Doing some data mining on "roll your own cables" a while back, what you describe below is
exactly how some make there single wire rx/tx connection. Others just connect the rx and tx
wires together and let the software deal with the echoes.


From: Robert Terzi <rct@r-t.org>
To: c@suleske.com; Discussion of CHIRP <chirp_users@intrepid.danplanet.com>
Sent: Friday, November 29, 2013 12:15 PM
Subject: Re: [chirp_users] Icom IC-T90A: Rolling an OPC-478 cable with a CP-2102 USB board

On 11/29/2013 4:00 AM, Chris Suleske wrote:

"So I'm interpreting your results as:  When you've got TX and RX shorted the software
is seeing the data (probe) it sends to the radio back and but isn't seeing any
response from the radio.  However, when the diode is being used to connect TX and RX
together, the software isn't seeing it's data being echoed."