[amsat-bb] input power question
va7kbm at outlook.com
Sun Jun 16 16:17:19 UTC 2019
Picking up on your comment about UHF pre-amps that "can be had for less
than $150 from several manufacturers", could you provide a list or some
suggestions. I haven't searched exhaustively but some of seen are north
of $300 and I would love to find a less expensive, but quality, option.
Thanks & 73, Ken, VA7KBM
On 2019-06-16 6:46 a.m., Mark D. Johns via AMSAT-BB wrote:
> This is a very common issue for newcomers to the linear satellites.
> Almost every pass, there is someone calling CQ over and over again
> with a loud signal, but completely oblivious to the several stations
> trying to answer them.
> Downlinks on the linear satellites, especially on UHF, are MUCH weaker
> than on the FM satellites. Remember that the transmit power of the
> satellite is being distributed across an entire passband that many
> stations are sharing -- unlike FM, where all the power is just on one
> frequency for one station at a time (ideally).
> You are going to need the best, low-loss feedline you can afford for
> UHF, and that feedline needs to be as short as possible. If your
> feedline is more than about 50 feet (or about 15 meters) you are going
> to want to have a pre-amplifier very near the antenna. A good pre-amp,
> with RF switching so that you don't accidentally blow it up by
> transmitting through it, can be had for less than $150 from several
> manufacturers. Or, there are designs around to roll your own, if you
> are good at that sort of thing.
> Good luck, and hope to work you on the linear sats very soon!
> Mark D. Johns
> KØJM / MØGZO / ex-9H3DJ / ex-KØMDJ
> Brooklyn Park, MN USA EN35hd
> "Heaven goes by favor; if it went by merit,
> you would stay out and your dog would go in."
> ---Mark Twain
> On Sun, Jun 16, 2019 at 7:26 AM WB8PFZ via AMSAT-BB <amsat-bb at amsat.org> wrote:
>> I have completed my sat station but am having trouble hearing myself. I have checked cables and antenna ( M2) sat antenna. All seems well with low SWR. I can hear on the 2 meter downlink. How much power is needed on the UHF uplink? Hope to figure this out shortly. This is being done on the SSB sats. Thanks Mike WB8PFZ
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> Sent via AMSAT-BB at 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: https://www.amsat.org/mailman/listinfo/amsat-bb
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