My microwave activity concerns the 1296 MHz band and the 10 GHz band. I got into these high frequencies the same way many others have. Starting out on 2 meters, I found it fascinating, and went to the 432 MHz band next. Having a good deal of success, the 1296 band seemed the next logical choice. Wanting to push the limits as far as frequency is concerned, this band represented a new frontier for me.
Because I have never operated any equipment above about 900 MHz, I really did not know what to expect. The radio broadcasters use 900 MHz for their studio to transmiter links, and having some experience on those systems, I knew that these frequencies have a much more "line-of-sight" characteristic. However, the same can be said about 432 MHz as well, so I thought it would be interesting what one can do on 1296 using weak signal, narrow band techniques.
Twelve Ninety Six turned out to be a flop for me. Range was not very good, and I just could not seem to get a decent signal out on this band. I am still not certain what is wrong. The Down East Microwave transverter (built about 10 - 15 years ago seems to function, the antenna appears to be quite sharp, but stations 20 miles away seem to have problems hearing me and I dont hear them as well as I should. I even ordered a 30 wat amplifier, which hasnt helped very much.
When I heard all of the hype over 10 GHz operation, that was the next band I wanted to try. I did a fair amount of reading on the internet about other ham's experiences on this band, and I have come to the conclusion that the only way for me to go is to operate portable so I can take advantage of certain propagation conditions unique to various locations. As I was building my station for this band, the thought had occured that my location may be the cause of my problems that I was having with 1296 MHz in the past. Therefore, when I built my 10 GHz station, I didnt even consider the option of setting up a home station on 10 GHz.
What is the Equipment Diference
Technical wise, building a portable microwave operation is far easier than a home station. Certainly you will need a transverter and an IF rig to actually generate the RF, but beyond that, a portable setup is far easier to implement. For example, on my VHF station, I have about 50 feet of feedline between the transverter or radio and the antenna. With a portable setup, it is easier to mount the antenna very near to the antenna feed, thereby eliminating feedline loss. That point alone will make your microwave station much more successful, as you will not have a long run of lossy feedline in the antenna system.
I live in an area that has a large number of tall trees, most of which are taller than I could even think of clearing with a tall tower. Trees are microwave absorbers. My ground elevation is about average. I have a decent view to the east from my rooftop (provided there are no trees in a particular direction), but to the north and west, I'm lucky if I can see 500 feet in those directions. The idea of operating portable is that one can find a temporary location which is much better than what I can do at home. A nice hilltop with a far away horizon will allow your microwave signal to travel much farther. Being I live near Lake Erie (50 miles north of me), I can take the 1-hour drive to a public park on the lakeshore and take advantage of some interesting propagation that occurs over the water. Although when I operate, my elevation is only 10 - 20 feet over the water, I have worked over 200 KM with only 1/4 watt and a 2 foot diameter dish on 10 GHz.
What does One Need to Get On
I think the best way I can answer this is to give a rundown of my station. Here is what I am running on 10 GHz: 1. A radio that will run 2 meter SSB for use as a laison to make the microwave contact. FT-857D 2. A 2 meter antenna, Horizontally polarized. I have used a homebrew halo or a small yagi. 3. Another 2 meter QRP radio. I use an FT-817ND, but some have used rigs like the Radio Shack HTX-100 and a small transverter to get it operating on 2 meter SSB with a couple milliwatts output to drive the microwave transverter. 4. A microwave transverter. I use the DB6NT transverter which I built as a kit. Down East Microwave makes a very good unit as well. 5. The DB6NT rig requires an RF relay that is rated for 10 GHz. I found such a relay at a local hamfest for about $10. Mine has SMA conectors, that are rated for microwave frequencies. 5. Some small pieces of solid copper hardline with SMA connectors. This cable is typically unjacketed, solid copper, "semirigid" teflon dielectric hardline. The type number is UT-141. Small cable assemblies can be found on ebay for a couple bucks or less. 6. An antenna. A little satellite dish is perfect! Those little 2 foot diameter "Dish Network" style dishes are ideal. 7. You will have to make yourself a feed horn and a coaxial to waveguide transition. All 10 GHz antennas use a waveguide feed, so you will have to build one. There is information on this by visiting the W1GHZ website. Look at his QEX articles as well as his online antenna book.
Here is a photo of my current microwave unit. This photo contains the DEMI 3 Watt amplifier. The Microwave Unit had to be repackaged to fit the new modules.
I will provide some links as time permits that will lead you to the internet's best information on building up a microwave station.
I will also be providing some photos of my station and "action photos" of some of my portable operations.
Stay tuned, and come back often! I have been adding stuff almost daily!