AMSAT-BB May 2009

188 participants
264 discussions

Call for Papers--2007 ARRL/TAPR Digital Communications Conference

by Ford, Steve, WB8IMY

Technical papers are solicited for presentation at the 26th Annual ARRL and TAPR Digital Communications Conference to be held September 28-30, 2007 in Hartford, Connecticut. These papers will also be published in the Conference Proceedings (you do NOT need to attend the conference to have your paper included in the Proceedings). The submission deadline is July 31, 2007. Please send papers to: Maty Weinberg ARRL 225 Main St Newington, CT 06111 or you can make your submission via e-mail to: maty(a)arrl.org Papers will be published exactly as submitted and authors will retain all rights. 73 . . . Steve, WB8IMY ARRL

9 years, 11 months

Re: EggBeater

by Bill Dzurilla

Steve, I have both a commercial and a homebrew Eggbeater and am disappointed with both, especially in light of its rather high price. Connected to my IC-7000 via an ARR mast-mounted preamp, performance is far less than with an HT and an Arrow. Guess an omni can't cut it, at least not from my QTH. Maybe if I could get it up higher, clear of all roofs, it would do better. I can make contacts at relatively high sat elevations, but can do just as well with a $10 dual band ground plane. My friend has an Eggbeater and the same preamp at a clearer QTH, and he hears substantially better, down to 10 degrees elevation in some directions. Good luck and 73, Bill NZ5N > > Hi Steve, > > > > It is surprising to read that you are not hearing > anything. I have > > repeatedly used a 2m and 70cm Eggbeater for the sats > and have had no > > problem hearing things. No pre-amp. > > > > I was using a short cable (e.g. less than 10 meters). > The rigs I > > used were a FT-736r (deaf) and a FT-847 (so-so). > > > > 73, > > > > Dave

10 years

2.4 Gig

by Arlon Nelson

Are there any satellites on 2.4 gig so I can check out my old AO-40 dish. 73, Nels, WØTUP Minot, North Dakota nels(a)w0tup.com http://www.w0tup.com Ward County - Grid Locator DN98if TRIPLE PLAY AWARD No. 75 - A1 OPERATOR CLUB SKCC 31T - Flying Pigs 590 - QRPp-I #760 ARRL - FISTS #8610 - CC #1310 - FISTS WAS #143 FISTS PLATINUM #365 - FISTS SILVER #367 ARRL SSTV WAS #33 - IVCA MIXED BAND SSTV #1 40 MTR CW WAS - DXCC # 39623 - RTTY WAS # 585 COMMERCIAL RADIO OPERATORS LICENSE *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* CLUB CALL - WØJER (MAGIC CITY QRP CLUB) FISTS #11975 SKCC #1000 *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* Two antennas met on a tower, fell in love and got married. The ceremony wasn't much, but the reception was excellent. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*

13 years

Re: eggbeater rx performance (Mobile Operation)

by Bob Bruninga

> I found a trunk mounted 2 meter half wave >(dual bander) to work well when the satellite > was behind me, but not at all overhead... > I currently have a 2 meter quarter wave > (dual bander) mounted... into the center > of the roof. It works in all directions... Any "gain" antenna on a car is not good for satellites. Because by definition, "gain" in a mobile means "gain" on the horizon where mobiles need it, and this means LOSS everywhere else. The better the antenna is for "mobile" the worse it is for satelliites. (basic law of physics).. Eevn the "dual bander" 2 meter 1/4 wave has a decopuling loop for UHF, to keep the angle of UHF radition low on the horizon, because without it, the 1/4 2m whip is a 3/4 UHF whip and results in gain ABOVE 25 degrees which is BAD for terrestrial work (but GOOD by 2 dB or mnore for satellites). So, when we say a 19.5" 1/4 wave 2m whip for mobile satellite, then that is all it is. No matching, no coils for UHF, no nothing. Just a 19.5" vertical whip. BUT for satellites, this 19.5" whip is also a 3/4 wave UHF whip which has almost 7 dBi of gain ABOVE 25 degrees which is where it really yields solid performance for LEO satellites when above 25 degrees. A 5/8 wave 2m whip has a NULL at 15 degrees and so it is useless for satellites. They are too far away below 10 degrees to hear, and then there is the null up to say 45 degrees. And above that the satellite is only in view for 2 minutes or less! AND this antenna cannot be used on UHF at all. So that is why the 19.5" vertical in the middle of the roof is the best for mobile satllite (and not all that hot for terrestrial... but useable, since repeaters are a lot closer). See details about 75% down this page: www.aprs.org/astars.html Good luck. Bob, Wb4APR

13 years

true duplex radios

by D. Craig Fox

At the request of several following my late night post, set forth below is the list I copied off this or the VX-8 listserv. I have added the new Alinco. I do not think this list is complete so others please feel free to add to it. 73s Craig N6RSX HTs - Icom IC-W2A Icom IC-W31A Icom IC-W32 Yaesu FT-470 Yaesu FT-530 Yaesu FT-50R Yaesu FR-51R Kenwood TH-D7 Kenwood TH-77 Kenwood TH-78 Alinco DJ-G5T Alinco DJ-580T Alinco DJ-G7 Mobile rigs - Kenwood TM741 Kenwood TM742 Kenwood TM941 Kenwood TM942 Kenwood TM732 Kenwood TM-D700/710 Yaesu FT-5100 Yaesu FT-5200 Yaesu FT-8800 Yaesu FT-8900 Icom 2728H Icom IC2800 Base rigs - Yaesu FT-736 Yaesu FT-847 Kenwood TS-2000 Icom 820 Icom 821 Icom IC-910H NOTICE: This communication may contain privileged or other confidential information. If you are not the intended recipient of this communication, or an employee or agent responsible for delivering this communication to the intended recipient, please advise the sender by reply email and immediately delete the message and any attachments without copying or disclosing the contents. Thank you.

