on sideband, that it's even a waste of time. One said that he performed a frequency mod utilising the mode switch because he wouldn't even consider using it on ssb. One of few valve ssb cb radios around and he disabled upper and lower!
For me, this is one of those myths going around. It's a shame myths like these deter so many keen hobbyists. My advice is don't listen to the hype, find out for yourself.

 

[Crawdad]

Makes you wonder if the naysayers have ever actually heard a MKIII on SSB. Back in the day (yes, I'm one of those), IMHO, there were a few tubers (CB's) that sounded as good, but none better. No one I knew back then hacked on theirs to get 3 more watts, they just added a VFO and called it done.

73

 

[Flatop]

Makes you wonder if the naysayers have ever actually heard a MKIII on SSB. Back in the day (yes, I'm one of those), IMHO, there were a few tubers (CB's) that sounded as good, but none better. No one I knew back then hacked on theirs to get 3 more watts, they just added a VFO and called it done.

73

Yes, I am saying more and more these days 'less is more'. Mine does 10W PEP, which is apparently healthy for these. I know there are two versions of the MKIII, my one is the first, I think they have a reputation for being better on sideband. And I don't know what modifications have been done to the radio if any. All I have to do is fix the transmitter's mode switch, maybe give the receiver an alignment, and fix the input impedance of the 180 linear that I have. The swr is 2:1 looking into it, so if anybody knows a good way to correct this, I'm all ears.

 

[Dmans]

The swr is 2:1 looking into it, so if anybody knows a good way to correct this, I'm all ears.

Search this forum for "Negative Grid Bias" modifications and/or "Tuned Input" modifications and you will probably find your answer.

https://www.worldwidedx.com/threads/hygain-afterburner-plus-482-grid-bias.228873/

Above link may get you started.

73
David