would work with the alinco but the plug was moulded on, with only a 2
core cable. I've got another 4 pole minijack plug but the plug body
needs filing down to fit the alinco.
tested the red 'longwire balun' i'd been using for my 12m vertical. I
put 2 resistors in series between the wire terminal and the outside of
the coax socket. These added up to about 490 ohms. Then i used my
antenna analyser to measure the input impedance. At 10mhz it was
showing 36ohms no reactance, so an impedance transform of around 14:1.
I've gone and ordered one of the Alinco microphone adaptors now to convert a 2.5mm and 3.5mm jack to the 4-pole jack.