Why should someone replace ALL the capacitors on old Tube eq

>"I found a company that made an electrochemical equivalent. It was
housed in a glass cylinder, similar to a common 3AG glass fuse. Inside
was some chemical solution. When a few volts of DC was applied,
electrolytic action caused one end to slowly turn dark, thus
indicating the amount of time that the DC was applied. Sorry, but I
couldn't find the vendor or an equivalent online. When the required
maintenance was performed, the indicator would be replaced as it could
not be reset. "

They used something similar in time lapse video recorders. When those links or whatever went, you are required to replace the video head.

 

On Fri, 3 Feb 2017 22:05:48 -0000, "Benderthe.evilrobot"
<Benderthe.evilrobot@virginmedia.com> wrote:

True. But the reason to replace them ALL is that if you only replace the
one(s) causing a problem, another will fail later, then another still
later. It is much easier to do them all at once than to have to repair
the same unit over and over as they fail one after another. Been there,
done that.

So have I.

I can totally understand what you are saying. However, I am not so sure
about whether I would want to replace all of them in certain parts of a
radio or tv. Here are my thoughts on this.

Lets take my Hallicrafters SX-99 (which I paid for but dont have yet).
That radio is 62 years old. (made in 1955). The seller said it works
fine, (and I was sent a video of it working. I did detect a very slight
hum. (But the video's audio is not the greatest).

So, as soon as I get it and play around with it, I will replace the
electrolytics in the power supply and any other 'lytics (if there are
others). Even if there is no hum, I'd replace them, just based on age.

However, this is a working radio. I ask myself if I really want to
replace all the other (small) caps. [Then I say to myself.... if it
works, dont fix it].

But, I know there are caps in specific circuits more likely to fail,
than in other circuits. Those would be caps connected to the high plate
voltages, especially at the audio output tubes and in the power supply.
I also know that if those short out, they can damage other parts, such
as tubes, resistors, and more. So, I would likely consider replacing
those. I might even consider replacing ALL the caps in the power supply,
and all audio stages, and feel safe doing that, since those caps are not
real critical as far as affecting the overall performance of the radio,
even if the new caps are a little different in their capacitance.

Where I do NOT feel comfortable changing them, are in all RF and IF
stages. The reason is that I know that a cap/coil circuit plays a big
part in the inductance, which affects the radio alignment. I am not
equipped to align the radio coils, and would prefer to leave them alone,
as long as the radio is getting good reception.

I also know that those RF and IF stages do not operate on as high
voltages as do the audio output stages. So, once again, I ask myself,
"Do I really want to risk throwing this radio out of alignment, when
it's working fine, and knowing those caps are not as likely to fail".

I answer myself "Probably not".... (As long as the radio is working
well, dont screw up a good thing.... Then too, if the caps in those
circuits are .05 or .003, I WANT a .05, not a .047. (And it seems that
..05 is no longer made).

So, if I'm satisfied with the performance of this radio, I will replace
the 'lytics regardless. I may also replace all caps AFTER the volume
control, as well as all caps in the power supply. But I will likely NOT
touch any caps in the RF and IF stages.

That's my thinking on all of this right now. Not just for this radio,
but anything..... Now, if it were simply an audio amplifier, I'd likely
replace all the caps, because audio is not all that critical.

 

[Foxs Mercantile]

On 2/4/2017 4:28 AM, oldschool@tubes.com wrote:

Lets take my Hallicrafters SX-99 (which I paid for but don't have
yet). That radio is 62 years old. (made in 1955). The seller said
it works fine, (and I was sent a video of it working. I did detect
a very slight hum. (But the video's audio is not the greatest).

However, this is a working radio. I ask myself if I really want to
replace all the other (small) caps. [Then I say to myself.... if it
works, dont fix it].

To quote a good friend of mine, "There are only two kinds of paper
dielectric capacitors. Those that are bad, and those that are going
to be bad."

Where I do NOT feel comfortable changing them, are in all RF and IF
stages.

The paper caps in the RF and IF stages are bypassing and coupling
capacitors. They need to be changed as well.

