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:
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
73 . . . Steve, WB8IMY
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,
> > 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
Are there any satellites on 2.4 gig so I can check out my old AO-40 dish.
Minot, North Dakota
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.
> 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:
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.
Mobile rigs -
Base rigs -
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--- 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.
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
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
Disagree: I learn....
Pulling for P3E...
> 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...
> 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