Richard,
well here is an easy test to verify function of the pre-amp, if you can access a local UHF repeater. Just open the repeater without any preamps (neither internal nor external), and note the S-Meter. Then do the same with the internal pre-amp and then the external preamp and compare. Use attenuator if necessary. That at least should give you an indication if the preamp if the preamp is working and how it's amplification compares to the internal one. Wouldn't give you much info about the S/N ratio as compared to the internal. Thats best tested on a real bird. But the Mirage being a GeAsFET, it should be quieter.
I recently installed a (ebay'd) mast head Dressler preamp from the 80's, and the difference is _huge_. The downlink signals went from 'just-about-intelligible' to nice and comfortable readable all the way thru the pass.
Andreas - VK4FHAW
--- On Sun, 7/8/11, Richard Lawn rjlawn@gmail.com wrote:
From: Richard Lawn rjlawn@gmail.com Subject: [amsat-bb] Mirage kpc1 problems To: "Amsat BB" amsat-bb@amsat.org Received: Sunday, 7 August, 2011, 10:13 AM
I suspect that one primary reason I'm not hearing the birds as I try several home brew stationary antennas is the used 440 preamp I bought on eBay. It seems like the internal TS-2000 internal is better and that shouldn't be. And just when I'm getting results with these home brewed antennas! Is there any way I can verify failure in the mirage kpc1/440? I too got tired of mistakenly putting too much rf in an old ARR preamp I had and fried it, suggesting that I switch to the mirage amps like those I use at the home qth with good results. Rick W2JAZ _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb