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

SatPC32: How to change a K3 to DATA mode for PSAT-1 ?
by Bob KD7YZ 07 Nov '15

07 Nov '15

I have been trying to lash-up everything for ops on 28.120 (USB) PSK31 Uplink and 435.350 (FM) Downlink for PSAT-1 . Well, in order for my K# to be keyed by the soundcard SIGNALINK-USB, the K3 must be in DATA mode ("MD6;" is the K3's command I believe). I have moderate success telling SatPC32 that the 2nd radio is a Kenwood, other . So when SatPC32 reads the Doppler.sqf file, it will change my K3 to CW or to FM or USB. None of which, if used, will allow MixW or DopplerPSK to do anything more than "switch" on the SignaLink and also cause the K3 so "switch" to the xmit (red lite on) position. Yet there is, as expected, no RF output that way, in USB. So using two different SignaLink's I have the IC910H going to the 435 rx freq and listening. I have the K3 on another SignaLink, going to 28.120 and switching to xmit when asked. Just that I need to K3 to automatically go into DATA mode when being used for PSAT-1, or any other PSK type bird. When I manually switch the K3, then either MixW or DopplerPSK do, in fact, switch the K3 to xmit as-well-as output RF . This is not a very good solution as sometimes SatPC32 re-reads Doppler.sqf and thus puts K3 back to USB. Anyone have a solution? tnx ! -- 73, Bob KD7YZ www.qrz.com/db/kd7yz AmSat LM#901

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Link Budget
by Joe 07 Nov '15

07 Nov '15

Can anyone here run a link budget for me? I'm in an slight heated debate with some people, About how they have heard about the possible Geo synchronous bird coming up, and they are all wondering why don't "THEY" I like the "THEY" part, anyway why don't they just put it on the moon. I gave them several reasons why a Geo bird is better, 1- It is there 24/7 where the moon is visible less than 50% of the day 2- the Geo bird doesn't move ( or extremely little) so set the antenna and forget it. Where the moon requires tracking programs and antennas that can move in AZ and EL 3- Useable "Window" The amount of the earths surface that can see either is soo close to the same why bother I bet a geo bird would be at least close to 90% of what the moon see's 4- And finally antennas and power required. The moon being soooo much farther away the amount of power needed each way has to be MUCH more. And thats what I was wondering say you had a nice decent transponder in Geo orbit. what power levels say ERP I guess is needed each way? then drop the same transponder and how much more erp each way will be needed to have the same level of contact quality? Joe WB9SBD

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Re: [amsat-bb] Link Budget
by Edward R Cole 07 Nov '15

07 Nov '15

Maybe. Ever heard of Moonbounce (eme)? I have a 16-foot dish (4.9m) which can make 5w very loud on 5-GHz! Compared to a 3-foot dish it is 20Log(16/3) = 14.5 dB more gain (28 times as much signal strength). It moves slow so would not track a LEO at all and only track HEO at the highest part of the orbit where angular rates are slow. It tracks the Moon very nice. I use in on 1296-eme with 125w. 5-GHz eme typically have 50w or more power. Most run TWT's. Some have hundreds of watts! 73, Ed - KL7UW Date: Sat, 7 Nov 2015 16:22:13 -0500 From: Paul Stoetzer <n8hm(a)arrl.net> To: KA9QJG <KA9QJG(a)comcast.net> Cc: Joe <nss(a)mwt.net>, "amsat-bb(a)amsat.org" <AMSAT-BB(a)amsat.org> Subject: Re: [amsat-bb] Link Budget Message-ID: <CABzOSOoLpP05UzjiE2fHkZ-7pwbH2+eBmcOJJYzc7EB78Da1VA(a)mail.gmail.com> Content-Type: text/plain; charset=UTF-8 The good thing is that high power at 5 GHz is expensive, so I doubt anyone will be running too much more than they have to on P4B! 73, Paul, N8HM 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: dubususa(a)gmail.com