I answer myself "Probably not".... (As long as the radio is working
well, don't screw up a good thing.... Then too, if the caps in those
circuits are .05 or .003, I WANT a .05, not a .047. (And it seems
that .05 is no longer made).

"Working" is a subjective thing. Known failure prone parts are just
a time bomb waiting to convert working to not working. And possibly
causing collateral damage when they fail.

Back then, they liked "round numbers." Then the industry standardized
on incremental changes.
As a matter of course, .02 now is .022, .03 is .033 and .05 is .047.
Unless you're playing with tuned audio filters, the difference is
statistically zero.







--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com

 

[Tom Biasi]

On 2/3/2017 8:47 PM, Carter wrote:

On 2/3/2017 5:16 PM, oldschool@tubes.com wrote:
On Fri, 3 Feb 2017 14:08:37 -0500, Nick Danger <nick@third.eye.net
wrote:

On 2/2/2017 9:13 PM, Jim Mueller wrote:

While tube electronics may survive a nuclear war, it is irrelevant.
There won't be any electricity to run them. The power plants are
controlled by computers. Likewise, having your own generator won't
help
either. Many of the new ones are also semiconductor based, and you
won't
be able to get gas to run them since the pumps at the gas station
are run
by electricity which won't be available. Solar cells are also
semiconductors and the inverters used with them also use
semiconductors.
So, if there is a WW3, don't count on ANYTHING electrical working.


Seeing as you brought up WW3, for those of you that may not know it, a
new president singlehandedly advanced the Doomsday Clock by 30 seconds
just last week. Heck of a job!


Yes, precisely why I feel WW3 is a lot closer and more likely than
before. This has nothing to do with my own political party preferences,
or anything else, just the "person" himself (president). However, lets
NOT get into a political discussion on here. Seems like everywhere on
the internet has turned to politics lately. But I still do not feel
safe, with the current state of the world and the current US president.
It seemed a lot safer before, even though the world in general seems a
lot worse than it was in the last few decades.

On 2/3/2017 5:45 PM, Tom Biasi wrote:

It's a very complex issue. Your feelings are just that, yours.

Sorry, personal, individual "feelings" has NOTHING to do with moving the
Doomsday Clock ahead. The whole world might take exception, do ya think?

No

 

[Michael Black]

On Sat, 4 Feb 2017, oldschool@tubes.com wrote:

On Fri, 3 Feb 2017 22:05:48 -0000, "Benderthe.evilrobot"
Benderthe.evilrobot@virginmedia.com> wrote:


True. But the reason to replace them ALL is that if you only replace the
one(s) causing a problem, another will fail later, then another still
later. It is much easier to do them all at once than to have to repair
the same unit over and over as they fail one after another. Been there,
done that.

So have I.


I can totally understand what you are saying. However, I am not so sure
about whether I would want to replace all of them in certain parts of a
radio or tv. Here are my thoughts on this.

Lets take my Hallicrafters SX-99 (which I paid for but dont have yet).
That radio is 62 years old. (made in 1955). The seller said it works
fine, (and I was sent a video of it working. I did detect a very slight
hum. (But the video's audio is not the greatest).

So, as soon as I get it and play around with it, I will replace the
electrolytics in the power supply and any other 'lytics (if there are
others). Even if there is no hum, I'd replace them, just based on age.

However, this is a working radio. I ask myself if I really want to
replace all the other (small) caps. [Then I say to myself.... if it
works, dont fix it].

YOU ask around about the radio. There's a point where capacitors got
better, so the bypass capacitors may not need replacing. With some old
radios, it even happened during the production run, so the specific radio
early in the run may need the capacitors replaced, while later the
capacitors were better and don't need replacing.

SOme specific radios may have some problem that is common, so there'll be
warnings "change this capacitor right away, or else it may take other
things with it". Those may not be that the capacitor is likely to fail,
but that if the capacitor fails, it can do damage.

SOme vintage and/or models of radios suffer because the capacitors inside
the IF transformers go bad over time. Asking about the radio will uncover
that sort of thing.

There were periods when a brand of capacitor came along and got heavy use,
only later it's discovered that they don't have long life. It's those
that are the issue, not "all capacitors".

Where I do NOT feel comfortable changing them, are in all RF and IF
stages. The reason is that I know that a cap/coil circuit plays a big
part in the inductance, which affects the radio alignment. I am not
equipped to align the radio coils, and would prefer to leave them alone,
as long as the radio is getting good reception.

But those low value capacitors are the ones least likely to go bad. Any
capacitor can go bad, but generally this is about old types of capacitors.
Nobody uses paper capacitors anymore, but those were used for audio
coupling and bypass capacitors decades ago, and not only can go bad, but
have limitations based on how paper capacitors are made.

Small value capacitors (like below .001uF) are much more likely to be
ceramic or mica, which generally are okay, at least after a certain point
in time. I don't think those are included in the "change all the
capacitors" except if the radio is really old, or a specific model has
some known problem. Yes, if you change the low value capacitors, you risk
upsetting alignment or calibration, and you may inadvertently shift wiring
that needs to stay where it is.

Any component can go bad. This is about doing most of it all at the same
time because once the radio is apart most of the work is done. And some
capacitors are way more likely to give trouble.

Michael

 

[Michael Black]

On Sat, 4 Feb 2017, analogdial wrote:

oldschool@tubes.com wrote:



I have been reading alot of websites about caps. One of them said the
wax coated ones were less leaky (for moisture), than the old plastic
coated ones. I am referring to the ones called "black beauties", that
have color code bands on them.Yet, back in the early 70's, I knew a guy
who was a retired radio-tv repairman as well as a Ham operator, and he
used to say those "black beauties" were far better than the wax ones.
(as well as the other plastic encased ones with the numbers on them
instead of the color bands).

That's conflicting info. Yet I know that all of them are paper caps.

In my opinion, the Black Beauties with color bands on them are bad news.
Worse than wax dipped paper caps. They crack, leak oil and sometimes
fail hard -- short circuit. As far as I know, all the Black Beauties
with bands are oil filled.

I've seen old 50s magazines with full page ads claiming wonderful things
for the oil filled Black Beauties and it sure seemed like a good idea.
Steel can paper in oil caps are much more reliable than wax dipped
paper caps, why not paper in oil in a plastic tube? Didn't work out
that way, I don't know why. Maybe the plastic outgassed something nasty
into the cap. Some of the paper in oil Black Beauties had standard
numeric marking rather than bands. The paper in oil Black Beauties can
be identified by a soldered lead on one side of the cap.

The second generation Black Beauties were actually OK. They used a
mylar-paper dielectric which held up about as well as all the
advertising promised for the first gen Black Beauties.

But the damage to the reputation of the Black Beauty had been done and
the Orange Drop became Sprague's high end film cap.

And with names like "Black Beauty" and "Orange Drop", who would question
at the time that they weren't good products?

Michael

 

On Sat, 4 Feb 2017 12:10:54 -0500, Michael Black <et472@ncf.ca> wrote:

However, this is a working radio. I ask myself if I really want to
replace all the other (small) caps. [Then I say to myself.... if it
works, dont fix it].

YOU ask around about the radio. There's a point where capacitors got
better, so the bypass capacitors may not need replacing. With some old
radios, it even happened during the production run, so the specific radio
early in the run may need the capacitors replaced, while later the
capacitors were better and don't need replacing.

SOme specific radios may have some problem that is common, so there'll be
warnings "change this capacitor right away, or else it may take other
things with it". Those may not be that the capacitor is likely to fail,
but that if the capacitor fails, it can do damage.

What you are saying here is true for almost everything produced. All
cars have certain common problems specific to the brand/model. Same for
other machinery, and for electronics and even plumbing faucets and so
on...

I would like to find out what problems are specific to the Hallicrafters
SX-99. Where is a good place to look?

SOme vintage and/or models of radios suffer because the capacitors inside
the IF transformers go bad over time. Asking about the radio will uncover
that sort of thing.

There were periods when a brand of capacitor came along and got heavy use,
only later it's discovered that they don't have long life. It's those
that are the issue, not "all capacitors".

I'd be interested in which of the old caps were known to have "issues".
or to fail. Sure, they are all old (in any tube equipmnent), and they
are paper caps, which are no longer made, but I'm sure some brands were
better or worse than others.
And just because newer caps are made from plastics rather than paper,
does not necessarily make them better. Plastics can have issues too. Not
to mention that everything made today is made for a short lifespan.
Considering that, if most of the old paper caps still work, 50, 60, or
70 years later, they obviuosly were not poorly made or a poor design.
I always say, "New does not necessarily mean Better". Today, this is
quite apparent in a lot of things. Old cars far outlast the new ones,
old homes were built better than new ones, and while many will disagree,
I'll take Windows XP, or even Windows 98, (I use both) any day over
Windows 8.x or 10. So, often times, new is NOT better and sometimes it's
worse.

Where I do NOT feel comfortable changing them, are in all RF and IF
stages. The reason is that I know that a cap/coil circuit plays a big
part in the inductance, which affects the radio alignment. I am not
equipped to align the radio coils, and would prefer to leave them alone,
as long as the radio is getting good reception.

But those low value capacitors are the ones least likely to go bad. Any
capacitor can go bad, but generally this is about old types of capacitors.
Nobody uses paper capacitors anymore, but those were used for audio
coupling and bypass capacitors decades ago, and not only can go bad, but
have limitations based on how paper capacitors are made.

One thing I've noticed is that all caps seem to be a lot smaller these
days. (For the same value and voltage). I'm taking a wild guess, when I
figure this is because paper was thicker than the plastic materials used
today. But is this really better? Thinner means that high voltages have
a shorter distance to arc across, causing a short. And which of these
plastics will still be good in 5 years, or 20 or 50 years? Paper caps
seem to have passed the test of time. We wont know if these newer
materials pass the test of time or not, until we get there.

I'm not saying any material is better or worse, because I am only
guessing, but it does appear that old technology, made from things like
steel, wood, brick and other natural materials, are lasting longer than
most plastics. It's like when Chevy started using plastic timing gears
in their engines, which soon proved to fail much sooner than the old
steel ones.

So, are the newer caps really better? I dont know... I can only go with
the advice of those in the repair end of the business, and that is all
based on time. The manufacturers always claim they have a better
product, because they want to make sales, so their words mean nothing.

When I finally do get to recapping this radio, I am still clueless what
type of modern caps to use. In the old days, they were all paper caps,
and it just came down to knowing which manufacturer had a better
reputation. But now there are multiple different plastics in use, which
makes it a lot harder to know what to use.

Small value capacitors (like below .001uF) are much more likely to be
ceramic or mica, which generally are okay, at least after a certain point
in time. I don't think those are included in the "change all the
capacitors" except if the radio is really old, or a specific model has
some known problem. Yes, if you change the low value capacitors, you risk
upsetting alignment or calibration, and you may inadvertently shift wiring
that needs to stay where it is.

Any component can go bad. This is about doing most of it all at the same
time because once the radio is apart most of the work is done. And some
capacitors are way more likely to give trouble.

Michael

 

On Sat, 4 Feb 2017 08:56:42 -0600, Foxs Mercantile <jdangus@att.net>
wrote:

However, this is a working radio. I ask myself if I really want to
replace all the other (small) caps. [Then I say to myself.... if it
works, dont fix it].

To quote a good friend of mine, "There are only two kinds of paper
dielectric capacitors. Those that are bad, and those that are going
to be bad."

Everything will fail some time in the future..... It dont matter what it
is. But will it be tomorrow, or 100 years from now?
So, somtime in the future, every paper cap, as well as every modern cap
is going to fail. But at my age, I only have to think 2 or maybe 3
decades at most into the future. After that, it's someone else's
problem.

