New Claimed World and North American Distance Record (61.8km) for the 241GHz Amateur Radio Allocation
I'd like to claim a new DX record for the 241GHz band. We had some rather dry WX here in Virginia and I just couldn't pass up trying to better our own DX record for the band. After shorting out a set of gel cell battery terminals while setting the gear up, I thought we'd never make the QSO! No fire, just a melted 1/4" plug on the cable end of the CW straight key.
The new claimed record is 61.8km and here are some specifics:
Date: Dec 3rd, 2003
W2SZ/4 (WA1ZMS op) FM07fm 37-31-04N 79-30-40W
W4WWQ/4 EM97xe 37-10-49N 80-03-59W
The weather at the time of the QSO at the W2SZ/4 QTH was:
Dew Point: -17C
Relative Humidity: 40%
Station pressure: 876mb
These WX conditions result in a total atmospheric loss of 0.541dB per km.
The weather at the W4WWQ/4 QTH was not logged. But since his elevation was around 600 meters lower than mine, his dew point should have been slightly higher.
I elected to use the W2SZ/4 club callsign for this QSO since several people within the club have helped me with this 241GHz project.
Brian, WA1ZMS/4 op for W2SZ/4
(Please note that this record was set prior to the one announced above. It is here as the station details and other information are relevant. -ed)
Old: New Claimed World and North American Distance Record (34.9km) for the 241GHz Amateur Radio Allocation
The cold and dry WX was calling and we just had to try to break our own World DX record of 11.4km on 241GHz. Here are the specifics of the new claimed 34.9km record:
Detais of the QSO
Date: Nov 14th, 2003
WA1ZMS/4 FM07fm 37-31-19.3N 79-30-14.4W
W4WWQ/4 FM07ji 37-21-14.1N 79-10-13.6W
The weather at the time of the QSO at the WA1ZMS/4 QTH:
Dew Point: -14.4C
Relative Humidity: 42%
Station pressure: 874mb
The WX conditions result in a total atmospheric loss of 0.673dB per km.
The weather at the time of the QSO at the W4WWQ/4 QTH:
Dew Point: -12.2C
Relative Humidity: 31%
Station pressure: 992mb
The WX conditions result in a total atmospheric loss of 0.820dB per km.
The WX conditions being different at each end of the QSO make for some interesting predicted signal margin calculations. The actual measured signal margin on the WA1ZMS/4 end was as high as 13dB. The wind was very strong at both locations and that made for some signal fading.
241GHz Station Details
Here are some details of the 241GHz station as it has been modified for the latest 34.9km DX record.
241GHz QSO Pictures
241GHz QSO Audio
You can listen to a an excerpt from the 61.8km 241GHz QSO (44 sec, 948kB .WAV file).
Description: "W2SZ/4 DE W4WWQ W4WWQ W4WWQ QTH EM97xe"