HFU HF Underground
Technical Topics => The RF Workbench => Topic started by: moof on May 21, 2016, 1817 UTC
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Let's say I have 2 grenade style boxes and x number of WWII crystals all the same frequency. All work perfectly in box #1 with close to 10 watts from the IRF510. In box #2, half are associated with power close to 10 watts, half get anywhere from a couple needlewidths of power to about 1 watt. Any suggestions of what components to mess with? About all I can guess to start is mess with the nice mica caps right before the antenna output and see if jacking around the values +/- 50-100 pF fixes things for the bad crystals yet makes the good crystal output suffer a bit. I already optimized those when I built the boxes. Theoretically speaking.
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The osc section of box 2 sounds dodgy.
Do you have a 'scope?
Having one would be most useful.
Str.
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No. Don't have a couple hundred bucks laying around and don't have much of an electrical background. Read some books and figured stuff out.
So check connections and component values with multimeter where possible I guess in the oscillator area. Maybe try to replace a few bits I can't test.
Thanks for input.
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Get a 'scope, you don't need an 'Electrical Background' but you will be able to 'See' what's going on.
What you're dealing with is invisible!
;)
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Sounds like box # 2 has a weak oscillator transistor, or something isn't right on the crystal loading side.
...Also something I wouldn't tackle without a scope. I've been using one for so long, I can't imagine not having one.
Good luck grasshopper!
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