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All posts for the month August, 2016
During last weekend I was playing with a temporary setup of an old Cushcraft 13B2 145MHz yagi that I had lying around. The aim was to try and decode some EME traffic with a simple station setup, but the old 13B2 did not yield any result. Then I decided to build a more efficient antenna by myself.
After considering many design options I decided to build a 12-El.-Yagi EF2012B modified for 50 Ohm-V and optimized by DK7ZB. Here is a preliminary progress report:

VNA results not so good. I suspect that the elevation rotor is to close to the boom. I have to make a new rotor arm to get the rotor out of the way. …………….to be continued
LATEST UPDATE:

Been working on the matching problem all evening and it has nothing to do with the proximity to the rotor.
It’s all about fine tuning this part, the radiator. Trimming the V-dipole length and bending angle did the trick.

Now it looks very close to the EZNEC simulation.
I think there may be potential for better return-loss by some more fine tuning, but it is not going to happen tonight!
MORE PIX.
After over nine years with the DK7ZB 4-Element-28-Ohm-OWA-Yagi with 2,20m-Boom I decided to do an upgrade. During about 7 hours work on August 19, 2016 I dismantled the old 2,2m boomer, recycled a lot of its parts and build a new DK7ZB 6-Element-50-Ohm-Yagi with 6,00m-Boom
Here are some pictures:

Radiator is from the old antenna, but as this is a 50-ohm antenna the old DK7ZB match is replaced with a choke. Here I have 4 ½ turns, ID approx. 50mm. I threw in some surplus ferrite beads to, but I don’t know if they will do any good.
Testing the AE20401 5.8 GHz Frequency Counter / RF Power Meter kit from Ascel-Electronics.

Here testing a dummy-load for return loss @ 2,2GHz generated by the MiniVNA (old style) and the Extender. I measure 29.5 dB which equals about 1.07 in VSWR. Pretty good for this kind of equipment at these frequencies.
I have just ordered one of these pneumatic towers from Mr. Hero Ba’s company PHT in China.
The plan is to put my new 3m EME dish on it, but it may take a while because it is shipped by the sea.