Re: problems with my PTC-IIpro

Rob Giuliano

According to the PTC-IIpro manual I downloaded, this is a multi mode modem which includes AFSK 1200 or 2400 baud, as well as FSK for 4k8, 9k6 and above. The manual had an APRS section.

Robert Giuliano

On Wednesday, June 2, 2021, 8:52:12 PM EDT, AE7G <gthornton@...> wrote:

The PTC-IIpro is a PACTOR modem.  That particular modem can handle PACTOR 1 through 3.   Mail programs like AIRMAIL and WINLINK are set up to work with PACTOR.


I am not aware that a PACTOR modem will work with APRS. 


From: <> On Behalf Of Rob Giuliano via
Sent: Wednesday, June 2, 2021 5:34 PM
Subject: Re: [APRSISCE] problems with my PTC-IIpro


I am not all that familiar with the PTC-IIpro.


Although I understand the comments are to highlight the issue, for problems with AIRMAIL I suggest posting in a dedicated forum.  Main thing here appears to be that the computer and modem are talking.



For APRSIS32, you indicate:

a) Your modem goes into KISS mode

      Are you sure? Did you check the RF port logs to be sure?

b) The program says everything is correct. 

      An OK for an RF port in the top left corner isn't a good indicator everythin is okay.

      This just indicates APRSIS32 can open the computer's COM port - not in use by something else.

c) Lights blink. AND you hear bursts of incoming message.

      How do you hear the "bursts" if the cable is connected tot eh TNC?  (Data port on the radio in use?)


You don't list any <OpenCmd> commands used to put the modem in KISS mode - or is that done outside of APRSIS32?


A few troubleshooting options:

1. Have you opened a LOG for the RF port and made sure you didn't have any error

    messages there (specifically missin <C0>)?  Posting any messages could help!

2. Does anything show up in a Terminal program (like TeraTerm or TerMite)?

    This may not be readable if the TNC is in KISS mode

3. Does the TNC key the radio and transmit audio when connected to other programs (Terminal)?


I am pretty sure that APRSIS32 is only able to TX on PR-1 in KISS mode, unless you can control the KISS stream in a different way.

Robert Giuliano



On Wednesday, June 2, 2021, 7:36:34 PM EDT, giuseppe menga <menga@...> wrote:



I’m returning to the modem PTC-IIpro after a long time.


When I power my PTC-IIpro connected to the radio (power is coming from the radio), at first all lights on the left briefly blink first red then green. On the right the green light briefly blink indicating that is connected the extension 1,  I have for packet.

Then after all lights switch off.

On the message window  the sequence




Then the only repetitive message is


Press CR

When some signals were present on the radio I was used to see some of the lights indicating the tuning of  pactor blinking, now everything is dead.

The computer see the serial port, however, from Airmail I cannot change the frequencies.


For RPR when I start APRISIS32 the modem correctly goes in KISS mode. The program say that every thing is correct. Now the lights of the tuner blink, I hear clearly the bursts of the incoming messages, however the program doesn’t recognize them.


There are only three possibilities:

  1. the modem is broken
  2. the cable/connectors transferring the data from the radio are failed (not the power)
  3. Because of the long time, I forgot some operation at the start.


Can you help me, and suggest the experiments to perform for finding the failure.

In particular, how to test the presence of signals in the connection with the radio.




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