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Author Topic: talking via satellites and ISS How  (Read 1576 times)
2E0BSS
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Posts: 85




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« on: September 18, 2007, 03:41:39 PM »

I read here on the forums and other forums that people talk through Satellites and to the ISS my question is how?

Ive got some Satellite software a dual band radio, all be it a hand held and if it's a HF satellite a dual band all singing all dancing Radio I check the software see which satellite/ISS is near me then turn on and hey presto nothing not a sausage I don't even hear others talking to the ISS just hiss and crackle if I'm lucky most of the time nothing at all

What am I doing wrong? I even take into consideration the +/- Hour for the software etc I check AMSAT to see if the satellite/ISS is functional if it is still nothing


Charlotte 2E0BSS
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KB9CRY
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« Reply #1 on: September 18, 2007, 05:46:40 PM »

Check AMSAT again and go to the beginners articles a link to is posted on the main website.  After reading those articles, then ask more questions.  You need to do some homework before you ask "How to talk to the ISS?"  That's just too basic of a question and my answer would be, "Track them with some tracking software, enter in the frequencies you need to uplink and downlink, point your antennas and then have at it."

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KB9CRY
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« Reply #2 on: September 19, 2007, 06:17:50 AM »

What kind of hand held yagi antenna are you using with your HT?

If you're just using the HT's built in whip, you  won't be hearing any Sat QSOs.  You need more antenna: HT opn is very demanding and somewhat hard to do.
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W7AIT
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« Reply #3 on: September 20, 2007, 02:04:03 PM »

You need to have 9600 baud packet and appropriate software to code / decode for ISS packet communications and do all the following:


Consider these requirements:

1.   Do NOT TRANSMIT UNLESS YOU CAN HEAR YOUR OWN SIGNAL OR HEAR OTHERS.  Otherwise you will be jamming the rest of us!
2.   Make your RECEIVE work BEFORE transmitting.
3.   Using the right kind of antenna makes a huge difference.  A discone Will NOT work.  A fixed beam horizontal to the earth will not work.  Antenna patterns and pattern shapes is extremely critical and you must keep the antenna pattern aimed at the satellite.  Mine is a simple ARROW (3 el on 2, 7 el on 435) on a mast tilted 20 degrees elevation AND ARR mast mounted preamps AND low loss coax AND it all meets or exceed the system up link and downlink budget margins with S5 to S7 margins OR MORE.  I reliably work AO7, AO51, VO52, SO50 and ISS every day.
4.   Pointing at the satellite make a huge difference.  The fact that you hear anything at all with the discone & horizontal beam is seer luck, the satellite footprint just catches a slight corner of the discone pattern.  Point!
5.   Knowing WHEN AND WHERE satellite is REQUIRED!  Use SATPC32 software for this and doppler control.
6.   Doppler control REQUIRED!  Trying to tune 3 KHZ/ minute rates and a 20 KHZ change is impossible without SATPC32.
7.   DON’T USE HAM RADIO DELUXE.  IT DOESN’T WORK!  Especially for SSB birds.
8.   Calculating your system up link and down link path margins and adjusting your equipment gains and losses to get satisfactory S-meter signal margins (make it so you can be heard and can hear) ABSOLUTELY REQUIRED!
9.   Eggbeaters - NOT a good antenna.  No gain- you need 6 to 10 db gain antennas at least and POINT.  Need a footprint and tight main lobes eggbeaters don't. Eggbeaters with preamps won't do it either.  Eggbeaters too expensive too.  A 4 or 7 ele 2 meter, 440 coat hanger beam works and cheap!
10.   I attached my spreadsheet to this email (see me on this).  You can put in your own numbers and see what you "have" and then do it again with what you "need to make it work".
11.   Yep radio to computer to do doppler a must, too much knob twisting manually.  A few guys do it but they are always off frequency and distracted tuning.  Minimum is doppler, direction data (az and el).  Auto rotor control optional.
12.   If you get into the bird then disappears likely freq WAY off toward the end of the band.  You are dealing with as much as 20 khz changes.  Sliding?  I think you are trying to hear your DL and I do that by sending CW and listening and tuning slightly a few hundred hz at most to tune in, then the tracking is right on the rest of the pass.  Get SATPC32 and it will solve that problem.
13.   Low loss coax- you MUST use low loss coax.  9913 minimum.  LMR 600 better.  RG58 will NOT work.  RG8X will not work.  RG8 marginal.  All runs as short as possible. No extra.
14.   Hot Rod Arrow – AMSAT  Journal Jan/Feb 2007:  My antenna is FIXED at 20 degrees elevation and 90% of all ham satellite orbits don't go above 45 degrees, so there is really not much reason for an expensive az - el rotor.  You can get away without elevation if you follow my design carefully.  The  design takes into account the beamwidth angles, orbital mechanics, satellite foot prints, satellite antenna patterns, etc, so it works, and allows me to work most all satellites reliably and consistently every day. The cost is cheap if you don't add the receiver pre amps.  Those make a huge improvement on receive and make it armchair copy, but if you have a good transceiver and its sensitive enough*, you can do without, though received signals will be very weak on most passes.  After all, there are guys using nothing but a ARROW and a W32A or THF6 hand held to successfully work the satellites, though its not armchair copy.
15.   If you want the link budget path calculators to see what equipment and coaxes you need see me.
16.   I have more.  Enough for now………

