the ranges. In this
case, all good! I
secondaries of the
antenna coils as well,
and they also checked
out. On to the
This radio has
three oscillator coils
total: one on its own
coil form beneath the
chassis, and two
wound on the same
coil form and
mounted up next to
the variable capacitor
on the top. These are
devices, so they're easy to check out.
There will be two sets of lugs with
continuity to each other, but not to
the lugs from the opposite winding.
In this case, all oscillator windings
tested good too.
Next up are the IF transformers.
These cans are mounted to the
chassis, and each has two windings:
a primary and a secondary. It's fairly
straightforward to trace out the
wiring and find two pairs which have
On the first IF transformer, the
secondary has one connection out
the top to the grid cap of the 6D6 IF
amplifier tube. On the second IF
transformer, they're both on the
bottom. After checking continuity on
both, the IF transformers are also
Some more advanced radios
might have tapped IF transformers or
other components hidden inside the
cans, but that's not something you're
likely to find on an entry-level radio
like this one.
Moving on, since this is a
transformerless AC/DC radio, the
only items left to check are the filter
choke, the output transformer, and
the field coil. The filter choke sits on
top of the chassis, with the leads
heading towards the power supply
section. There's only one winding,
and the approximate DC resistance is
given on the schematic. These
tended to have a ±20% tolerance, so
the reading of 345 ohms isn't
indicative of any problems.
May 2015 55
Bare radio chassis with tubes removed.
The other two oscillator coils
sharing a common coil form on
top of the chassis.
Back side of the radio showing