[Packet] MFJ-1270B Help

[Gerald]

On Tue, 2005-11-22 at 11:19 -0700, W0OXJ wrote:
> New to packet and just bought this TNC.It just came out of service.For the
> life of me I cannot get my PC to talk to this device.It sends and receives
> at all baud rates but the characters are jumbled and the CR/LF is
> intermittent based on config.
> 
> .I have changed everything in the PC,comm port,terminal program,drivers and
> tried every comm port parameter available.I tried the comm setup on Winpac
> 6.80 and Hyperterm but am using Bitcom until I establish communications.I
> have verified all TNC straps and replaced the button cell.The RS-232 cable
> has pins 2-8 and 20,22 wired on the TNC end and a db-9 plugs into the PC.I
> assume this is not a null modem as I can receive characters and the enter
> key will move the cursor.I have 12vdc applied from a MFJ 500ma wall wart.
A STANDARD 9 pin to 25 pin modem cable is all that is needed for a
MFJ-1270B TNC. No modifications to that are necessary.

You need to match character length (7 or 8 bits) and parity (none, even,
or odd).

The TNC firmware gives a sign on message. Once you can read that you
have the communications parameters set correctly. Just hook up the
computer and the TNC and with the communications software running, turn
the TNC power on. 
> 
> I understand there are TNC commands to effect the communications but
> obviously I can't access the TNC for command entry.
> 
> I have worked on lots of rs-232 over the years but this one has me stumped.
> 
> Any help and guidance would certainly be appreciated.
> 
> 73,
> Bob
> W0OXJ


73, Jerry, K0CQ
Dr. Gerald N. Johnson, electrical engineer
All content copyright, Dr. Gerald N. Johnson