"jakdedert" wrote in message
.. .
Scott Dorsey wrote:
wrote:
hi again, tnx for the replies..i did clean all wafer sws
& pots,
didn't clean main tuning cap..have bama prints for
rx..will try
voltage & resistance checks..full alignment sounds like
a good idea..i
have sig gen..1st & 2nd ifs would be difficult because
sig gen calib
not great..i dont think if alignment is my main
prob..but will do all
hf aligns..i'm glad to get back into tubes..its like
restoring a
classic car, but alot cheaper...hi hi. tnx agn..if u
have any more
ideas, pse email me.

Before you touch the alignment, look for leaky paper
caps.
--scott

That's kind of like looking for when Bush is lying...it's
when his lips are moving. How do you know if they're
leaking? They're the paper ones--they all leak...or will.

jak

You need a capacitance bridge to measure the
dissipation factor. The by-pass and decoupling caps in the
HQ-180 appear to be mostly disc ceramic caps. These have
relatively low dissipation factor and are considered quite
reliable but can go bad. Electrolytic caps, mostly used for
power supply filter caps, at least in vacuum tube equipment,
have relatively high dissipation factors when new but mainly
fail when not used for some time. One plate of the capacitor
is s chemical film which depends on the presense of a
voltage to form so if not used for some time the thing
simply stops being a capacitor.
Paper caps can actually be pretty good. If reasonably
well sealed they have long lives. The notorious Black Beauty
caps, as used in Hammarlund SP-600-JX receivers, had a
manufacturing problem which caused them to be short lived.
Actually, they were intended and sold to be long lived high
performance caps and are found in all sorts of very high
quality equipment. I suspect that moisture getting into the
caps is the main cause of failures but they started getting
a bad reputation not long after they began to be used so it
might be something else.
Good paper type caps should have dissipation factors
(at 1 khz) on the order of 0.01 or less and very low leakage
types like ceramic, silver mica, and plastic (polyethylene,
etc.) of perhaps 1/10th of this. Electrolytic caps will have
dissipation factors much larger, however, they really should
be measured with DC on them and some capacitor checkers
allow for this.
My bet about the HQ-180 is that the power supply
filter caps are sick.


--
---
Richard Knoppow
Los Angeles, CA, USA

wrote:
hi guys,
i am restoring an hq180a. been a while since i messed with tubes,
(abt 20 yrs) am in need of a little direction. i checked & replaced
bad tubes, verified b+ v. 2 problems, may be related??? on top band,
very poor reception, & when u adj ant. control, u hit a spot that
causes oscellation or motorboating. prob #2...on top 2 bands, cw sigs
have a raspy note. not t9 at all. it is a high s/n rcvr 6377. kind
of neat, has spinner knobs, noise blanker, & 455 kc if brought out to
rear apron. i guess previous owner did mod, but it sure looks
factory....solder connections, etc.
would appreciate any and all guesses.
tnx, pete, k2iqk

Regarding front panels... Dee W4PNT (Patty and Dee's Marine) does the
180A panel. He's the guy who also does Valiants and Rangers.

http://w4pnt.8k.com

Regards de K3HVG

"K3HVG" wrote in message
. ..
wrote:
hi guys,
i am restoring an hq180a. been a while since i messed with tubes,
(abt 20 yrs) am in need of a little direction. i checked & replaced
bad tubes, verified b+ v. 2 problems, may be related??? on top band,
very poor reception, & when u adj ant. control, u hit a spot that
causes oscellation or motorboating. prob #2...on top 2 bands, cw sigs
have a raspy note. not t9 at all. it is a high s/n rcvr 6377. kind
of neat, has spinner knobs, noise blanker, & 455 kc if brought out to
rear apron. i guess previous owner did mod, but it sure looks
factory....solder connections, etc.
would appreciate any and all guesses.
tnx, pete, k2iqk

Regarding front panels... Dee W4PNT (Patty and Dee's Marine) does the
180A panel. He's the guy who also does Valiants and Rangers.

http://w4pnt.8k.com


This website shows the last update of Sept 2005. At that time
they were not going to do ant more painting.






