[ICOM] Fw: ICOM 756 PRO 3 - PTT?

[Don Cunningham]

Conrad,
I had a subscription problem I had to clear, so this message bounced.  I am 
forwarding it to keep from re-creating all that, hi.  Hope it helps your 
situation.
73,
Don, WB5HAK
----- Original Message ----- 
From: "Don Cunningham" <donc at martineer.net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Saturday, February 19, 2011 1:36 PM
Subject: Re: [ICOM] ICOM 756 PRO 3 - PTT?


> Conrad,
> I have not been truly following this thread as I no longer have a Pro III. 
> However, I still have the Signalink, and its manual.  Where are you 
> entering the Pro III for transmit, through the mic jack or the rear 
> accessory port??
>
> My Signalink manual mentions PTT in MANY places, even showing how to check 
> the PTT on the jumper pins on page 9.  PTT on the Signalink is a sort of 
> VOX circuit, that closes a transistor when it senses audio being sent.  It 
> is NOT like we are used to, but it works.
>
> Whichever jack you are entering, you should be able to look in your Pro 
> III manual and determine which pin is the PTT line so you can figure out 
> which pin on the Signalink cable plugging into that jack is the PTT 
> signal.  Check with an ohmmeter if the plug on the end of the Signalink is 
> sending the PTT signal (completion to ground on transmit).  In other 
> words, when transmitting, the pin on the signalink cable that is PTT will 
> have continuity to ground.  It's really that simple.
>
> If the pin is showing continuity to ground on transmit, the problem is in 
> the Pro III, if not, the Signalink either has a jumper problem or 
> component problem.  That make any sense??
> 73, and good luck,
> Don, WB5HAK
>