[App_rpt-users] Ok..simple DMK interface....

[Bryan D. Boyle]

On 2/19/2011 7:56 PM, Ken wrote:
>>
>> So, the question is...is this pin basically a contact closure (which IS
>> what I'm looking for), or some other logic level that I'll have to
>> convert?  If so...any pointers or ?
>>
> 
> It's like a contact closure, except it will not pull the voltage all the way
> to ground and it will not handle much current.  It works fine for radios
> that use logic-level kinds of signals. That is the vast majority of ham
> radios.
> 
> I have had to add an additional relay and/or transistor externally to switch
> big things (like my Motorola Nucleus 300 watt paging transmitter).

Relays...now, that's something I can sink my teeth into...turn on the
mic here in my broadcast recording studio, and you can hear them
clunking all over the place...shutting off speakers and turning on 'On
Air' lights.

Guess it's time to pick up a small 12V relay, 2n4401, couple diodes
(need to replace the rectifier bridge on a VU meter, too...) and get the
iron warmed up..

Which one would you prefer for the ptt line off the dongle?  Basically
just going to pull the relay in when the thing goes to transmit...and
use the contacts to close the PTT circuit on the rig.

73 (and good talking with you last week...)
WB0YLE