Re: [amsat-bb] RCA/DSS dish feed resources?

[K5OE@xxxxxxx]

Dale,

kf4sir@earthlink.net writes:
> I'm kicking around the idea of trying to set up an AO-40 receiving station 
>  using this dish and my HF rig.

Since you seem to be shopping for bargains, there are several easy ways to 
go, with the cheapest being a surplus MMDS downconverter and a used 
Hamtronics (or equal) downconverter.  For MMDS downconverters, here are a few 
sources to try:
 - Mark N0NSV, http://www.markfossum.com/productindex.html
 - Bob, K5GNA, 
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1241393182 
 - here's another one on eBay, 
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1244911684

They show up all the time on eBay.  I saw an unmodified Drake 2880 with a 
Conifer preamp go a few weeks ago for about $80 for the pair!

The Hamtronics downconverters are only $49 in kit form (I use one to my 
TS-2000 receive-only port).  

Go thru the archives of this reflector and you will find lots of references 
and examples of other people using and experimenting with offset dishes.  
W1GHZ has an online treatise on this subject and Howard, G6LVB just put up 
some pix and audio files of his latest "tinkering":  
http://www.g6lvb.com/60cm.htm

The discussion of feeds is an art form still being defined.  Consensus is a 
helix is a good choice, but what kind of helix?  You will see experiment with 
the G3RUH design, feed horns (coffee cans), and my personal test case, the 
"cup"  see:  http://members.aol.com/k5oe/helix_cup04.jpg

Finally, you will eventually want a preamp (can add it later once you get the 
basic system working).  Stay tuned for an avalanche of preamp options (an 
easy prediction to make right now).  Ready-made preamps such as the 
well-regarded DB6NT design are available from SSB Electronics as well as both 
kits and ready-to-wear from Down East Microwave here in the USA.  I just 
built a DEM 13UNLA kit and while it appears to perform to specs, this is not 
a kit for beginners.  I might write a short article on this particular kit 
under the premise of:  You "Can" Teach An Old Dog New Tricks.  You can see a 
pic of it at:  http://groups.yahoo.com/group/AmsatTech/files/done_18.JPG

Hope all this helps...
73,
Jerry, K5OE
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