On Tue, 3 Jun 2008 15:04:11 UTC, Don Bowey wrote:

On 6/3/08 6:01 AM, in article BJ4mQCBKg9HM-pn2-Bzcrp6NzzYDu@localhost,
"Count Floyd" wrote:

On Tue, 3 Jun 2008 12:47:16 UTC, "COLIN LAMB"
wrote:

Find something else that is broken and needs fixing.

You have a problem - you do not have enough radios that need repair. In
short, you have not done your part to rescue old radios.

Once you have a pile of old radios that do not work, because someone twisted
all the if adjustments until they failed, or used Windex to clean all the
lettering off the dial, you will not have enough time to recap a radio that
is working fine.

In fact, you will not even have room on your bench for a working radio, nor
have time to enjoy them.

Colin K7FM
What the hell are you talking about? I have two old radios that I
recapped: an S-38 and an HE-10. I was told by several boatanchor
owners that this particular Hammarlund would not need a recap as most
of them were ceramic disk with no black beauties. What are you on?
This sounds like some rant against the man? I just wanted good radio
advice!


You also need to examine your sense of humor level. It appear to be low.
I have a great sense of humor at the appropriate time, not when asking
a question and getting the old "USENET" rant. I expected more out of
him, and I was wrong.

I have heard that there are very few electrolytic capacitors in this
machine, as most of them are ceramic disk. The only ones are in a can
on the chassis. If the radio is working well as original, would it be
better to just leave well enough alone? I always try to live by the
maxim: If it ain't broke.....
Thanks,
Bob Grimes

In my experience, old electrolytic capacitors seldom get shorted; they rather
become an open circuit. But when this occurs, you will hear hum in the speaker.

In Italy there is an old saying that I'll try to translate in English (wow, I
was even able to preserve the rhyme):

"if it works and does not go off the rails
do not touch or it surely fails"

As to the issue whether the other capacitors are all ceramic, I am sorry I
cannot help you as I do not know the HQ-145. But I spare you another silly
answer in addition to the many you have already received.

73

Tony I0JX

On Tue, 3 Jun 2008, Count Floyd wrote:

I have heard that there are very few electrolytic capacitors in this
machine, as most of them are ceramic disk. The only ones are in a can
on the chassis. If the radio is working well as original, would it be
better to just leave well enough alone? I always try to live by the
maxim: If it ain't broke.....
Thanks,

Of course, there were never many electrolytic capacitors in tube
equipment. In the power supply, and bypassing the cathodes of the
audio stages, and maybe at some point to bypass the B+ line close
to the audio output stage.

They weren't common because they weren't needed. Since tubes are
high impedance, large value capacitors weren't needed much, and
hence no shift to electrolytics.

Solid state equipment uses a whole lot more electrolytics because
of their low impedance operation, so you need large value capacitors
for coupling and bypassing. Electrolytics are the only reasonable
way to get those larger values.

All the talk of recapping old radios is basically due to old capacitors.
Badly designed capacitors at the time, or simply the best at the time,
end up aging badly. The capacitors were fine at the time, it's just
few gave much thought to the equipment being used decades past their
prime. So decades later, those low value capacitors often need replacing
because they just don't work properly nowadays. So you get bad bypassing
at RF, and you get weak or non-existent audio because the coupling
capacitors have gone.

Replacing an electrolytic in the power supply is hardly "recapping", it's
repair. "Recapping" is when someone feels they should replace all
the capacitors, or actually needs to replace a specific capacitor. And
then once you've done one, it often makes sense to do the whole lot,
especially if it requires a complicated disassembly. IN some cases
capacitors known to go bad over the decades were used, so it's worth
replacing all of them because they will go bad eventually, or enough
have gone bad that it's hard to get a handle on where the exact problem
lies, and replacing the capacitors gets that variable out of the way.

Michael VE2BVW

On Tue, 3 Jun 2008 20:02:50 UTC, "Antonio Vernucci"
wrote:

I have heard that there are very few electrolytic capacitors in this
machine, as most of them are ceramic disk. The only ones are in a can
on the chassis. If the radio is working well as original, would it be
better to just leave well enough alone? I always try to live by the
maxim: If it ain't broke.....
Thanks,
Bob Grimes

In my experience, old electrolytic capacitors seldom get shorted; they rather
become an open circuit. But when this occurs, you will hear hum in the speaker.

In Italy there is an old saying that I'll try to translate in English (wow, I
was even able to preserve the rhyme):

"if it works and does not go off the rails
do not touch or it surely fails"

As to the issue whether the other capacitors are all ceramic, I am sorry I
cannot help you as I do not know the HQ-145. But I spare you another silly
answer in addition to the many you have already received.

73

Tony I0JX
Thank you Tony, that is my brother's name BTW, for your answer. I
appreciate courtesy as I try to give it to others when they ask for my
opinion.

On Tue, 3 Jun 2008 20:29:05 UTC, Michael Black wrote:

On Tue, 3 Jun 2008, Count Floyd wrote:

I have heard that there are very few electrolytic capacitors in this
machine, as most of them are ceramic disk. The only ones are in a can
on the chassis. If the radio is working well as original, would it be
better to just leave well enough alone? I always try to live by the
maxim: If it ain't broke.....
Thanks,

Of course, there were never many electrolytic capacitors in tube
equipment. In the power supply, and bypassing the cathodes of the
audio stages, and maybe at some point to bypass the B+ line close
to the audio output stage.

They weren't common because they weren't needed. Since tubes are
high impedance, large value capacitors weren't needed much, and
hence no shift to electrolytics.

