Joerg wrote:

wrote:

and here we have a fine group i shall dub "the mu men" or "the
mu-see-ums" ;-))

solid, easy to get along with and sensible, no foolishness with p-layer
punch thru or bonding failures!

and tubes may actually be repaired too, nothing like those flimsy
silicon flakes!

:-))


Tubes are for real men. When they fail, they often do so in a rather
spectacular manner. Molten glass splattering about and all that.


And just what tubes were those? Of the about about 1000 failed tubes that i
have seen well over 95% were just filament / heater failures; and not one
broken envelope except for two mechanical shock victims.

--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â*
--Schiller

Michael A. Terrell wrote:

Joerg wrote:

Tubes are for real men. When they fail, they often do so in a rather
spectacular manner. Molten glass splattering about and all that.


Real men used tubes made with Beryllium Oxide Ceramic, instead of
wimpy glass. Forced air cooling ruled! Arrh! Arrh! Arrh!


Somewhere in my stuff i still have a pair of 4CX600Js. Someday i will want
sockets and "chimneys" for them.
--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â*
--Schiller

joseph2k wrote:

And just what tubes were those? Of the about about 1000 failed tubes that i
have seen well over 95% were just filament / heater failures; and not one
broken envelope except for two mechanical shock victims.



I've seen horizontal output tubes where the glass melted when the
drive failed. It also destroyed the flyback transformer. A few of the
melted tubes had a hole in the glass, while others just softened and
shrank till they were touching the plates. Maybe a half dozen melted
tubes in 30 years.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

joseph2k wrote:

Joerg wrote:


wrote:


and here we have a fine group i shall dub "the mu men" or "the
mu-see-ums" ;-))

solid, easy to get along with and sensible, no foolishness with p-layer
punch thru or bonding failures!

and tubes may actually be repaired too, nothing like those flimsy
silicon flakes!

:-))


Tubes are for real men. When they fail, they often do so in a rather
spectacular manner. Molten glass splattering about and all that.



And just what tubes were those? Of the about about 1000 failed tubes that i
have seen well over 95% were just filament / heater failures; and not one
broken envelope except for two mechanical shock victims.


PL509. Those are European color TV tubes used to drive the flyback
transformer. Similar to the 6KD6, probably. Just taller. There used to
be an odd rule for ham operator that had the highest license class in
Germany. This rule didn't limit max RF out but it placed a cap of 150W
on plate or collector dissipation as per data sheet. The PL509 was rated
30W so you were allowed to have up to five in there. Of course, everyone
knew that 30W was conservative and they were rated for continuous duty.
In SSB you could easily peak to 80W or more. How much more? That was the
white knuckle question. So, in the heat of the game there was the
occasional tube melt-down. Plates creaking, getting red, then bright
red, followed by orange, a wee spot of whitish glow ... KAPOOF!

I have seen PL509 tubes where the glass barely held on but was deformed,
basically sucked snugly onto the plate. They looked like a dog's chew toy.

--
Regards, Joerg

http://www.analogconsultants.com

Michael A. Terrell wrote:

joseph2k wrote:

And just what tubes were those? Of the about about 1000 failed tubes
that i have seen well over 95% were just filament / heater failures; and
not one broken envelope except for two mechanical shock victims.



I've seen horizontal output tubes where the glass melted when the
drive failed. It also destroyed the flyback transformer. A few of the
melted tubes had a hole in the glass, while others just softened and
shrank till they were touching the plates. Maybe a half dozen melted
tubes in 30 years.


Hmmmph. Failed protective circuits or hardware. Fuses should have blown
and circuit breakers tripped before that that happened. They weren't a
Muntz brand were they?
--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â*
--Schiller

Joerg wrote:

joseph2k wrote:

Joerg wrote:


wrote:


and here we have a fine group i shall dub "the mu men" or "the
mu-see-ums" ;-))

solid, easy to get along with and sensible, no foolishness with p-layer
punch thru or bonding failures!

and tubes may actually be repaired too, nothing like those flimsy
silicon flakes!

:-))


Tubes are for real men. When they fail, they often do so in a rather
spectacular manner. Molten glass splattering about and all that.



And just what tubes were those? Of the about about 1000 failed tubes
that i have seen well over 95% were just filament / heater failures; and
not one broken envelope except for two mechanical shock victims.


PL509. Those are European color TV tubes used to drive the flyback
transformer. Similar to the 6KD6, probably. Just taller. There used to
be an odd rule for ham operator that had the highest license class in
Germany. This rule didn't limit max RF out but it placed a cap of 150W
on plate or collector dissipation as per data sheet. The PL509 was rated
30W so you were allowed to have up to five in there. Of course, everyone
knew that 30W was conservative and they were rated for continuous duty.
In SSB you could easily peak to 80W or more. How much more? That was the
white knuckle question. So, in the heat of the game there was the
occasional tube melt-down. Plates creaking, getting red, then bright
red, followed by orange, a wee spot of whitish glow ... KAPOOF!

I have seen PL509 tubes where the glass barely held on but was deformed,
basically sucked snugly onto the plate. They looked like a dog's chew toy.

