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Author Topic: Symptoms of an oscillating amplifier?  (Read 14214 times)

Offline ff

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Re: Symptoms of an oscillating amplifier?
« Reply #15 on: October 23, 2014, 1357 UTC »
I understand your frustration Antennae, AND your determination, having felt both many many times throughout my building career.  The determination you have inside will carry you far if you continue building radio gear, whether pirate or legal.  Doggedly pushing through problems and faults will usually produce a working unit eventually.  Determination is what many would-be builders lack.  It's refreshing to see someone like you who is truly committed to his/her project.  With that in mind I again urge you to put your efforts into a better design once you are satisfied with your Mighty Mike.  I believe you can do it.  And above all... have fun... 73!
Hailing from the upstate boondocks region of the progressive paradise which once was New York State

Offline audiokaos

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Re: Symptoms of an oscillating amplifier?
« Reply #16 on: October 24, 2014, 1843 UTC »
makeRF: I'm using the LM386 chip as an amp.

kaliic: The audio sounded fine, just quiet. The LM386 chip would get warm when transmitting.  It would get really hot running a speaker without resistors. It wouldn't get warm when running a speaker with resistors. 

Its not assembled anymore.  It was bugging me why the sound didn't carry very far.  I thought maybe because it was oscillating? I'll reply here if I tweak with it.

thanx

FYI you do realize that on a frequency such as 6925, the signal doesn't go that far locally right? It skips. Could have been clear as day 150 miles away.
Using Kenwood TS930SAT, Dipole cut for 15M
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Offline Antennae

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Re: Symptoms of an oscillating amplifier?
« Reply #17 on: October 24, 2014, 2146 UTC »
I should have given more background.
I could hear the carrier wave on the sidebands up to 2 miles away. 
But the audio I could faintly hear only about 100' away. 
California Coast
Antenna: random wire