[Icom] 746PRO- need a simple test.

Thu, 13 Feb 2003 01:08:04 -0800

  I built a circuit to allow having a seperate receive antenna for the 
746PRO.
Anyway, can someone measure the HSEND voltage on ACC1 or ACC2 when the 
PTT on the microphone is pressed?  I am pretty sure it behaved the way I 
felt, ie going to gnd when pressed. It now does not go to gnd.   Icom 
disagrees.. see the  e-mail below.  
Thanks,
Marsh, NC7V
[email protected]

-------- Original Message --------
Subject: RE: IC-746PRO problerm
Date: Wed, 12 Feb 2003 14:29:14 -0800
From: "Amateur Tech Support" <[email protected]>
To: "Marsh Parker" <[email protected]>

Good Afternoon...

Thanks for your e-mail.

>From your description, the radio is operating as is should.  The HSEND is for externally keying the radio and should not go to ground if the PTT button is pushed.  It will go to ground when other features are engaged since they are part of the SEND keying circuit.

Best Regards;

Mike

 -----Original Message-----
From: 	Marsh Parker [mailto:[email protected]] 
Sent:	Sunday, February 02, 2003 11:56 AM
Posted To:	Amateur
Conversation:	IC-746PRO problerm
Subject:	IC-746PRO problerm

I have an IC-746PRO which was working fine until a day or two ago. It is 
still under warrenty until 2/20/2003.
SN 001739.

I was using pin 3 of ACC(1)  HSEND, to control a transistor  which in 
turn controled a relay.

At this time, HSEND behaves properly, ie goes to ground when 
transmitting except when using the microphone PTT.  The mic PTT goes 
into transmit OK and keys the send control jack but does not force HSEND 
to ground.  The TRANSMIT button on the front panel , the VOX in SSB and 
CW keying semi-break in all force HSEND to ground.  Also grounding HSEND 
causes the rig to go into transmit OK.

I have the service manual and I am unable to account for this behavior.
I must have caused something to fail..
Any suggestions on what part(s) might be damaged.?

Thank you,
Marsh Parker, NC7V