 

On Sat, 4 Feb 2017 12:13:30 -0500, Michael Black <et472@ncf.ca> wrote:

And with names like "Black Beauty" and "Orange Drop", who would question
at the time that they weren't good products?

Michael

It could have been PURPLE HAZE! <LOL>

 

[Nick Danger]

On 2/4/2017 12:13 PM, Michael Black wrote:

And with names like "Black Beauty" and "Orange Drop", who would question
at the time that they weren't good products?

Michael

I know from years of personal experience that "Black Beauties" were
*notoriously* bad. However, I always thought the Orange Drops were
pretty good. Not so?

 

On Sat, 4 Feb 2017 14:39:13 -0500, Nick Danger <nick@third.eye.net>
wrote:

On 2/4/2017 12:13 PM, Michael Black wrote:

And with names like "Black Beauty" and "Orange Drop", who would question
at the time that they weren't good products?

Michael

I know from years of personal experience that "Black Beauties" were
*notoriously* bad. However, I always thought the Orange Drops were
pretty good. Not so?

Back in the mid 60's into the 70s, I was told the black beauties were
one of the better caps made. But after reading a lot of websites about
caps, it now appears they have proven to be bad.

On the other hand, back then, and still now, it appears that the orange
drops were highly rated, as well as being some of the most costly.
Except for one poster in this thread, I have never heard anything bad
about them. One of the websites I was reading said they are one of the
brands to consider for recapping, but went on to say that there are
cheaper caps which work just as well.

Back then, I used a lot of orange drops as replacements and I never had
problems with them. I will say that I did not always like the fact that
their wires come out of the bottom, since for non-circuit board
applications, they were a little clumbsy to fit into some places, versus
the tubular caps with wires on the ends.

 

[Benderthe.evilrobot]

"Ralph Mowery" <rmowery28146@earthlink.net> wrote in message
news:MPG.32fed7a04e3c916a989829@news.east.earthlink.net...

In article <4a0a9cli8rpk4puapomqfkn7lpmhmhgq0i@4ax.com>,
oldschool@tubes.com says...



By the way, why are all the caps now rated at some oddball figure.
For example, instead of .05, it's ,047? or instead of .003 it's .0033.

Same for the 'lytics instead of 30mf, they are 33mf and so on.....


A for electrolytic caps, it seems that the newer ones have a much
shorter life than the old ones did.

Nope. The old ones filtered at 120 Hz. The new caps filter at 100 to
300 KHz. Internal dissipation follows frequency.

Can you explain that. I dont understand...
(I would think that a 'lytic in a power supply would only need to filter
at 120hz, or would some filter at 60hz also, depending on the
configuration?

That's
why those old radios still work after 60 or 80 years, while most stuff
made today is in a landfill in less than 10 years.

Todays products are intentionally designed to be difficult to repair
and to only last as long as the warranty period. With the proper
design tools and models, it is possible to predict the life of an
electronic (or mechanical) product. Anything that lasts longer than
the warranty period is deemed to be "over-designed". It is then
redesigned using lower rating or cost components so that everything
blows up at the same time. I've seen it happen.

I totally agree. You cant identify parts anymore and if you can, you
cant get them. Especially ICs.

In the 60s and 70s, I loved to work on electronics. Mostly tube stuff.
The early transistor stuff was not too bad, but as soon as they began
using ICs, I lost interest in working on it.

Now, 40+ years later, I am gtting back into it, but only working on
antique tube stuff, which is what i enjoy. Modern stuff is far too
complicated, far too small (hard to see with my aging eyes too), and
does nothing but frustrate me.

Sure, I have built every computer I have owned (or rebuilt from parts of
thrown away ones). But with computers you just change boards, not
individual components.

I guess going back to the tube stuff makes me feel young again!


Capacitors such as .047 have been around a long time. I don't know why
it is such an odd value as I doubt the extra .003 would be noticable in
the circuits most of them are used in. As the tollorance on most of the
electrolytics are very broad I don't understand the odd values either.

The preferred values were worked out so you can fill the spaces between them
with series/parallel combinations.

