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#1
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I need to obtain an SSB receiver suitable for receiving WEFAX and RTTY (as
well as audio weather transmissions) with an output which I can use to input to a PC running something like JVFAX. I know nothing at all about this sort of radio reception, but anticipate some problems with any sort of sophisticated unit as I need to use this on a boat cruising in UK, Europe and Med. Would I be better off with portable, battery powered receiver - or installed RTX with backstay antenna etc.? And can you suggest/recommend make/models appropriate to your advice? |
#2
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Don't you have a marine single-sideband transmitter-receiver on board? Use it.
Bon voyage, Bill, K5BY |
#3
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Years ago I used my old DX-440 (Sangean ATS-803a) with decent results.
You can find these on eBay very reasonable. I've had good results with my Grundig Sat-800 and the Sangean ATS-505 both are currently in productuion. The main thing is to be able to tune lsb 1.9 khz below the assignrd frequency for hffax in lsb (or variable bfo) "Roger Cordrey" wrote in message ... I need to obtain an SSB receiver suitable for receiving WEFAX and RTTY (as well as audio weather transmissions) with an output which I can use to input to a PC running something like JVFAX. I know nothing at all about this sort of radio reception, but anticipate some problems with any sort of sophisticated unit as I need to use this on a boat cruising in UK, Europe and Med. Would I be better off with portable, battery powered receiver - or installed RTX with backstay antenna etc.? And can you suggest/recommend make/models appropriate to your advice? |
#4
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The main thing is to be able to tune lsb 1.9 khz below the assignrd
frequency for hffax in lsb (or variable bfo) Good point. That may prevent use of the standard marine ssb unit that I suggested. I don't know, though, what has hit the market in the past 12 years since I worked on the stuff. My DX-392 does a fine job of receiving WEFAX. Bill, K5BY |
#5
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On Thu, 23 Oct 2003 17:48:32 +0100, "Roger Cordrey"
wrote: I need to obtain an SSB receiver suitable for receiving WEFAX and RTTY (as well as audio weather transmissions) with an output which I can use to input to a PC running something like JVFAX. I know nothing at all about this sort of radio reception, but anticipate some problems with any sort of sophisticated unit as I need to use this on a boat cruising in UK, Europe and Med. Would I be better off with portable, battery powered receiver - or installed RTX with backstay antenna etc.? And can you suggest/recommend make/models appropriate to your advice? Roger, I'm a bit of a premium radio fanatic when it comes to home use. However, for my Hunter 310 I bought an Icom R-75 receiver to feed my laptop for HF-Fax, Halifax (CFH) RTTY weather broadcasts and NAVTEX broadcasts. The receiver works well with either its AC power brick on AC shorepower, or directly from a 12v accessory socket. Best of all, it's a pretty good approximation to my mulit-$k rackmount receivers for US$450 (from Ham Radio Outlet). Another possibility you might consider (as I did) is the somewhat dated (but still very good) Yaesu FRG-100 (at the same price). Yet another receiver option is the Ten-Tec RX320. It's a better receiver than either the Icom or Yaesu, using digital signal processing for its IF filtering and demodulation functions. It also runs on 12vdc, either from an included power brick or boat power, and only costs $300. However, it is a "black-box" computer-controlled receiver, that would require you to use additional (free) software to control it. The advantage of the R75 is that I can listen to broadcast programming (or voice weather broadcasts) without powering-up the laptop. As you probably know, the best freeware fax decoder software is WxSat, but I find the little $35 software combo SeaTTY to be a very good buy for decoding HF-Fax, RTTY and NAVTEX messages in a simple and convenient package. Both packages merely require a soundcard - no serial-port hangers-on. (I also have the Hoka Code300-32 suite of professional decoders for my digital intercept hobby, but that's over-complicated extravagence for cruising weather broadcats.) In any case, you need to be able to tune so that the audio tones coming out of the receiver to your soundcard are reasonably close to the standard values for best decoding. With a professional (rack-mount) receiver, you just use CW mode with an appropriate BFO offset value. However, with consumer-grade receivers (including most recreational boating "sideband radios") you have to use SSB mode. This requires you to de-tune from the listed frequency by the amount that you'd have offset the BFO in CW mode. Having the ability to quickly tune to this "diddled" frequency by recalling a digital memory when underway is pretty desirable in any but the smallest seas. This could be from a laptop over a cable, but I find the R75's built-in memories with the ability to label them as "CFH" or whatever a big help. If you want to do FEC-mode (NBDP) broadcast reception, you'll appreciate the R75's "RTTY" mode, which is jst CW mode with the required BFO offset as a canned value appropriate for 170Hz RTTY. However, if you want NAVTEX, unless your boat (and those at nearby slips) don't have battery chargers on, you'll need an optional 500Hz filter to get a reasonable signal-to-noise ratio on 518kHz. The (cheaper) 500Hz filter at the 9MHz IF makes the most difference, and adding the more expensive 500Hz filter down at the 455kHz IF is only a minor further improvement that, in my judgement, is a lower priority than the oven-controlled "high-stability" frequency standard. (which you can also live without unless you experience very wide temperature swings in the cabin. I assume you'll not try any of this shirtsleeve environment equipment in your cockpit.) Good listening, Al ================================================= Location: 42N39, 71W09 (Near Boston, MA) HF Antennas: 65ft TFD, 45ft T2FD, 28ft vertical, 65ft doublet HF Receivers: Ten-Tec RX340, RX320, Harris R2368, Cubic R3030A Decoders: Code300-32, Universal M-8000, PK-232MBX/DSP ================================================= |
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