[TRLog] PTT output and 1000MP

kl7ra kl7ra@blizzard.gcgo.nasa.gov
Wed, 8 Aug 2001 11:24:13 -0800

>> I am using the standard TR  LPT port keying and PTT interfaces with a
>> 1000MP Mark V (1K resistor to base of open-collector 2N2222, emitter to
>> strobe line, open collector to plus of keying or PTT jacks).  Previously
>> these interfaces worked fine with my TS-930.  Either one will key the Mark
>> V's CW, but neither one will key the PTT line at the jack on the back (in
>> other words, the interfaces appear to be functioning as designed).
>> Anyone else had this problem?  How did you cure it?
>Try putting the emitter to ground.  The strobe pin will limit how
>much current can be sunk - and also result in a slightly higher
>"low" voltage.  This could be the difference.

This will probably fix his problem, often it's PC LPT port dependent
and another PC will work fine. The strobe is a good idea however
as the program doesn't come up keying the radio PTT. I solved
this by having the 2n2222 key a reed relay for both CW and PTT.
Also adds isolation between the radio and PC port.

73 Rich KL7RA 

FAQ on WWW:               http://www.contesting.com/FAQ/trlog
Submissions:              trlog@contesting.com
Administrative requests:  trlog-REQUEST@contesting.com
Problems:                 owner-trlog@contesting.com
Feature Wishlist:	  http://web.jzap.com/n6tr/trwish.html