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

TS2000 on dualband antenna (for sat work)
by John Geiger 13 Jun '10

13 Jun '10

Has anyone on the list tried using a Kenwood TS2000 on full duplex satellite operatation using a dualband VHF/UHF antenna and a diplexer? Is it possible or is there too much desensitization thru the diplexer to make full duplex work? 73s John AA5JG

2 1

VO-52 - OK to Work in FM?
by Clint Bradford 12 Jun '10

12 Jun '10

The Bengal ham club posted about five years ago instructions for working V)-52 in FM mode. Is that still OK to do? "HAMSAT or VO-52 is a satellite intended for SSB/CW operation. However as in VU land very few of us can afford multimode VHF/UHF radios we are accessing Hamsat on FM for which it is best to stick to the centre frequencies (435.250 uplink and 145.900 downlink). It is also best to simultaneously monitor your own signals on the downlink using a separate radio. Hamsat requires around 100 watt ERP for solid 59 signals. So if you are using 10 watts RF the recommended antenna gain is around 10 db. However Hamsat or VO-52 have been accessed on high elevation passes using 25 watts ERP. If you want to use omni directional antennas you can build a turnstile or an eggbeater antenna which has a dome shaped radiation pattern with circular polarisation. Separate 10 element UHF and 5 element VHF crossed yagis with circular polarisation would give excellent results. Only keep the transmission line loss (particularly on UHF) minimum. Use hardline CATV cable if transmission line is more than 100 feet. Otherwise if you use RG-213 keep the feeder length to around 20 - 30 feet. I have been using a handheld arrow yagi antenna with RG-58U cable of around 1 meter length. Doppler compensation is needed particularly on the UHF uplink where the signal will shift around 10 KHz. So for the uplink it is best to start from 435.240 MHz during AOS and end at 435.260 MHz at LOS and on the downlink start receiving 5 KHz up at 145.905 MHz and end at 145.895 MHz. Currently the VU transponder is on and it has a beacon (continuous carrier) on 145.936 MHz though we have not yet received the beacon from Calcutta / Kolkata." Clint, K6LCS

3 2

IKAROS Solar Sail Successfully Deployed
by B J 12 Jun '10

12 Jun '10

http://www.jaxa.jp/press/2010/06/20100611_ikaros_e.html 73s Bernhard VA6BMJ @ DO33FL

4 4

elevation rotor 4 sale
by Bob- W7LRD 12 Jun '10

12 Jun '10

I have a "extra" T-45 Alliance rotor. It is the 5 wire version on the U-110. Contact direct. A portion of the proceeds go to AMSAT. 73 Bob W7LRD

1 0

Re: VO-52 - OK to Work in FM?
by andy thomas 12 Jun '10

12 Jun '10

I don't, and I think that VU says basicaly that it's ok if you haven't anything else - so why foul up the transponder or others by grabbing its power? I can see it MIGHT be acceptable if you were testing a rig. but not to treat as '51, IMHO. But AMSAT-VU will say for sure, it's their bird. 73 de andy G0SFJ

1 0

Re: VO-52 - OK to Work in FM?
by Alex 12 Jun '10

12 Jun '10

Hi Clint. Check out this page on the Amsat India web site http://www.amsatindia.org/payloads.htm Alex / VK5ALX

