[NLRS] Getting onto 5760 MHz

[tosca005 at umn.edu]

Hi, gang. I'm looking for some information to help me get going on 5760 MHz.

I bought Lenny's 5760 transverter system. He sold it to me with a Kenwood 
751-A 2 meter IF radio which is unmodified, and said that there were a 
couple of highly recommended mods that should be made to the radio when 
using it for driving a transverter. I've been Googling around but haven't 
come up with much. If any of you are using this radio for IF, are there any 
specific mods you have found to be useful, and do you have pointers to 
where I can find out about them?

Also, his transverter was one of Down East Microwave's older models with a 
power output of 200 mW. Since I could imagine myself lined up with a bunch 
of you guys all operating at 2 watts, and my turn coming up and not being 
heard at 10 dB lower than the rest, I checked into raising the output 
power. I looked at DB6NT's offerings, and while he has a fantastic array of 
PA's at quite a few different power levels, they are a bit too rich for my 
blood. Especially when I discovered that Down East had a few "cutoff" 
boards from their 2 watt transverters that contain the 2 watt PA and a 
low-noise preamp, for a very reasonable price on their "surplus" page. 
(They are probably sold out of the kits with components, but had a lot of 
the PC boards in stock when I bought mine.) Anyway, I'm looking for someone 
who has actually built one of the 2 watt Down East 5760 transverters, 
because I have a few questions about the assembly process. (I got the 
circuit board and a set of components, and copies of some of the 
transverter assembly manual, but it is not really a "complete kit" or a 
manual that is directed towards the specifics of this semi-kit. I believe 
that the real transverter kit has an aluminum "pallet" which is part 
enclosure, part heat sink, part stabilizer for the thin and flexible 
circuit board, and I am wondering about the configuration of that piece of 
aluminum, since I will need to make up something to mimic it.)

I have a weatherproof aluminum box to use as an enclosure, and my idea is 
to put the T/R relay inside this box along with the built-up board. The box 
would be mounted very close to the dish feed with a short semi-rigid 
SMA-to-SMA jumper between the feedhorn and the box. Then, the actual 
transverter could be mounted a little bit further away, either on the back 
of the dish, or even further, since some attenuation will actually be 
NEEDED between this box and the transverter. The 2 watt PA probably needs 
only 10 to 20 mW of drive, vs about 200 mW available, so I need to lose 
10-13 dB. I'm not sure of how much gain the preamp has, but most of that 
gain can be offset with feedline loss to the transverter while keeping the 
low noise figure of the first gain stage close to the feedhorn and 
simultaneously avoiding overloading the transverter's internal first gain 
stage...

Anyway, I always have more projects in the pipeline than time to work on 
them, so there's no urgent need to get back to me ASAP, but I do hope to 
get this system on the air, at which time I will have equipment for ALL tha 
bands between 50 MHz and 10368 MHz. (And of course, SOMEday I'll even have 
time to turn them on and talk with them! So where was I during Rovermania? 
Right here, at my desk at work, like I usually am on many Saturdays and 
Sundays and nights and holidays and...)

73 de WØJT