Rank Arena Widescreen CRT

Michael A. Terrell wrote:
<snip>

Have you ever used a water cooled
power tetrode with two, 1000 A, 1.5 volt filaments? The AC had to match
to a few millivolts, or it would modulate the output current. You had to
use an open ended wrench to adjust the length of a copper buss bar. Its
resistance went up as it was stretched. This was in the RCA TTU-25
series UHF transmitter.
Click to expand...
Was that adjustment in one direction only (to increase resistance)? How
much range did it have before the copper would need replacement?

Michael
 
"b" <reverend_rogers@yahoo.com> wrote in message
news:df5fd49a-8620-49fd-909c-26e06b6c0e91@k17g2000yqh.googlegroups.com...
Rank Arena were old UK names, the Rank/Bush/Murphy brands were all
used in the 60s and 70s. Likely bought out by some chinese/turkish
firm, as have other former respected names like Dual, wharfefdale, and
Sansui.
Click to expand...
**Dual was purchased by Thorens. Thorens is still a European made product.


--
Trevor Wilson
www.rageaudio.com.au
 
On 11 nov, 12:19, Sylvia Else <syl...@not.at.this.address> wrote:

The switching transistor for the EHT transformer has no base drive. I
traced backwards through a transformer, another bibolar transistor, a
pair of FETs, a pair of bipolar transistors and ultimately reached two
outputs from the programmable LSI circuit. So the reason there was no
EHT was that the outputs from the LSI were unchanging. I surmise that it
had probably detected some fault, and disabled the EHT for that reason,
but since it's programmable, I have no way of determining what it might
be objecting to.
Click to expand...
if you had checked the RGB and frame stages, I'm sure you would have
found something amiss causing the set to prevent the EHT starting.
This sounds like a classic case of 'don't look for the fire, look for
the boy with the matches' . Still, another one for landfill :-(

-B
 
On 11 nov, 21:51, "Trevor Wilson" <tre...@SPAMBLOCKrageaudio.com.au>
wrote:
**Dual was purchased by Thorens. Thorens is still a European made product.
Click to expand...
Sorry, not true. In the last 4 years, have seen the Dual name,
including the logo, on chinese made DVD player and a Turkish vestel
TV.
-B
 
msg wrote:
Michael A. Terrell wrote:
snip

Have you ever used a water cooled
power tetrode with two, 1000 A, 1.5 volt filaments? The AC had to match
to a few millivolts, or it would modulate the output current. You had to
use an open ended wrench to adjust the length of a copper buss bar. Its
resistance went up as it was stretched. This was in the RCA TTU-25
series UHF transmitter.

Was that adjustment in one direction only (to increase resistance)? How
much range did it have before the copper would need replacement?
Click to expand...

The originals were still in the transmitter, and it was built in
1952. Backing the bolts off allowed some change in length, so they were
backed off and then set to a minimum torque. The new tube was
installed, and the voltage measured. Then each was tightened to the
recommended filament voltage. A new tube would last a couple years, so
it didn't have to be done very often. What bugged me was 3 KW of
electricity was used to get 25 KW out of the tube. :(



--
The movie 'Deliverance' isn't a documentary!
 
b wrote:
On 11 nov, 12:19, Sylvia Else <syl...@not.at.this.address> wrote:

The switching transistor for the EHT transformer has no base drive. I
traced backwards through a transformer, another bibolar transistor, a
pair of FETs, a pair of bipolar transistors and ultimately reached two
outputs from the programmable LSI circuit. So the reason there was no
EHT was that the outputs from the LSI were unchanging. I surmise that it
had probably detected some fault, and disabled the EHT for that reason,
but since it's programmable, I have no way of determining what it might
be objecting to.

if you had checked the RGB and frame stages, I'm sure you would have
found something amiss causing the set to prevent the EHT starting.
Click to expand...

