[Elecraft] Using basic K2 with Tokyo Hy-Power HL-50B amp

[Vic K2VCO]

Jason Marten wrote:
> I'd like to use my basic K2 with this amp (5W in, 50W out) in CW.
> 
> It has an RF keying circuit, so that means all I have to do is hook up 
> the K2 antenna out to the amp, and the amp to the antenna, right?  Can I 
> ignore the ALC socket and other connections?
> 
> Also, as to QSK on the K2, should I slow this down to semi-QSK via 8R 
> hold (I don't have K60XV) or is there something else I need to do?  The 
> amp is not QSK.

The RF keying circuit will hot-switch (that is, the relay in the amp 
will not start to pull in until the K2 is already delivering RF).  This 
will not be good for the K2, and it will probably not be good for your 
CW signal quality.

What you need to do is disable the RF keying circuit and have the K2 
directly operate the relay in the amp.  This can be done with an 
amplifier keying circuit that operates from the K2's 8R line.  See 
<http://www.elecraft.com/Apps/Amp_keying_ckt.htm>.

The K2 8R line is activated a few milliseconds before RF appears, so 
that will solve the hot-switching problem unless the relay is very slow. 
  You should set 8R HOLD on and use the delay that is comfortable for 
you to reduce relay clicking at your customary CW speed.

You can ignore ALC connections.

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco