[Elecraft] SB-221 for K3 need some help.

[John King]

My old SB-220 works just fine with my K3 on CW.

Yes, the SB-220's key line is 120 VDC. The kind that
will make you let go real quick if you accidentally
grab it. The K3 doesn't mind it. The K3's Key Out is
rated for +200V at 5 Amps.

The stock SB-220 won't do QSK, of course. Set the
K3 to semi-breakin with a hold delay long enough to 
keep the amp keyed between characters, and you're
good to go. FB

73,
  john WA1ABI



> 
> 
> 
> > I found out this week that K3 is good with Heathkit
> > SB-220 amps, all you need to do is connect a shielded
> > RCA cable between the units - how easy is that? !!!
> 
> Are you sure?  Most of those amplifiers had high voltage PTT 
> circuits.  If I recall correctly the TR relay is a 120V 3PDT
> unit.  You may need a buffer or soft-key circuit in your 
> amplifier to make it safe with the K3. 
> 
> Elecraft web page: http://www.elecraft.com