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KB2HSH
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« Reply #4 on: October 15, 2007, 06:48:21 PM »

W7AIT:

Yes, we know from your other postings here on eHam..."try my Hot Rod Arrow".  We get it.  Some of us perhaps don't have $1200 to spend on a satellite antenna setup.  I don't want to come off as being mean or critical, but it is a bit elitist and assuming to think that EVERYONE can afford...or eben WANTS a setup such as that.  Yes it would be nice to have "armchair copy" on every pass, but for most it is a little unrealistic.  I respect your accomplishments, and don't want you to think I'm being harsh, but some don't have the resources that you may have.

For the info of anyone interested, I use eggbeaters.  And I make contacts...with a 5 watt FT-817ND, mind you.  Sure, I would love a steerable array, but 5 watts and a lousy receiver CAN (!!) make QSOs...with the eggbeater antennas to boot.

Charlotte, I have spent almost 20 years PROVING the so-called "experts" wrong in ham radio.  Use the best stuff that YOU can afford, not what someone else THINKS you should.  If it's not "ideal", so what?  Make it ideal step-by-step.  My eggbeaters are homebrew.  And they are my third attempt at satellite antennae, with my first two being poor, and then better...with level 3 being pretty darn good.

If you want to try an easy homebrew antenna to hear the satellites better, try a crossed-turnstile antenna.  It's nothing more than 2 dipoles fed 90 degrees ut of phase.  It's like a FLAT version of an eggbeater.  After that...if you can build an antenna with a good SWR, try a Lindenblad.  I'm building a Lindy for 440 MHz downlink.

In closing, Charlotte, e-mail me if you need "long distance" assistance in building a modest setup that will work.

73 to all.

John KB2HSH
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TF3JB
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Posts: 6




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« Reply #5 on: January 27, 2008, 01:59:06 PM »

I just want to say thank you for your excellent information. This is valuable information for myself and other newcomers. In my case, the last QSO's I had via satellite was through the Oscar 6 and 7's back in 1976 and 1977...

I have recently acquired a new Icom IC-910H transceiver. Yes, I bought the xtal oven as well, but not a CW filter which I assume will be needed.

Just the other day I was listening in on both SSB and CW QSO's between 145.900 and 145.990 MHz only using my 20m Delta loop antenna... I have no idea which satellite that was. I have since joined AMSAT and am currently going through the beginners literature...

Again, thanks and 73 de TF2JB.
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