[Hallicrafters] Newbie help requested

[Lorne Bohn]

I'm just new to the tube radio hobby and just beginning to find out what a
great hobby it is.  I have a Hallicrafters 5R30 which I think is a rather
pretty "domestic" Hallicrafters that I would like to restore.  There is a
faint hum when it is turned on and all the tubes light and I have the
schematic for it.  I also have a EICO 625 tube tester but when I went to
test the tubes, it suddenly quit on me.  I suspect the meter itself is
faulty as I already tried to replaced the 6H6 with not success.  Can I test
the tubes using the pin voltages recommended in the schematic?  That's the
first time I've seen a schematic with that information.

This radio doesn't have a power transformer and I noticed that it has two
grounds?  If I am reading the schematic correctly it looks like there is a
chassis ground and a separate (negative?) ground wire running throught the
radio as well.  I haven't seen this method wiring on other radios before
which puzzles me.  Why are these separated?  I assume they must join at some
point but I haven't been able to detected where yet.

I felt even though I can't test the tubes, I should replace the paper
capacitors and the electrolytics (one at a time?).  The schematic shows
three electrolytics--20mfd, 60mfd, and 90mfd.  I have a 22mfd, two 33mfd's
in parallel and a 100mfd that I can replace them with.  It looks like some
reason someone has put a 40mfd in parallel with the 60mfd. which I can't
find in the schematic.   Could this be to help filter a.c. hum?  The
negative wires on the electrolytics are connected to the "wire" ground and
not to the chassis.  Is this just for convenience or is it important to keep
them separated?

I realize this is a rather simple Hallicrafters but it has several other
components I haven't seen in other "domestic" radios.  One is what looks
like a paper capacitor with a coil around it.  I figured I better leave THAT
one alone and not try to replace it. Any advice bringing this neat old radio
back to life would be welcome.  Thanks in advance for your patience.  Best
regards,


Lorne Bohn,