Thursday, December 16, 2010

Experimental V4 Chat Sked with PE2KM

More then a decade ago there were two guys with packetradio, one on a Island and one nearby on the coast. They found each other on the airwaves and had a chat on converse mode almost every evening. Nice story isn't it. It actually really happened, I was the one on the coast and the other guy was Kees (now PE2KM) who was living on Schiermonnikoog Isl. at that time. I think we made chats via packetradio on CB for over a year. Several years ago we discovered we both obtained our licenses and so now and then we contact each other on 80m and via e-mail. Reading about V4 Chat it did bring old memories back, it would be great to have a chat again. Of course PSK is a option, but V4 is more similair to packet converse mode. Anyone can join the chat very uncomplicated that's the nice thing but could be also very chaotic. Anyway, I had a sked with Kees yesterday evening to see how this "robust" mode is behaving. I did see his signal in the waterfall very clearly, but V4 fails to decode. The same with G4VCG who joined the chat. Experimenting with the audio input gave some better results when setting it just before the red stripe in the rcv level meter. Squelch is also not yet behaving like it should as  the program already transmits before the received signal in the waterfall was over. It doesn't matter as the program is under development. It was a nice experiment though, and I hope to see the program growing within time. Is it a interesting mode for those who want to DX with QRP for instance? I don't know, it first should prove itself to be better as PSK or Olivia under difficult circumstances. Till now I think the best program for DX with QRP is JT65-HF. The problem with that program though is the lack of chat or text possebilities.

Meer dan een decennium geleden waren er twee stations met packetradio bezig. 1 station zat op een Eiland en het andere dichtbij aan de kust. Ze vonden elkaar via de radiogolven en hadden regelmatig 's avonds een chat via chatmode op packetradio. Mooi verhaal hé! Toevallig is dit echt zo gegaan, ik was het station aan de kust en Kees (nu PE2KM) woonde op Schiermonnikoog. Ik denk dat we wel meer dan een jaar heel veel gechat hebben via packet op 27MC. Een aantal jaren geleden kwamen we er achter dat we beiden ondertussen onze licentie hadden behaald en nu hebben we nog af en toe contact via 80m en e-mail. Na het lezen over V4 chat bracht het wel wat herinneringen naar boven. Dus gisterenavond een sked met Kees op 80m V4 chat mode om te zien hoeveel beter deze mode nou zou zijn. Natuurlijk is PSK ook een prima optie, maar het voordeel van V4 Chat is dat het ongecompliceerd is, iedereen kan zo meedoen aan de conversatie. Nadeel is natuurlijk dat het al snel een rommeltje word. Maar goed, dat was op packet converse mode niet anders. Ik zag het signaal van Kees prima, maar helaas werd meer dan de helft niet gedecodeerd. Hetzelfde had ik met toevallige voorbijganger G4VCG die ook meedeet aan de chat. Spelende met het ingaande geluid kwam ik er achter dat het wel iets beter werd als ik meer input gaf. Ook de squelch werkt nog niet naar behoren, althans bij mij begon het programma alweer te zenden als het binnenkomende signaal nog aanwezig was midden in een decode. Maar het geeft niks, het programma is nog in ontwikkeling. Ik ben heel benieuwd naar verbeteringen en het uiteindelijke resultaat. Zou dit een geschikt programma zijn voor bijvoorbeeld DX onder moeilijke omstandigheden met QRP. Geen idee, het moet eerst maar eens bewezen worden. Tot nu toe denk ik dat voor QRP DX het beste met JT65-HF gewerkt kan worden. Het probleem is alleen dat daar geen tekst of chat mee gedaan kan worden.


  1. Hallo Bas, mooi resultaat. Af en toe zet ik V4 aan maar heb tot nu toe geen station kunnen horen met V4. Dus ga ik gauw over naar een andere mode. 73 Paul

  2. Hi Bas,

    I saw your call and PE2KM, but I wasn't able to reliably copy much of what you said. I was able to copy G4VCG, and I think he was running 70 watt? Can you confirm? It might be possible I need to increase my audio input like you did.

    I agree, a lot of work is still needed, including developing a best practice for operating. If you want workable reliable comms now, in a situation with multipath and/or poor propagation, it will be best to use DominoEX FEC or Olivia mode I think. Maybe even Robust PSK? However they do need more band width...

    73 André

  3. Hi André, thanks for your comment. I don't know about the 70W as I could only decode snippets like what you see in the picture. I hope to read from others what they experienced till know with V4 Chat. One thing is for shure, til now it's not decoding nearly as good as PSK. So there is a lot of work to do. And for me seeing is believing ! 73, Bas

  4. Hi All,

    Bas, I could not have written it more beautifull than you did, tears in my eyes from those good memories...
    [Really big and evil grin]

    But you are right, it was fun back then and always good to meet you on air. As I said yesterday, we need to do that more often!

    @ Andre, Bas and I were typing partly in Dutch before and after Don came in so maybe some of the received text is not garbage at all. HI
    You are right, Don G4VCG was working with 70 Watt out of a Kenwood TS-2000. I saw he asked me what antenna I was using but did not seem to receive my answer wich I gave 2 times. I was running a Icom IC-7200 running 40 Watt into a ZS6BKW wire dipole. And that is high power for me, usually I run about 20 watt in RTTY or similar mode, PSK about 5 Watt or less...
    Bas was running his FT-817 with 5 Watt, heavily emulating bad propagation... ;-)

    As for V4, I think we all agree, it is not finished yet, today another new version to try. I like the concept though, could be some sort of "round table" mode. That was the case also yesterday between Don Bas and myself. If the stations receive eachother well and the TX squelch does its job you could type ahead and buffer send out as soon the frequency is clear.

    I will try to be qrv on 3.583 tomorrow at about 20:00 UTC!

    73, Kees PE2KM

  5. I can read and understand a little written Dutch ;-) so the garbage was really garbage .. no double Dutch hi hi

    I will see if I can give it another crack, maybe I have better luck this time.

    I usually have no problems working into Netherlands on other modes, even 5 watt SSB. It is my RX that might suffer on 80m, I sometimes have a high noise floor due to some faulty electrical equipment at a local school nearby.

    73 André

  6. Hello Kees and André, I hope to be on the frequency this evening. And try the new version. 73, Bas

  7. Mooi verhaal Bas,
    Heb goede herinneringen aan het 27 MHz tijdperk :-)
    73 Ron


Thanks for your comment. Bedankt voor je reactie. 73, Bas