[Elecraft] K3 with a Kenwood TL-922A

[Joe Subich, W4TV]

 > Anything I need to know before I hook the K3 up to it.

Don't do it!  The TL-922 has a high voltage PTT line with *no* current
limiting and no reverse EMF diode across the relay coils.  The relay
current is rather high and the "spike" when releasing PTT is quite
high.  You will need to add a Harbach engineering "soft key" board -
   www.harbachelectronics.com/main/page_products_kenwood_tl922a.html -
in order to keep from blowing the K3's keying FET and potentially
causing other damage to the K3 due to the spike.

Even if you add the soft key board, I would recommend adding "back
diodes" across the T/R relay coils and adding a series resistor in
the relay line to keep the current down and minimize the potential
for a spike.

73,

    ... Joe, W4TV


On 9/2/2011 8:57 PM, Chris Hembree wrote:
> I am buying a Kenwood TL-922A Amp. Anything I need to know before I hook the K3 up to it.
>
> Thanks
> Chris W7CTH
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