The balun will read near 0 ohms across the antenna input
AFTER the networks on the ant terminal board.
Each leg will also measure near 0 ohms to ground. Its
marked L1 on the schematic. Also test L2 for an open.
Cant tell by pic where yours is BUT they are usually mounted
outside the tuner on the rear. Usually standing up,
sometimes pointed back. Two antenna wires hook to it &
one wire goes into the tuner. In this case it may have been
built into the tuner. I have little experience with pre 60's
sets, they were quickly junked due to no UHF tuner.
BTW you can inject a signal as far as the RF amp GRID
using the center of the coax from an RF source. Be
SURE to use an isolation transformer.
73 Zeno
