June 2015 - AMSAT-BB - mailman.amsat.org

Fair Price for Yaesu FT847
by Bill ACITO, W1PA 24 Jun '15

24 Jun '15

Make sure you get a later model year that has bi-directional CAT, and not uni-directional. Bill W1PA

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Fair Price for Yaesu FT847
by Steve May 24 Jun '15

24 Jun '15

What would the group say is a fair price to pay for an 847 in really good condition? I am working on a possible deal for one but I don't really want to overpay for it. Steve, W5IEM

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Field Day ISS voice contact probability
by Nicholas Mahr 24 Jun '15

24 Jun '15

Yes, it still is a split... RX: 145.800, TX 144.490. I also believe they wont be making field day contacts, look here http://www.ariss.org/current-status-of-iss-stations.html . Seems all radios are not in use except one are being used to school contacts. Heres some info http://www.issfanclub.com/frequencies 73's KE8AKW

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AO-7
by Nicholas Mahr 23 Jun '15

23 Jun '15

Hello, I heard AO-7 mode B today at around 18:45, It was very warbly and weak. On June 22 at 19:31 Mode B was not heard, but I heard the mode A beacon. It seems to switch modes now between NA and SA, Because I will see people from SA saying mode B is on than when it comes over NA, Mode A is on.. Seems it not fully powering down in eclipses. 73's KE8AKW

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Field Day ISS voice contact probability
by John Brier 23 Jun '15

23 Jun '15

Looks like there are only three folks on the ISS now: Commander Gennady Padalka, RN3DT Scott Kelly Mikhail Kornienko, RN3BF Kelly is not a ham, right? So since Field Day is a US/CA event mostly, it's very unlikely the Russians will get on, right? John Brier, KG4AKV, Raleigh, NC, FM05 P.S. I found this video of Astronaut Reid Wiseman talking about his field day contacts from last year. One thing I found especially interesting is that he said afterwards he got on for random contacts about once a week. I didn't hear anyone reference this in previous correspondence on the topic. [1] [2] It's always exciting to hear of increased possibilities. https://www.youtube.com/watch?v=5nLFNG-Njlo 1) http://amsat.org/pipermail/amsat-bb/2015-April/052618.html 2) http://amsat.org/pipermail/amsat-bb/2015-April/052623.html P.P.S Here is a teaser video I made of an SO-50 pass I recorded for a new YouTube channel I am slowly creating https://youtu.be/hbu5xZEsBTE

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ISS and Field Day 2015
by Clint Bradford 23 Jun '15

23 Jun '15

I have been told both by NASA and by ARISS officials that we should not expect FM voice contacts this Field Day like we enjoyed last year. BUT - You KNOW many are programmed for FM Voice for regions 1 and 2/3, as well as Packet and SSTV - just in case something occurs ... Not necessarily for FD points, but for the public relations value for visitors to Field Day locations. Clint K6LCS

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PC sat 32
by John Becker 23 Jun '15

23 Jun '15

Can PCsat be run on a windows box or does it have to be dos. either way not a problem as I do have DOS 6.22 ans XP/ JAB

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SatPC32 actinh wierd
by Scott Smith 23 Jun '15

23 Jun '15

Hi, I fired up my SatPC32 in the wrong order from the way I usually do it, I usually turn on radio and my LVB tracker first then fire up the computer. The LVB works fine,but I got a message “could not open Com3 and to check if It was available” this is weird as this laptop is dedicated only for satellite use, and I have not changed anything. I use a Kenwwod IF232r between my computer and my TS790a radio. I opened the device manager and it says for the FT232r USB UART “the drivers for this device are not installed (Code 28). I tried to downoard the driver from ZLP and it still does not work?, any ideas? Tnx in advance. 73 de VE6ITV Scott

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AMSAT-UK Colloquim 2015 Speaker Slots
by David Johnson 23 Jun '15

23 Jun '15

Hi, I have a couple of speaker slots available over the weekend of the 25/26 July at the colloquium if you want to make your activities known to the Amateur Satellite community. Please contact me via email to discuss. 73 Dave, G4DPZ AMSAT-UK Committee Member

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Doppler shift and oscillator offset
by Peter Kazakoff 23 Jun '15

23 Jun '15

Hi folks, I'm in the process of designing the modem for a university-developed cube satellite. We'd like amateurs to be able to use the packetized data channel for interaction with the satellite. The plan is for amateurs to be able to do stuff like initiate file downlink (there's a small camera on board), write text files for use as a message board, query the telemetry files, and possibly route packets from ground -> satellite -> ground. Right now I'm trying to gauge the capabilities of amateur ground stations. Obviously, the ground stations will be attempting to correct for Doppler shift, but there's only so far that can go. Does anyone have a good idea what the typical velocity error is between a NORAD TLE and a cube satellite TLE? This will go into my maximum frequency error specification. The other issue, frequency wise, is oscillator drift and offset error. The satellite will be using a very stable Stratum-3 TCXO with 280 ppb or better stability, which gives me good accuracy on the satellite side (within 100 Hz or so on 70cm). The other side of the link would be the amateur transceivers. What's a reasonable oscillator stability spec for a typical SSB transceiver used on amateur satellite frequencies? For modulation scheme I'm leaning towards either pi/4 DQPSK or standard QPSK with a BPSK barker code preamble on each packet. Both schemes will use convolutional coding for FEC. Which scheme I go with depends on which ends up being more robust under severe doppler while still fitting into hardware constraints - the comms system is all going to be done in SDR. Suggestions for alternate schemes are welcome though. Thanks for your help, -- *Peter Kazakoff* ECOSat <http://csdc.uvic.ca/> Communications Lead 4th Year Electrical Engineering Student University of Victoria *(250) 920 - 6870*

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