Hi folks,
I am in the process of trying to set up a station here and have been researching equipment. While I suspect there will be a fair amount of variety, I am curious to the responses to my question:
Do you use the relatively less expensive “indoor” NON RF switching preamps in an enclosure near the antennas (on the tower) with RF relays and with a sequencer in the shack (do the preamps holdup up on the tower even if protected?) OR
Do you use RF sensing preamps mounted at the tower OR
Both (for those that are extra careful)? I suspect operators that do other VHF/UHF low signal work tend toward sequencers (one for 2 meters and one for 440), i.e. moon bounce, meteor scatter, etc.
Also, I am curious what type/brand/model of RF relays folks use?
As usual, I really appreciate your time. Best, Fred Castello, KF4FC
Sequencers are generally only needed for high power operations over a few hundred watts, which are inappropriate on satellite. I think you'll find most of us use RF switched preamps at the antenna, with a few using them in the shack but with very good feedline.
73, Drew KO4MA
-----Original Message----- From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Fred Castello Sent: Monday, August 01, 2016 8:05 PM To: amsat-bb@amsat.org Subject: [amsat-bb] RF Sensing Preamps, Sequencer, or both?
Hi folks,
I am in the process of trying to set up a station here and have been researching equipment. While I suspect there will be a fair amount of variety, I am curious to the responses to my question:
Do you use the relatively less expensive “indoor” NON RF switching preamps in an enclosure near the antennas (on the tower) with RF relays and with a sequencer in the shack (do the preamps holdup up on the tower even if protected?) OR
Do you use RF sensing preamps mounted at the tower OR
Both (for those that are extra careful)? I suspect operators that do other VHF/UHF low signal work tend toward sequencers (one for 2 meters and one for 440), i.e. moon bounce, meteor scatter, etc.
Also, I am curious what type/brand/model of RF relays folks use?
As usual, I really appreciate your time. Best, Fred Castello, KF4FC
_______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Hi Fred,
With most satellite operation being somewhat weak, a preamp at the antenna is best. I put mine where the flex cable from the antenna couples to the hardline going down to the shack, and use the outdoor models for weather protection. RF sense switching is not needed in theory (most satellite operation is cross-band), but it's good protection for the inevitable inadvertent mis-configuration down in the shack. Also needed if you do terrestrial work.
You didn't ask, but I supply power to the preamps separate from the coax, because the lightning protection devices I have are DC-blocking. Of course, that separate wire should be protected too, and (currently!) isn't. I think if I could have used the rig's internal preamp power, the sequencing of power would be handled automatically.
I believe my 2m preamp is from SSB Electronics. The 70cm one (a ham-swap find) might be from ARR. Both have been up there for years, no problems.
Greg KO6TH
Fred Castello wrote:
Hi folks,
I am in the process of trying to set up a station here and have been researching equipment. While I suspect there will be a fair amount of variety, I am curious to the responses to my question:
Do you use the relatively less expensive “indoor” NON RF switching preamps in an enclosure near the antennas (on the tower) with RF relays and with a sequencer in the shack (do the preamps holdup up on the tower even if protected?) OR
Do you use RF sensing preamps mounted at the tower OR
Both (for those that are extra careful)? I suspect operators that do other VHF/UHF low signal work tend toward sequencers (one for 2 meters and one for 440), i.e. moon bounce, meteor scatter, etc.
Also, I am curious what type/brand/model of RF relays folks use?
As usual, I really appreciate your time. Best, Fred Castello, KF4FC
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (3)
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Andrew Glasbrenner -
Fred Castello -
Greg D