October 2006 - AMSAT-BB - mailman.amsat.org

SSB uplink to AO-51 on 2 meters and 1268 MHz
by OZ1MY 29 Oct '06

29 Oct '06

Hi all, >From Monday AO-51 will be in SSB mode on the uplink like it has been before. October 30 to November 6 Cross Mode Repeater, V(SSB)/U(FM) Uplink: 145.880 MHz USB Downlink: 435.300 MHz FM Those of you who have tried it before know that you must hit the frequency correct to get a good downlink signal. If you use automatic doppler shift correction from your tracking program it is a little bit easier. Personally I use SatPC32 to do the correction with the following line in the doppler.sqr file: AO-51,435300,145879.25,FM,USB,Nor,0,0,Voice V/U This worked very good last time we had this mode running on AO-51. Your transceiver may need small adjustments to the uplink frequency. The coming week can be used to get the feeling for running SSB up to AO-51. The experience gained will be needed when AO-51 is the new mode with L-band SSB up in December. That is going to be very interesting since the doppler shift will be very fast with this much higher uplink frequency. The rate of change of frequency will be something like 340 Hz pr. sec. Worst Case. Of course it will be less most of the time so that it might be possible to do the tuning by hand. December 8 to December 11 New Mode! Cross Mode Repeater, L(SSB)/U(FM) Uplink: 1268.700 MHz USB Downlink: 435.300 MHz FM I ran some tests on HITSAT. It has a Worst Case rate of change of approximately 300 Hz. pr. sec. since it has a perigee of 290 km. That is not easy on close passes. Lessons learnt : Make sure the PC clock is correct within 0.1 s Make sure your position is correct (a friend with a GPS receiver helped on that one) The keplerian elements must be correct ( difficult to control) The tracking program MUST use SGP4/SDP4 (I tested with an older program with PLAN 13 and that was up to 2 kHz off) Your transceiver/PC/tracker combination must be able to update once every 0.1 s or faster (special version of SatPC32 in my case) Frequencies must be correct in the PC or possible to correct on the fly Then there are frequency drift of the satellite, your transceiver and so on This means that you must update the keplerian elements at least once a day. Unfortunately this is not necessarily a guaranty since the keps sometimes are "bad". Synchronize the PC clock before each pass. Lessons learnt are about using automatic full doppler tracking. If you use manual frequency correction try it on the low elevation passes first. The mode has never been tried before therefor it is very interesting to see how it will work. Hope to hear you on AO-51 mode-L(SSB)/U(FM). Thanks to Colin, VK5HI, and Erich, DK1TB, for help with the doppler correction. 73 OZ1MY Ib

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Hand Held?
by VE3CJE 29 Oct '06

29 Oct '06

Greetings to all, Just getting back into the sats and I am looking to purchase a hand held.. Not sure which one, any suggestions? Cross band full duplex I would like and it appears that the Icom W32A seems to be the choice of many.. best regards, Norman

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LA/W5ACM MM ops to begin on 30 OCT 2006
by Andy MacAllister 29 Oct '06

29 Oct '06

LA/W5ACM will be active starting on 30 OCT 2006. The endeavor begins @ 5 PM CST 29 OCT 2006 from Galveston, Texas, with first satellite activity later that evening (30 OCT 2006 UTC). Ports of call include Jamaica, Grand Cayman and Cozumel. NO operation will be attemped from land, but many grids will be made available while at sea. Target satellites include SO-50 and AO-51. Due to the difficulty of SSB up/FM down ops via AO-51, better results are expected via SO-50. We will give it our best shot! Andy LA/W5ACM QSL to home call. Other satellite ops on this cruise include WB5RMA, WA5TWT, WA5WOD and WD5BDX.

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info
by w3vvp 28 Oct '06

28 Oct '06

I may have transposed the call WB3IGR heard it was W0UV.George

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info
by w3vvp 28 Oct '06

28 Oct '06

I have listened and transmitted the last 2 passes of vo-52,but I heard nothing. I was on 435..268.9 listesing on 145.900. WB3IGR heard W0UV on the 0352 pass in cw. Is there a common frequency where you call and listen and then go to another frewuency.I heard the beacon on 9360. Is there any one close to the eastern shore of maryland I can call and talk to for help. I am out in the boonies and no one that I know of within 60 miles of me that is in satellites. Thanks George

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XF4DL on AO-51 @ 29 Oct 0315 UTC
by Patrick STODDARD (WD9EWK/VA7EWK) 28 Oct '06