1 0

HO-68 Schedule -13-20 June 2010
by Alan Kung 12 Jun '10

12 Jun '10

UTC: 13 June 2010 ================================ 16:25...Turn On--CW/SSB India, Africa, Middle East, Europe,NA 17:10...Turn Off 18:10...Turn On--CW/SSB Africa,Europe,Middle East,NA 18:55...Turn Off 22:15...Turn On--CW/SSB NA,North Asia,East Asia,Oceania 23:00...Turn Off 14 June 2010 ================================ 01:05...Turn On--CW/SSB South America,NA,North Asia 01:50...Turn Off 01:56...Turn On--CW/SSB North Asia,East Asia,South Asia 02:11...Turn Off 02:50...Turn On--CW/SSB South America,NA,North Asia 13:35...Turn Off 17:55...Turn On--CW/SSB Africa,Europe,NA 18:40...Turn Off 15 June 2010 ================================ 23:45...Turn On--CW/SSB South America,NA,North Asia 00:30...Turn Off 00:45...Turn On--CW/SSB South America,NA,North Asia 01:30...Turn Off 01:39...Turn On--CW/SSB North Asia, East Asia, South Asia 01:54...Turn Off 09:50...Turn On--CW/SSB Oceania,Asia,Europe 10:35...Turn Off 12:30...Turn On--CW/SSB NA,Europe,Africa,South America 13:15...Turn Off 17:35...Turn On--CW/SSB India,Middle East,Europe,NA 18:20...Turn Off 19:05...Turn On--CW/SSB Africa,Europe,NA 19:50...Turn Off 16 June 2010 ================================= 01:23...Turn On--CW/SSB North Asia,East Asia,South Asia 09:37...Turn Off 09:35...Turn On--CW/SSB Oceania,East Asia,North Asia,Europe 10:20...Turn Off 15:15...Turn On--CW/SSB Oceania,East Asia,North Asia,Europe 16:00...Turn Off 17:20...Turn On--CW/SSB Africa,Europe,NA 18:05...Turn Off 23:10...Turn On--CW/SSB NA,North Asia,East Asia,Oceania 23:55...Turn Off 17 June 2010 ================================= 01:04...Turn On--CW/SSB North Asia,East Asia,South Asia 09:19...Turn Off 04:35...Turn On--CW/SSB NA,North Asia,Middle East, Europe,Africa 05:20...Turn Off 09:20...Turn On--CW/SSB Oceania,Asia,Europe,NA 10:05...Turn Off 13:45...Turn On--CW/SSB Europe,NA,South America 14:30...Turn Off 17:05...Turn On--CW/SSB Africa,India,Middle East,Europe,NA 17:50...Turn Off 18:50...Turn On--CW/SSB Africa,Europe,NA 19:35...Turn Off 22:55...Turn On--CW/SSB Oceania,Asia,Europe,NA 23:40...Turn Off 18 June 2010 ================================ 02:41...Turn On--CW/SSB North Asia,East Asia,South Asia 02:56...Turn Off 10:50...Turn On--CW/SSB Oceania,Asia,Europe,NA 11:35...Turn Off 13:35...Turn On--CW/SSB Europe,NA,South America 14:20...Turn Off 16:45...Turn On--CW/SSB India,Africa,Europe,NA 17:30...Turn Off 22:35...Turn On--CW/SSB South America,Africa,NA, Europe,North Asia,East Asia 23:20...Turn Off 19 June 2010 ================================ 01:25...Turn On--CW/SSB South America,NA,North Asia 01:10...Turn Off 02:19...Turn On--CW/SSB North Asia,East Asia,South Asia 02:35...Turn Off 10:35...Turn On--CW/SSB Oceania,Asia,Europe,NA 11:20...Turn Off 13:15...Turn On--CW/SSB Europe,NA,South America 14:00...Turn Off 16:30...Turn On--CW/SSB Africa,Europe,NA 17:15...Turn Off 20 June 2010 ================================ 00:05...Turn On--CW/SSB South America,NA,North Asia 00:50...Turn Off 02:03...Turn On--CW/SSB North Asia,East Asia,South Asia 02:18...Turn Off 05:35...Turn On--CW/SSB North Asia,Europe,Africa 06:20...Turn Off 12:55...Turn On--FM Europe,NA,South America 13:40...Turn Off 73 Alan Kung, BA1DU HO-68(XW-1) Project Manager www.camsat.cn

2 1

SO-67 Back Next week?
by John Meeks 12 Jun '10

12 Jun '10

From Jan-Albert Koekemoer via sumbandila.googlegroups.com : "We've indeed have a long "radio silence" now. Some good news is that we're reprogramming the command transceiver on the satellite used by the SA-AMSAT payload (CTR-VU2) tonight. This will hopefully sidestep the issue we've had with the cut-off at the PTT tail. The idea is to keep the PTT active for the 15 minute duration that the SA-AMSAT payload will be active at a time, i.e. uncouple the PTT functionality from the rest of the SA-AMSAT payload functions. We will then make sure it works as expected (hopefully first half of next week) and if all goes well, aim to have the payload fully operational and in service again by the end of the week." From SARLNEWS: "SUMBANDILASAT SOON BACK IN AMATEUR RADIO MODE SA AMSAT announced that SumbandilaSat will soon be back in the Amateur Radio Mode. Currently Sunspace will re-program CR2 with a fix for the SA AMSAT PTT problem . This is expected to be completed by mid May. Programming of the Amateur Radio Payload will in future be carried out by the CSIR Satellite Application Centre at Hartebeeshoek. SA AMSAT will work with SAC to coordinate operational requests. More details on how to request operation will be announced in the next two weeks and published on www.amsatsa.org.za <http://www.amsatsa.org.za>. We will not be using googlegroups."

