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Beacon Reception -- Any Interest?

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Chris Russell

Thu Nov 23 2006, 05:15AM

... not Russel!
Registered Member #1 Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052

Hello all,

With the near-completion of my magnetic loop antenna project, I wonder if any of the hams and short wave listeners out there would be interested in doing some beacon reception. Simply put, I would beacon my identification and a short message, perhaps some telemetry, using a low-power mode like slow-hell or QRSS. This would go on for 24 hours or so, and then people could report what they did or didn't receive. Recognition on the front page of 4hv.org and my thanks would go out to everyone who participates.

The only equipment needed would be a computer with a sound card running Windows or Linux, a relatively stable receiver capable of sideband reception from 14.0 to 14.1MHz or from 10.1 to 10.15MHz, a way to interface the receiver audio to your computer's line-in or mic jack, and a program like argo (

), or Spectrum Lab (

). I would gladly provide assistance to anyone who needs technical help on getting any of the above set up. Of course, I'd also give at least a week or two of warning, so that nobody misses it.

If you're interested, please post here and let me know. I hope there is someone out there that's at least curious about low power long range communications.

rev

Thu Nov 23 2006, 10:45AM

Registered Member #112 Joined: Fri Feb 10 2006, 01:19AM
Location:
Posts: 48

i would gladly play if i can get a receiver built in time.

i'm also interested in satellite comm. any help on that would be greatly appreciated.

Steve Conner

Thu Nov 23 2006, 11:27AM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Count me in!

I wonder if there's a way to serve the Spectrum Lab screen as a web page, so people can see what we're receiving in real time? *edit* yay there is!

ShawnLG

Thu Nov 23 2006, 07:43PM

Registered Member #286 Joined: Mon Mar 06 2006, 04:52AM
Location:
Posts: 399

I would love to participate. Thats if I have the crystals with those frequencies.

Chris Russell

Thu Nov 23 2006, 07:46PM

... not Russel!
Registered Member #1 Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052

rev, the key here is "relatively stable." Unless you're doing a PLL VFO, you will likely not have enough stability. Satellite communications is a whole other ball of wax. Dave Marshall has much more experience in that field than I do. But that belongs in another thread.

Hooray, Conner is on board! I know you use Spectrum Lab, so there are all sorts of fun possibilities there. Being able to look at your receiver's output into speclab in realtime would be at least twelve kinds of awesome. If your receiver is stable enough to work with QRSS30, 5W should lead to fairly reliable communications on 30M.

Any other takers?

ShawnLG

Fri Nov 24 2006, 01:18AM

Registered Member #286 Joined: Mon Mar 06 2006, 04:52AM
Location:
Posts: 399

Will my reciver be good enuff? The mixer output would be fed into the sound input instead.

EDIT: I looked through my crystal collection and I do not have any within those ham bands. Is there anything I can do?

[Edit: Image size...]

Steve Conner

Fri Nov 24 2006, 11:55AM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Yup, get more crystals

I'm sure the frequency accuracy will be good enough, especially since the computer sucks in a ~20kHz slice of spectrum, so you would see our transmission even if it was several kHz away. Sensitivity may be pretty good too, since the Spectrum Lab or Argo software uses pretty high-powered DSP to tell signals apart from noise. (Still, I'd take the soundcard feed from after the 2-transistor audio amp section, and try to run the soundcard in 24-bit mode if it supports it.)

The areas where it might *not* be good enough are short-term stability and selectivity. If the frequency jitters and jumps around due to noise getting into the oscillator, it could blur out the QRSS signal you're trying to see. And stronger unwanted signals at totally different frequencies might deafen it, especially since it'll have a very strong image response. The LC thingo in the red box would help that a lot by limiting the bandwidth of crud that can get into the RF amp.

BTW: For those who're not sure, QRSS means "Really slow morse code" generated by computer. QRS is the radio Q-code for "Please send slower".

ragnar

Fri Nov 24 2006, 12:04PM

Registered Member #63 Joined: Thu Feb 09 2006, 06:18AM
Location:
Posts: 1425

I'll see if I can get a rig or amplifier of some description going. =)

WaveRider

Fri Nov 24 2006, 01:24PM

Registered Member #29 Joined: Fri Feb 03 2006, 09:00AM
Location: Hasselt, Belgium
Posts: 500

I have a couple of Analog devices AD9835 DDS chips that I'm dying to play with (0.04Hz-25MHz output).. This could be an opportunity to make a frequency agile HF receiver.. Just gotta find the time, given work and other projects.

When will you start your transmissions?

Avalanche

Fri Nov 24 2006, 01:28PM

Registered Member #103 Joined: Thu Feb 09 2006, 08:16PM
Location: Derby, UK
Posts: 845

I'd love to have a go at this, but again I'd need to build a reciever...

I did a bit of searching, would this be a good reciever? If so I'll probably give it a go, but it looks like obtaining the right crystals might be a problem...

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