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zz0468

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The MSP144VDG-160 shown on the link you posted would have a good enough noise figure for EME, but unless you're running WSJT or some similar mode, it's not going to handle the power required when you switch to transmit.


 

kb2vxa

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I can see right from the start we're headed in the wrong direction, FM is not considered a weak signal mode. Space communications are conducted using extremely high gain steerable antenna arrays consisting of several stacked circularly polarized beams rather than extreme transmitter power levels alone, getting a signal up there is only half the battle, getting a usable one down is the other half.

As for weak signal work (CW, SSB and now a few digital modes) still a whole lot of transmitter power is seldom used, usually <100W and typically 50W into a high gain horizontal Yagi specifically designed for performance on the bottom of the band where weak signal modes are found is the preferred method. Then there are those who for whatever reasons "big gun" operation is precluded so they use at least one omni delta loop, preferably 2 or better yet 4 stacked and do pretty well with them.

Now to the major point in all of this, a high gain low noise band specific preamp preferably mast mounted always helps. After all if you can't hear them you can't work them. Oh and almost an afterthought, preamps suck raw eggs on FM. Experience of myself and others has shown all they do is raise the S meter reading and do absolutely nothing to improve the signal to noise ratio which is crucial. A strong signal swamped by noise is as useless as straining to hear a weak one, again if you can't hear them you can't work them.

As an aside, oh now wouldn't you just LOVE to get your hands on the Arecibo PR dish and its 70cM planetary radar mapping array? Don't look now but a couple of the scientists are hams and every once in a while announce when they'll be playing around with it for the benefit of terrestrial hams. Even with the transmitter throttled back to the legal 1500W with all that antenna gain the ERP is still well into the terawatt range, the loudest EME returns on a ham band for sure. I remember a few years ago they did planet bounce, for months the standing joke was "Hey, I just worked Uranus!"

Now shut up, don't even go there! (;->)
 

k9rzz

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Those AR Squared pre-amps are highly regarded. That's a good one. Yeah, watch out if you're running power and by all means use a sequencer. Even with 160 watts, use a sequencer to protect that baby. I've done some 2m SSB work. Lots of fun!
 

prcguy

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Angle Linear is regarded as making the best VHF/UHF preamps, best being great noise figures, very immune to overload and unconditionally stable with any load. They are the industry standard for high performance repeaters and weak signal record holders.

If a preamp will improve weak signal reception on SSB it will have the exact same effect on FM, despite what other posts might lead you to believe.
prcguy
 

MB

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I would only be transmitting at 100 watts max and this preamp is rated for 160 watts so it should handle the power..

The MSP144VDG-160 shown on the link you posted would have a good enough noise figure for EME, but unless you're running WSJT or some similar mode, it's not going to handle the power required when you switch to transmit.
 

k9rzz

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Still, keep a sequencer in mind. Might save you a blown pre-amp, and especially if you tower mount it (where it should go), save you some climbing as well. Just say'n.
 

zz0468

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Still, keep a sequencer in mind. Might save you a blown pre-amp, and especially if you tower mount it (where it should go), save you some climbing as well. Just say'n.
I'll second the motion. A sequencer can be pretty cheap insurance against blown preamps.
 
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