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.
On Wed, 08 Jun 2005 09:55:46 -0400, -ex- wrote:
Dirty Q. Tip wrote:
Here's the deal. I've got a Hallicrafters Mark II (2) 6 channel CB
radio. This thing is really old - it still has my grandfather's old
radio ID taped to it (xxx####, x=letter, #=number). Anyhow, I took it
to my friend's house the other day, and wired it up to his existing CB
setup's connections to test it.
once again after I released the mic key. During the time the mic was
keyed (tried it several times, never longer than 1 second), the radio
would squeal. I'm not talking about squeal through the speaker, I
mean the circuit itself squealed/whined.
Any thoughts or ideas?
Bringing a 40-50 year old set back from the dead usually involves a
serious effort of checking/replacing components. If they are (or once
they are) all good then it stands a good chance of working. Any
electrolytic or paper capacitors probably need replacement, maybe even
some of the plastic molded ones from that era (I'm guessing late 60s?).
Check resistor values for drift, clean controls, etc.
Its not expensive to do but if you've never done anything like that
before this might not be the best set to learn on. On the positive
side, you can't hurt it at this stage.
If you want to give it a go, first try to find a schematic for it - ie
road map for an unknown journey. It should be in SAMs which is
available at many big city libraries.
My grandpa was a smart man, and kept all of
the documents on this radio (including the receipt and the business
card of the guy he bought it from, they're in my closet somewhere), so
I've got the schematics and the user's manual for the unit. Problem
is, I know almost nothing about troubleshooting radio equipment.
Hence, I have no clue where to even begin. A starting point and any
additional guideance would be much appreciated.
I openly admit, I'm not certified to work on radios. However, once I
can get this thing to transmit without squeal/whine and receive again,
it's going back on a shelf until I can afford to get a cert'd tech to
inspect and tune it as needed. I don't intend to break any laws by
working on the unit, I just desire to get it operational again. I'm
thinking it could be feedback from a blown final transistor (complete
guess).
I consider what I'm going to do akin to fixing your car before taking
it in for a smog test..... I'm just fixing it, and I'm not going to
operate it until after a tech inspects it (and even then, I might not
operate it, instead opting to keep it as a collector's item and family
memorabilia).
My reasoning for wanting to fix this CB rather than use it as a boat
anchor is that it was my grandpa's radio, and I'd love to restore it
in his honor (might seem lame, but it's a personal thing).
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