[Elecraft] Any EME gurus with the XV-144 monitoring?

[Edward R Cole]

Charlie,

EME depends on the abilities of both stations.  For CW-eme on 2m this 
means the sum of antenna gain of both stations should equal 40 dBi, 
and the transmit station runs a minimum of 600w output.  JT65 
effectively increases station performance by roughly 10-dB.  That 
means two stations running 15 dBi antennas and 600w.

The number that you need to calculate is EIRP=Effective Isotropic 
Radiated Power.  15-dBi converts to a power ratio of 
31.6.  EIRP=31.6*600 = 18.97 kW

When I began using JT65 in 2005 I had four 10-element yagis with 
total of 21 dBi and ran 150w.  My EIRP = 125.9*150= 18.88 kW.

I could make contact with a single 10-element yagi station running 
600w, or a station with two 10-element yagis and 300w.  That was 
right down at the bare minimum needed.

So you can trade off less antenna gain with more transmit power or 
vice versa.  I recommend at least two antennas as this helps receive 
other small stations.  With that you can get started with a 150w amp 
if you realize that you will be limited to working larger 
stations.  If you want to work many stations then upgrading to 600w 
will make a huge difference.

I currently run 1300w on the four antenna so my EIRP = 163.67 kW

My website has a lot of info about eme:
http://www.kl7uw.com

73, Ed - KL7UW


-----------------------------------------------------------------
From: "Charlie , W5COV" <cvest at cox.net>
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] Any EME gurus with the XV-144 monitoring?
Message-ID: <53321A35.4000801 at cox.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

I too would like to see more information, especially on how minimal this
station can be and still be able to work a decent amount of contacts.

Many years ago, before the current digital modes, and better, more
precise equipment was being used, I made a handful of EME 2 meter
contacts with a 4 long boom yagi station, using a home brew 500 watt
amplifier.

Not really enough interest these days or enough of a budget to duplicate
that setup, but still have an interest in it .

Charlie, W5COV



73, Ed - KL7UW
http://www.kl7uw.com
     "Kits made by KL7UW"
Dubus Mag business:
     dubususa at gmail.com