[NLRS] 857D

[Melvynkc0p at aol.com]

Hello Joe, I am using a Kenwood 9130 2M all mode  to drive a DEMI
10GHz transverter that is set for about 2 watts of drive.  below is a
note that describes how I have used the 4 stage sequencer  and
4.5 V penlight batteries to inject ALC to control the drive. This  allows
me to use the regular PTT on the microphone to go to  transmitt
without getting a spike. I have used it for about 300 QSO's so  far
with no problems. The 9130 is capable of putting out 25 watts on  SSB
if there is no ALC to hold it back.

Subject: Using a DEM 4 stage  T/R  Sequencer

3 Sep  2008

I have the sequencer built and it works. Now how
to  use it ? I think I have figured a way to sequence
things without breaking  open the microphone PTT
circuit. Here is a State diagram of how it would  work.



State 4  Transciever ALC forced to  -2.5v=SSB  Operate,
cuts 5 watt power out down to about 2  watt.
Hello, CQ DX !


State 3  DEM Transverter to TX by  PTT low


State 2  DEM 3W amp On by Ctl  Low


State 1  Pick Microwave T/R relay to put in Xmt  mode


State 0  Transciever ALC forced to  -4v=Cutoff
no power out  allowed.
Transciever in Receive  mode
Transverter in Receive mode

Transition from State 0 to State 1 is  initiated by
Microphone PTT or Manual CW hold switch. Transitions
to  States 2, 3, and 4 are controled by the sequencer
time constant. When the  Microphone PTT is released,
the sequence is reversed all the way back to  State 0
and I am again in receive mode.

I could use one circuit of the  stage 4 relay to control
the ALC being fed back to the IF  Transceiver;
Common to Transceiver ALC input
N/C    Tied to a -4 volt source
N/O    Tied to a -2.5 volt source

I think this should  work. Any comments about something
I may have missed ?

Mel  KC0P