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New Claimed North American Distance Records for the 241GHz and 322GHz Amateur Radio Allocations

Hi all and happy holidays-

I'd like to claim what I believe are a pair of North American DX records for the upper two amateur radio allocations, that being 241GHz and 322GHz.

At 01:45z on Dec 15th, 2001 a QSO was made between W2SZ/4 (op:WA1ZMS) and WA4RTS/4 on the 322GHz band over a whopping distance of .05Km. Both stations were located in FM07ji.

I know it's not much as far as DX is concerned, but it's on par with DB6NT's 411GHz DX record and is a North American first for the >300GHz band, excluding light.

About an hour later.....

At 02:35z on Dec 15th, 2001 a QSO was made between W2SZ/4 (op:WA1ZMS) located at 37-21-13N 79-10-15W (FM07ji) and WA4RTS/4 located at 37-21-49N 79-10-19W (FM07ji) on 241GHz over a distance of 1.1Km. This is a North American first for the band and a new NA record at the same time.

Both of the about QSOs were made using MCW and wideband FM IF receivers. Power output on 322GHz is estimated to be just a few microwatts while on 241GHz the power is a measured 0.75mW.

The stations are constructed of 80.6GHz free running Gunn oscillators driving GaAs diode triplers (Virginia Diodes, Inc. design) to give output on the 241GHz band. The triplers have a tiny amount of 4th harmonic output which was used for the 322GHz QSO. Both stations use homebrew 6 inch parabolic dishes with hyperbolic sub-reflectors.

It is hoped that the Gunns will be phase locked in the future allowing the use of narrow band modulation thus resulting in better DX.

Photos of the station(s) and .WAV files will be forth coming (updated: Brian has fowarded some pics of one the stations, and an audio file. They are attached below -ed.)

I'd like to also thank Pete, W4WWQ and Geep, WA4RTS for their help with tonight's QSOs.

Brian, WA1ZMS
wa1zms @ arrl.net

241GHz Station

[] [] []

322GHz QSO Audio

You can listen to a 6 second excerpt from the 322GHz QSO (the file is a 1.3MB .WAV file).


6 seconds of audio tone, the "WA4RTS WA4RTS de W2SZ W2SZ W2SZ FM07....."

This is the best sounding audio file I have. It's a raw recording of the wide band audio output of the R-7000 made with a Sony Mini-Disc recorder. It sounds much better if you play it back through an audio equilizer or a cheap pair of headphones to cut out the white noise. The audio tone is around 1200Hz.

Wx at time of QSOs:
Temp 13.8C
R.H 55%
Dew Point 5C

Loss at 241GHz: 2.87dB/km
Loss at 322GHz: 16.9dB/km