[Milsurplus] Tuning Units for APR-1 and APR-4

[J. Forster]

Hi,

Does anyone know the differences between the various tuning units for the
APN-1 / APN-4

TN-1
TN-2
YN-3

TN-16
TN-17
TN-18

It doesn't seem to be the motor driven frequency scan, because the 'B'
vertsions of the TN-1/3 have that too.

Thanks,

-John

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