9/10/92

SP VK3ZGL @ VK3KVW < VK4BRG
 Hello..I am using an IC-275A on 9600 baud...mods I used were essentialy by
W0SL, Roy. I only have a hard copy...its here some where!!. I also added a
bit about access to the rear of those 2 sockets.
 However, the nitty gritty is that the TX audio can be fed to pin #2 of the
AQS socket with no mods to the radio. There is a pre-set gain control in the
circuit (R 152). I did not touch this, but adjusted the deviation via the AF
output level from the modem.
 The mods that Roy described were on the receive side and to do with wiring
the mic up/down to one of those rear sockets...used for AFC.
 Good luck..can guarantee it does work..hi.
 73, Ron, VK4BRG @ UO-22 or @ VK4AJL.


7/6/91




HOW TO MODIFY THE ICOM IC27H 2MX TRANSCEIVER FOR USE WITH THE
9600 BAUD MODEM (FOR USE WITH UOSAT-3)


ŽŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸø
„ MAIN UNIT SIDE                        „
„                                       „
„                                       „
„                  ŽŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸ¥
„                  „                    „
„                  ˆŸŸŸŸŸŸŸŸŸŸø         „
„                  „ VCO UNIT „         „
„                  „    x-----„---------„-- "x"= D4 1SV50.
„                  ˆŸŸŸŸŸŸŸŸŸŸ�         „   Connect wire
„                  „                    „   direct to cathode
„                  „                    „   side of diode.
„                  „                    „
„                  „                    „
„                  „                    „
„                  „ PLL UNIT           „
¿ŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸ¡ŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸŸ�

FRONT OF THE ICOM IC27H. VIEWED FROM BOTTOM.

Bring a thin single core shield audio cable through the hole
on the rear of the set where the power cable comes out, there
was quite enough space on my radio. Feed this cable up the
side of the radio to the front panel and along to the PLL
UNIT where the other wires come in. Take the cable over to the VCO
UNIT enclosure, where there are 2 small holes. Pick the hole
closest to D4, solder the shield to the outside of the metal
case and feed the inner conductor through the hole and direct
solder to the cathode of D4 1SV50, keep the lead as short as
possible.


                          73'S DAVID VK3YLV