2 1

Re: [Mw] Fwd: Power splitters circular polarization?
by Joe v Murray 11 Jun '10

11 Jun '10

My apologies gents The attached was the second reply to Gary (WE9Y) that was not sent to the BB As you can see after reading the attached a few pictures would have been a must to really get into a axis discussion about my original query. I took a chance that Gary might have had some secret way of lining up the axis of those two antennas in his back yard. Dom ( I8CVS) I still have your bench lab alignment pictures from years ago. It has been a long dry spell for us. And as usual Dr. Johnson (K0CQ) can add helpful information which we are all thankful for. My problem as you all now can grasp is outdoors , far field , 23 feet about ground using prime dish problems. Assuming good focus alignment on that dish and since it is AZ/EL mounted constructing the measurement ability on the selfsupporting tower 48 feet distant seems simple at first brush. However the desire to have the measurement capability be no worse than 1dB or the axial ratio results begins to provide tight axis alignment of the bore sight even using a single spinning dipole. I apoligize again for stirring up a problem by not sending the second post to the BB 73's Joe Murray K0VTY ======================== ----- Forwarded Message ----- From: Joe v Murray <k0vty(a)juno.com> To: gary.reed(a)sbcglobal.net Date: Thu, 10 Jun 2010 20:51:52 -0500 Subject: Re: [Mw] Fwd: Power splitters-errors circular polarization? I have been trying to determine a way to accomplish the line up of the two axis before I begin the construction. Keeping the entire system and measurement off the ground is a requirement. As we know on a CP antenna the minimum axial ratio is the measure that must be delivered or the notion of CP does not mean much. In my case I am using a 54 inch diameter spun aluminum dish mounted at 23 feet off the ground. A mono axial mode helical feed is used with > 22 dB return loss. A second self supporting tower at 48 foot distant is the location for the measurement dipole system However so far I have not convinced myself of a sure fire way to manage the axis alignment. Even when I make the measurement end adjustable I still have not arrived at a good enough way. So when you came up with your suggestion I thought maybe you have devised a method of aligning those axis with in some reasonable method. I do not believe that eye balls will cut the needed accuracy if 1dB of axial ratio is the goal. I should have provided the above in the first place Gary Thanks Gary Joe Murray K0VTY ====================== On Thu, 10 Jun 2010 17:59:12 -0700 (PDT) Gary K Reed <gary.reed(a)sbcglobal.net> writes: Well, I would say mount the dipole through a piece of PVC pipe of say 1 inch diameter. Make the pipe 3 feet long. Run the pipe through a PVC "Tee" of appropriate size. Mount that "Tee" on a stand of some sort. I would suggest more PVC for that - no metal of course. Then, site down through the pipe at the other antenna. Far field would be about 25-30 feet at 1296 so you should be able to see that far easily. (Far field depends on the antenna aperture so it varies. Large arrays would entail longer distances.) Don't know if this helps, but it might be a start. Gary WE9Y --- On Thu, 6/10/10, Joe v Murray <k0vty(a)juno.com> wrote: From: Joe v Murray <k0vty(a)juno.com> Subject: Re: [Mw] Fwd: Power splitters-errors circular polarization? To: gary.reed(a)sbcglobal.net, amsat-bb(a)amsat.org Date: Thursday, June 10, 2010, 8:42 PM Hi Gary Any good suggstions on how to keep the axis of the rotating dipole lined up with the axis of the CP antenna in the far field? Thanks Joe Murray K0VTY ==================== On Thu, 10 Jun 2010 17:24:55 -0700 (PDT) Gary K Reed <gary.reed(a)sbcglobal.net> writes: > To measure axial ratio, why not rotate a dipole in front of the yagis > (or other antenna) , and measure the signal strength. If the axial > ratio is 1 then there should be NO change in signal strength as the > dipole is rotated. It would necessary to stay in the far field. > > Or have I been working too long today? > > Gary WE9Y > _______________________________________________ > Microwave mailing list > microwave(a)lists.valinet.com > http://www.valinet.com/mailman/listinfo/microwave > > ____________________________________________________________ Penny Stock Jumping 2000% Sign up to the #1 voted penny stock newsletter for free today! http://thirdpartyoffers.juno.com/TGL3141/4c1186ca9383d82045m03vuc

1 0

Fw: Re: [Mw] Fwd: Power splitters-error circularpolarization?
by i8cvs 11 Jun '10

11 Jun '10

Hi Yanco, KC9RDT My message to you bounced back to me for three times. Please give me another email address. 73" de i8CVS Domenico ----- Original Message ----- From: "Yanko Yankov" <samy_b1(a)shell4you.net> To: "i8cvs" <domenico.i8cvs(a)tin.it> Sent: Friday, June 11, 2010 5:51 AM Subject: RE: [amsat-bb] Re: [Mw] Fwd: Power splitters-errors circularpolarization? Can I see your setup . 73 de KC9RDT - original message - Subject: [amsat-bb] Re: [Mw] Fwd: Power splitters-errors circularpolarization? From: "i8cvs" <domenico.i8cvs(a)tin.it> Date: 10/06/2010 9:51 PM Hi Joe K0VTY and Gary WE9Y In a separate email I have sent to both of you few photograph of my lab set-up for circularity measurements using a rotating dipole against a LHCP steady 3.5 turns helix feed for 2400 MHz under test. Also I have added the radiation diagram for a G3RUH type patch feed for 2400 MHz made with the same set-up when the patch is azimutally rotated by +/- 90° and is illuminated by the steady horizontally polarized dipole. If someone is interested to see the above set-up for microwave please let me know off line. 73" de i8CVS Domenico

1 0