My first HF oscillator!!!

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MN785
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My first HF oscillator!!!

#408307

Post by MN785 »

Today was a good day... I tried making a simple HF Hartley oscillator for the first time. I started out with fake MPF102's, That makes for some real discouragement right there. Of course, my old galaxy part radios already had the J310's stripped out and there was not a single jfet in the desk drawer. I managed to find an old cobra 29 in the shed that still had the 2SK192's, soldered it all together without a board just to see if the rats nest would work, nope. Started banging my head against the desk which happened to move the oscillator off the bandana and onto the metal desk, and there it was, a little spike on the spectrum analyzer! She came alive for a moment!! So, all it took was a little 60hz noise off this desk to give it enough kick... That's when I learned how important the amount of feedback is! Two lessons learned today... Never buy capacitors or active devices on amazon, and, when things don't work, just bang stuff around until the one clue you need presents itself! Being this is the first LC oscillator (for 27MHz) I ever made, I'm going to bed before I wreck it somehow :P







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MDYoungblood
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#408314

Post by MDYoungblood »

On most old radios that came across my bench I would start out snapping a few pics of all the pots, get a good reference of there positions. Then I would hose them down with some deoxit and work them back and forth a few times to break any tarnish or corrosion that might have built up. It sounds like it took a while for those old dried up capacitors to come alive. That said it probably won’t be long before they smoke.

3’s

Greg






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TNT1450
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#408350

Post by TNT1450 »

Only buy electronic components from electronics supply places like Mouser, Jameco, or All Electronics. Getting parts on Ebay or Amazon is a crapshoot with the proliferation of fake components.







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