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  #1  
Old 07-07-2020, 11:27 AM
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Testing a Signal Generator

Any tips on verifying whether a signal generator is working? I have a Heathkit SG-8. I've replaced all the caps and swapped a 1N4004 in for the selenium. It powers up, no smoke, but I'm not sure how to verify that it's producing a signal.

Any ideas are appreciated. I'd like to get this working so I can start injecting signals on my SW-54 chassis.
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Old 07-07-2020, 11:46 AM
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Dangle the output cable near a radio, turn the rf output and modulation up... set to band b on the generator.... you should be able to hear it at near the correct frequencies on the AM band. likewise, you should be ablr to hear band d signals on the FM band.

jr
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Old 07-07-2020, 12:29 PM
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You won't be able to confirm the generator dial frequencies without a frequency counter or at least a good oscilloscope that can work at the RF frequencies.
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Old 07-07-2020, 01:28 PM
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Quote:
Originally Posted by Notimetolooz View Post
You won't be able to confirm the generator dial frequencies without a frequency counter or at least a good oscilloscope that can work at the RF frequencies.
Some service generators are so non sinusoidal that some counters won't indicate correctly...My Heathkit and tripplet counter don't like each other so I dial in the digital tuner in my Sony ICF7600GR world band radio to the frequency I want and adjust the Heathkit for peak volume.
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Old 07-07-2020, 01:43 PM
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Is there a frequency on the B band you'd recommend I ballpark to test with an AM radio? Something that I could try and hone in on with the dial?

I'm not looking for accuracy here so much, just want to figure out if I need to do any more servicing on this.
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Old 07-07-2020, 01:58 PM
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Okay, I set it to band B and heard some warbling around. I was able to move the RF frequency and find it on a different part of the band. I'd say this thing is working. Thanks, all!

Now I just need to figure out how to use it for signal tracing.
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Old 07-24-2020, 10:44 AM
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I dial in the digital tuner in my Sony ICF7600GR world band radio to the frequency I want and adjust the Heathkit for peak volume.
That's a really good idea, I think I will use the same technique to verify my Stark RF generator's dial accuracy.
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Old 07-24-2020, 02:21 PM
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That's a really good idea, I think I will use the same technique to verify my Stark RF generator's dial accuracy.
Thanks. If your set has continuous coverage from 150KHz ( Long Wave ) to 30MHz like my Sony you can use that method to get accurate 455 or 260KHz IF from your generator....

I can also use the Sony to do sneaky troubleshooting with tube radios....If I tune the Sony to the IF freq an antigue AM or FM (I didn't expect FM but found that it works) radio that is working between the antenna and converter/mixer stages (having atleast 1 good IF stage helps) the Sony will pick up any signal making it to the IF chain of the tube radio.
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