Neutralizing Finals in HW-101

[Mark Graalman WB8JKR]

 Doug, here's the way to do it:

1) Tune the rig into a dummy load on 28 MHz to
full output.
2) After tune up don't touch ANY adjustments,
disconnect the screen voltage AND plate
voltage from the 6146's
3) Connect a RF voltmeter or scope capable
of decent sensitivity at 28 MHz across the dummyload
4) Turn on the rig and place into CW transmit mode,
turn the MIC/CW level all the way up.
5) Adjust the neutralization capacitor for MINIMUM
RF indication on the RF voltmeter or oscilloscope.
6) After performing step #5 you are done, DO NOT
repeak the driver tune or anything else and try again.
7) Reconnect the 6146 screen and plate voltage.

 The best place to disconnect the plate voltage is
at the base of the plate choke, the best place to
disconnect the screen voltage is disconnect
R 920 the 100 ohm resistor.

 This procedure isn't the only way to do it, but it
IS the most straight forward accurate way.

Mark  WB8JKR

On Thu, 16 Dec 2004 16:44:05 -0800 "Davies, Doug A FOR:EX"
<Doug.Davies at GEMS3.GOV.BC.CA> writes:
> I'm at the point in the HW-101 refurbishment where I need to know how
> to
> neutralize the 6146's in the final.  As I have been made aware, the
> best way
> to do this is with the plate and screen grid voltages disconnected.
> The
> HW-101 manual doesn't mention this method in the instructions.
> Would
> someone who has done it this way please explain it to me.  I've
> gotten
> everything to work up to this point.  I don't want to blow it (no
> pun
> intended) now !!!
>
> Also, how does one hook up an oscilloscope to the antenna output to
> watch
> the RF output?  I'm sure I can't transmit directly into the 'scope
> <grin>.
> Help here is also appreciated.
>
> Doug  VA7DD

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