IW8PGT

G7GVV  > TECH     17.09.15 18:35l 71 Lines 2015 Bytes #999 (0) @ WW
BID : 14941_GB7COV
Read: GUEST
Subj: TNC to data-port interface
Path: IW8PGT<F1OYP<F1OYP<ZL2BAU<N4JOA<GB7CIP<GB7COV<GB7COV
Sent: 150917/0935Z @:GB7COV.#29.GBR.EU #:14941 [Coventry] $:14941_GB7COV
From: G7GVV@GB7COV.#29.GBR.EU
To  : TECH@WW


Modern rigs have adopted a STANDARD data-port socket! - The 6 pin mini-DIN.
e.g. Icom, Yaesu.

However, when connecting this to most standard TNCs, the TNC will not
transmit because the audio from this data-port is unsquelched. However
a separate line on the port carries a squelch signal, going to ground
to indicate the presence of a signal.

In the style of G8MNY, I have decided to share a circuit that allows this
port to be used. It requires no external power and can be built into the
lead, simply requiring a break on the audio line.

I take all the credit (/blame) for the entire design, except for those
parts suggested by G8MNY (the transistor, etc).

It is working, and there is no smoke coming out of the equipment yet ;-) .

This has been tested with a few rigs and TNCs, but it is possible due to
component tolerances that some adjustment of values will be required.




  RADIO                         TNC


Squelch ùÄÄÄÄÄÄÄÂÄÄÄÂÄÄÄÄÄÄÄÄÄù Squelch
                ³   ³ 
           150K ±   ±
                ±   ± 10K
          2K    ³   ³
                ³   ³
  RX AF ùÄÄı±ÄÄÅÄÄÄÄÄÄÄÄÂÄÄÄÄù AF In
                ³   ³    ³
                ±   ³  ³/
                ±   ÀÄÄ´   Any NPN?
           100K ³      ³\ 
                ³        Ù
 Ground ùÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÁÄÄÄÄù Ground



Now the same with dots:-


 .RADIO . . . . . . . . . . . . TNC


Squelch ùÄÄÄÄÄÄÄÂÄÄÄÂÄÄÄÄÄÄÄÄÄù Squelch
 . . . . . . . .³ . ³ . . . . . . . . .
 . . . . . 150K ± . ± . . . . . . . . .
 . . . . . . . .± . ± 10K . . . . . . .
 . . . . .2K . .³ . ³ . . . . . . . . .
 . . . . . . . .³ . ³ . . . . . . . . .
 .RX AF ùÄÄı±ÄÄÅÄÄÄÄÄÄÄÄÂÄÄÄÄù AF In .
 . . . . . . . .³ . ³ . .³. . . . . . .
 . . . . . . . .± . ³ .³/ . . . . . . .
 . . . . . . . .± . ÀÄÄ´ . Any NPN? . .
 . . . . . 100K ³ . . .³\ . . . . . . .
 . . . . . . . .³ . . . .Ù. . . . . . .
 Ground ùÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÁÄÄÄÄù Ground.


This circuit has been successfully used for over a year now.

73 de Phil G7GVV


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