Thanks for the replies so far, much appreciated.
I can tune the loop diameter size for resonance but there is still a biggish mismatch of impedance. If I tune for minimum SWR then resonance is miles away. I am told not to worry too much about it being none resonant, but tests with the borrowed Yaesu antenna matching unit showed a near perfect 1.02 to 1 SWR, something loop size adjustment and playing with 75 series stubs has failed to approach.
I knocked together a variable cap and a roller inductor, parts of the used home brew ATU I bought at a rally. (I now believe the home brewed ATU is an "Ultimate Transmatch" with a split stator variable of 250pF per section, a roller inductor and a separate single stage variable cap of 250pF, but the wiring is suspect and i think incorrect). If you look at the drawing I found on line, in theory image 2 should be what I need, with the load higher resistance than the source. But that would not match the antenna. I tried connecting the input and outputs in reverse, in effect creating image 1. This was able to generate a near perfect match of 1.03 to 1 at really close to 50 Ohms. I don't understand why this version should match when it's really for matching a load of lower impedance than the source...?
I think I will examine the home brew used transmatch and now I have the details for the "Ultimate Transmatch" I am pretty sure it was based on, rewire it properly and see what it does then.
http://www.arrl.org/files/file/Technology/tis/info/pdf/7007024.pdfBut any other suggestions very welcome. I have a scan of the antenna using the AIM "refer to antenna" option, which is similar to having the analyser connected at the actual antenna feedpoint, if it's of help?