13 years

Re: BBC - Judica-Cordiglia brothers

by Trevor .

--- On Sun, 31/5/09, Doug Faunt N6TQS +1-510-655-8604 <faunt(a)panix.com> wrote: > Only for the next 5 days, as I send this. And it's > not very good. Hi Doug, Yes for some reason the BBC only hold shows on the site for a few days. I've just got home after being away for a few days and I see that as they don't do a podcast version it'll need converting to MP3 to listen to in the car tomorrow morning. Must admit I'd never even heard of the Judica-Cordiglia brothers before. 73 Trevor M5AKA

13 years

Help with Satscape

by Cotejaune2＠aol.com

For some reason I have lost S050 and A027 from my list and the format has changed to instead of just A051 it now says Echo 51. Has anyone else had this problem? **************An Excellent Credit Score is 750. See Yours in Just 2 Easy Steps! (http://pr.atwola.com/promoclk/100126575x1221823251x1201398665/aol?redir=htt… ExcfooterNO62)

13 years

Jewelry contests

by Dave Guimont

I've had several questions on the reflector regarding the "jewelry contests" we ran at the conventions for about eight years... For the newbies they were formulated to provide some interest for the wives of those hams, not interested in ham radio...OT's will remember... The "jewelry" was designed to be electronically similar to some part of our hobby...yet be wearable as jewelry.. A local friend suggested that those interested google my callsign, wb6llo, or Leanore's, ka6ucd, for several entry explanations....so as not to belabor it here.... Please, direct to me for questions... 73, Dave, WB6LLO dguimon1(a)san.rr.com Disagree: I learn.... Pulling for P3E...

13 years

Mobile Coax?

by Bob Bruninga

> Other Car Tips: > Convert from RG-58 to LMR-240-UF > or RG-213. I'd take that with a grain of salt. The length of coax in a car is about say 10 feet. The loss of 100 feet of RG-58 is say 5 dB? and the loss of fancy stuff might be 3 db? But the diffrence for only a 10 foot run is only .5 dB versus .3 dB or only 0.2 dB. Nothing at all to even consider compared to all the work it will take, and the lack of flexibility and trying to run something almost like pipe through places where a simple wire (RG-58) fits. My lesson was learned 40 years ago when I go my first 100 lb UHF mobile rig (tubes) just after highschool. The boat anchor filled the entire trunk of my MGB. But the first thing I did when we go the lot of them in my club was spend a day replacing the 8" internal piece of RG-58 in mine from the Transmitter output over to the chassis connector with a 8" run of RG-8. It was hard work getting that 8" piece of RG-8 coax inside the radio and routed all around the internal chassis. The elmer at the time laughed. He said you just wasted a day and all that work to save 0.01% of loss. So now your radio works at 100% where as before it worked at 99.99%. Losing 3 dB of course is one thing (50%), but trying to worry about that last 1% when the effort is tremendous is just not effective. Anyway, just my 2 cents... Bob, Wb4APR

13 years

Re: Re eggbeater performance - mobile

by Bob Bruninga

> For mobile work on AO27, SO50, AO51 > a 2 metre quarter wave whip is all > you need... to work the LEO's mobile > and the satellite is 15 degrees or > more above the horizon, Absolutely, For a 19.5" whip in center of roof: 1) Has 5 dBi gain above 20 deg on 2m 2) Has 7+ dBi gain above 30 deg on 70cm 3) Is an omni 4) does not sacrifice 3 dB for circular 5) Above 25 deg, satellite is 6 to 10 dB closer! 6) works the birds solid for the center of high passes 7) Simplicity at its best! Read about it: www.aprs.org/rotator1.html Disadvantage: The only disadvantage is TIME. On the above web page you can also see that satellites spend 70% of their daily pass times below 25 degrees. BUT! For those best passes in the morning and the evening (or whenever) you can make solid contacts while mobile for about 5 minutes. Also note, that you do NOT need any tracking program to predict passes. AO51 schdule repeats evry 5 days for example. Just write down the CENTER pass of the morning and evening for each day for 5 days. Update those 10 times on a small 3/5" card on the dash about once a month or so will predict all passes whenever you are mobile. There will be a pass 100 minutes earlier and 100 minutes later each day too. So you can predict all 6 passes a day from those same 10 times. See how: www.aprs.org/MobileLEOtracking.html Bob, WB4APR

13 years

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AMSAT-BB May 2009