Behold, Dirty Q. Tip scribed on tube chassis:

Update - It's a Hallicrafters CB-5 Mark II.

I have schematics already. I guess it's time for me to exercise that
capacitor meter I blew $200+ on. I can easily test diodes, transistors,
diodes, capacitors, and resistors, and I'm pretty good at soldering as
well, so this should hopefully this will just be a time-consuming
project.

I was wondering if perhaps someone might know what section of the CB
could be causing this (final stage, etc - it's not the main power supply
section). That might get me going the right direction... as is, aside
from removing components and checking their values, I'm stumped.

Hi,

I had two of those babies and I miss them.

The squeal is likely in the T/R switching - the audio isn't getting
cutoff from the speaker and sent to the plate of the 6AQ5 (IIRC) final
tube correctly.

The only caps you'll need to change are electro's and dust off the
variables.

Watch the driver coil assembly - it buggers up and causes touchy tuning.

Enjoy your treasure! :-)

--
Gregg "t3h g33k"
http://geek.scorpiorising.ca
*Ratings are for transistors, tubes have guidelines*

Are you sure you're thinking of the right rig? This critter uses a
pair of "3B4" tubes, and one "3A4" tubes... I checked all three, and
they're all genuine Hallicrafters tubes. And honestly, I haven't even
looked at the scats for it very closely. Driver coil assembly.......
I'll have to locate that and avoid mucking with it.

Just out of curiousity, is there anything "special" this unit can do
if one were to, say, modify an actual functioning CB-5 Mark II in a
manner which it shouldn't necessarily be? I know nothing about these
older tube units other than they can give you a decent lil zap.

Also, I inspected the mic wiring - talk about horrid. I suppose
several years of storage will dry rot some wire insulation. Only the
mic wires are showing this deterioration, and it has been temporarily
rectified. Still, the radio will not transmit nor receive.

I'll be re-capping the electrolytics soon enough, and much to my
surprise, this unit is dust-free on the inside! Well, almost
completely dust-free. I'll also be testing the power transistors
attached to the back - there's four 2N376A's and one 2N555 (all
Motorola) I can check while I'm at it. You might be hearing more
inquiries from me, or you might soon hear that the unit is alive once
again. Who knows. But either way, thank you everyone for responding,
and if you can think of anything else, feel free to pass along the
info.

--Dirty Q-Tip

On Wed, 08 Jun 2005 16:51:23 -0700, Gregg wrote:
Hi,

I had two of those babies and I miss them.

The squeal is likely in the T/R switching - the audio isn't getting
cutoff from the speaker and sent to the plate of the 6AQ5 (IIRC) final
tube correctly.

The only caps you'll need to change are electro's and dust off the
variables.

Watch the driver coil assembly - it buggers up and causes touchy tuning.

Enjoy your treasure! :-)

Behold, Dirty Q. Tip scribed on tube chassis:

Are you sure you're thinking of the right rig?

D'oh!

Brainfart on my end.

CB-3A were the ones I had.

Sorry for the confoosion :-(

--
Gregg "t3h g33k"
http://geek.scorpiorising.ca
*Ratings are for transistors, tubes have guidelines*