[Elecraft] Amp keying circuit K2

[Don Wilhelm]

David,

Best solution: Change the output transistor to a mosfet device which will be
capable of handling the higher voltage. See the .pdf from Tom Hammond's
website - http://www.n0ss.net/k2_basic_8r_line_t-r_adapter.pdf for the
re-designed output device (HEXFET).  It will require changing one of the
resistors in the present keying circuit as well as the output device.

Another solution would be to use the present amp keying circuit (and a power
supply) to key a relay - use the relay contacts to key the amp.  Depending
on the speed of the relays, that may slow things down a bit and you will
cause problems with QSK keying.

73,
Don W3FPR


> -----Original Message-----
>
> Thanks for all the responses to this - much appreciated.
>
> I'm afraid it was a simple case of me not reading the instructions on the
> keying circuit.
>
> The FL-2100B pulls 20v on its keying input, whilst the circuit
> for the K2 is
> only designed for 5-12v !! This is clearly written on the
> instructions with
> the circuit, which I neglected to read.
>
> Does anyone have details of a simple circuit I can build, so I
> can use this
> with my FL-2100B ??
>
> Again, many thanks for the all the replies !!
>
> David, VK2NU
>
>