 

[Benderthe.evilrobot]

<oldschool@tubes.com> wrote in message
news:1o2a9cp0ormk0jqmmmrm0gcpvnetogkmt8@4ax.com...

On Fri, 3 Feb 2017 21:12:30 -0000, "Benderthe.evilrobot"
Benderthe.evilrobot@virginmedia.com> wrote:


oldschool@tubes.com> wrote in message



And what are these newer ones made from?

I know the mica and ceramic caps are reliable and last almost forever.

I've seen loads of ceramic caps fail - but mostly in TV horizontal scan
sections where the frequency is over 15kHz and high voltage pulse
conditions.

This got worse with ever increasing PC monitor resolutions.

AFAICR; mica caps were pretty reliable - in most of the places I found
them,
they were used for precision and a specific tempco.

I could see them failing in the HV sections of ol CRT televisions and
monitors. Alot of stuff seemed to fail at those high voltages.

I've never seen mica in TV or monitor HV sections - and I can't think of any
advantage from using them for that.

 

[Benderthe.evilrobot]

<oldschool@tubes.com> wrote in message
news:k09b9cd4005htcn0her4bur83hpij5rhgk@4ax.com...

On Fri, 3 Feb 2017 22:05:48 -0000, "Benderthe.evilrobot"
Benderthe.evilrobot@virginmedia.com> wrote:


True. But the reason to replace them ALL is that if you only replace
the
one(s) causing a problem, another will fail later, then another still
later. It is much easier to do them all at once than to have to repair
the same unit over and over as they fail one after another. Been there,
done that.

So have I.


I can totally understand what you are saying. However, I am not so sure
about whether I would want to replace all of them in certain parts of a
radio or tv. Here are my thoughts on this.

Lets take my Hallicrafters SX-99 (which I paid for but dont have yet).
That radio is 62 years old. (made in 1955). The seller said it works
fine, (and I was sent a video of it working. I did detect a very slight
hum. (But the video's audio is not the greatest).

The whole thread is based on a bit of a generalisation - you have to apply a
bit of common sense.

Generally; coupling and decoupling caps close to tubes that run hot are good
candidates.

Caps that may affect tuned circuits tend to be close to small signal tubes
that run much cooler.

 

On 03 Feb 2017 02:13:07 GMT, Jim Mueller <wrongname@nospam.com> wrote:

The old electrolytic capacitors you are talking about don't sound like
the oil filled variety. Indeed, if they are electrolytic, they aren't
oil filled. Oil filled capacitors aren't polarized and many of them are
good today. They were the high quality capacitors used in military and

I always thought those were oil filled, but I see I was wrong. I looked
on the web too, and it appears that most of them were filled with a
boric acid solution, which is not really harmful. They all had the tiny
vent hole in the top, and had a large threaded mounting on the bottom,
which required a sizable nut.

It's been years since I touched one of them. I only remember (vividly)
getting sprayed by one of them many years ago. It was boiling hot and it
hurt like hell. After that incident, I just replaced them before I even
pluggd in anyting that had that type of cap. (Or put a soup can over
them temporarily) They were probably the worst caps ever made.

Here is a pic I found online.
https://antiqueradio.org/art/Midwest18-3621.jpg

 

On Fri, 03 Feb 2017 16:26:47 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

Sigh. My collection of test equipment looks more like a museum than a
working test bench. I also find myself fixing 40+ years old test
equipment as I do fixing radios etc. Looking at the old stuff, all it
does is make me feel old and tired.

Thats all I have too, and some of it has not been used in years and may
likely no longer work. I'm not looking to get heavily into this stuff
anymore. My eyes are not that good anymore either. I just want a project
or two so I have something useful to do indoors during these long cold
midwest winters. In the warm weather I am mostly outdoors working on
building stuff and fixing antique machinery. But in winter it's either
stare at the lousy programming on tv, waste a lot of time reading (a lot
of crap) on the internet, or do something with rewards, which means
restoring some ancient electronics. I'll never fit in with the current
cellphone/facebook crowd.....

