Keying Problems

[n4si@pobox.com]

> > and the problem mostly goes away.  Still sounds like RF,
> > but here's where it got weird.  K4HA says, "I never have
> > the problems with CT", so we fire up CT on all the same
> > H/W, and we can run full power to the amp with no keying
> > problems.  It almost seemed like the TR program itself was
> > more susceptible to RF than CT, but I've never heard anything
> > like that.  Anyone got any ideas?
> > 
> > 73, Jim Stevens, K4MA (ex KI4HN)
> > 
> 
> One possiblility...

> On the other hand, I may be completely wrong.
> 
> 73 Kevin w9cf

My 2 cents, and I hasten to add that this is definitely not my strong 
suit, if I even have one:

I built the simple interface for keying LPT1; it's basically the same 
in the TR manual, brand "C", manual, and others. It worked just fine 
on brand "C", brand "N", N4ZR's Morse keyer, another Morse keyer, and 
TR. My logging program, LOGic (highly recommended), added CW keying 
in an update and I could not key CW with it.

I heard from a few sources that there may be a "floating" high or
low on one of the LPT lines that caused that, and that pull-ups or
pull-downs were needed on certain computer/interface cards, so I
ordered an interface from Dennis (WN4AZY, creator of LOGic), which
uses opto-isolators, among other things, to avoid the problem.

I installed it, and everything keys flawlessly. Incidentally, RF was 
not an issue here; it wouldn't key with 100 watts.

By the way, check Dennis' page at:

          http://www.mindspring.com/~pda/

I hope this helps, and as Kevin says, "I may be completely wrong..."

73, Rod N4SI
    The DXer formerly known as N9AKE
         (c) 5 November, 1996