Building a Tape Measure Yagi for LEO Satellite Operations

 The Moxon Yagi which I have been using for my LEO Satellite operations had a Moxon rectangle for VHF and five UHF Yagi elements which were passively coupled to the VHF Moxon driven element. The gain was not that high when I thought of working SO-121 QRP satellite. VU2TEK had good success with his Tape Measure Yagi which motivated me to go for one. But I don't expect the same success as he was operating outdoors, pointing the Tape Measure Yagi in the direction of the satellite pass. I am planning to use only in a mast mounted fashion which will limit its usability for satellite passes to a short period of about 4 minutes. I have chosen the DK7ZB design which I have been looking at for a quite a long time. That design has 5 elements for VHF and 8 elements for UHF with a boom length of about 1.5m.

First step was to get a wooden reaper to use as the boom. Earlier it used to be available in all electrical wiring accessories shops. But now with the usage of PVC channels for wiring, I was finding it difficult to locate one. Finally checked with my electrician, who told me that wooden reapers are now available in mirror shops. I could locate one shop in my locality and from the rather junk like collection of reapers there, I could find this one which was 6 feet long and would suit my purpose.

Next I had to source the tape measure. I was thinking that it will be available as such. But VU2TEK told me that we have to go for the steel tapes from the market which comes in a spring loaded enclosure meant for use in the field and cut it according to over requirements. So this is one of the three which I bought online, as per the suggestions of VU3TBU.

Screws, nuts and bolts needed for fixing the elements, most of them made of stainless steel, were also bought from the mirror shop.

I had a used SO 239 chassis mount type of connector in my store, which I thought I would fix on the boom for connecting the coax. Many had directly connected the driven elements to the coax without any SO 239 in between.

There was surplus RG 213 in my store, which had PL 259 connector at one end and the other side was a cut end. I could either connect it directly or use a PL 259 crimping type of connector there. But I have not made up my mind whether I should really use RG 213 or use my existing antenna cable with PL 259 at both ends, which is a light weight and easy to use HLF 200 cable. So the procurement part is over and now I have to start the painstaking homebrewing project.