OK, but even the text of post shows that that the tubes were being
intentionally operated well beyond their ratings. My dad talked about
pushing 6L6s like that, but never seemed to have a meltdown.
--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â*
--Schiller

On Sat, 24 Mar 2007 19:29:51 +0000, joseph2k wrote:
Michael A. Terrell wrote:
joseph2k wrote:

And just what tubes were those? Of the about about 1000 failed tubes
that i have seen well over 95% were just filament / heater failures; and
not one broken envelope except for two mechanical shock victims.

I've seen horizontal output tubes where the glass melted when the
drive failed. It also destroyed the flyback transformer. A few of the
melted tubes had a hole in the glass, while others just softened and
shrank till they were touching the plates. Maybe a half dozen melted
tubes in 30 years.

Hmmmph. Failed protective circuits or hardware. Fuses should have blown
and circuit breakers tripped before that that happened. They weren't a
Muntz brand were they?

Actually, fuses and circuit breakers aren't intended primarily to protect
the equipment itself - they're to keep the overcurrent from burning down
the house (or factory, or whatever).

Cheers!
Rich

joseph2k wrote:

Michael A. Terrell wrote:

joseph2k wrote:

And just what tubes were those? Of the about about 1000 failed tubes
that i have seen well over 95% were just filament / heater failures; and
not one broken envelope except for two mechanical shock victims.



I've seen horizontal output tubes where the glass melted when the
drive failed. It also destroyed the flyback transformer. A few of the
melted tubes had a hole in the glass, while others just softened and
shrank till they were touching the plates. Maybe a half dozen melted
tubes in 30 years.


Hmmmph. Failed protective circuits or hardware. Fuses should have blown
and circuit breakers tripped before that that happened. They weren't a
Muntz brand were they?


No, they were RCa, GE, Zenith, Motorola, Philco, Sylvania, Magnavox,
and a lot of other brands. No one has EVER claimed that the TVs were
well designed. Take the early sold state sets. The horizontal drive
would fail, and put a large DC bias on the deflection yoke, breaking the
the neck of the CRT. The company that made the so called "Safety
capacitor" filed bankruptcy, leaving a number of manufacturers
scrambling to find someone to make a replacement part, and take
responsibility for any damage if their design failed. The "Safety
capacitors went from three leads to four, to improve the chances that
the "Safety capacitor" would open if there was a failure in the
horizontal deflection circuit.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Rich Grise wrote:

On Sat, 24 Mar 2007 19:29:51 +0000, joseph2k wrote:
Michael A. Terrell wrote:
joseph2k wrote:

And just what tubes were those? Of the about about 1000 failed tubes
that i have seen well over 95% were just filament / heater failures;
and not one broken envelope except for two mechanical shock victims.

I've seen horizontal output tubes where the glass melted when the
drive failed. It also destroyed the flyback transformer. A few of the
melted tubes had a hole in the glass, while others just softened and
shrank till they were touching the plates. Maybe a half dozen melted
tubes in 30 years.

Hmmmph. Failed protective circuits or hardware. Fuses should have blown
and circuit breakers tripped before that that happened. They weren't a
Muntz brand were they?

Actually, fuses and circuit breakers aren't intended primarily to protect
the equipment itself - they're to keep the overcurrent from burning down
the house (or factory, or whatever).

Cheers!
Rich
Goodness the breaker panel / fuse panel stuff is for that, i was talking
about the fuses / breakers that are (supposed to be) part of the equipment
itself. It usually has much lower trip / blow ratings. The power to do
that to something like a 6DK6 is quite a lot.
--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â*
--Schiller

Michael A. Terrell wrote:

joseph2k wrote:

Michael A. Terrell wrote:

joseph2k wrote:

And just what tubes were those? Of the about about 1000 failed tubes
that i have seen well over 95% were just filament / heater failures;
and not one broken envelope except for two mechanical shock victims.



I've seen horizontal output tubes where the glass melted when the
drive failed. It also destroyed the flyback transformer. A few of the
melted tubes had a hole in the glass, while others just softened and
shrank till they were touching the plates. Maybe a half dozen melted
tubes in 30 years.


Hmmmph. Failed protective circuits or hardware. Fuses should have blown
and circuit breakers tripped before that that happened. They weren't a
Muntz brand were they?


No, they were RCa, GE, Zenith, Motorola, Philco, Sylvania, Magnavox,
and a lot of other brands.
News to me. But then again "Madman Muntz" _was_ unique. Extreme corner
cutting seems to be the norm today.
No one has EVER claimed that the TVs were
well designed.
Well, properly (safety) designed consumer products are an exception.
Take the early sold state sets. The horizontal drive
would fail, and put a large DC bias on the deflection yoke, breaking the
the neck of the CRT.
Never saw an instance of that either. Maybe it was a good thing that i got
out of the TV repair business as a teen.
The company that made the so called "Safety
capacitor" filed bankruptcy, leaving a number of manufacturers
scrambling to find someone to make a replacement part, and take
responsibility for any damage if their design failed. The "Safety
capacitors went from three leads to four, to improve the chances that
the "Safety capacitor" would open if there was a failure in the
horizontal deflection circuit.
I vaguely remember hearing about that.