Well, perhaps. But by the time I'd got the metal box partly apart, which
required desoldering, I'd already managed to cut myself on it, and I
wasn't feeling particularly goodwilled towards the set. There was also
the question of what I was going to do with it if I managed to fix it.
It was rather bigger than I envisaged when I bid for it, so it wasn't
really going to suit my living room. I wouldn't feel entirely
comfortable about selling a TV that I'd taken a soldering iron to the
insides of. So if I'd fixed it, it might have ended up on the tip anyway :(

Sylvia.
 
"b" <reverend_rogers@yahoo.com> wrote in message
news:28bf06ef-fc81-42ea-aa62-12d0ea0003db@l2g2000yqd.googlegroups.com...
On 11 nov, 21:51, "Trevor Wilson" <tre...@SPAMBLOCKrageaudio.com.au
wrote:


**Dual was purchased by Thorens. Thorens is still a European made
product.

Sorry, not true. In the last 4 years, have seen the Dual name,
including the logo, on chinese made DVD player and a Turkish vestel
TV.
Click to expand...
**Dual was STILL purchased by Thorens. Thorens may have recently on-sold the
name. Or not. It is not beyond the realms of possibility that the Chinese
are illegally using the name.


--
Trevor Wilson
www.rageaudio.com.au
 
On Wed, 11 Nov 2009 14:01:33 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net>wrote:

Meat Plow wrote:

On Tue, 10 Nov 2009 22:46:14 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net>wrote:


Trevor Wilson wrote:

"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:00f2f033$0$23353$c3e8da3@news.astraweb.com...

Whatever happened to circuits that just contained a couple of valves?


**There never were any "circuits that just contained a couple of valves".
When they first arrived, TV sets were mindbogglingly complex devices
compared to anything that preceded them (in domestic appliance-speak). They
were also fabulously unreliable. You could figure that the average TV set
would require several repair jobs every year. Your incredibly complex, LSI
controlled, TV set is likely to be vastly more reliable. You've probably
found the first fault it has ever had.


It sounds like they only sold crap in Australia, and that you've
never seen the very low parts count in a Muntz TV.

My parents had three service calls in 15 years. Two of those were
due to lightning taking out the front end in the VHF tuner. The third
was a bad electrolytic in a voltage doubler that took out a fusible
resistor. That isn't a couple times a year.

My dad always bought RCA even though the RCA tube guy seemed to visit
monthly. (color sets)


I did TV repair for about 20 years, and never saw anything that bad.
Most customers got three or four years out of a new set before the first
service call. By the time a set needed a lot of repairs, it was cheaper
to replace. I went on some calls on Zenith sets that were almost 20
years old, and it was the first service call. The cost of 12 service
calls in one year would be higher than a new TV set.


Only tubes I deal with these days are in guitar amps.


Whoopie. I won't touch tube sets, unless they get a full overhaul.
I no longer work with multiple 65 KW Klystrons, or transmitter tubes
made with beryllium oxide ceramics. Have you ever used a water cooled
power tetrode with two, 1000 A, 1.5 volt filaments? The AC had to match
to a few millivolts, or it would modulate the output current. You had to
use an open ended wrench to adjust the length of a copper buss bar. Its
resistance went up as it was stretched. This was in the RCA TTU-25
series UHF transmitter.
Click to expand...
I have seen a TV transmitter, a Doppler radar transmitter and a huge
mercury vapor rectifier. Have seen a walkin klystron but only in
pictures.
 
On Thu, 12 Nov 2009 00:05:44 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

msg wrote:

Michael A. Terrell wrote:
snip

Have you ever used a water cooled
power tetrode with two, 1000 A, 1.5 volt filaments? The AC had to match
to a few millivolts, or it would modulate the output current. You had to
use an open ended wrench to adjust the length of a copper buss bar. Its
resistance went up as it was stretched. This was in the RCA TTU-25
series UHF transmitter.

Was that adjustment in one direction only (to increase resistance)? How
much range did it have before the copper would need replacement?


