[1000mp] Computer Interface

[Art Searle]

Hi Doug,

I remember hearing about PTT problems on the rear of the rig.  They 
solved the problem by using the PTT connection at the mic connector.  I 
don't know if this helps you.  It's just what I heard and I have 
Selective Total Recall so I'm sure I heard right.

73 Art W2NRA

Doug Rehman wrote:

>I just finished building an interface for my Field for both CW and digital
>modes. I used the circuit found at http://www.qsl.net/wm2u/interface.html
>for both the CW key and the PTT. The CW key works perfectly from the
>computer, but I am having a problem with the PTT line. The PTT line is
>connected to Pin 3 of the "Packet" connector.
>
>When keyed by the computer, the PTT voltage drops from 13.4 volts to about
>2.7 volts- not enough to key the radio. If I parallel 50 ohms across the
>opto isolator's output, it works like it is supposed to (the standby voltage
>on the PTT line drops to about .7 volts, but the radio isn't keyed until the
>computer keys it).
>
>I've tried to use the CW key output for PTT, but it does the same thing so I
>don't think it's a wiring or component issue.
>
>I've also checked the ground connection- no problem (.1mV difference
>according to my DVM). 
>
>It won't key the radio from the  PTT connector on the back either.
>
>I've used this exact same circuit before on a Kenwood TS-430S and TS-2000
>without any problems.
>
>Any ideas? Anybody experienced this before?
>
>Hanks,
>Doug
>K4DDR
>  
>