[amsat-bb] Re: Barebones L mode uplink

[W1BFN@xxxxxxx]

Mike, thanks very much for your comments re: my Journal article.

If I knew more about Varactors, I might be able to say something like "Just 
use an "XXX-XXX" varactor instead of the 914 diodes, and get 3 watts out for 
10 watts in." The efficiency of the varactor tripler is pegged at 30%. 
Remember, this is Very old tech, and much has been written about it, but 20 
years ago, and further back than that.

The varactor tripler is not really hard to tune up: something like tune for 
maximum current thru the diodes. The next iteration will use a Diamond SX1000 
power/swr meter looking at the top of a half-wave stub at 1268 MHz. It is 
good up to 1300, and measures down to the single watt range. The filter is 
simple cavity, made from brass shim stock and a copper tube, with a brass 
tuning screw - worked first time.

Since P3D is likely to be easy to track, there is no reason I can see why you 
couldn't put a few watts directly into a very high gain antenna to work it.

For the original attempts, I purchased an ICOM PCR1000 recvr, and that was a 
great help - that and a Ramsey 2.8 GHz counter. 

Let me see what I can do about a how-to on the tripler.

Best Regards

Mike
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