DK5OH
VHF Contest May 2017
Hi VHF friends,
it had been a long time that we did not get wet but this time we were lucky throughout the weekend. No rain on top of the Wasserkuppe ! Amazing!
Lessons learmed this weekend:
1. new and optimized rx amplifiers and bandpass filters worked flawlessly and our rx-capabilities are back to normal.
2. a newly acquired spectrumanalyser continously monitors our tx signal
3. even more advanced rx equipment (TR144H + K3) ist not always able to handle high rf levels at certain locations. One of our competitors in line of sight had suffered from increased rx noise
(10dB) when DA0FF had been transmitting. First attempts (crystal filters for rx and tx) to solve the noise problem were a waste of time and money.
But the cure was cheap and easy: A low loss bandpass filter was placed in their rx line and the noise was gone. It seems that TR144h transverters may like bandpass filtering in the rx path if you
have got the same noise problem like they had.
4. The good news. Unbelievable, but there is still really good music equipment on the market. Clever businessmen organized a techno and trance party with 5 discjockeys and 2 dancefloors in
the radome just 50 meters away from our antennas. Admittetly we did not really like that idea because we feared some rf interference......but their first soundcheck in the afternoon revealed
no rf problems at all.
If all neighbours had such a nice equipment the world would be a better place for radio amateurs. The only drawback was some serious NF QRM from with hammering basses from 9pm to 5am. The
noise level in the radome itself must have been hellishly!
The contest itself:
Flat to average conditions dominated the contest and we missed 1000 QSOs by a whisker. Again the longest range QSO was YU7ACO (thank you). This time the guys were located in KN05RD some
1042Km away from us.
Our result on144Mhz: 988 QSOs; 105 locator; 327.467 Points (331 km/QSO)
Similar to our 144Mhz setup we use 4 vertically stacked groups of 4x9 element yagis on 70cm. In contrast to 144Mhz all these antennas are placed in a “star configuration“ on the same tower.
This means that we just have to turn the antennas by 45 degreess to be able to rx and tx into all directions.
The longest range QSO on 70cm was G3CKR/p in IO93AD (870 km).
Our result on 432Mhz: 400 QSOs;78 locator; 123.732 Punkte (309 km/QSO)
MNI TNX for the QSOs
we look forward to working you in July!
73 DL6FBL DK2CX, DK5MX, DK5OH, DL2ZXA, DL4XX, DO9EE
