Heathkit SG-6 signal generator
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Hi Guys- I have an old SG-6 generator that I haven’t been able to figure out. It’s had out of spec resistors etc. replaced but I haven’t been able to get it to work. The instruction sheet isn’t much help as the information given is minimal. Any suggestions or questions are appreciated. Thanks! - Rob Q.
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I just finished up a SG-7, it's a pretty awful generator. Have been using it for years along w/a counter or the Kenwood TS-440 to figure out what frequency it's on.
I downloaded the manual and it's the same as the SG-7.
https://elektrotanya.com/heathkit_sg-6_r...ad.html#dl
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 01-27-2022, 11:26 AM by Radioroslyn.)
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have you checked the tubes?
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If you follow the hv around thru the 6C4 osc tube the plate and cathode should be at about the same potential. Unless the variable cap is shorted (rubbing plates). I think it's about 80vdc. RF wise the plate is at ground thru that .01 cap.
I'm assuming you've replaced the caps, out of tolerance resistors, and the power supply is making 140vdc or so at the cathode of the rectifier. Q Tips and denatured alcohol does wonders for the switch contacts.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
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City: York
State, Province, Country: PA
Thanks for the help Terry! I’ll let you know what I find. - Rob Q.
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I have an SG-8. They are all pretty awful.
The waveshape is bad, and the accuracy is questionable, so using it without a counter is just unwise.
I restore old radio and I understand why I do that, but why I would use bad inconvenient tools, is beyond me, And I did for awhile, until I saw the light.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
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Me too.
For many years I used an old, inaccurate, unreliable Clough-Brengle signal generator; adding a B+K frequency counter some years later in an attempt to make the setup somewhat more reliable. Finally, a few years ago, I finally wised up and bought a Siglent SDG1032X function generator and then added an inline 20 dB attenuator. It is just what I had always wanted - I can punch in the frequency I want and it stays there, rock solid. It wasn't cheap, but it was a lot cheaper than the "gold standard" HP function generators.
In between the Clough-Brengle and the Siglent I owned a used B+K 4040 for a while. It was better than the Clough-Brengle, but it would also drift. The Siglent does not drift.
--
Ron Ramirez
Ferdinand IN
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Wow. And I thought I just picked up a gem when I got a Heathkit SG-8 for $6.00 at a garage sale. Not a precision instrument, but better than nothing. Will invest in a frequency counter down the road. Take care and BE HEALTHY! Gary
"Don't pity the dead, pity the living, above all, those living without love."
Professor Albus Dumbledore
Gary - Westland Michigan
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Hi Guys- Checked out voltages and cleaned tube pins, switches etc. The signal generator works but accuracy is an issue. Time to consider an upgrade. I got it awhile back when taking a radio repair class at the museum in Bowie Md.
It was good as a learning tool so I consider the $12 I spent for it as an investment. Thanks for the input! - Rob Q.
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Adding BK counter (same as Ron did) helped but it was a half-measure. I mean, I paid $20 for a working unit so either Leader SG-11 or Heath SG-8 paired with it was an inexpensive setup, so I did not lose much by retiring it to the shelf.
Half-measure it was because the SG, in addition to the absolurte inaccuracy (scale vs the actual frequency), and the waveshape that was all but sinewave (and I was playing with the cathode follower that made it such - nothing helped), the frequency also drifted. Slowly, but by time you adjusted the trimmer or what have you it could go away by 100Hz, and if you did not re-adjust it every time netween the adjustments, at the end of it the frequency could easily drift by a few hundred HZ to 1kHz. No amount of warm-up helped.
So, yes, get thee a nice synthesizer, old or today's, make a protective cable with two back-to-back diodes, and this will make you a very happy alingnment person.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
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I used a Heathkit signal generator for years.
[Image: https://64.media.tumblr.com/6861d67d1a12...25a64f.jpg]
One had to let it sit for about an hour to warm up well for it to be at all stable. It was fairly accurate for rough alignment work, but I found a good work around. For fine work I used my Tecsun PL-600 digital readout radio to double check the frequency. For IF work I would tune the radio to double the IF frequency, and then set the signal generator to the correct frequency and listen to the harmonic to get the loudest signal. For instance, I would tune the radio to 910 KC and then tune the signal generator to 455 KC and be able to set it exactly. For general work it was fine using these work arounds.
I also purchased a modern signal generator
[Image: https://64.media.tumblr.com/8de05b2cdb1b...05747a.jpg]
It was not any more accurate than the Heathkit over its bands, and so I never use it.
The signal generator I use most is my EICO model 342.
[Image: https://64.media.tumblr.com/a5460038db65...867b95.jpg]
I was able to align it properly since it has adjustments for both ends of the scale on each band. Once warmed up it is very stable. I still use the Tecsun and the harmonic method for setting IF frequencies, just to get them right on instead for 10 or so KC either way. I also double check the frequency on the AM broadcast band just to be sure and get things exact, but find that the settings are tack on. For higher frequencies, aligning shortwave bands, I really don't have to double check, it is close enough so it comes out fine, but I still do.
I suppose my point is, don't be afraid of this older gear. Once you learn how to use it, and learn a few tricks, it will do the job fine.
(This post was last modified: 01-29-2022, 06:56 PM by mikethedruid.)
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Rob, check out post#14 in this link https://philcoradio.com/phorum/showthread.php?tid=23161. It shows what I did to my SG-8. Makes my setup fairly easy to use and easy to make the mods!
Ron
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(This post was last modified: 01-31-2022, 08:57 AM by 462ron.)
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Hey Ron- Neat! It’s a great way to make the old Heathkit much more functional! Now you’ve got me thinking. Thanks! - Rob
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I have a HK tube tester, the paper roll is getting loose, may need a recap too. The HK stuff was pretty good overall.
Paul
Tubetalk1
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I’ve been reading a few of the radio magazines from the 1920s. Compared to what they had to work with the HK stuff is pretty remarkable. I guess it’s all relative.
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