Regards de K3HVG

Richard Knoppow wrote:
"jakdedert" wrote in message
.. .
Scott Dorsey wrote:
wrote:
hi again, tnx for the replies..i did clean all wafer sws
& pots,
didn't clean main tuning cap..have bama prints for
rx..will try
voltage & resistance checks..full alignment sounds like
a good idea..i
have sig gen..1st & 2nd ifs would be difficult because
sig gen calib
not great..i dont think if alignment is my main
prob..but will do all
hf aligns..i'm glad to get back into tubes..its like
restoring a
classic car, but alot cheaper...hi hi. tnx agn..if u
have any more
ideas, pse email me.
Before you touch the alignment, look for leaky paper
caps.
--scott
That's kind of like looking for when Bush is lying...it's
when his lips are moving. How do you know if they're
leaking? They're the paper ones--they all leak...or will.

jak

You need a capacitance bridge to measure the
dissipation factor. The by-pass and decoupling caps in the
HQ-180 appear to be mostly disc ceramic caps. These have
relatively low dissipation factor and are considered quite
reliable but can go bad. Electrolytic caps, mostly used for
power supply filter caps, at least in vacuum tube equipment,
have relatively high dissipation factors when new but mainly
fail when not used for some time. One plate of the capacitor
is s chemical film which depends on the presense of a
voltage to form so if not used for some time the thing
simply stops being a capacitor.

Good info which explains 'why' old electro's should simply be replaced.

Paper caps can actually be pretty good. If reasonably
well sealed they have long lives. The notorious Black Beauty
caps, as used in Hammarlund SP-600-JX receivers, had a
manufacturing problem which caused them to be short lived.
Actually, they were intended and sold to be long lived high
performance caps and are found in all sorts of very high
quality equipment. I suspect that moisture getting into the
caps is the main cause of failures but they started getting
a bad reputation not long after they began to be used so it
might be something else.

I've read that the paper was not all that high quality...contains acids
which will inevitably break it down. Moisture is the main culprit, but
only leads to breakdown sooner than later. Wax as a sealer was never
going to have as long life as the other parts of the electronics in
which these were installed.

Good paper type caps should have dissipation factors
(at 1 khz) on the order of 0.01 or less and very low leakage
types like ceramic, silver mica, and plastic (polyethylene,
etc.) of perhaps 1/10th of this. Electrolytic caps will have
dissipation factors much larger, however, they really should
be measured with DC on them and some capacitor checkers
allow for this.

Conventional wisdom is that they'll leak sooner or later anyway. Better
to shotgun them and be done with it. The wax will likely melt sooner or
later, anyway.

OTOH, Chuck says there are no paper caps in the 180, so I'd defer to that.

My bet about the HQ-180 is that the power supply
filter caps are sick.

....and should be replaced. If they're not sick now, they could fail in
spectacular (or not) fashion down the line. It's about the easiest
thing to do...replace the filters. If they're not bad now, it's just
one less thing to worry about.

I operate some vintage tube gear in which I've not replaced the filters;
but I realize I'm sitting on a potential time bomb. First sign of a
hum, I'm turning power off...which might be too late. Just because I
don't follow my own advice (all the time) doesn't make it bad advice.

jak

"jakdedert" wrote in message
. ..
Richard Knoppow wrote:
"jakdedert" wrote in message
.. .
Scott Dorsey wrote:
wrote:
hi again, tnx for the replies..i did clean all wafer
sws & pots,
didn't clean main tuning cap..have bama prints for
rx..will try
voltage & resistance checks..full alignment sounds
like a good idea..i
have sig gen..1st & 2nd ifs would be difficult because
sig gen calib
not great..i dont think if alignment is my main
prob..but will do all
hf aligns..i'm glad to get back into tubes..its like
restoring a
classic car, but alot cheaper...hi hi. tnx agn..if u
have any more
ideas, pse email me.
Before you touch the alignment, look for leaky paper
caps.
--scott
That's kind of like looking for when Bush is
lying...it's when his lips are moving. How do you know
if they're leaking? They're the paper ones--they all
leak...or will.

jak

You need a capacitance bridge to measure the
dissipation factor. The by-pass and decoupling caps in
the HQ-180 appear to be mostly disc ceramic caps. These
have relatively low dissipation factor and are considered
quite reliable but can go bad. Electrolytic caps, mostly
used for power supply filter caps, at least in vacuum
tube equipment, have relatively high dissipation factors
when new but mainly fail when not used for some time. One
plate of the capacitor is s chemical film which depends
on the presense of a voltage to form so if not used for
some time the thing simply stops being a capacitor.