Live and learn.
--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â*
--Schiller

joseph2k wrote:

Michael A. Terrell wrote:

joseph2k wrote:

Michael A. Terrell wrote:

joseph2k wrote:

And just what tubes were those? Of the about about 1000 failed tubes
that i have seen well over 95% were just filament / heater failures;
and not one broken envelope except for two mechanical shock victims.



I've seen horizontal output tubes where the glass melted when the
drive failed. It also destroyed the flyback transformer. A few of the
melted tubes had a hole in the glass, while others just softened and
shrank till they were touching the plates. Maybe a half dozen melted
tubes in 30 years.


Hmmmph. Failed protective circuits or hardware. Fuses should have blown
and circuit breakers tripped before that that happened. They weren't a
Muntz brand were they?


No, they were RCa, GE, Zenith, Motorola, Philco, Sylvania, Magnavox,
and a lot of other brands.
News to me. But then again "Madman Muntz" _was_ unique. Extreme corner
cutting seems to be the norm today.
No one has EVER claimed that the TVs were
well designed.
Well, properly (safety) designed consumer products are an exception.
Take the early sold state sets. The horizontal drive
would fail, and put a large DC bias on the deflection yoke, breaking the
the neck of the CRT.
Never saw an instance of that either. Maybe it was a good thing that i got
out of the TV repair business as a teen.
The company that made the so called "Safety
capacitor" filed bankruptcy, leaving a number of manufacturers
scrambling to find someone to make a replacement part, and take
responsibility for any damage if their design failed. The "Safety
capacitors went from three leads to four, to improve the chances that
the "Safety capacitor" would open if there was a failure in the
horizontal deflection circuit.
I vaguely remember hearing about that.


Live and learn.


It nearly put Zenith out of business.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Michael A. Terrell wrote:
joseph2k wrote: the neck of the CRT.
Never saw an instance of that either. Maybe it was a good thing that i got
out of the TV repair business as a teen.
The company that made the so called "Safety
capacitor" filed bankruptcy, leaving a number of manufacturers
scrambling to find someone to make a replacement part, and take
responsibility for any damage if their design failed. The "Safety
capacitors went from three leads to four, to improve the chances that
the "Safety capacitor" would open if there was a failure in the
horizontal deflection circuit.
I vaguely remember hearing about that.

Live and learn.


It nearly put Zenith out of business.

Zenith is in the TV business?

-Chuck

On Tue, 27 Mar 2007 17:33:47 -0400, Chuck Harris wrote:
Michael A. Terrell wrote:
joseph2k wrote: the neck of the CRT.
Never saw an instance of that either. Maybe it was a good thing that i got
out of the TV repair business as a teen.
The company that made the so called "Safety
capacitor" filed bankruptcy, leaving a number of manufacturers
scrambling to find someone to make a replacement part, and take
responsibility for any damage if their design failed. The "Safety
capacitors went from three leads to four, to improve the chances that
the "Safety capacitor" would open if there was a failure in the
horizontal deflection circuit.
I vaguely remember hearing about that.

Live and learn.

It nearly put Zenith out of business.

Zenith is in the TV business?

Apparently:
http://www.zenith.com/index.asp?flash=false

Cheers!
Rich

Chuck Harris wrote:

Michael A. Terrell wrote:
joseph2k wrote: the neck of the CRT.
Never saw an instance of that either. Maybe it was a good thing that i got
out of the TV repair business as a teen.
The company that made the so called "Safety
capacitor" filed bankruptcy, leaving a number of manufacturers
scrambling to find someone to make a replacement part, and take
responsibility for any damage if their design failed. The "Safety
capacitors went from three leads to four, to improve the chances that
the "Safety capacitor" would open if there was a failure in the
horizontal deflection circuit.
I vaguely remember hearing about that.

Live and learn.


It nearly put Zenith out of business.

Zenith is in the TV business?

-Chuck


It was, at the time that the safety capacitor problem cropped up. It
was a US corporation, making most of its electronics in the US, as well.
That was 25 or 30 years ago on the "E" and "F" series of color TV
chassis.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

and the mains lines even began warming the ckt breaker boxes too! ahhhh,
memories!

"joseph2k" wrote in message
t...
Michael A. Terrell wrote:

joseph2k wrote:

And just what tubes were those? Of the about about 1000 failed tubes
that i have seen well over 95% were just filament / heater failures;
and
not one broken envelope except for two mechanical shock victims.



I've seen horizontal output tubes where the glass melted when the
drive failed. It also destroyed the flyback transformer. A few of the
melted tubes had a hole in the glass, while others just softened and
shrank till they were touching the plates. Maybe a half dozen melted
tubes in 30 years.


Hmmmph. Failed protective circuits or hardware. Fuses should have blown
and circuit breakers tripped before that that happened. They weren't a
Muntz brand were they?
--
JosephKK
Gegen dummheit kampfen die Gotter Selbst, vergebens. Â
--Schiller