The weather was relatively kind to us at the Activity Day on Saturday 4 August – little wind and only a few spots of rain. Here is a brief summary of what happened. We:

• Repaired a broken feed line wire to the 20M Europe LP yagi. Fortunately this fault could be repaired from ground level and did not require the antenna to be lowered.

• Secured the front stabiliser ropes for the 10M Europe/Asia yagi – they had come untied from the supporting stake.

• Resurrected the 160M Northwest sloping dipole. The terminating stake had pulled out of the ground, allowing the antenna to fall to the ground. Fortunately the antenna itself did not appear to have suffered any damage.

• Shortened the length of the 160M Northwest sloping dipole to move the resonant frequency up into the 160M band. This antenna is now resonant around 1815 kHz and exhibits an SWR of less than 1.5:1 from 1800 kHz to 1840 kHz.

• Shortened the length of the 80M Northeast sloping dipole to move the resonant frequency up into the 80M band. This antenna is now resonant around 3510 kHz and exhibits an SWR of less than 1.5:1 from 3500 kHz to 3650 kHz. The SWR rises to around 1.75:1 in the SSB DX window near 3790 kHz.

• Checked the insulation resistance of the coax feeders to the various antennas. In most cases this was acceptable, except for the 10M Europe/Asia yagi which exhibited a relatively low resistance of around 1 Megohm, suggesting that there may be some moisture ingress at the balun termination for this antenna.

• Investigated the reported switching fault on the rhombic but could find no evidence of the fault. We did notice that the SWR was typically higher in the south direction than the north direction. This variation was slightly puzzling considering that the antenna is designed to have the same electrical configuration in each direction. We checked the DC resistance of the open wire feed line at the balun, and found that it was the same in both directions - approximately 650 Ohms. So the observed variation is due to some other form of asymmetry between the two directions.

• Investigated possible locations for new masts to support the future antenna farm at ZL6QH.

• Cut the grass and carried out some weed eating (thanks to ZL2ABC for bringing the weed eater).

• Tidied up the interior of the building, including removing some of the club items from the rooms that are likely to be used by Meridian Energy in the future, and checking the smoke alarms and first aid kit.

• Dismantled some of the seized and rusted rigging hardware in the workshop area.

• Noted that the protruding anchor pipes for the stays on the VHF/UHF mast had been cut back to ground level by ZL2AOV in the previous week.

In addition to the above we also spent some time checking out the DX on 20M. Todd ZL2SP made a number of solid QSOs with various American stations.

Thanks to Brian ZL1AZE, ZL2TTS, ZL2SP, ZL2AOH, ZL2ACG, ZL2AOV and ZL2ABC (along with Pam) who came out for the day. Apologies were noted from ZL2AMI, ZL2CA, ZL2BSJ and ZL2BCW.

ABOVE: The 42 metre tall anemometer mast supporting the sloping dipoles for 160M and 80M, and the LF longwire.

ABOVE: A shot of the famous ZL6QH 20M 5 element yagi antennas.

Posted by ZL1AZE on August 04, 2007