---
I overheard a young guy bragging about his new Iphone. I walked up and
told him I had something better, AN EARPHONE!

 

[Nick Danger]

On 2/4/2017 12:13 PM, Michael Black wrote:

And with names like "Black Beauty" and "Orange Drop", who would question
at the time that they weren't good products?

Michael

On Sat, 4 Feb 2017 14:39:13 -0500, Nick Danger <nick@third.eye.net>
wrote:

I know from years of personal experience that "Black Beauties" were
*notoriously* bad. However, I always thought the Orange Drops were
pretty good. Not so?

On 2/4/2017 2:49 PM, oldschool@tubes.com wrote:

Back in the mid 60's into the 70s, I was told the black beauties were
one of the better caps made. But after reading a lot of websites about
caps, it now appears they have proven to be bad.

I discovered that from experience. BBs were notoriously leaky, both
electrically and physically.

On the other hand, back then, and still now, it appears that the orange
drops were highly rated, as well as being some of the most costly.

I never worried about the cost -- I always figured the labor to put in a
good one or to put in junk was the same.

Except for one poster in this thread, I have never heard anything bad
about them.

Ditto and thus the reason for my original question.

One of the websites I was reading said they are one of the
brands to consider for recapping, but went on to say that there are
cheaper caps which work just as well.

Back then, I used a lot of orange drops as replacements and I never had
problems with them.

True in my case too. I also used them along with 88 mh toroidal
telephone loading coils to make Mark / Space filters for radio teletype
decoders --and the orange drops were very stable. (I know, I'm dating
myself in this day and age of software/sound card RTTY decoders).

 

[Foxs Mercantile]

On 2/4/2017 4:58 PM, Nick Danger wrote:

True in my case too. I also used them along with 88 mh toroidal
telephone loading coils to make Mark / Space filters for radio
teletype decoders --and the orange drops were very stable. (I
know, I'm dating myself in this day and age of software/sound
card RTTY decoders).

You and me brother. You and me. ;-)
As a side note, I'm still playing with RTTY and using a real
machine. A Lorenz Lo-15c. ;-)



--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com

 

[Foxs Mercantile]

On 2/4/2017 1:49 PM, oldschool@tubes.com wrote:

Back then, I used a lot of orange drops as replacements and
I never had problems with them. I will say that I did not
always like the fact that their wires come out of the bottom,
since for non-circuit board applications, they were a little
clumsy to fit into some places, versus the tubular caps with
wires on the ends.

They are good parts. A bit over priced however. And yes, radial
leads instead of axial. Can be an issue when you're replacing
axial lead parts.

--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com

 

[Jim Mueller]

On Sat, 04 Feb 2017 15:26:31 -0600, oldschool wrote:

On 03 Feb 2017 02:13:07 GMT, Jim Mueller <wrongname@nospam.com> wrote:

The old electrolytic capacitors you are talking about don't sound like
the oil filled variety. Indeed, if they are electrolytic, they aren't
oil filled. Oil filled capacitors aren't polarized and many of them are
good today. They were the high quality capacitors used in military and


I always thought those were oil filled, but I see I was wrong. I looked
on the web too, and it appears that most of them were filled with a
boric acid solution, which is not really harmful. They all had the tiny
vent hole in the top, and had a large threaded mounting on the bottom,
which required a sizable nut.

It's been years since I touched one of them. I only remember (vividly)
getting sprayed by one of them many years ago. It was boiling hot and it
hurt like hell. After that incident, I just replaced them before I even
pluggd in anyting that had that type of cap. (Or put a soup can over
them temporarily) They were probably the worst caps ever made.

Here is a pic I found online.
https://antiqueradio.org/art/Midwest18-3621.jpg

Progress is incremental. Those capacitors had major advantages over what
came before. The "dry" electrolytics that followed them had further
advantages. That's how things go.

--
Jim Mueller wrongname@nospam.com

To get my real email address, replace wrongname with dadoheadman.
Then replace nospam with fastmail. Lastly, replace com with us.