December 2008 - AMSAT-BB - mailman.amsat.org

Doppler correction too choppy on HRD?
by Mike Ryan 31 Dec '08

31 Dec '08

I'm using the beta HRD (rev 4.1 build 2055) that offers the new Sat module. This was very handy in the ISS SSTV passes of late but I'm having some difficulties with FM and SSB birds with Doppler. I run a pair of Yaesu FT-857Ds and It corrects very quickly, several times per second, interrupting audio with each correction. This makes for near impossible copy on the downlink, often causing me to disable correction and follow manually. SATPC32 corrects less frequently and is easier to copy with, but I'd really like to get HRD working right with the integrated logging and all. I've been unable to locate any settings to adjust the frequency of correction and I seem to recall the "old" Sat module could do this. Has anyone else encountered and resolved this challenge? I have posted on the HRD forum with no responses. BTW, thanks to all for posting the manual process for following Doppler. Being new to SSB sats, this is very handy to have. I was wondering why I would hear a quick whistle noise as folks locked in! Regards, Mike WB1AAT

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Re: FM receiver filters
by Bob Bruninga 31 Dec '08

31 Dec '08

>> We did that on the uplink receivers >> for PCSAT-1 and -2 ... to make the >> receiver about 30 KHz wide. > > Yes, this is a similar venture. > We did buy a Hamtronics RX ... but > decided we could reduce the size > significantly. Yes, its size is very wasteful. But we were surprised that we could hack-saw off one edge of the board and make it fit inside a 4" cubesat and only have to move the first coil a little bit. Though we have since found a smaller receiver, though not crystal controlled... Even with the hamtronics and modern APRS pic processors, we could easily fit a full 5 Watt APRS digipeater into HALF of a cubesat, leaving the other half for other experiments.

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Congrats on ISS contact
by Rick - WA4NVM 31 Dec '08

31 Dec '08

Hi Alan and fellow AMSAT, I just heard your contact with Drew on the ISS. (WA4SCA - KO4MA) Happpy New Year to all, Rick - WA4NVM

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Mode L/V
by Scott Schmautz 31 Dec '08

31 Dec '08

WA4SCA with KO4MA via L/S with good signals at 1443 UTC Scott/WB2UZR --

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LOTW &/or eQSL ?
by Alan Sieg WB5RMG 31 Dec '08

31 Dec '08

I started using eQSL a year or so back, and have only recently seen enough action in my log to warrant uploading new contacts. I've been trying to go back thru old logs, and get caught up on returning some QSLs... Seems what I'm hearing is that some do eQSL, some LOTW, others only paper... Reckon is there any harm in also doing LOTW ? How many do both ? I'm sure that there are some that don't do either - no great loss I guess. /;^) -- <- Licensed in 1976, WB5RMG = Alan Sieg * AMSAT#20554 -> <- http://www.somenet.net * http://wb5rmg.somenet.net -> <- http://www.linkedin.com/in/alansieg * My 'Day Job' ->

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Brazil and Mexico on AO-7
by Luciano G Nachif 31 Dec '08

31 Dec '08

To those who won't go after a satellite mode B contact on AO-7, I just talked to Alvaro, XE2AT, on that bird using a three elements 2 meters yagi with no preamp at all. Get a chance, give yourself a new excitement, put some life into your life, go for satellites! HAPPY NEW YEAR! 73, Luciano PT9KK

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Station Heard on ISS
by Peter Gibson 31 Dec '08

31 Dec '08

Hi Heard the downlink this morning at 8.30 local time in SW UK Heard IW4DVZ Very strong audio Tried to uplink but had no luck. 73 Pete

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ARISS Antenna Specifics
by Frank H. Bauer 31 Dec '08

31 Dec '08

All, The ARISS L-band/S-band antenna systems are Left Hand Circularly Polarized. There are some good details of the antenna systems in this paper: http://www.amsat.org/amsat/ariss/Papers/Phase%202%20AGM03Final.pdf And this presentation: http://www.amsat.org/amsat/ariss/Presentations/AMSAT%20Symposiums/AMSAT03.pd f Chart 25 of the above presentation shows the antenna locations looking down the axis of the Service Module. In this picture, the ISS velocity vector is either in or out of the page and Earth is towards the bottom of the page. This assumes they are in the normal Earth pointing mode (which is not always a given). We have some good on-orbit views of the antennas in this set of charts too. Enjoy! I hope this helps. And thanks for all the interest in ARISS. 73, Frank, KA3HDO

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ISS Repeater
by n1jez＠burlingtontelecom.net 31 Dec '08

31 Dec '08

Got on the ISS Repeater this morning during the 1127 UTC pass here in Vermont FN34im. No one else heard. I took the opportunity to play with doppler/power/antenna alignment/modulation etc. As suspected, everything needs to be pretty much right on for good access. By paying close attention to AZ/El and Doppler, I was able to hold the repeater down to less than 5 degree El. Even at my power level, 2-3 kHz seemed to be the maximum error on doppler. Power here was set at ~ 5 kW EIRP. I did drop 10 dB and still got in as the ISS passed overhead. (33 degrees El). Unfortunately that was the last pass I can get on... Did I read there was the possibility of 2.4 GHz operation? I have a transverter and 60 watts that I can use. That would be fun!! 73, Mike, N1JEZ AMSAT 29649 "A closed mouth gathers no feet"

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Re: FM receiver filters
by G0MRF＠aol.com 31 Dec '08

31 Dec '08

Many thanks to Tony, Drew, Bob and Art. Mouser appear to be the source of choice for 30kHz 10.7M filters HNY David G0MRF

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