WA6MEM/AM 10 GHZ Aeronautical Mobile

Here are the pictures from my June, 2001 10 GHz airborne expedition. Although I didn't work as many stations as I would have liked, it still proved to be an interesting experiment and one that I will try again in the near future.


Here are a few details; the aircraft is a 1977 Cessna 182Q, with a constant speed prop and fixed gear based out of the Torrance (KTOA) California airport. The aircraft turns out to be a very stable platform for airborne work. The radio equipment is a Kenwood TR-9130 as the I.F. and a converted M/A-COM unit augmented with a high gain front end pre-amp and a WA6CGR PLL. The transmitted output power at the waveguide connection on the back of the system is about 150-mw pep. To keep the amateur equipment isolated from the aircraft systems, the microwave equipment was powered by a separate, 12 volt, 57 amp hour, gel-cell. The antenna used was an omni directional 13 dbi slotted paddle type. To keep everything mechanically stable with low wind loading at 130 kts airspeed I fed the antenna with small, low loss, coax cable. The cable loss is about 2 dB at 10368 MHz. In addition to the X-band equipment I also used a Yaesu FT-817 for liaison and working stations on 50, 144 and 432 MHz.


Operating on 10 GHz turned out to be very interesting. As we departed the runway the first thing I noticed was the affect that a three bladed prop rotating at 2400 rpm has on received signals. The doppler noted on the N6CA Palos Verdes beacon was unusual even though we were only about four miles from the beacon.

Our flight path took us straight west to the coastline then turned south to follow the Palos Verdes Peninsula over to the radar site located on the east end. We climbed to about 8,500 feet and circled to establish a "fixed" point for other stations to point their antennas. I worked the first station at this location and quickly noted it was tough to stay on frequency with the incredible doppler shift. I worked two more stations from this position then we decided to move east. We chose to establish a position over Saddle Peak in eastern Orange county thinking that it would help ground based stations to find us more quickly. We maintained an altitude of 8,500 feet and slowly circled the peak. I worked three more stations from this location. I learned at this point that is was much easier to work a station if we were flying parallel to the station verses towards or away from the station at 130 kts.

I did hear stations that I could not work and I heard one station in CM98. Unfortunately I did not work 6D2VHF which I thought would be a slam-dunk!

I worked a few stations on 50, 144, and 432 MHz. It was fun to be able to work and hear so many stations and since it was a contest weekend there were plenty to work.

I plan on taking the station aeronautical mobile again and may also include wideband 24 GHz.