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Re: [amsat-bb] Link Budget
by Edward R Cole 07 Nov '15

07 Nov '15

I don't recall exactly but there is geostationary and there geocentric orbits. The orbit that is not zero inclination will trace a figure 8 in the sky but its not a large deviation in position. If 5GHz is being considered for the link, antenna gain may be fairly high but will they have a beamwidth narrower than the angular deviation that the figure 8 makes? How big a dish? 2-foot? 3-foot? Get out your sliderules and calculate the beamwidth (no I will not do it for you). I think the inclination in geotationary is not very high (maybe a few degrees; i.e. <10). The apparent motion would be diurnal so nothing rapid. One could probably use a manual setting for a few hours. Just a guesstimate. 73, Ed - KL7UW From: Burns Fisher <burns(a)fisher.cc> To: Joe <nss(a)mwt.net> Cc: AMSAT BB <amsat-bb(a)amsat.org> Subject: Re: [amsat-bb] Link Budget Message-ID: <CABX7KxVtXXFHvm_3_BLd4SKyTDRSpOdYwsA+x+kXJrTNHG0Eew(a)mail.gmail.com> Content-Type: text/plain; charset=UTF-8 While it appears that you are right about the link budget, one of you arguments holds only *some* water, and that is tracking. GeoSTATIONARY birds would require to tracking, but there are geosynchronous orbits (i.e. 24 hours, but not necessarily 0 inclination and 0 eccentricity) which would move north/south or east/west in the sky over the course of a day. And regarding the moon: Another argument against it is that it is darned hard to land on the moon. Lots more deltaV required. 73, Burns W2BFJ 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: dubususa(a)gmail.com

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a big thanks!
by KG4BYN - Ben Harold 07 Nov '15

07 Nov '15

well, i asked and you all came through. SO - thank you! i've got MORE knowledge to get me underway, now, than i did upon a few weeks of hunting around on the internet and just getting more and more confused. fwiw, i'm running windoze 7 on the box in my office and can easily switch from windoze to linux on my notebook in the shack. also, i'm NOT - particularly - "cheap" when it comes to this, but fighting the cancer took its toll not only on ME, but on our pocketbook, as well. anyway, thanks for ALL the info! i'm sure i'll be popping in and out of here, now that you know who i am, as well as my level of "marksmanship" in this endeavor. 73, ben --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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Re: [amsat-bb] dumbest questions in the world
by Pedro Converso 07 Nov '15

07 Nov '15

Hello, It is not a dumb question, is what most starting bird chasers' ask. Trying solve this question I made a simple & free one screen application showing at a glance most required information. You can try it at http://amsat.org.ar/pass.htm Will show in your local time what next passes are coming. If you click on a satellite icon, will see azimuth/elevation + graphics, modes, doppler adjusted uplink/downlink frequencies, and a beep alerting coming or leaving satellites. Good luck with your renewed interest on the birds !! Best 73, lu7abf, Pedro Converso

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PSK31 on PSAT-1 (was elbow room)
by Robert Bruninga 07 Nov '15