Solid state equipment uses a whole lot more electrolytics because
of their low impedance operation, so you need large value capacitors
for coupling and bypassing. Electrolytics are the only reasonable
way to get those larger values.

All the talk of recapping old radios is basically due to old capacitors.
Badly designed capacitors at the time, or simply the best at the time,
end up aging badly. The capacitors were fine at the time, it's just
few gave much thought to the equipment being used decades past their
prime. So decades later, those low value capacitors often need replacing
because they just don't work properly nowadays. So you get bad bypassing
at RF, and you get weak or non-existent audio because the coupling
capacitors have gone.

Replacing an electrolytic in the power supply is hardly "recapping", it's
repair. "Recapping" is when someone feels they should replace all
the capacitors, or actually needs to replace a specific capacitor. And
then once you've done one, it often makes sense to do the whole lot,
especially if it requires a complicated disassembly. IN some cases
capacitors known to go bad over the decades were used, so it's worth
replacing all of them because they will go bad eventually, or enough
have gone bad that it's hard to get a handle on where the exact problem
lies, and replacing the capacitors gets that variable out of the way.

Michael VE2BVW
Michael, thank you for the very informative and detailed answer. I
always thought the opposite, that older radios had many capacitors
that needed replacement, my little S-38 had about 10 that had to be
replaced! My Lafayette HE-10, not so many.
Again, thank you for the courteous and very helpful answer.

"Count Floyd" wrote in message
news:BJ4mQCBKg9HM-pn2-kdlcYKcmzOkn@localhost...

Count..

Whatever you do, please consider fusing that
chassis! The HQ-145
has no line fuse, and that is a must to protect the
power transformer!

The electrolytic is your call, chances are it will be
okay, or it may fail open. But, if fails shorted,
you will likely lose the rectifier tube in the process,
and maybe the transformer if the fuse isn't quick
enough.

By the way, the biggest problem in my HQ-145 was
internal shorts in a few of the IF transformers.
A few of the fixed mica caps developed leakage
paths to the transformer shells, shorted to
ground, took a few resistors, and caused a big
restoration headache since the plastic coils fell
apart when touched

Pete

On Tue, 3 Jun 2008 21:59:19 UTC, "Tio Pedro"
wrote:


"Count Floyd" wrote in message
news:BJ4mQCBKg9HM-pn2-kdlcYKcmzOkn@localhost...

Count..

Whatever you do, please consider fusing that
chassis! The HQ-145
has no line fuse, and that is a must to protect the
power transformer!

The electrolytic is your call, chances are it will be
okay, or it may fail open. But, if fails shorted,
you will likely lose the rectifier tube in the process,
and maybe the transformer if the fuse isn't quick
enough.

By the way, the biggest problem in my HQ-145 was
internal shorts in a few of the IF transformers.
A few of the fixed mica caps developed leakage
paths to the transformer shells, shorted to
ground, took a few resistors, and caused a big
restoration headache since the plastic coils fell
apart when touched

Pete
Pete,
That sounds like a real horror story! How do I fuse the chassis or
put in and inline fuse. As electrical work goes, I depend on some
older hams who know how to solder. I hope that this HQ-145 is in good
shape, the gentleman who is giving it to me says it plays well, no
problems. I hope that there are not the problems that you described!

In your original post, you claimed:

"If the radio is working well as original, would it be
better to just leave well enough alone? I always try to live by the
maxim: If it ain't broke....."

My light hearted reply was simply trying to justify your continuing to
follow the maxim you claimed to live by.

Moreover, a prior post you made requested information on someone who could
recap the HQ-145. That implied that you were not able to do the work
yourself. So, my post gave you a reason to save your money or save you from
attempting to do something you were not able to do.

And, if you did not have a chip on your shoulder, you would have noted that
my reply contained a bit of envy that you could be worried about such rather
trivial matters. Most real boatanchor collectors can barely stay above
water with things that they consider more pressing. We inherit broken
radios and some literally show up at our door. Others, we feel sorry for
when we see them at a swap meet under a table.

The fact is that you were worrying about the wrong components. Ceramic
capacitors are going to be closer to specified tlerance than the carbon
composition resistors. So, if you are going to change out all the ceramic
capacitors, you will want to change out all the carbon composition
resistors. Seems like a lot of work for an HQ-145.

If your feelings were hurt, it was not intended.

Colin K7FM

Count

Have the gent who is working on the radio add a fuse
in series with the off/on switch on the AC line.
A 1 amp fuse should do it.

My HQ145 had the IF problem when it was given to
me. I suspect only a few ever have the problem. But,
that's why mine was "free" when I got it! If yours
plays, it is probably okay.

Pete

Replacing an electrolytic in the power supply is hardly "recapping", it's
repair. "Recapping" is when someone feels they should replace all
the capacitors, or actually needs to replace a specific capacitor. And
then once you've done one, it often makes sense to do the whole lot,
especially if it requires a complicated disassembly. IN some cases capacitors
known to go bad over the decades were used, so it's worth
replacing all of them because they will go bad eventually, or enough
have gone bad that it's hard to get a handle on where the exact problem
lies, and replacing the capacitors gets that variable out of the way.

Fully agreed.

However the bare minumum one should do is to replace the paper capacitors
located on the high impedance points", that is the plate-to grid coupling
capacitors and those on the AGC line.

In my experience main problem of old paper caqpacitors is not the loss of
by-passing properties, but the birth of a non-negligible reeistance (1 to
several Mohms) in parallel with capacitance. In some cases such resistance does
not create problems (e.g. screen bypassing), but it does when the capacitor is
placed on a high impedance points.

73

Tony I0JX