Amateur radio (256)

M0RVB

Feldhell - well, almost

I managed to decode some Feldhell tonight after scrabbling about for the document showing what various data modes look like. It's a strange mode! Unfortunately the Spanish station sending it could not receive me so no QSO, but now at least I know what to look for. It takes me back to when I was interested in telegraphy systems as a kid, some decades ago now, but I'd never seen it in any form of action - represented by computer now rather than the machinery of old. Mind you what's to say the Spanish station does not have said machinery! There's a whole bunch of info over at https://www.nonstopsystems.com/radio/hellschreiber-function-operation.htm

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M0RVB

Rather obvious EMC problem...

I noticed just now that the Raspberry Pi that runs my ADBS receiver and also has '1-Wire' temperature sensors for the central heating registered a pipe temperature of a theoretically impossible -1700C. Oh, did I mention that my 20m / 6m dipole is in the loft... and the Pi is in the loft... about 2 feet from one leg of the dipole... Hmmm. I can see a connection here given the timestamp was the same as a JT65 transmission.

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M0RVB

JT9 blues

I've had a couple of JT9 attempts these past two days on 20m where I've answered a CQ and received a signal report back, and sent mine but then received the same -nn signal report again. And again. Presumably the remote station has not been able to decode my reply. So I never get to the 73. I'm guessing the band just fades away from underneath me... If I remember right it was the same remote station each time. I've had successful JT9 QSOs so I am putting these down to bad luck and I hope the other guy isn't getting frustrated!

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M0RVB

JT9

Well another first for me tonight, a JT9 QSO, and on my second attempts at answering a CQ. This was with a USA station apparently over a 5,600km path. But again the replies come in the Band Activity window on a different frequency. Not sure what I am doing wrong there, but this was a complete QSO 'by the book'. Edit: I never did follow up on this post. This is, of course perfectly normal operation, for example where someone sits on a quiet part of the segment but listens across the whole.

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M0RVB

JT65 - mostly

I spent a couple of hours yesterday with WSJT-X trying to make some contacts by answering CQs and getting nowhere. After a lot of fiddling with settings (I spotted the ALC on the FT450D was going haywire - who'd have though it had a display!) I now have much better settings of sound system output and Tx control on the SignaLink. The Tx is now set to just below to 9 o'clock position, so almost to the third tick mark, and the sound system output is set to 29% via the Pulseaudio volume control. The power setting in WSJT-X is set to -0.9db at which level the signal still triggers the PTT relay in the SignaLink but at 100% (-0db) the ALC triggers. But no luck with answering CQs. Actually the Pulseaudio setting threw me at first because WSJT-X uses ALSA, but the ALSAmixer shows the same 29% as set by Pulseaudio so I'm not fussing. Also, it still gives the expected power output on the PS modes and a test call on BPSK31 worked fine, so it's all be written down. And today I got a reply to my reply to a CQ. But it was confusing. WSJT-X has two windows, one for Band Activity and one for Rx Frequency. It's all made very easy, you double-click on a CQ in the band Activity window and it moves your Tx and Rx frequencies to that station and pre-fills standard messages. The system can also be set to enable Tx when you click but I've not done this. There is time (seconds) between clicking the callsign, checking everything is ok and clicking Enable Tx. So back to my first JT65 QSO. I clicked on a CQ as above and clicked Enable Tx and off went my reply. Remember these take a full minute each, with replies coming in a few seconds ahead of the minute mark, and everyone's clock must be very accurate or it does not work. Well, the next message from the CQ'ing station, the reply to me showing my remotely received signal strength came on a different frequency. So it displayed in the Band Activity window and not the Rx window as I had expected. But it was a valid reply and so my next one went out - my reply including R-xx, R for received and the -xx being the strength of the station as received by me. The next message from the remote station was the same as the previous, i.e. my signal strength as received. So I halted the transmission there assuming I had got something wrong. So not a complete QSO but I received an eQSL card for it and so I am counting it as my first ever on JT65, and it proves my system works. Anyway I persevered amongst other things and managed a complete JT65 QSO later in the day, but the replies still came back in the Band Activity window on a different frequency than my transmissions, and the original…

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