The originals were still in the transmitter, and it was built in
1952. Backing the bolts off allowed some change in length, so they were
backed off and then set to a minimum torque. The new tube was
installed, and the voltage measured. Then each was tightened to the
recommended filament voltage. A new tube would last a couple years, so
it didn't have to be done very often. What bugged me was 3 KW of
electricity was used to get 25 KW out of the tube. :(
Click to expand...
Amazing, isn't it! <g> What was used to measure the filament voltage
with that accuracy?
 
Meat Plow wrote:
On Wed, 11 Nov 2009 14:01:33 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net>wrote:


Meat Plow wrote:

On Tue, 10 Nov 2009 22:46:14 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net>wrote:


Trevor Wilson wrote:

"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:00f2f033$0$23353$c3e8da3@news.astraweb.com...

Whatever happened to circuits that just contained a couple of valves?


**There never were any "circuits that just contained a couple of valves".
When they first arrived, TV sets were mindbogglingly complex devices
compared to anything that preceded them (in domestic appliance-speak). They
were also fabulously unreliable. You could figure that the average TV set
would require several repair jobs every year. Your incredibly complex, LSI
controlled, TV set is likely to be vastly more reliable. You've probably
found the first fault it has ever had.


It sounds like they only sold crap in Australia, and that you've
never seen the very low parts count in a Muntz TV.

My parents had three service calls in 15 years. Two of those were
due to lightning taking out the front end in the VHF tuner. The third
was a bad electrolytic in a voltage doubler that took out a fusible
resistor. That isn't a couple times a year.

My dad always bought RCA even though the RCA tube guy seemed to visit
monthly. (color sets)


I did TV repair for about 20 years, and never saw anything that bad.
Most customers got three or four years out of a new set before the first
service call. By the time a set needed a lot of repairs, it was cheaper
to replace. I went on some calls on Zenith sets that were almost 20
years old, and it was the first service call. The cost of 12 service
calls in one year would be higher than a new TV set.


Only tubes I deal with these days are in guitar amps.


Whoopie. I won't touch tube sets, unless they get a full overhaul.
I no longer work with multiple 65 KW Klystrons, or transmitter tubes
made with beryllium oxide ceramics. Have you ever used a water cooled
power tetrode with two, 1000 A, 1.5 volt filaments? The AC had to match
to a few millivolts, or it would modulate the output current. You had to
use an open ended wrench to adjust the length of a copper buss bar. Its
resistance went up as it was stretched. This was in the RCA TTU-25
series UHF transmitter.

I have seen a TV transmitter, a Doppler radar transmitter and a huge
mercury vapor rectifier. Have seen a walkin klystron but only in
pictures.
Click to expand...

Ever seen a klystrode?


--
The movie 'Deliverance' isn't a documentary!
 
PeterD wrote:
On Thu, 12 Nov 2009 00:05:44 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:


msg wrote:

Michael A. Terrell wrote:
snip

Have you ever used a water cooled
power tetrode with two, 1000 A, 1.5 volt filaments? The AC had to match
to a few millivolts, or it would modulate the output current. You had to
use an open ended wrench to adjust the length of a copper buss bar. Its
resistance went up as it was stretched. This was in the RCA TTU-25
series UHF transmitter.

Was that adjustment in one direction only (to increase resistance)? How
much range did it have before the copper would need replacement?


The originals were still in the transmitter, and it was built in
1952. Backing the bolts off allowed some change in length, so they were
backed off and then set to a minimum torque. The new tube was
installed, and the voltage measured. Then each was tightened to the
recommended filament voltage. A new tube would last a couple years, so
it didn't have to be done very often. What bugged me was 3 KW of
electricity was used to get 25 KW out of the tube. :(

Amazing, isn't it! <g> What was used to measure the filament voltage
with that accuracy?
Click to expand...

An RCA VTVM on the lowest AC scale. If the needle moved at all, it
was out of spec. Yo connected it to the filament end of the pair of
copper resistors and adjusted for zero volts, like a Whetstone bridge.
That transmitter was built in 1952. :)


--
The movie 'Deliverance' isn't a documentary!
 
