[amsat-bb] input power question

[Dave Webb KB1PVH]

160 watt mast mounted http://www.advancedreceiver.com/page10.html

25 watt RF switched http://www.advancedreceiver.com/page7.html

Dave-KB1PVH


Sent from my Galaxy S9

On Sun, Jun 16, 2019, 12:19 PM Ken M via AMSAT-BB <amsat-bb at amsat.org>
wrote:

> Hello Mark,
>
> 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.
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> AMSAT-NA.
> > Not an AMSAT-NA member? Join now to support the amateur satellite
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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
>