October 2007 - AMSAT-BB - mailman.amsat.org

Equipment.
by John Hackett 20 Oct '07

20 Oct '07

Dave, You wondered if I¨d share with the other satellite enthusiasts a few words about my equipment. > John, > > Having read your prior e-mail "AO-7 report" and the warnings about > running too much uplink power .... and using better receive, > I wonder if you would share with the readers what antennas, power at > antenna, resulting EIRP, and receive antenna and preamp you are using on AO-7. > > Maybe your example will help folks figure out what they need to > do. You probably remember that I have hammered on about using a > preamp (at the antenna) for years on this reflector. Certainly Dave, happy to oblige. First it must be noted, as I've been waffling on about for donkey's! years (Manchester slang = a long! time) that you *DO NOT* have to affluent to have a fully automated satellite station ... (nor does one need to be fully automated) ... that's just a "convenience". Let me also say, that if I could afford one of the "all singing, all dancing fully automated rigs with a CAT interface, I'd buy one, it's just that I've never been able to afford !!! one. My QRP power levels are not *ONLY* due to my being "sensible" ... (note the parentheses) ... the main reason has always been lack of availabler funds for satellite gear. One of my first "OBSERVATIONS" was entitled "Oscar 13 on a Shoestring" ... I digress. The radios are the FT-290/790 pair, now well over 20 years old but still providing adequate service. For AO-7's uplink the FT-790 feeds a modified Norwegian Telenor mobile base station amplifier that originally operated on 460Mhz. I hack-sawed off the first two stages, added a 6dB pad, "tweaked" the filter and fed it with 200mW from the 790 to produce 8 watts. I have 6dB of loss at 70cm with the RG-214 coax ... (scrounged from the oil industry installation here) ... so I have an EIRP of about 20 watts from the elliptically polarised home brew 2 x 6el beam. I have never found an elevation rotor to be a necessity. The 290 for AO-7's downlink is preceeded by a home brew BF981 preamp mounted at the aerial. At 2m an ultra-low noise gaAsFET preamp in my opinion is not necessary ... due to the inherant sky noise of approximately 2dB at 145Mhz *IN CERTAIN PORTIONS OF THE SKY* ... though at microwave and above, where the sky is quieter, they are a must. For LEO's, more important than a preamp IMHO is a polarity switcher. The debate of circular polarisation vis-a-vis ellipticasl can be found on the website ... <http://www.observations.biz/> The aerials at ... <http://www.observations.biz/Observations_from_Norway/Observations_15_04_200…> ... at the bottom of the page. For AO-7 at 1400-1600Km above the earth you don't need to bother too much about doppler correction but for LEO's like VO-52 that literally streak across the sky some sort of auto-doppler tuning is recommended. Even newcomers will be aware of the "One True Rule" ... (doppler tuning). This is all very well if you do! have the latest all singing/all dancing rice-box but what do you do if you operate with 20 year old rice boxes that don't have !!! CAT tuning?. You use a program called InstantTUNE together with InstantTRACK which allows automated doppler tuning using mic pushbutton rigs. Instantune only allows tuning EITHER the uplink or the downlink so if you want to be FULLY automated, you'll need a pair of old 386 IBM's (or equivalent) and a pair of monitorsd from the nearest computer company/school skip. Everything else I can think of is home brewed and is to be found on the OBSERVATIONS page mentioned earlier. A couple of useful links are ... <http://www.observations.biz/Observations_from_Norway/how_much_power_is_enou…> ... which illustrates what can be done with QRP and a shoestring buget. <http://www.observations.biz/Observations_from_Norway/howmuchpowerisenough.h…> Self explanitory. <http://www.planetemily.com/ao7/ao7log.php> ... everything you ever wanted to know about AO-7 is on this site ... I know, cos' I maintain it. If it's not there, ask me, it'll be in my archives. You'll find a lot of useful information here ... <http://groups.yahoo.com/group/eu-amsat/?yguid=188558692> ... and it's all free. I hope this mail illustrates thast it is possible to operate amateur radio satellites on a shoestring buget. Remember, a *BIG* signal is not necessary a good signal. Have a nice day, all. 73 John. <la2qaa(a)amsat.org>