Good info which explains 'why' old electro's should simply
be replaced.

Paper caps can actually be pretty good. If
reasonably well sealed they have long lives. The
notorious Black Beauty caps, as used in Hammarlund
SP-600-JX receivers, had a manufacturing problem which
caused them to be short lived. Actually, they were
intended and sold to be long lived high performance caps
and are found in all sorts of very high quality
equipment. I suspect that moisture getting into the caps
is the main cause of failures but they started getting a
bad reputation not long after they began to be used so it
might be something else.

I've read that the paper was not all that high
quality...contains acids which will inevitably break it
down. Moisture is the main culprit, but only leads to
breakdown sooner than later. Wax as a sealer was never
going to have as long life as the other parts of the
electronics in which these were installed.

Good paper type caps should have dissipation
factors (at 1 khz) on the order of 0.01 or less and very
low leakage types like ceramic, silver mica, and plastic
(polyethylene, etc.) of perhaps 1/10th of this.
Electrolytic caps will have dissipation factors much
larger, however, they really should be measured with DC
on them and some capacitor checkers allow for this.

Conventional wisdom is that they'll leak sooner or later
anyway. Better to shotgun them and be done with it. The
wax will likely melt sooner or later, anyway.

OTOH, Chuck says there are no paper caps in the 180, so
I'd defer to that.

My bet about the HQ-180 is that the power supply
filter caps are sick.

...and should be replaced. If they're not sick now, they
could fail in spectacular (or not) fashion down the line.
It's about the easiest thing to do...replace the filters.
If they're not bad now, it's just one less thing to worry
about.

I operate some vintage tube gear in which I've not
replaced the filters; but I realize I'm sitting on a
potential time bomb. First sign of a hum, I'm turning
power off...which might be too late. Just because I don't
follow my own advice (all the time) doesn't make it bad
advice.

jak

Electrolytics can have a very long life. Generally,
they go bad slowly with an attendant drop in supply voltage
and increase in hum. They rarely have catastrophic failures
except after a long period of disuse when they become
non-capacitors. Sometimes they can expode resulting in a bad
smelling mess. This is pretty unusual. The power supply caps
also act to by-pass some signals, especially audio, to
ground. So one symptom of bad filter caps may be audio when
the volume control is all the way down or noise or
distortion.
I would not replace good caps simply beause they are
old. As long as they are being used the film which
constitutes one plate, will stay formed. Occasionally
something will cause a short but, again, thats not too
common.
Paper caps are all over the place. The old oil-filled
ones were quite reliable and of high quality but were large.
Most are high-voltage types. Unfortunately the dielectric
oil used for many years turned out to be a form of PCB which
is a cancer risk. These were sold with names like Pyranol,
Dykanol, etc. Again, if you have some and they are not
leaking, leave them alone. The main virtue of these oils was
that they are not inflamable which was not true of the
mineral and vegetable oils used previously.
Some tubular caps used a wax impregnant as the
dielectric. Some were simply wax covered. Keep in mind that
the latest of these guys is probably getting on toward half
a century so its not surprizing that there are failures.
The Black Beauty caps found in a lot of 1950s equipment
were intended to be deluxe, low leakage, long life types.
For some reason they began to fail after only a few years. I
think an improved version was made because some later
equipment has caps that look the same but don't seem to fail
early. Another type of capacitor was made by the same
company under the name Orange Drop. These shared the same
plastic impregnated paper dielectric but were equipped with
dipped epoxy cases rather than the molded Bakelite cases of
the Black Beauty types. Orange Drop caps seem to be quite
reliable which leads me to think the problem wtih the BBs
was the casing rather than some problem with the impregnant
or paper. Of course, at this late date, I doubt if we will
ever know.
Hammarlund got burned badly with the BB's which had to
be replaced in thousands of military receivers so I think
they avoided them afterward.