28 Oct '06

Hi! I just got back in the house from working AO-51, and had a most pleasant surprise on that pass. The XF4DL DXpedition to Socorro Island (Revillagigedo) was on the satellite. At times, the pileup was just like on HF, but sometimes nothing was coming through the satellite with all the signals trying to make it through. In addition to a few XE stations, I heard KB5BOB and W6GMT also make contacts with the station after I made mine. Thankfully, my Sony digital recorder picked it all up, and I will hold onto this recording until that QSL card arrives from the DXpedition QSL manager. :-) :-) 73! Patrick WD9EWK/VA7EWK - Phoenix, Arizona USA http://www.wd9ewk.net/

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wanted KLM 20c and 22cx sat antennas
by Frank viggiano 28 Oct '06

28 Oct '06

I am looking for both the KLM 144 20C 2-meter crossed yagi beam and a 440-22CX 70 cm crossed yagi beam. In any condition willing to ship. Thanks Frank/kb2mvn

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Help Uni-Trac and keps
by Frank viggiano 28 Oct '06

28 Oct '06

I am getting my station back up and running after several years of dormancy. It's just been sitting so last I used it, all was fine. Yesterday I ran uni-trac and got a error about incorrect keps. I played with it for a while and got no ware so I reloaded the entire program from a zip file that had keps from 2003 and they work fine but if I update the keps file in unitrac it does not seem to like the new ones. I get error message. Did some thing change in the way two lines keps are written in the last few years? Any one else have this problem? Thanks for any help Frank/KB2MVN

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Re: KCT problem
by Roy 28 Oct '06

28 Oct '06

Dave, if you are using the DOS driver for the KCT, DRV.COM you may be having a problem with the KCT not sensing the rotor is turning which will then give the stalled message. There must be a changing voltage fed back to the KCT on pin 13 (Horizontal Analog Input) of the KCT DB25 plug within a designated time limit or the KCT will assume the rotor is stalled. Measure this voltage and see if it starts changing with the rotor movement. This problem can also occur when the rotor is set fully CCW and the sensed voltage is very low or zero. When the rotor starts turning it sometimes takes a few seconds for the rotor pot wiper to contact the wire wound resistance wire in the rotor pot causing the KCT to assume the rotor is stalled. This can be adjusted for in this case by setting the STALL timer value in the DRV.COM parameters. It defaults to a value of 18 which allows a two second time limit for the rotor to be found moving. See page 14(?) in the KCT manual. As of now there is no repair facility for the KCT. There are schematics for it on the AMSAT web site. Let me know what you find. -- Roy -- W0SL > Message: 8 > Date: Sat, 28 Oct 2006 18:19:34 -0400 > From: "Dave Marthouse" <dmart(a)pure.net> > Subject: [amsat-bb] KCT Problem > To: <amsat-bb(a)amsat.org> > Message-ID: <000c01c6fadf$2b7b7500$fadc2b0c@none> > Content-Type: text/plain; charset="iso-8859-1" > > I am experiencing what may be a problem with my Kansas City Tracker card. I am using the latest version of N4HY's QuickTrack with the KCT and Yaesu rotator. The rotator works fine in all directions. The tracker card is seated tightly in its slot in the computer. The cable connecting the KCT with the rotator is firmly connected. When I boot up I get an indication that the kct is stalled in azimuth. That is what the cw readout tells me. Elevation works fine. I re installed the software driving the KCT and this doesn't seem to help. In addition I re installed Bob's software. I still get a stalled azimuth. This leads me to believe that the KCT has a problem. Does anyone have any ideas? Any information would be appreciated> > > I know LL Grace isn't in business and the KCT isn't manufactured. Does anyone know where a used one can be obtained? Is anyone involved in repairing the KCT cards? > > > Dave Marthouse N2AAM > dmart(a)pure.net >

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Re: KCT Problem
by Alan P. Biddle 28 Oct '06

28 Oct '06

Dave, It has been at least that long since I have had a KCT. However, there are a couple of things external to the KCT which could give you a stalled error. One is a loss of the azimuth reference signal. I dimly recall a test program which would let you read the ADC data. If so, see if both the azimuth and elevation are indicating correctly. If not, check the signal at the back for the rotator box, and at the DB-25 connector to the KCT. I would think that you would see the rotator run away in one direction or another, however. The other case is if there is a problem with the left/right controls. You should be able to check that at the same points by grounding the appropriate lines manually. Perhaps a solder connection has opened up. In any case, you can check this easily with a VOM and a jumper wire in a few minutes. If all that is working, then the KCT or software is the culprit. As I recall, there were not many chips there, so it may be possible to fix by substitution. It will, probably, be either an ADC chip or the control driver chips. I hope this will help a bit. I did the above exercise a couple of times, and both times found a bad connection in my work. With luck, somebody using the unit will have some more specific suggestions, and possibly the specific pinouts and chips. Alan WA4SCA

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