[amsat-bb] Re: Mirage Preamp Setting
Sun Aug 20 17:20:08 PDT 2006
Hello richard- this is Patrick N2OEQ on long island. Sorry our contact on
fo-29 was short. Try to keep your downlink frequency steady by adjusting
your uplink frequency. It was a good contact nontheless.
I recently did a little homework before purchasing a Hamtronics recieve
only preamp. Apparently, adding a preamp increases the dynamic range
possibly introducing unwanted signals but then I thought, Hay!, wouldnt
that make it easier with a 5khz seperated channelized FM radio? Not sure.
Anyway, I seem to be doing OK with rated 18 Bb of gain which is close to
the low setting of your mirage. Are you using seperate antennas, how far
apart, and how long and what type of coax? Best thing I guess is to
experiment. Calculate station gain subtracting and adding gains to help
figure out your setting requirements.
I use for FM satellites; icom 229H @ 50 watts into short vertical for omni
coverage, a homebrew 8 element UHF yagi-uda beam with preamp at antenna
and 25 feet of 9913 coax to FT 8800 dual band rig. I tried using a
diplexer before the preamp but better signals are had without the filter
and good seperation of the antennas. I'm pretty new to this so the other
techies should have a lot more for you.
Thanks for the contact, you sounded strong on fo-29, thanks & 73, pat
On Sun, 20 Aug 2006, Richard Lawn wrote:
> I'm about to mast mount a new Mirage 70cm preamp. It has a high/low setting.
> Any suggestions from the group as I'm sure many of you are using this
> preamp. Is the high setting too much gain? I got tired of forgetting I had
> the ARR preamp on an frying it by sending too much RF into it.
> Richard Lawn, Dean
> College of Performing Arts
> University of the Arts
> Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
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