Today little success with the new antennas. Had a close pass of FO-29, but saw only faint signals which couldn't be decoded. Then I noticed some CW at 435.780 MHz and caught the following.....
Sunny and 25 degrees today, which is unusual for Chinese New Year. Put the finished yagis onto the tower with help of Tim. It took a little elbow grease but it was done by noon. Disappointment came when I measured the SWR at the antennas: the VHF beam was resonant around 139 MHz and the UHF beam around 441 MHz. Due to my design parameters I already guessed the UHF beam would be a bit high, but at 436 MHz SWR is 2.4:1 and that sucks. At 145 MHz the VHF beam also has a SWR higher than 2:1 which sucks even more, because when I took the last measurements before putting it up it was 1.4:1. It almost seems antenna building is a black art.
Monitored two passes of AO-85 in the afternoon, but both times signals were weak and only one DUV frame was decoded. CAS-4a also came in, although not with stellar signals, but at least I could hear JR6RM in CW calling CQ without much problem (nobody answered him). Before the depression set in I monitored the evening pass of AO-92. It went from south to north and the first 15 degrees of elevation were lousy. But then signals started stronger and they peaked at +30dB over ground noise. Never heard AO-92 that strong and over the whole pass I decoded 80 DUV frames, which is also a record. The last frame was decoded just above 0 degrees elevation and when signals were strong I could even hear the DUV tones humming from my amplifier. So for reception the VHF side is working well and that is a great relief, because I am more into listening than transmitting anyway.
And with 20 meters of coax between the antennas and the shack my rig-on-loan is still happy, because the SWR is around 1.5:1 in the shack. I know this is cheating, but still.....
The final stages: everything but the leads are mounted and most of the nuts and bolts have been covered in PlastiDip.
Lousy weather, so time to do something in the shack for a change. Finished boxing up the impedance stubs and mounted them as well. SWR 1:1 across the 2 meter band, which makes me very happy. Another thing to cross off the list.
The box that will house the impedance transformer.
After a lot of prepping classes I started late working on the antennas. I finished mounting the N-connectors on the alu-box and mounting that on the mast plate. Did some other small adjustments, but then dusk already set in and no time (and light) to take photos. Will have to wait till Monday.
Sunny and warm, so I cut some tubing and finished the vertical 70cm yagi. Unfortunately I ran out of element clamps, so I have to wait for BV6HJ to bring them along when he gets up north.
Luckily I don't go to Taipei often: an hour parking cost me 75 NT dollars, but I did find some LMR-200 coax cable, which was "only" 170 NT dollars per meter. Better than RG-142 which was 380!!! Still, I spent more money than I should have. The shop where I found the LMR-200 is called JMO and I almost forgot about them. They have everything a ham could wish for, as long as that everything is cables and connectors. The owner is very knowledgable and will go out of his way to find the right product for you. It comes at a price, because everything is pricey there. But better have a place where you can find what you need than being without.
Last Saturday night I started with the build of the 70 cm yagi. On Sunday I finished the mast clamp and today I had a productive morning where I drilled and threaded all the holes for the elements (56 in total). I fitted the mast clamp and the remaining element saddles and the result looks like this.....
Will have to go to Taipei tomorrow to get some extra aluminum rod because I don't have enough to finish the build.