[Elecraft] K2/XV144 Power Overshoot

[Dick Hanson]

Hi Glenn...

You have done a good job of sleuthing and pondering the various
solutions.

Bottom line is that you may well need to communicate via email with the
boys at Elecraft about this. If they have had other similar reports (or
even if they have not), they will try for a solution. Also, you may well
get a response from other VHFers that have been down this road.

First, I believe you're correct in figuring it is the K2 and not the
transverter.
I have run into exactly the same issue with one of my VHF combos. I have
a Yaesu FT-897 driving a Lunar 2 meter amp (pair of 3CPX800, with very
sensitive grid trip circuitry). Same exact problem. Yaesu tech support
told me how to adjust some of the ALC circuitry to "tune out" or at
least minimize the initial ALC related overshoot.
This helped a lot. Then I "slowed down" the pulse in the grid trip
circuit in the amp by adding slightly more capacitance to one of the
time constant caps. The combination of these two things solved my
problem. I did not try the in-line attenuator approach, but that may be
helpful too. You could easily fashion a 3 db attenuator out of a length
of RG-174 mini coax. It has a healthy amount of "loss" per foot, so you
could quickly calculate how many feet you would need to arrive at 3 db.

I have both the XV-50 and XV-144 now to use with my K2 but have not yet
used them in our VHF contest station with an external amp to observe
whether this phenomenon exists. I will hasten to do some testing and get
back to you on this.

Good luck.
Dick

-----Original Message-----
From: elecraft-bounces+k5and=adelphia.net at mailman.qth.net
[mailto:elecraft-bounces+k5and=adelphia.net at mailman.qth.net] On Behalf
Of Glenn McNeil
Sent: Saturday, May 21, 2005 22:55
To: elecraft at mailman.qth.net
Subject: [Elecraft] K2/XV144 Power Overshoot