Tube circuits..... drive me nuts.
That is all. You may go on about your business.
That is all. You may go on about your business.
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A minor vent...
- Thread starter guitar_199
- Start date
Funny how you mention that...
These guys bang on them all day...and night.
These guys bang on them all day...and night.
Well solid-state circuits can be a real funhouse at times and I have been working on them for over 50 years and although I have learned a lot over the years every once in a while I get one that is just not following my idea of how it should just jump up and say hear I am fix me. Tube circuits are no different in that respect I cut my I teeth on tube circuitry and the truth is if you follow the same troubleshooting approach it really isn't that much different except of course you can get lit up if you screw up.
Lit up isn't going to be a problem.
The current problem is a tube mixer stage in a Regency Range Gain. We are crawling up on the point of.....
1) tried another tube in that position... no joy.
2) no broken/bad/cracked solder joints in the area....
3) two newly purchased crystals have been tried... no joy
4) tube socket pins have been examined and appear to be clean and snug....
we are not quite AT THE END of the rope..... but we aren't far either.
Just can not figure why that 7.5 Mhz oscillator is not running and mixing up to the 27 mhz mark like it should.
Just exasperating.
The current problem is a tube mixer stage in a Regency Range Gain. We are crawling up on the point of.....
1) tried another tube in that position... no joy.
2) no broken/bad/cracked solder joints in the area....
3) two newly purchased crystals have been tried... no joy
4) tube socket pins have been examined and appear to be clean and snug....
we are not quite AT THE END of the rope..... but we aren't far either.
Just can not figure why that 7.5 Mhz oscillator is not running and mixing up to the 27 mhz mark like it should.
Just exasperating.
That is correct. We can tell that the 19 mhz product IS being generated from the 8mhz and 10-11 mhz oscillator mixer.
In fact... we are using one of your signal sniffer probes on a Nano VNA like a spectrum analyzer and it works remarkably well. As we change channels we can see the specific 8mhz and 10-11mhz spikes
.... and we can see the 19 mhz spike out of the first mixer.
The next stage is a combination 7.5 mhz oscillator.... and it mixes the 7.5 with the 19 to give the final 27 mhz.
We flat can not see the 7.5 mhz oscillator running AND we can not see the 27 mhz product.... and I believe that is because the 7.5 mhz isn't running at all.
Thanks a million for that sniffer probe video..... I am serious.... one of those
. For hf freqs.... plugged into the Nano VNA... It is incredible!!!!
In fact... we are using one of your signal sniffer probes on a Nano VNA like a spectrum analyzer and it works remarkably well. As we change channels we can see the specific 8mhz and 10-11mhz spikes
.... and we can see the 19 mhz spike out of the first mixer.
The next stage is a combination 7.5 mhz oscillator.... and it mixes the 7.5 with the 19 to give the final 27 mhz.
We flat can not see the 7.5 mhz oscillator running AND we can not see the 27 mhz product.... and I believe that is because the 7.5 mhz isn't running at all.
Thanks a million for that sniffer probe video..... I am serious.... one of those
. For hf freqs.... plugged into the Nano VNA... It is incredible!!!!
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