--
---
Richard Knoppow
Los Angeles, CA, USA

I just fixed up an HQ-145 of about the same vintage as the HQ-180 and
my canned electrolytics, a triple section capacitor containing the two
power supply filters and an audio capacitor failed the "smoke" test.
I recapped those three caps. I did save the can in case I ever want
to reinstall modern caps inside the can, but that seemed like an awful
lot of work when even the most ardent collectors acknowledge that
capacitor substitution should be done anyway in the interest of
safety. Since small radio parts failed even when new and parts
replacement was a normal activity (that's why there were so many
radio/TV repairment around...where have they gone?) I guess this sort
of restoration isn't quite as anal retensive as restoring Corvettes.

Jon Teske, W3JT

Jon Teske ) writes:
I just fixed up an HQ-145 of about the same vintage as the HQ-180 and
my canned electrolytics, a triple section capacitor containing the two
power supply filters and an audio capacitor failed the "smoke" test.
I recapped those three caps. I did save the can in case I ever want
to reinstall modern caps inside the can, but that seemed like an awful
lot of work when even the most ardent collectors acknowledge that
capacitor substitution should be done anyway in the interest of
safety.

I thought a lot of "recap everything" was based on the assumption
that some would fail, and once you're at it, you might as well do
them all.

This is especially significant in things that would actually classify
as boatanchors, since getting them open can often require quite a bit
of work. Once you've done that to fix that one capacitor embedded way
down in layers of shielding, changing the other capacitors at the time
hardly adds much time to the effort. But if you don't simply change
all the capacitors at that time, you're doomed to going through the
disassembly process at some later point.

It actually seems to be the real collectors that drive the notion
of keeping things intact. They want that original look, so they
will stuff new capacitors in old cases, and print up new paper wrappers
to put on new capacitors when that fits the situation. SOme will even
decide that "keeping it original" is more important than using the thing,
so they don't do anything to it, letting it sit on the shelf unused
rather than do anything to it. But they are collecting, which is different
from someone who wants an old radio to actually use.

Michael VE2BVW

You have made a good start by cleaning the controls and doing some voltage
checks.

I would NOT try to align it at this stage. That's one of the last things
likely to be a serious problem, unless somebody gave the receiver to a child
with a screwdriver.

I would definitely replace the electrolytic capacitors. They are the most
failure-prone components in the radio. Until you are sure that the power
supply is healthy, it's pointless to try diagnosing more specific problems.

In my HQ-180AC, which I restored and then sold a few years ago, I don't
remember seeing any paper or plastic ("bumblebee") capacitors.

All of the small capacitors were ceramic or better, as I recall. Here is a
photo of the chassis when I got the set. It's possible that someone had been
there before me -- it has been a while.

http://www.antiqueradio.org/art/hamm04.jpg

In any case, I would not "shotgun" all of the small capacitors unless they
are paper or plastic. Ceramics can fail, but they are generally much more
reliable.

This article may help you identify different capacitor types:
http://antiqueradio.org/recap.htm .

After you replace the electrolytics, you can try the set again, and if the
problems persist, do more specific troubleshooting.

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Chuck Harris wrote:

I sure am glad you could clarify that. HQ-180A's don't have paper caps.

Are you sure about that? I know the vast majority of caps in there are
ceramic discs, but I recall some paper stuff as well in the detector stage.

The ceramics do fail sometimes too, but not very often. It's a major pain
to find them when they do, though.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

It has been a while since I was in one, but I am pretty sure.
There are some of those paper covered low voltage (3V?) electrolytics
in the audio section, IIRC.

-Chuck

Scott Dorsey wrote:
Chuck Harris wrote:
I sure am glad you could clarify that. HQ-180A's don't have paper caps.

Are you sure about that? I know the vast majority of caps in there are
ceramic discs, but I recall some paper stuff as well in the detector stage.

The ceramics do fail sometimes too, but not very often. It's a major pain
to find them when they do, though.
--scott