On Fri, 13 Nov 2009 01:14:38 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net>wrote:

Meat Plow wrote:

On Wed, 11 Nov 2009 14:01:33 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net>wrote:


Meat Plow wrote:

On Tue, 10 Nov 2009 22:46:14 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net>wrote:


Trevor Wilson wrote:

"Sylvia Else" <sylvia@not.at.this.address> wrote in message
news:00f2f033$0$23353$c3e8da3@news.astraweb.com...

Whatever happened to circuits that just contained a couple of valves?


**There never were any "circuits that just contained a couple of valves".
When they first arrived, TV sets were mindbogglingly complex devices
compared to anything that preceded them (in domestic appliance-speak). They
were also fabulously unreliable. You could figure that the average TV set
would require several repair jobs every year. Your incredibly complex, LSI
controlled, TV set is likely to be vastly more reliable. You've probably
found the first fault it has ever had.


It sounds like they only sold crap in Australia, and that you've
never seen the very low parts count in a Muntz TV.

My parents had three service calls in 15 years. Two of those were
due to lightning taking out the front end in the VHF tuner. The third
was a bad electrolytic in a voltage doubler that took out a fusible
resistor. That isn't a couple times a year.

My dad always bought RCA even though the RCA tube guy seemed to visit
monthly. (color sets)


I did TV repair for about 20 years, and never saw anything that bad.
Most customers got three or four years out of a new set before the first
service call. By the time a set needed a lot of repairs, it was cheaper
to replace. I went on some calls on Zenith sets that were almost 20
years old, and it was the first service call. The cost of 12 service
calls in one year would be higher than a new TV set.


Only tubes I deal with these days are in guitar amps.


Whoopie. I won't touch tube sets, unless they get a full overhaul.
I no longer work with multiple 65 KW Klystrons, or transmitter tubes
made with beryllium oxide ceramics. Have you ever used a water cooled
power tetrode with two, 1000 A, 1.5 volt filaments? The AC had to match
to a few millivolts, or it would modulate the output current. You had to
use an open ended wrench to adjust the length of a copper buss bar. Its
resistance went up as it was stretched. This was in the RCA TTU-25
series UHF transmitter.

I have seen a TV transmitter, a Doppler radar transmitter and a huge
mercury vapor rectifier. Have seen a walkin klystron but only in
pictures.


Ever seen a klystrode?
Click to expand...
And you need to know why?
 
Meat Plow wrote:
Michael A. Terrell wrote:

Ever seen a klystrode?

And you need to know why?
Click to expand...

Then that's a NO.

The Klystrode 'was' the replacement for Klystrons in UHF TV
transmitters, but was short lived because new designs switched to all
solid state. They were more efficient than the Klystron, and cut the
electric bill by thousands of dollars a month. A technology between
the two tubes was to add a 'Pulser' to a Klystron to lower the electric
bill.


--
The movie 'Deliverance' isn't a documentary!
 
On Fri, 13 Nov 2009 19:29:38 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net>wrote:

Meat Plow wrote:

Michael A. Terrell wrote:

Ever seen a klystrode?

And you need to know why?


Then that's a NO.
Click to expand...
Wouldn't matter one way or the other because you were going to tell me
about a klystrode regardless.

The Klystrode 'was' the replacement for Klystrons in UHF TV
transmitters, but was short lived because new designs switched to all
solid state. They were more efficient than the Klystron, and cut the
electric bill by thousands of dollars a month. A technology between
the two tubes was to add a 'Pulser' to a Klystron to lower the electric
bill.
Click to expand...
I'll remember that the next time I apply for an engineer position at a
UHF TV station.
 
Meat Plow wrote:
On Fri, 13 Nov 2009 19:29:38 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net>wrote:


Meat Plow wrote:

Michael A. Terrell wrote:

Ever seen a klystrode?

And you need to know why?


Then that's a NO.

Wouldn't matter one way or the other because you were going to tell me
about a klystrode regardless.

The Klystrode 'was' the replacement for Klystrons in UHF TV
transmitters, but was short lived because new designs switched to all
solid state. They were more efficient than the Klystron, and cut the
electric bill by thousands of dollars a month. A technology between
the two tubes was to add a 'Pulser' to a Klystron to lower the electric
bill.

