ORIGINAL MESSAGE:
On Sun, 4 Apr 2010 04:29:34 -0700, "Jim Thomson" <Jim.thom@telus.net>
wrote:
>## Both the 875A and 875B operate at 1 khz square wave. What freq
>does the
>AADE operate at ?? I rechecked my notes from yrs ago... and don't know if
>the choke
>was in the circuit or not.[ when measuring tune cap C.. after the fact]. I
>do know that
>when the mfj in rvs test was done... that I chassis grnded the cold end of the
>plate choke.
> IE: bypass capS at base of plate choke was shorted out.
>
>## The notes say, that with choke removed... and mfj in rvs test was
>conducted, that everything
>resonated just fine. LCR meter used to tap the coils initially. When
>plate choke was added back
>into the circuit, the TUNE C had to be INCREASED by 40 pf. [160m only]
>..and 10 pf on 80m.
REPLY:
The AADE changes frequency automatically depending on the value being
measured, but I think the max is 100 kHz. If this is incorrect,
someone please correct me.
The nifty part about doing this procedure is that when the RF choke
"eats" some C, it really doesn't matter as long as you have enough
spare C in the tune cap. When you re-connect the RF choke and re-tune
the tune cap, you end up with exactly the same net value of C anyway.
73, Bill W6WRT
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