Terry,
I've not researched your model, but if it's a winding on the back
cover it has to be right or the thing won't track worth a damn. I
would wind one experimentally. I've got one on the bench that I use,
separately tuned, with all type of radios - gets more signal in my
basement than a ferrite rod. It's 26 turns in an 11 1/2 x 5 3/4 inch
race-track oval with a 50 to 500 pF tuning cap across it. There's a 2
turn antenna tap on the ground end.
Start with a 12 x 6 inch piece of card, Slot it with an uneven number
of 3/4 inch slots, Start with, say, 33 turns, externally tuned to
check the radio RF, Then connect it to the radio tuning cap and take
turns off until it tracks. Then make one that fits the radio.
Hope this helps.
Cheers,
Roger