CQWW CW, 29 - 30 November 2008
HB9CZF - SOA 80m HP CW
For a long time I had plans to build a vertical antenna for 80 and 160m on our second tower. Finally one week before the contest we were able to attach the ladders at the side of the tower which simplifies climbing very much. On Friday we started to build the 80m antenna: extend the tower by 10m with a 3m section of army pole and 7m of a Spider-pole. The wire was 26.28m long and for matching I was using the BT1500A tuner (converted to asymmetrical).
Weather conditions on Friday afternoon. The vertical can be seen in the background as well as my father, HB9CZI.
3m army pole and 7m Spider pole attached to the top section of the ex SBB tower.
The vertical wire was pulled away from the existing tower. Therefore, the total length was 26.28m.
The wire was wrapped around the tree ...
... and terminated on the BT1500A (already wrapped up). 20 radial were attached to a aluminium U-section which in turn was connected to the tuner. Although the BT1500A is a symmetrical tuner it can easily converted into asymmetrical setup. Simply connect the left output (seen from the back) to the housing.
On Monday morning I measured the feeding impedance with my K3 and LP-100 Digital Vector Meter
| Radials | R [Ohm] | X [Ohm] |
| 1 | 173 | 174 |
| 2 | 138.3 | 188.5 |
| 3 | 104 | 166.3 |
| 4 | 96.3 | 160 |
| 8 | 87 | 151.4 |
| 12 | 84 | 148.3 |
| 16 | 81.5 | 145.8 |
| 20 | 81 | 145 |
The measurements with 20 radials coincides very much what EZNEC tells. I'm not so sure if the numbers with only a few radials are correct.
Dial readings of the BT1500A (default settings and no power
applied to the relais) were:
L = 127 and C = 31.
During the contest I operated all three nights and also for the first time I was using
DXCluster.
Claimed Score (13h50' operating time)
The 40m detour on Sunday evening was mainly for the 5Band DXCC via LotW. Before the contest 4 band points were still missing.
On 80m I soon figured out that I have a receiving problem. On my K3 with the 400Hz filter deployed I had a noisefloor of S5 - S6 and with the 2.8kHz it was even reading S9. I suspect I have hut-internal QRM. Something to track down. Therefore, I worked S&P almost the entire contest and TX-wise my antenna seems to work. I also compared the existing 41m LW against the vertical on the receiving side. The vertical is definetely better towards North America. JA was easier to copy in the LW and Europe was louder on the LW (as expected). Due to weather we didn't setup two beverages.
Rig: K3 & Henry 3KD
Ant: 26m vertical and 41m LW
Win-Test 3.21.0
Logbook