October 2010 - AMSAT-BB - mailman.amsat.org

LHCP or RHCP?
by Tom 06 Oct '10

06 Oct '10

On the premise that the only dumb question is the one that goes unasked, here goes. If I'm building an antenna of circular polarization for use with the birds what determines if it should be LHCP or RHCP? I've read the ARRL Satellite Handbook and "sort of" searched the AMSAT-BB archives but found nothing about this question. Thanks. Tom - K0TW

5 5

Help required for KiwiSAT.
by Terry Carrell 06 Oct '10

06 Oct '10

>From the KiwiSAT team. Can you help us? We require four (4) Cypress CY7C383A-0JC or QuickLogic QL12x16-2PL68C FPGA chips, used & un-programmed. To date we have had 2 lots of 4 from two different sources but all proved to have been compromised and could not be programmed. We had a small stock but they have all been used during our development work and while we can purchase new units, the source requires us to buy a significant number more than our requirement which is proving to be very expensive. We are happy to pay for good units once we have confirmed they are clean. A matter of twice bitten, thrice shy. These chips will fly so it is important we have perfect units. If you help in any way, please let me know. Terry, ZL3QL. – AMSAT-ZL

1 0

Symposium Audio/Video Feed?
by Joseph Armbruster 06 Oct '10

06 Oct '10

Attn: Symposium Coordinators Will there be an audio or video feed coming from the symposium this year? Unfortunately, I am unable to attend in person this year. However, I would love to tune in to hear the latest news and what is planned for the future. Thank you! Joseph Armbruster

1 0

S band
by Jack Barbera 06 Oct '10

06 Oct '10

Need a little help. First I'd like to thank everyone for your answers to my question concerning ISS beacon. I am all set to add L band to my station using my IC910 including Rohn 25 folder over tower to be mounted to the side of my house. While I'm at it I wonder if it would make sense to add S band as well, if so, should I add transmitting as well as receiving capabilitie? Should I use a two meter or a 70 cm radio knowing that two meter would provide less loss? Any thoughts on this would be appreciated & most likley I will have further questions as I get into this project. Thanks for any input. Jack WA1ZDV

1 0

HO-68 FM audiostream via internet
by PA3GUO 06 Oct '10

06 Oct '10

HO-68 is in FM mode, I will put a live audiostream this evening at: http://www.pa3guo.com/webradio.html There is approx. a 12 seconds delay. 18:10...Turn On--FM/PACSAT Africa,Middle East,Europe,NA 18:55...Turn Off 19:35...Turn On--FM/PACSAT Africa,Middle East,Europe,NA 20:20...Turn Off Depending on the interest I may leave it on also the next days. Henk, PA3GUO

2 1

Re: SatPC32 Help Needed
by Edward R. Cole 06 Oct '10

06 Oct '10

David, I'll step in here with a brief comment which you may already have considered: Doppler frequency offset changes throughout a pass, so if you transmit on a fixed frequency on the uplink, the downlink frequency will change due both due to Doppler effects on the uplink and downlink frequencies. If this is mode-UV the amount of Doppler will be more on the uplink due to the higher frequency. Another effect that many do not take into mind is that Doppler changes at a non-linear rate; in other words it changes faster near the point where Doppler goes from positive shift to negative shift in the rest frequency of the satellite. I know it sounds like a lot of math. But as an operator you just need only realize that this will happen resulting in tuning the signal over the duration of the pass (tune faster at mid-point of pass). When one gets up to modes like LS, it gets more challenging because both Doppler and rate of Doppler change are greater. Probably should consider computer tuning of the radio at this point. Note that Leo satellites go thru faster frequency change due to the quicker pass overhead. Heo's taking hours for a pass require retuning less often. Others may provide more definitive help with your question. 73, Ed - KL7UW At 11:35 AM 10/6/2010, David Palmer wrote: >Hi Guy and Amsat-List! > >I'd like to know the answer to this too! I just recently started >using twin FT-817ND's and SatPC32 as well, and notice the exact same >thing -- audio drifts slightly thorughout the pass, even though I have >the dopper correction set pretty close. For me, it only drifts a few >hundred Hz at most, but it's still enough that I have to tweak the >offset on the uplink. I'm new to SSB sats so not sure as well if >there's something I'm doing wrong. I've got the time on the PC clock >set within 1 second, and my lat/long within 0.01 degrees. > >I'm measuring the drift just roughly based on my own audio coming back >over the downlink -- unfortunately as I've called CQ on FO-29 and >VO-52 the last few evening's passes (0100-0500 UTC), no one else has >been on the sats for a direct QSO! My own audio comes back nice and >clear (even out to 5 degrees elevation) so it's not a reception >problem, as far as I know. > >Any help for those of us new to the satellites would be appreciated! > >Thanks, > >Dave KB5WIA CM88 Northern California >2xFT817-ND, Elk Log-Periodic, MH-72 Duplexer, Samsung Netbook running SatPC32. > > > Is anyone else using two Yaesu FT-817 > > / 857 / 897 rigs with SatPC32? If so, what do you think I am doing wrong > > and what are your DOPPLER.SQF data lines for AO-7, VO-52, and > FO-29 (as well > > as any other critical settings)? > >_______________________________________________ >Sent via AMSAT-BB(a)amsat.org. Opinions expressed are those of the author. >Not an AMSAT-NA member? Join now to support the amateur satellite program! >Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-QRT*, 432-100w, 1296-QRT*, 3400-winter? DUBUS Magazine USA Rep dubususa(a)hotmail.com ====================================== *temp

