[sdiy] OT: $5 Wards Airline AM/FM radio cum guitar (synth?) a mp (most likely)

[jean-pierre.desrochers at ville.quebec.qc.ca]

A good way I found to test suspicious old devices 
while putting 120vac power is to put
a big 300 watts 120vac bulb
in series with the 120vac power cord.
For example testing a power amp:
At power up the bulb 'pumps' bright 
for a short moment while the big caps
are charging up then the lamp dims low
and get at idle. Now I know the tested power amp
behaves correctly at power up.
I can even test the amp with a 8 ohms load
and a signal. Ok the bulb will glow brighter
increasing my signal output but still
I can figure out the amp circuitry is correct.
But if anything goes wrong inside the
tested device (shorts for instance) the 300w
bulb will let me know. In front of my repair bench
I set some power outlets with TRUE direct 120vac
and 2 separates with the 300w bulb wired
in series with the sockets. So I start testing
my devices on the bulb socket then when
everything is safe I move the power cord
to the real 120vac outlet.
By the way this is very handy for testing
tube amps that have intermittent power pentode
that get inner shorts while getting warm only.
You can see them sparking inside without blowing
a fuse or anything inside the amp circuitry.
You also know which one in a duo or quad pentode
is bad! If this is not a tube problem then the
tube socket related circuit has a problem.

Hope this could help.

Jean-Pierre Desrochers
Quebec City, Canada