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: [email protected] [mailto:[email protected]] On Behalf Of Guy Brauning Sent: Thursday, December 25, 2008 7:44 PM To: [email protected] 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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