I'll remember that the next time I apply for an engineer position at a
UHF TV station.
Click to expand...

They will laugh in your face if you aren't familiar with the new
Harris solid state transmitters.


BTW, I found four high power GE X Ray heads yesterday. They use
about 100 KV DC to power them. Heavy bastards, with cooling fans. I
wonder if the store has any idea what they are really work, or just how
dangerous?


--
The movie 'Deliverance' isn't a documentary!
 
Michael A. Terrell wrote:

Meat Plow wrote:

On Fri, 13 Nov 2009 19:29:38 -0500, "Michael A. Terrell"
mike.terrell@earthlink.net>wrote:


Meat Plow wrote:

Michael A. Terrell wrote:

Ever seen a klystrode?

And you need to know why?


Then that's a NO.

Wouldn't matter one way or the other because you were going to tell
me about a klystrode regardless.

The Klystrode 'was' the replacement for Klystrons in UHF TV
transmitters, but was short lived because new designs switched to
all
solid state. They were more efficient than the Klystron, and cut
the
electric bill by thousands of dollars a month. A technology
between the two tubes was to add a 'Pulser' to a Klystron to lower
the electric bill.

I'll remember that the next time I apply for an engineer position at
a UHF TV station.


They will laugh in your face if you aren't familiar with the new
Harris solid state transmitters.


BTW, I found four high power GE X Ray heads yesterday. They use
about 100 KV DC to power them. Heavy bastards, with cooling fans. I
wonder if the store has any idea what they are really work, or just
how dangerous?
Click to expand...
If its just the heads they could be worth more for the lead in them !

--
Best Regards:
Baron.
 
Baron wrote:
Michael A. Terrell wrote:

BTW, I found four high power GE X Ray heads yesterday. They use
about 100 KV DC to power them. Heavy bastards, with cooling fans. I
wonder if the store has any idea what they are really work, or just
how dangerous?

If its just the heads they could be worth more for the lead in them !
Click to expand...

What lead? This is the aluminum waveguide & tube part. The lead is
part of the moving arm and holds the X ray assembly. They still weigh
about 5o pounds each for the smaller pair. I didn't know it was legal
to dispose of these outside the medical electronics industry. I would
think they would be rebuilt, like all the other types.



--
The movie 'Deliverance' isn't a documentary!
 
Michael A. Terrell wrote:

Baron wrote:

Michael A. Terrell wrote:

BTW, I found four high power GE X Ray heads yesterday. They use
about 100 KV DC to power them. Heavy bastards, with cooling fans.
I wonder if the store has any idea what they are really work, or
just how dangerous?

If its just the heads they could be worth more for the lead in them !


What lead? This is the aluminum waveguide & tube part. The lead is
part of the moving arm and holds the X ray assembly. They still weigh
about 5o pounds each for the smaller pair. I didn't know it was legal
to dispose of these outside the medical electronics industry. I would
think they would be rebuilt, like all the other types.
Click to expand...
Oh ! I'm thinking about the wrong bit. I've seen a couple in scrap
metal yards. Didn't have a tube in them though.

--
Best Regards:
Baron.
 
Baron wrote:
Michael A. Terrell wrote:


Baron wrote:

Michael A. Terrell wrote:

BTW, I found four high power GE X Ray heads yesterday. They use
about 100 KV DC to power them. Heavy bastards, with cooling fans.
I wonder if the store has any idea what they are really work, or
just how dangerous?

If its just the heads they could be worth more for the lead in them !


What lead? This is the aluminum waveguide & tube part. The lead is
part of the moving arm and holds the X ray assembly. They still weigh
about 5o pounds each for the smaller pair. I didn't know it was legal
to dispose of these outside the medical electronics industry. I would
think they would be rebuilt, like all the other types.


Oh ! I'm thinking about the wrong bit. I've seen a couple in scrap
metal yards. Didn't have a tube in them though.
Click to expand...

No problem. :)


--
The movie 'Deliverance' isn't a documentary!
 
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