----- Original Message -----

From: John Hansen

To: tnc-x@yahoogroups.com

Sent: Tuesday, July 07, 2009 17:40

Subject: Re: [tnc-x] Quick questions - Yaesu FT-8900R

TNC-X supports a wide range of audio input levels so there should be
no issue there. I think you are ok with the TX audio as well, though
I vaguely remember someone with one Yaesu radio or another finding he
did not get enough audio out of it to drive the data jack on the
radio. I'm not sure which model it was, so perhaps someone else will
chime in on that. If you need more audio drive from the TNC-X, you
can handle it one of two ways:

1. Try shorting out resistor R11 in the TNC-X.
2. Alternatively, you could feed the audio in the mic jack instead of
the data jack.

But first I would try it straight through.

Finally, ignore the squelch line and keep the squelch on the radio
fully open. Virtually all modern TNC's (including TNC-X) support
using the radio with the squelch open. This results in faster tx/rx
turn around times and greater channel efficiency.

John W2FS

On Tue, Jul 7, 2009 at 4:36 PM, Chris Wall<chris@kd8lci.net> wrote:
>
>
> Good afternoon,
>
> I'm mostly done with my TNC-X assemble, but want to be sure before I
> wire in my tx/rx/ptt. I have a Yaesu FT-8900R, and according to the
> manual it uses pin 1 for data in 10k ohm/40mV for 1200, pin 5 for data
> out (10k ohm / 300mV) and 3 for PTT (ground to assert). There is also
> pin 6 for squelch control (+5 open, 0v close).
>
> Are these levels that the TNC-X will "live" with if I wire straight into
> phono plugs (1/3 into a TRS, 5 for the TS)?
>
> Lastly, should I have any concerns about using the squelch control?
>
> Thanks in advance,
> Chris
>
>