3 4

RS22 telemetry
by Mike Rupprecht 20 Oct '07

20 Oct '07

Radio Sputnik 22 (Mozhayets 4) ---------------------------------------------------------------------------- ---- Date: 20.10.2007 Time: 11:51 UTC UBS 139 IBS 20 USUN 147 ISUN 68 ITXA 0 ITXB 0 TTXA 109 TTXB 107 TNAP 107 TCTR 108 TSBA 106 TSBB 124 MODB 129 MODC 6 MTX 163 MRX 32 OnBoard Voltage: 13,9 V OnBoard Current: 0,2 mA Charge Voltage from Solar Batterie: 14,7 V Charge current from solar battery 0,68 mA D.C. current of the 435 MHz TX: 0 mA D.C. current of the 145 MHz TX: 0 mA Temperature of the 435 MHz TX: 9 °C Temperature of the 145 MHz TX: 7 °C Temperature of the Navigation Unit: 7 °C Temperature of the Controller: 8 °C Temperature of the inner case: 6 °C Temperature of the outer case: 24 °C Housekeeping info: 129 Housekeeping info: 6 Housekeeping info: 163 Housekeeping info: 32 73, Mike DK3WN www.dk3wn.info

1 0

AO-7 Full Power
by John Meeks 19 Oct '07

19 Oct '07

Orbit 50685 over North America AO-7 seemed to be in full MODE B. By the time I tuned in she had crosse3d 45 North with easy S7-9 signals coming in to my 7x7 RH Yagi. It's not so easy to type with my fingers crossed. John KC8ZFN

1 0

Last Chance!
by Martha 19 Oct '07

19 Oct '07

This is your last chance to register through the AMSAT website for the 2007 AMSAT Space Symposium. Registration on the web will cut off at the close of business on MONDAY. After that you must register at the hotel. -- 73- Martha

1 0

symposium
by Nick Pugh 19 Oct '07

19 Oct '07

The guy that I was traveling with to the symposium had to change this plans I am willing to share a room at the symposium. If you want to save $52 a night contact me off list nick k5qxj

1 0

HITSAT heard
by Mike Rupprecht 19 Oct '07

19 Oct '07

All, today (both european morning passes) I heard HITSAT. It seems she is still active but only in full sunlight. 0938UTC hit 1 jr8yjt hit2 00000000002e hit3 2d5956s -> Reset hit1 jr8yjt hit 2 very very weak hit 3 3f53535655555555 hit4 4fe1d1e4 hit1 jr8yjt Temp +X face : 61,203 °C Temp -X face : 27,573 °C Temp +Y face : 22,769 °C Temp -Y face : 37,181 °C Temp +Z face : 22,769 °C Temp -Z face : 29,975 °C Temp Transceiver: 32,377 °C Temp Battery : 37,181 °C Prim. Battery : 7,539 V Sec. Battery : 7,969 V 5 Volts : 4,974 V 5.5 Volts : 5,448 V RSSI : 0,898 V 1114 UTC hit1 jr8yjt hit2 000000000028 hit3 2956535654555255 Temp +X face : 116,452 °C Temp -X face : 8,356 °C Temp +Y face : 15,562 °C Temp -Y face : 8,356 °C Temp +Z face : 13,160 °C Temp -Z face : 10,758 °C Temp Transceiver: 17,964 °C Temp Battery : 10,758 °C RSSI : 0,781 V 73, Mike DK3WN

1 0

SSB Electronics SP-2 2 meter preamp
by Joseph Trombino Jr 19 Oct '07

19 Oct '07

I recently picked up an SSB Electronics SP-2 2 meter preamp. Can any SP-2 users out there in Amsat land comment on its performance?? Anyone have a copy of the manual they could send to me as a PDF??? Is the performance of the SP2000 light years ahead of the SP-2??? I'm planning on using this preamp for the HEO downlinks when the birds are finally in orbit. Thanks in advance for any info. 73, Joe W2KJ

1 0

Wow !!!.
by John Hackett 19 Oct '07

19 Oct '07

Hi All, Friday 15:39Z. I've not heard the AO-7 mode-B transponder this loud for 2 years !!!. Somebody had better keep an ear out for the beacon ... stranger things happen at sea !!!. 73 John. <la2qaa(a)amsat.org>

1 0

For Sale
by Bill Miller 19 Oct '07

19 Oct '07

For Sale: Yaesu 736R SYMEK IF Modifications 9600 and 38400 (144 & 440mhz only) SYMEK TNC3S High Speed Packet Controller If interested, contact me - kk2l@comcast .net

1 0

FO-29 new schedule
by Mineo Wakita 19 Oct '07

19 Oct '07

Oct. 22 none 23 03:32 - 24 04:22 - 25 03:28 -, 05:11 - 26 04:18 - 27 03:23 -, 05:10 - 28 02:30 -, 04:13 - 29 none 30 04:08 - 31 03:15 -, 05:00 - Nov. 1 04:05 - 2 03:10 -, 04:55 - 3 04:00 - 4 03:05 -, 04:50 - 5 none 6 03:01 -, 04:46 - 7 03:50 - 8 02:55 -, 04:41 - 9 03:45 - 10 02:53 -, 04:35 - 11 03:41 - 12 none

1 0