[NLRS] 1.2 ghx eme

Thu Sep 3 12:27:58 EDT 2020

I thought this was a useful document even though at least 10 yrs old,

http://www.n2re.org/downloads/EME-23CM.pdf

I've wondered for a long time how successful one would be with an array of
helix, one group for uplink, RHCP and one group for downlink, LHCP.
In theory, this could solve the circularity issue, eliminate T/R
switching and be practical, on a tower, for a yard where a dish won't
work.

I see one station in the above document using a single helix for uplink
and another for downlink.  So, still curious.

Chris NØJCF

On Thursday (09/03/2020 at 02:51PM +0000), Jon Platt via NLRS wrote:
> Hi Kirk.  
> I may be two pages ahead of you in the "1296 EME book".   A few summers ago I acquired four used and beat up 12' loopers with their H frame, I refinished them, rebuilt the phasing lines, and have mounted them on my rover rack that I can wheel in and out of my garage on a small cart.  My goal was to see what (if) I could actually hear any 1296 EME signals.  My setup is these 4 loopers, a power divider, DB6NT preamp, Yaesu Az/El rotator driven by an EA4TX USB interface box that is in turn connect to the PC running F1EHN moon tracking software, a DEMI 1296 transverter, my FT897 on 2m using a SignaLink USB for the digital interface.  Most of this stuff I already had ... I did purchase the EA4TX interface box.  A few weeks ago I was successful in seeing the ON0EME beacon that is on 1296.000.  On occasional peaks I could hear CW tones, but they were much to weak for me to copy.  A few days later I was successful in decoding SM5DGX who was calling CQ and was running 400 watts into a 8m dish ... a big gun station.  I was copying him at -16 and again I could occasionally hear his tones.  
> So my first goal was to see if I could actually hear stations with four loopers ... the answer is yes you can, albeit its the big gun stations.   
> Now I am continuing onward to get my transmit power going.  Just 50 watts.  I have to surgically operate on my 1296 transverter to split the RF side and I have to do some system designing for sequencing and to control my latching RF relay, so this is a work in progress with my goal to be ready for the October EME contest and to work a station or two.  Again, I have done all of this using stuff that I already have, with some exceptions.  
> Because circular polarization is used on 1296, a linear polarized antenna system like my loopers surrenders 3 dB (theoretically).  An advantage of going with a dish is that you can build/buy a circular feed.  If I was starting from scratch like you may be I would go with a dish, not loopers.  Also, you need to be able to see the moon without trees .... not through trees.  My lot has lots of trees which is one reason I have my four loopers on a small cart; I can move it around on my driveway to maximize my view to the moon.  I do have a fair treeless EU window that is usable when the moon has high declination.  So check to see if you have a treeless shot .... that is where the antenna needs to go.
> Starting out from scratch, you need a dish, circular feed, dish mount with tracking capability, to be able to see the moon, a good preamp, sequencing, 1296 xmt/rcv, and a digital interface.  Also, some power .... right now I have just 50 watts which is marginal.  Also, the HB9Q logger seems to be the place to see active stations and real time activity, and the Moon-Net reflector for help and discussions.  
> Barry, VE4MA, has been helping me along on my journey and is on this reflector.   
> 73, JonW0ZQ
> 
> -----Original Message-----
> From: Kirk P <inservice2him at hotmail.com>
> To: NLRS <NLRS at mailman.qth.net>
> Sent: Wed, Sep 2, 2020 8:40 pm
> Subject: [NLRS] 1.2 ghx eme
> 
> Good evening,
> I think Id like to try 1.2 EME
> Looking for equipment Id need.
> Antennas...loopers?
> Demi..I run IC-9100 with SDR modification for RX?
> 1.2 unit for 9100?
> Any other input. Appreciated
> Kirk, N0KK
> 
> 
> Sent from Outlook<http://aka.ms/weboutlook>
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-- 
Chris Elmquist