07 Nov '15

> How about a PSK-31 Cubesat within VHF/UHF? Because the 6000 Hz and 18,000 Hz of Doppler change on VHF and UHF simply cannot be done with PSK31 that requires tuning accuracy of +/- 1 Hz. By using ten meter uplink and FM downlink we eliminate the downlink Doppler and reduce the nominal Uplink Doppler on ten meters to an average around 1 Hz/sec for the lower portions of most passes. Bob, WB4aPR > Not many of us have a 10m dipole… as part of our satellite setup A simple portable fishing pole with an 8’ piece of wire on and another 8 foot counterpoise laying on the ground would make a great ten meter vertical for PSAT-1 PSK31 uplink. (Sorry though, that it takes more than 5 watts due to cramming an HF antenna on a 6” cubesat). Bob, WB4APR *Sent:* Tuesday, November 03, 2015 10:43 PM *Subject:* Re: [amsat-bb] AO-85 Rudeness (elbow room) > I like to see the 10m uplink "arrow" approach :-) > While PSAT-1 is a nice "proof of concept for PSK-31" > in reality it does nothing for the portable operator and > that is what the original post is all about. …. > Using PSK31 is a great idea, the 10m uplink is the real issue > for the non-use of PSAT-1. Should I say "fatal flaw"? > Not many of us have a 10m dipole ready as part of our satellite setup > (stationary or mobile for that matter). > It is time that we move on and promote digital modes on > frequencies that are actually used within the allocated satellite > bands and even better on higher bands where we have allocations > and we don't use them. > How about a PSK-31 Cubesat within VHF/UHF? > ... and leave 10m on the ground where it belongs LOL :-) ------------------------------ On Tue, Nov 3, 2015 at 4:27 PM, Robert Bruninga <bruninga(a)usna.edu> wrote: Take a break from the congestion.... come to the wide open multi-user wideband transponder on PSAT-1. Downlink is good on a handheld arrow on 435.350 MHz FM. It should be able to support dozens of simultaneous full duplex QSO's in the PSK31 waterfall. Just pick an empty spot and key your TX solid for the full 8 minutes of the pass on your 10 meter PSK31 uplink 28.121 MHz.. To run fullduplex, just run two copies of your favorite PSK31 software. One receiving the FM downlink and the other transmitting on the SSB uplink. Even better is to run Andy K0SM's TX-only uplink client that pre-adjusts for Doppler so everyone can decode you with no adjustments. http://aprs.org/psat.html Text with everyone all at once. Bob, WB4aPR _______________________________________________ Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

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Re: [amsat-bb] AO85 vs SO-50
by GW1FKY＠aol.com 07 Nov '15

07 Nov '15

Reference the comments on operating AO-85 by Dani ( M0HXM /EA4GPZ ) and the frequencies that he states that he uses Dani - Typing error I am sure .- You make reference to 436 Mhz but it should be 435 Mhz on the uplink. Regards and good luck. Ken Eaton GW1FKY Amsat -UK Amsat NA

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dumbest questions in the world
by KG4BYN - Ben Harold 07 Nov '15

07 Nov '15

ok, these are, indeed, the dumbest questions for you folks, because i've determined you all ARE the experts. i'm a 60+ year old ham. never worked the birds, but have always been fascinated. yup typical story, right? our local, somewhat, non-existent radio club had someone (not from around here) provide a very brief demonstration one saturday morning in a walmart parking lot - circa 2001. needless to say that was a LONG time ago. most of my hamming has been cw, with a rare ssb qso. i got burned out on 2m/70cm, early on (many years ago), howver...i've got my vhf/gear and antennas updated for some sat work. MY MAJOR PROBLEM is _/where/_ can i find downlink/uplink freqs for the fm birds with transponders. to be honest, i'd be darned happy to just to RECEIVE a cw beacon or even some packet via rig and soundcard. i've weeded through tons of websites, tons of threads on this bb...and am STILL having a difficult time finding the info for what i want. i'm a dinosaur (OLD) and and recovering from extremely severe colon cancer surgery, BUT i'm looking to broaden my horizons/hobby. also a link to a DECENT free tracking program with updating pass predictions would be helpful, too. i have a refurb pc notebook in the shack for this project. yes, i've heard of google, and yes, i've read darned near everything i can find...but the more i read, the more confused this old guys gets. feel free to answer me via private email so as not to clutter this mailing list...which HAS provided great info, but also, sadly, adds to my confusion. at least, i've got the doppler effect problem reasonably figured out. sorry for the long email and stupid questions. i originally wasn't going to send it, but i figured i gotta start someplace. 73! --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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AO 85 operations
by James Brown 06 Nov '15

06 Nov '15

I am confused. is AO85 operational for FM? If so, what freqs. should I program. I will be in death valley the next 7 days and want to try it and so 50. ThanksJim KI6WJ

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