[Heathkit] Heathkit HW/SB transceiver AGC mod.

[Tom NØJMY - AAR7FV]

Ken and the group:

Is there a ready source of pots with push-pull switches somewhere.  I've 
never made a diligent search for them, but would sure like to stock up 
on some.

Tom

----- Original Message ----- 
From: "Kenneth G. Gordon" <kgordon at moscow.com>
To: "Old Tube Radios" <glowbugs at piobaire.mines.uidaho.edu>
Cc: <Heathkit at mailman.qth.net>
Sent: Tuesday, February 15, 2005 5:23 PM
Subject: [Heathkit] Heathkit HW/SB transceiver AGC mod.


> The purpose of this mod is to enable the operator to switch to a
> fast-release AGC when it is needed, and to yet retain the slow-
> release AGC for normal SSB use.
>
> 1) Replace the audio gain pot with one which has a push-pull
> switch included.
>
> 2) Find R-117, a 3300 ohm resistor on the IF circuit-board near
> its right rear corner. One end of this resistor is connected to C-
> 110, a 1 ufd "tubular"capacitor, the other end is connected to
> ground.
>
> 3)  Un-solder this resistor lead from ground, splice in a piece of
> wire long enough to reach the switch, and route it via the
> shortest route you can find to one of the switch connections.
>
> 4) Solder another wire to the other switch connection. The other
> end of the wire is connected to any handy nearby ground.
>
> Or, if there is enough material in the pad to which R-117 was
> originally connected, you can cut it between where R-117 enters
> the pad, and the grounded side, drill two small holes large
> enough to get the ends of the wires into, and solder one of the
> switch wires to the R-117 bit of pad, and the other switch wire
> to the ground end of that pad.
>
> The IF circuit-board is that board nearest the front panel on the
> right hand side when viewed from the top containing three
> tubes and three transformers.
>
> Ken W7EKB
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