HFU HF Underground
Technical Topics => Equipment => Topic started by: RCCI on April 04, 2014, 0149 UTC
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Back in the 80's I had an AEA decoder, connected to my Commodore 64 with a green screen monitor. As I remember, I really enjoyed decoding RTTY and CW but you had to have patience of a saint. I also recall it was alot of fun looking at Cuba's news feeds, and so forth. I could only drool over the Universal M-7000 decoder and it's smaller cousin the M-800. - (both priced out of my budget) Are these still usable?
I'd like to get back into this and was wondering what equipment is available today? I see a used M-7000 on Ebay for $250.00. Is everything now software/computer based? I looked at MFJ's decoder,but it did not seem to have super ratings on Eham, and most of the person's posting used it for CW, not RTTY.
Any suggestions?? ...TY-RCCI
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If you are looking to decode common modes such as hams use I suggest fldigi. It can be a lot of fun to do the VOA radiogram programs on Saturday & Sunday as they are intended to be decoded with fldigi. I also like multipsk although it has a god awful mess of buttons for an interface but it seems to work well & does lots more modes.
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Thanks glimmer.... Does the multipsk (looked up website) only work with SDR? It's a bit confusing. Are there any "stand alone" readers? I don't plan to get a SDR anytime soon. Is there an interface which couples a radio, (i.e. Kenwood R-1000) signal output, into a computer USB. It's been YEARS since I've fiddled with this stuff, and am hopelessly out of date ;D.
The MFJ multi-code reader seems a tad outdated, claiming one can decipher news sources, maritime, etc., signals - as many of the signals are from satelite sources, so I'm not buying their advertising (or decoder).
Thanks for any help... Steve
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I have several decoding apps for the iPhone/iPad, and a few for Android as well, RTTY/NAVTEX, FAX, SSTV, PSK31, ACARS, etc: http://www.blackcatsystems.com/iphone/index.html
There's even a Hellschreiber app!
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Hey Chris..thanks for the reply Sorry.... I'm not giving you guys all alot to work with ;D ---- I don't own an IPAD, IPHONE, a tablet, or even a cell phone. Pretty sad and crazy - huh! Just a 5 year old s l o w desktop computer, and the desktop radios. I appreciate the link to the apps, and they look awesome, but... it took me forever to just get a DVD player! No excuse though, just a bit stuck in a time warp.
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I've got one of those crappy little MFJ decoders that I have had for about 20 years & it was outdated when I bought it. I used to copy lots of morse code with it but I didn't have a precise enough radio to copy rtty with it although I do have one now & I still can't get the wretched thing to copy rtty. I have used fldigi to copy HF FAX, CW etc by acoustically coupling the radio & laptop (i.e. placing the radio near the laptop). I'm not sure if that works with multipsk though. I used to use my grundig G3 to copy fax images with both programs by connecting an audio cable from the PC/laptop to the G3. I mention the G3 specifically because for digital decoding it is a lousy radio but it worked well. I really recommend the VOA radiogram programs if you are interested in playing with HF digital stuff.
http://voaradiogram.net/
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Thanks glimmer!! Best to all who responded!! Steve / RCCI
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I've had very good luck with FlDigi with both my SDR and my Grundig. It requires a computer of course to run the software.
FlDigi works well with both Windows and Linux. It is in the software repositories for Mint and Ubuntu and probably other distros as well.
Other than a computer and receiving radio all that is needed to operate is an audio connection from your radio to the computer.
After you install the software make sure you point the software to your sound card. It may do so automatically or ask you during the install.
You should probably use some type of impedance matching scheme from between the radio's output and the computers microphone input,
maybe and audio output transformer from an old transistor radio for example.
I have always just patched them together directly. Just be very careful with the audio levels or you could / will burn out the input circuitry on the subject computer.
I also use Easy Pal for DRM type signals and SSTV (Windows) and Qsstv (Linux) for slow scan signals.
I once did a proof of concept test with two laptops and handhelds just holding the units up to the laptop computer speakers and microphone. (acoustic connection) Worked well using FlDigi and Qsstv in quiet conditions over 10's of miles.
Works even better with connectors robbed from the appropriate headsets!!!
Good Luck!!!
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Is it safe to download Multipsk from the NET? I get a message from my virus blocker that this site may not be safe . Is this program available on CD anywhere ? Last thing I need is another virus .
Please give some feedback
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I have downloaded the free version of multipsk several times on various pc's & never had a problem or a warning of viruses.
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First off, don't judge me for my POS PC I use for radio. So far it's been good for 8 years plus.
It's a Cyrix III / Via C3 / centaur what ever you wanna call it running at 800mhz with no L2 Cache, running Win2k as the OS. It's a dog and half. But only 40 watts at full CPU/GPU at the wall, can't complain.
I use MixW 2.18 for my PSK/RTTY needs. Even using this POS PC, I've had few issues. PSK decode is great as is the RTTY. It will even auto track if you are a few hz off. Does Hell, OLIVIA, ROS, SSTV and many other modes. For free also. But when you change modes, you have to wait 15 seconds, that's the trade off for free. Under good conditions and if they have a clean fist or using a keyer, the CW decoding using Mix W is more than passable.
MultiPSK seems to work pretty good, but that is the WORST UI imo of any software on earth. Seriously.
CW Skimmer is more than decent for just CW.
If your not going to transmit, the setup to the PC is cake. Just need to feed the radio audio to the PC input. No other cables needed for just decode.
Hope you find something that works well for you.
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So is this as simple as.... running a cable from "audio out" with the desktop radios to the "audio in" input on the computer, then matching the soundcard to the appropiate software / decoder program in stalled on the computer? The screen captures of the interfaces / software looks a bit daunting, but dueable.
If it's that simple.. then, thunk.... "I could have had a V-8" Is the "hardware setup" that simple or am I missing something? One cable from radio output to computer input, ( and a low volume). Then lots of patience working the screen? (patience I have)
Your responses have been in-valuable... Steve
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One addition - you may want to consider using an audio cable with an isolation transformer between the radio and computer, if you end up with AC hum on your audio due to a ground loop.