>
>Hi Ian,
>
>> Sorry, it appears I was confusing the Warrior with another amp...
>> maybe the Yaesu, though I don't recall ever seen that schematic.
>
>I'm not sure if all runs of the FL2100 do this, but the FL2100 I
>looked at takes a sample of RF after the pi-network and feeds it
>back to the input.
>
>Of course in that system the operating Q of the tank circuit mostly
>controls phase shift. In that system feedback would be all over the
>place as tuning and loading is adjusted. It would also vary with load
>impedance.
>
>I may be mistaken, but I swear this was a topic on this reflector
>about six months or a year ago? Someone even had the FL2100
>schematic on a web page.
>
>Anyway...
>
>To properly adjust the Heath Warrior neutralization, you can
>connect a low power ten or 15 meter RF source (backwards) to the
>tank output and measure the voltage at the filament with a diode
>detector or scope. Of course you do NOT apply HV or filament
>power.
>
>The tank is set to the band where drive is being applied and the
>tuning and loading peaked while applying a tiny amount of reverse
>drive.
>
>The neutralizing capacitor is nulled.
>
>What you will find is a clear sharp null in filament RF voltage when
>the feedback cap is set properly. Tank settings have very little
>effect on null, which is as it should be.
// The sticky wicket is not that the Warrior oscillates on the operating
frequency, it oscillates above the 811A's VHF grid resonance. This is
seemingly why subsequent Heath models abandoned so called
"neutralization".
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
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