[Moon-net] EME antenna/amp advice

[Edward R. Cole]

Tony,

I run four 3WL yagis with real QRP...125W at the antennas.  Naturally that
implies using JT65 until I have my 8877 finished which intially will
provide about 550W at the antenna.

Four 2M12's will almost equal my four 2M-xpol20's, except I am able to
switch polarity.  Being on only Horz-pol will occasioanlly leave you with
out eme due to Faraday shift.

Four 5WL will make a lot of difference but may be too big for your
satellite az-el rotator (I'm guessing that may be one of the Yaesu
rotators: B5400 or B5500).  I use a Ham-IV with satellite-TV actuator arm
for elevation.  Its been up since 1998 so guess its good enough.  I did
strip the gear out of a Ham-III in a bad storm.  Whatever you use balance
the weight of the antennas well so that the rotator only needs deal with
wind loading (eme arrays notoriously are rear heavy due to running of coax).

I am using a RFC 2-315 solid-state linear (170W out) and cool it with a
4-inch muffin fan with no problems on JT65 (with out the fan it gets too
hot).  My 103-inch feedline is 7/8-inch Heliax with LMR-400 on either end.

Using four yagis with an "H-frame" one doesnot need to bother with
mon-metallic framework.  If you were to put up a x-yagi array like I have
then the vertical ends need to be fiberglass.

I started out with a 0.5 dBNF ARR preamp (mgf-1302) with good results.  The
preamp must be mounted as close to the antenna as possible, though.  The
Mirage may be OK if it is trully 0.6 dBNF (many mfrs exagerate their specs).

For more ideas check out my website and GL!

At 02:42 PM 8/21/2006 -0400, Tony wrote:
>
>Greetings all:
>
>I'll be setting up a 2 meter EME station this fall and need advise on 
>antennas, amplifires etc.
>
>I already have an Az/El rotator from an existing satellite station and will 
>be replacing antennas, coax and pre-amp.
>
>The antennas I have in mind are M2, 2M12's and I was wondering how these 
>smaller 3WL antennas would compare to 5WL antennas?
>
>The best stacking arrangment for my situation would be horizontal and was 
>wondering about an inexpensive non-metalic crossboom.
>
>For the amplifier, I'm not sure which way to go, but it's obvious I'll need 
>something to withstand the high duty cycle of JT65.
>
>I have an old Mirrage 2m mast-mount pre-amp (0.6db NF) and was thinking of 
>replacing it with a unit that has a better NF.
>
>Any suggestions would be appreciated. Would like to hear from stations 
>running just 2 Yagis and how they perform. Hope to see you all on the air 
>this fall.
>
>73, Tony KT2Q
>
>
>
>
>
>
>_______________________________________________
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http://www.nlsa.com/nets/moon-net-help.html
> 
73's,
Ed - KL7UW  
=========================================
http://www.qsl.net/al7eb - BP40iq 
144-EME: FT-847, mgf-1801/1402, 4xM2-xpol-20, 170w
432-EME: FT-847, mgf-1402, 1x21-ele (18.6 dBi), 60w
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