[amsat-bb] Re: Any feedback on Mirage KP1-440 Preamp?
kl7uw at acsalaska.net
Fri Apr 18 18:26:36 PDT 2008
Well this happens until you modify your set up to prevent it. Luc is
taking the best approach with the FT-847 (which is simple to do...and
almost easy depending on your skill level with a solder iron and hand
drill). I modified my FT-847 about 4-5 years ago and have no preamp
"smokes" since. Other models of radios may or may not be easy to
modify for separate Rx antenna connector. I have planned to put a
short article on my website showing how to modify the FT-847 (google
DL4MEA for a good webpage showing how).
Instead of pruchasing an expensive RF switched preamp, you could get
a coax relay to place in front of your preamp so that it switches to
bypass in transmit. You need a second relay to place after the
preamp if still using a single coax feedline. Surplus relays can be
found at hamfest for as little as $10.
It is pretty inexpensive to run a dedicated receive coax out of the
preamp to your radio. You can use RG-58 since the preamp gain
offsets any coax losses (assuming a reasonable run of no more than
150-feet). I use better coax on my eme receive line but then I am
trying to squeeze out every 0.1 of a dB for moonbounce. The P144VGA
or P432VGA preamps only cost $79.95. You can replace the Gasfet in
them if you are skilled at surface-mount technique, or maybe find a
local ham that is. The MGF-1302 GasFet costs about $5. ARR does
repair but I do not know what they charge.
73 Ed - KL7UW
At 04:33 AM 4/18/2008, Luc Leblanc wrote:
>On 17 Apr 2008 at 23:13, Mike Ryan wrote:
>Zapped my ARR RX only preamp for the second time out of stupidity.
>Time for a switched model. Cant afford the $200+ amps from SSB and such.
>The Mirage seems attractive. Can anyone share their experiences with
>this model or suggest a differnt affordable preamp? I looked at the
>ARR switched models already. The high powerd mast mount is too much
>$$ and the low power one only handles 25 watts. I could easily smoke
>that one out of stupidity as well (my rig can do 50 watts).
>I beat you with 3 now and one to go. I will make separate RX
>connector on my FT-847 (Just get parts in a recent Hamfest) as per the already
>available mods. No more preamp use until theses mods.
>The last event a hand mike fell on a CW key...Its fun to see how
>things can turn bad so quickly! The next steps transistors change-over in
>this micro tiny container so many hours of pleasure to come...:)
>Luc Leblanc VE2DWE
>WAC BASIC CW PHONE SATELLITE
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