[Elecraft] External Sequencer / Amplifier Keying

Thu Feb 7 16:01:46 EST 2013

From: "Kevin Hobbs" <ve3kh at cogeco.ca>
To: "Elecraft" <elecraft at mailman.qth.net>
Subject: [Elecraft] External Sequencer / Amplifier Keying
Message-ID: <[email protected]>
Content-Type: text/plain;	charset="us-ascii"

Hi All
I am new to this list . had my K3/10 sitting on the shelf for the last 6
months as I made the transition from a Flex-5000A VU.

I am now scrambling get everything hooked up and running again. I only
operate 6m and 2m (plan on using external LT2S Transverter, but I may get
the internal unit). Always doing the opposite to the masses.

Since I use external amplifiers and preamps, I use sequencers and split RX
and TX coaxs. Plan to use ANT1 and RX Ant In for 6m and XVTR IN & OUT for 2m
(hopefully this will work).

The question is . is there a simple way that I can get a unique TX GND
signals for 6m and 2m to drive the sequencers?

I read about using Acc Pin 10 Keyout LP for 2m and standard rear Key Out for
6m, but I suspect that Key Out will be active on 6m and 2m?

Suggestions?

I am guessing that I will have plenty more questions as I try to get
everything including LP-Pan 2, Signal Link, and WSJT running to get back on
EME quick.

Thanks and 73
Kevin VE3KH
------------------------------------
Kevin,

Welcome back to eme.  I used many ideas from your website in the late 
1990's when designing my 2m-eme station.  Maybe I can return the favor.

I am using a K3/10 as my IF for eme.  I am using the LP-Pan as SDR to 
drive a Delta44 soundcard for running digital-eme modes (JT65 and 
MAP65).  I am not that familiar with the LT2S but sounds like it is a 
144-28 transverter and wonder if you are driving it at high level 
(several watts).  If it has a low-level input like 1mw the K3 
transverter interface it the right way to go.  That is what I do to 
drive a 50w 144-28 MHz Down East MW transverter.  Separate Rx and Tx 
RF connection is provided at 28-MHz and I use KEY OUT to key my 
sequencer.  All TR control emits from the sequencer including PTT 
back to the K3.  I have TRN selected for VHF which sets the BAND 0-3 
lines of the ACC to be keyed in conjunction with VHF band.  I am 
using the INHIBIT function in the K3 to prevent RF until the 
sequencer disables the inhibit line...works great!  This means I can 
connect CW keys and mics direct to the K3 without concern for the K3 
to emit RF too early.

I control the K3 directly using a USB/RS232 conversion cable from the 
computer, and connect K3 line-in/out lines direct to the soundcard 
without need of an interface like the Signal-Link.  Much simpler and 
reliable.  I only use line-in when running MAP65 as I route the K3 IF 
thru the LP-Pan which drives the soundcard.

If you have to use the high-level (0-12w) output of ANT1, then you 
could use an NPN transistor to control the KEY OUT line with base of 
the transistor controlled by BAND0 line of the ACC (+5v when 2m band 
is selected).  I do not have to do that with my setup.  I do use the 
ACC BAND lines to enable the INHIBIT function for only the bands that 
I desire it to operate (144-1296 at my station).  This automatically 
disables inhibit on HF where it is not needed.  I use the DIGOUT1 
line from ACC to enable inhibit on 6m as I will be using a 1100w PA 
on that band in the future.  Here are some links that might help:
http://www.kl7uw.com/eme144.htm
http://www.kl7uw.com/TX-INHIBIT.htm
http://www.kl7uw.com/controlbox.htm
http://www.kl7uw.com/MAP65.htm

I copied this to the Elecraft reflector in case there are others with 
similar questions.
73, Ed - KL7UW