19 Apr 2011

Com Ports

We need them, but why oh why have computer manufacturers stopped fitting normal serial com ports on new computers ?  Instead we now have to rely on a software alternative “Virtual com port”.

I have been spending a lot of time running DM780 over the last five days and it has been running flawlessly yesterday I called a station and it locked in transmit – not exactly the ideal situation, I could not see what had happened and HRD would not close down as I had switched the radio off manually – I re-started HRD/DM780 etc…  having re-booted the system and called CQ – a station called me and I promptly replied and it happened again Grrrr !

Now I noticed that HRD had lost it’s connection to the radio and trying to re-connect it failed, I even tried other combinations of RTS / DTE settings to no avail so I thought maybe the driver for FTDI devices had gone bad on me so downloaded an update – which could be rolled back if necessary if it didn't work out, incidentally it designated another com port number as well,  this was installed ok so tried again (this was all taking time instead of filling the log) Grrr !

I called CQ and it bombed again Grrrrr!  (What else had I done recently to upset the system) ?  Oh yes last Thursday I installed the latest HRD update – build 28xx something or other, luckily I kept the previous version so I could drop it back in place and see if that helps NO it does’nt ! Grrrr.

Looking back – I used version 4.1 of HRD on my old laptop for ages with my signalink (using a proper  serial com port connection) with the FT817 then upgraded later to HRD v5.00 xxxxBeta without any problems at all – in fact HRD has been rock solid but this USB device has started playing up – I was suspecting the interface but that’s working ok – I am beginning to wonder if there’s a little bit of Rf getting into the loop !  (Will fit some ferrite chokes on the cabling) next – interested to hear if anyone else has had USB CAT connection trouble.


  1. Hi Peter, I know what you mean. I have never managed to work properly with CAT control. One way or the other, but it doesn't work. I don't know what I have been doing wrong. So I still work with VOX on the digi modes which work well. Good luck, 73 Paul

  2. Computer manufacturers stopped fitting com ports because most people don't need them. However if you have a desktop PC with internal expansion slots it is an easy job to fit them. I have a 4 port board in mine which replaced the 2 port board I outgrew and one day I am going to see if I can put the 2 port board in because all 4 are used already.

    It is possible that RF is causing your CAT connection to foul up. A true RS232 port with screened cable should be just about immune to RF though.

  3. Hi Peter, had the same problem years ago. But a update of the FTDI driver did the trick. Since DM780 locks up when you're TXing I suspect some RF as well. Good luck. 73, Bas

  4. Thanks all:

    Nice to get some feedback - I am suspecting an RF problem as it happens on 20m running 20w (only) but not on 40m, I am planning a new antenna farm which will hopefully eradicate RF problems on Digi - Odd as it's been performing well to date - nothing has changed to my knowledge - the new antenna('s) will be away from the buildings.

  5. I've had simular problems with USB 'dongles' where HRD just crashes when I use the band scan function (useful when monitoring 6 Metres)I'm told this is due to the dongle itself, there are good and bad ones out there. I just got a two port serial card off eBay for a couple of quid. It was really just plug and play and now have two more real com ports to play with. You can get 4 port card which in hindsight I should have got, so may purchase a 4 port card now I know this solution works.

  6. Hi - Well I have removed the "End Fed" antenna (even running low power levels) the problem seems to have resolved itself - a Complete shack overhaul is on the cards fairly soon, which will involve replacing the main computer/Rigs/Antennas - and I'll be making sure we have "Proper" com ports by installation of a 4 port card.


Thanks for your comment. - Bedankt voor je reactie.
Gracias por tu comentario