2 1

SatPC32 Help Needed
by Guy Brauning 06 Oct '10

06 Oct '10

Thanks for reading this. I recently installed SatPC32 from an AMSAT purchased CD onto a new WIN 7 laptop with a dual-core Pentium processor. The laptop is interfaced with a Yaesu FT-857D for 144MHZ and a Yaesu FT-897D for 432 MHZ. The interface is via a STAR-TECH Express Card serial adapter which provides 2 COM ports. The program installed properly, I updated the KEPs file, and the program controls the radios. My problem is that I can't fine tune the Doppler shift properly for my set-up. I have tried using the CAT Tuning dialog box to adjust the Downlink in order to hear my own CW signal in the downlink, then reset the downlink adjustment to zero, and then adjust the Uplink by the same frequency amount in the opposite direction, and then save the uplink calibration. I was able to get AO-7 mode B working pretty well using this technique; however, for VO-52 even when I adjust the downlink to hear myself and then change the uplink and store the change, my signal is no longer heard in the downlink... even before saving any changes, I have to continually adjust the downlink in order to hear my own signal as my signal will move out of the downlink ....I can't seem to find the correct Doppler corrected frequency pair... I thought that once I adjusted the downlink so that my signal was peaked that that would be a constant "correction" throughout the pass. Are there other adjustments that I need to try in addition to the uplink calibration? FO-29 is even harder to try and figure out than AO-7 and VO-52. Is anyone else using two Yaesu FT-817 / 857 / 897 rigs with SatPC32? If so, what do you think I am doing wrong and what are your DOPPLER.SQF data lines for AO-7, VO-52, and FO-29 (as well as any other critical settings)? I have been manually adjusting for Doppler shift for about a year on the linear satellites but I never got proficient enough to tune around the passband and answer other calls... I just parked myself on an open frequency and called until someone answered me. I can greatly appreciate the benefits of Full Doppler Tuning, I just can't seem to configure SatPC32 in order to take advantage of it! I live in central Maryland, FM-19. Thanks for the help, Guy Brauning N3SCR guyjeanbraun(a)comcast.net

2 1

Possible ops from rare grids ..
by John D'Ausilio 06 Oct '10

06 Oct '10

I'm making a trip to the canadian maritimes .. I've borrowed an Arrow antenna, have a number of radios (still trying to find my VX-5 which is missing) .. should be able to do FM and maybe SSB/CW as well .. I'm staying in GN06, will certainly be in FN96/95 .. might be able to do GN05 then on the way home were going to Halifax, if there's a grid there that's near and dear to anyone's heart let me know direct. I'll try and identify specific passes once the route is settled, and I'll post updates here (unless there's a better place to do so?) de w1rt/john

1 0

Re: LHCP or RHCP?
by PA3GUO 06 Oct '10

06 Oct '10

Not sure which to pick, but having both is valuable. For example HO68 is tumbling a lot (looking at my switching between L and RHCP). AO51 has more stable results: 435.300 vs 435.150 ((I always forget which one is what). 73, Henk -- Henk, PA3GUO

1 0

Mini-Grid Expedition CP28
by John Boudreau 06 Oct '10

06 Oct '10

I'll be travelling tomorrow (Oct 7) to Aklavik, NT and will be active on the following passes as VE8EV/P from CP28 : Time-On Time-Off Satellite Coverage Area 1622z 1637z HO-68 Europe, North America 1645z 1657z SO-50 North America 1810z 1828z HO-68 Europe, North America 1830z 1836z SO-50 North America 1959z 2005z HO-68 Europe, Canada 2051z 2052z AO-27 North America 2108z 2119z AO-51 North America 2245z 2255z AO-51 North America 73 John - VE8EV

1 0