Deleted
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Post by Deleted on Oct 27, 2020 9:41:56 GMT -5
Thanks guys. I really appreciate the benefit of your knowledge and experience. I know I'm ill equipped for this project and am temporarily putting it on the back burner. If I can't find someone to check the amp I may update my tools, improve my education and take another stab at it sometime. Thanks again for your time and interest.
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Post by LTB on Oct 27, 2020 13:40:34 GMT -5
Haha, yes, no prob, pleased you’re back! Thanks for the DMM links, analog meters are too fragile and fininicky. Thanks sir! Now I will exit stage left and get out of ya'lls hair (Yep I am from Texas LOL )
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pdf64
Wholenote
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Post by pdf64 on Oct 28, 2020 7:28:09 GMT -5
Gibder, I suspect that meter has given your confidence a knock, but you can do this Just need a halfway decent meter and get used to using it. LTB - don't go too far
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Post by LTB on Oct 28, 2020 12:54:52 GMT -5
LTB - don't go too far At this stage I don't think I will be going far
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Post by Deleted on Oct 28, 2020 13:22:32 GMT -5
I appreciate your vote of confidence pdf and thanks for your meter suggestions LTB. I ordered the auto ranging version. I know it's a great improvement over my 30 year old Radio Shack model. If I can't find someone in my neck of the woods to take over this project I may send voltage results at a later date.
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Post by roly on Oct 29, 2020 3:34:32 GMT -5
I like the direction this thread is heading.
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Post by LTB on Oct 29, 2020 6:09:06 GMT -5
I appreciate your vote of confidence pdf and thanks for your meter suggestions LTB. I ordered the auto ranging version. I think you will enjoy the features on that meter. Looking forward to you finding your problem/s. At my electronics jobs at DFW Airport we started with Analog Simpson meters, evolved to Fluke Digital Multimeters with manual settings which was a big improvement over the Analog (needle vein meter) then in the late 80s to early 90's transitioned to the Fluke Digital Auto Ranging. I found if I was going to check components (ie resistors etc) within the same range I like setting the hold on that range just to keep it from having to auto adjust all the time (which is not an issue really, I just like the reading to come up instantly lol. Impatient aren't I ) Lastly DVM's are more accurate and have a much higher input resistance so they don't load the circuit as much as analog. Analog input resistance can range from aproximately 20K ohms on real cheap to 50K or so on better while DVM's are typically 10mega ohms. Now know this. Keep your analog handy for the rare scenario where there might be some residual small voltage left on circuit testing that can affect reading of resistance on DVM. Or once you get familiar with testing and suspect there might be residual voltage just put the DVM on DC Volts and see if there is. If so then resort to the jumper mentioned below and drain it then test resistance again. Not a biggy. This doesn't happen that often but if it does pull your analog meter out and double check as a small milli volt being on the circuit won't effect it as much because it being a lower input resistance will typically load small voltage left on a cap and drain that sucker. Anyway...enjoy your new meter. They are about all I use any more and if I run into a small residual voltage and I know the circuit has the voltage removed (unplugged and caps drained) I will use a jumper to drain the cap. It is recommended you make a jumper with a 1000 ohm 1/2 watt resistor in it so it will safely drain the cap and not "zap" the sucker all at once. Happy hunting
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Post by Deleted on Oct 29, 2020 13:26:27 GMT -5
Thanks again LTB.
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Post by Deleted on Jun 6, 2021 11:59:35 GMT -5
Attn: pdf64, LBT. Thought I would give you guys an update. After giving up on finding the issue myself I put it on hold until I finally found a tech I had used years before and lost his name and number. I offered him pdf64's diagnosis of bad plate resistor or connection. After checking the resistor connections with a wooden probe he was able to locate the bad connection and make the amp go in and out at will. He re-soldered the connection and it's all good again. Thanks again for all your advice and information.
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Ayns
Wholenote
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Post by Ayns on Jun 6, 2021 12:24:10 GMT -5
I love a happy ending ;-)
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