[amsat-bb] Re: Gulf Alpha Antenna Model No.2M 70CM Sat. (DualBandAntenna)
Alan
ve4yz at mts.net
Fri Dec 26 09:44:54 PST 2008
Hi Guy and the group...
Here is Pete's current dual band yagi which I believe you are referring to
http://www.gulfalphaantennas.com/Product%20Page%202M%2070CM%20sat%20yagi.htm
l
As Joe mentioned, the craftsmanship and material quality is first class. I
am also the owner of the older versions shown in the first couple of
pictures here:
http://picasaweb.google.com/ve4yz.alan/VE4YZ#
where I ran a pair of them with M2 matching tees and no mast mount preamps (
but with the internal preamps in the FT847 ) but with AZ and EL control.
This was satisfactory for me for a while and worked well especially on the
SSB sats, FO-29, VO-52, AO-7. On FM AO-52 and SO-50 there were fads due to
lack of polarity control. GO-32 and ISS TX are so strong that polarity
control was not an issue.
However, I eventually moved to abbreviated KLM's ( due to tower limitations
and roof clearance ) with polarization control and Landwehr preamps shown in
the later photos. The improvement was huge! I have the KLM's and HyGain's
full length at 2 other locations and the performance is a little better but
not a huge an improvement as going for no polarity control to the switchable
polarization.
Here... http://www.mts.net/~ve4wsc/photogallery/tour3.htm M2/KLM
And here... http://picasaweb.google.com/WinCube.Winnipeg/GroundStation#
HyGain
The GulfAlphas are in storage in the garage rafts and are ready for use at
Field Day and other events.
At my QTH I think I am an example of what is often heard in ham circles -
invest as much as you can on the antenna, on feedline and preamps. At home
I went from a rotator mounted Arrow to the GulfAlphas to the KLMs over the
course of about 4 years. They all worked. But they all worked differently
:-) Unfortuantely this is a case of $$$ being a big part of the solution.
... Alan
> -----Original Message-----
> From: amsat-bb-bounces at amsat.org
> [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Gary "Joe" Mayfield
> Sent: December 26, 2008 7:28 AM
> To: 'Guy Brauning'; amsat-bb at amsat.org
> Subject: [amsat-bb] Re: Gulf Alpha Antenna Model No.2M 70CM
> Sat. (DualBandAntenna)
>
> Guy,
>
> I have the previous version of the Gulf Alpha dual band.
> We use it at field day every year and it performs well.
> Your idea to add the pre-amp is wise as it is a little short
> for some of the UHF downlink signals.
>
> You may also want to plan for some classic mode J
> de-sense issues which aren't really a factor of the antenna
> as much as a reality of listening on the third harmonic of
> your transmit signal.
>
> On the whole it has been a great antenna, and that
> sucker is built like a battleship. I wish he had a larger
> line of antennas as he builds a VERY solid product. I
> believe Gulf Alpha is a one man shop so there may be some
> lead time as well, but definitely worth the wait!
>
> 73,
> Joe kk0sd
>
> -----Original Message-----
> From: amsat-bb-bounces at amsat.org
> [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Guy Brauning
> Sent: Thursday, December 25, 2008 7:44 PM
> To: amsat-bb at amsat.org
> Subject: [amsat-bb] Gulf Alpha Antenna Model No.2M 70CM Sat. (Dual
> BandAntenna)
>
> Hello and thanks for reading this. I am looking for some
> "Owner Experience"
> before making a decision about buying one of the Gulf Alpha
> dual band satellite antennas. I know the antenna is a
> compromise compared to a pair of circular polarized yagis;
> however, I am looking for a less expensive alternative for a
> basic 2M/70CM base set-up. My only experience with the
> satellites has been with handheld/portable radios (FT-60R and
> FT-817ND) and the Arrow and ELK handheld antennas. My guess
> is that the Gulf Alpha dual band satellite antenna (installed
> above obstructions and with an AZ rotator / low loss feed
> lines / and a 70CM mast mounted pre-amp) would be comparable
> if not considerably better than the handheld Arrow/ELK for FM
> work on AO-51 and SO-51 (for passes at or below 40 degrees
> max elevation) but I would also like to work some of the
> linear sats on SSB/CW and I don't know if the antenna would
> meet that need. (I already have a 2Meter all mode in addition
> to the FT-817 as well as a refurbished CD-44 rotor.) If this
> antenna would support reliable CW/SSB contacts on the linear
> satellites, it would be a good fit. I would install the
> antenna at approximately 25 feet in height, leave it fixed at
> 15 degs elevation using the supplied mast mount, and rotate
> it with a CD-44 rotator. I plan on using LMR-600 coax for
> the 432 run and LMR-400U for the 2 meter run (Total length
> for each run about 30 - 40 feet). I would also use an AR2
> mast mounted 432 preamp and Polyphasers at the shack entry
> with appropriate jumpers (best loss specs vs. needed
> flexibility) from the Polyphasers to the radios. Radios
> would be a Yaesu FT-290R MKII (2 MTR All-Mode) and a Yaesu
> FT-817ND for 432. I'm looking for someone with experience
> using the Gulf Alpha to let me know their opinion of how well
> the antenna might play given my anticipated installation specifics.
>
>
>
>
> Thanks for your help!
>
>
>
> Guy
>
> N3SCR
>
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