VHF RDF Loop with Integral Sense Antenna - 2nd Try

Ages ago I tried this loop, and abandoned it due to construction difficulties. I mentioned a few posts back that I have had a second try at it, and this is the write up!

The antenna design is this one here http://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/radcom/1991/06/page29a/ and the details of it are rather sketchy.

Now, one thing I do know, is that my dimensions are not exact! It is intended to have been cut for 145.500MHz, but im pretty sure im at least a couple of cm out in places! The handle is a section of LCF12-50 1/2inch Cellflex, and the loop itself if formed from a length of LDF2-50 3/8th inch Cellflex. The outer jacket, shield copper, and dielectric foam were removed from roughly one half of the loop, with the dielectric foam and outer jacket refitted later. So although it looks like its all one piece of coax, only one half (roughly 1/4λ) still has the outer copper shield, and this forms the 'sense antenna' element.

At the top of the 'handle' the outer shield and the inner conductor of the loop are both soldered to the outer shield of the 'handle'. The other end of the loop solders to the inner conductor. At the bottom of the 'handle' I have soldered on a single hole chassis mount BNC socket. Short 'tags' of the outer shield were left after cutting the parts, in order to solder to.

Detail of the connections to the 'handle'

Where possible, spaces were then filled with off-cuts of dielectric and/or jacket, and taped over. The red tape on the side of the antenna indicates the side with the 'sense' element.

Complete loop, with radio and switched attenuators, ready for testing

I have yet to perform any tests with the loop. Today has been too wet to work outside, and the indoor VHF QRM rules out testing inside. I also need to take some accurate measurements to calculate exactly what frequency it is resonant at.