I recently promised someone I'd xray the Chinese 6L6CGR I had.
Don't remember now which thread? Might as well start another...
There are no holes "for screen alignment" in plate of this tube.
Don't know if that is really what typical beam power plate holes
are for, or something else?
Don't remember now which thread? Might as well start another...
There are no holes "for screen alignment" in plate of this tube.
Don't know if that is really what typical beam power plate holes
are for, or something else?
Attachments
On the right side of the third image, it looks like parallax effect reaches a minimum and the grid-screen offset is about 20% of the winding pitch. Could probably be better...
Thanks for the x-rays!
Tim
Thanks for the x-rays!
Tim
Bah, I was just about to edit then it said it timed out...
Edit: here's the image, brightened up a bit (for analyzing relative density, refer to the original) and with a scale marker (based on the bulb being about 1.5" across). Evidently the grid pitch is about 14 TPI, so the misalignment is around 0.014".
Tim
Edit: here's the image, brightened up a bit (for analyzing relative density, refer to the original) and with a scale marker (based on the bulb being about 1.5" across). Evidently the grid pitch is about 14 TPI, so the misalignment is around 0.014".
Tim
The total diameter across the entire glass envelope,
which also happens to be the same diameter as the
octal base, is only 1.3 inches. Rather small for a 6L6.
Dunno what breed of monster you thought this was?
I think you might have diameter mixed up with radius.
There is simply no way this tube is 3 inches across...
Its probably too late to edit your post now, but you
seem to be hosting the picture elsewhere. I would
assume you still have access to edit the scale?
How does this affect your calculation regarding the
pitch of the grids?
which also happens to be the same diameter as the
octal base, is only 1.3 inches. Rather small for a 6L6.
Dunno what breed of monster you thought this was?
I think you might have diameter mixed up with radius.
There is simply no way this tube is 3 inches across...
Its probably too late to edit your post now, but you
seem to be hosting the picture elsewhere. I would
assume you still have access to edit the scale?
How does this affect your calculation regarding the
pitch of the grids?
D'oh! Yeah, mod that to like 0.5 inch...
I saw 1 9/16" max. diameter, so I divided it by three, forgetting to double it (i.e. assuming 1.5" across).
Give it a refresh.
Tim
I saw 1 9/16" max. diameter, so I divided it by three, forgetting to double it (i.e. assuming 1.5" across).
Give it a refresh.
Tim
Close, but still not even that big. Measure an ordinary Octal base.
You can see from Pic 2 the glass here is not any bigger than that.
1 and 5/16 maybe??? My ruler has only decimalized inches, and
centimeters on the flipside... 1.3 inches is the closest tick I see.
If the guts then seem even smaller by comparison, they really do
seem kinda small for what its gonna be asked to do. Is this really
the same 6L6CGR as the one that Tubelab said was hard to kill?
I have very few power tubes at this time except transmitter types.
The closest normal sized beam power tube I have on hand for a
fair comparison is a 6GT5A compactron. And its not really all that
similar...
6GT5A plate is no taller than the Chinese 6L6GCR, yet maybe 15%
wider in the wings where the beams would strike, and with the
"normal" pattern of holes and supporting rods. The glass on the
GE compactron is a MUCH bigger bottle in diameter, though easily
an inch shorter in total height. Nope, its an RCA in a GE box, and
its marked on one end "Low", great....
---------------------------------------------------------------------------
I can't measure anything meaningful but "pass/fail" emissions at
this time. I intend soon building a high voltage curve tracer as part
of my Labview training, at least thats the excuse I'm giving at work.
Can swing only 68Volts DC on the GPIB enabled supplies we got
now. And I would need a safe way to kick that up a notch or two
without affecting accuracy of the measurement, or endangering
any elite gear I could never afford to replace.
You can see from Pic 2 the glass here is not any bigger than that.
1 and 5/16 maybe??? My ruler has only decimalized inches, and
centimeters on the flipside... 1.3 inches is the closest tick I see.
If the guts then seem even smaller by comparison, they really do
seem kinda small for what its gonna be asked to do. Is this really
the same 6L6CGR as the one that Tubelab said was hard to kill?
I have very few power tubes at this time except transmitter types.
The closest normal sized beam power tube I have on hand for a
fair comparison is a 6GT5A compactron. And its not really all that
similar...
6GT5A plate is no taller than the Chinese 6L6GCR, yet maybe 15%
wider in the wings where the beams would strike, and with the
"normal" pattern of holes and supporting rods. The glass on the
GE compactron is a MUCH bigger bottle in diameter, though easily
an inch shorter in total height. Nope, its an RCA in a GE box, and
its marked on one end "Low", great....
---------------------------------------------------------------------------
I can't measure anything meaningful but "pass/fail" emissions at
this time. I intend soon building a high voltage curve tracer as part
of my Labview training, at least thats the excuse I'm giving at work.
Can swing only 68Volts DC on the GPIB enabled supplies we got
now. And I would need a safe way to kick that up a notch or two
without affecting accuracy of the measurement, or endangering
any elite gear I could never afford to replace.
kenpeter said:
I'm pretty sure George got his Chinese 6L6 from AES. I'm thinking these tubes can't be the same ones. I've got a bunch similar to the ones in the X-ray (actually slightly larger, as the glass comes out a little just past the base) and I'll agree they are pretty wimpy. 450 volts and 60 mA will get a slight glow started around the plate seams. Perhaps they won't "blow up" but they don't look happy at high wattage. They sound fine, though.
I've got some of these running in my RA-100 clone with about +640V on the plates and screens(UL).
They will show color above 40ma or so. But other than that,they don't complain! They sure seem pretty 'beefy' for what they are.
Some pics and short video clips:
http://s199.photobucket.com/albums/aa154/Nothing40/Assorted Audio stuff/RA-100 Amp/
They will show color above 40ma or so. But other than that,they don't complain! They sure seem pretty 'beefy' for what they are.
Some pics and short video clips:
http://s199.photobucket.com/albums/aa154/Nothing40/Assorted Audio stuff/RA-100 Amp/
I think Hoktuna's amp in Lars' Anti-triode thread shows even
smaller envelopes than the ones I got. The straight sides of
his batch appear to fit entirely inside the base.
smaller envelopes than the ones I got. The straight sides of
his batch appear to fit entirely inside the base.
Russian G-807 pictures
Here are some pictures on the internals of a broken Russian G-807 which I believe is quite similar to the 6L6:
http://picasaweb.google.com/lcsaszar/G807
Here are some pictures on the internals of a broken Russian G-807 which I believe is quite similar to the 6L6:
http://picasaweb.google.com/lcsaszar/G807
Clearly the exact same thing, only completely different...
There is no doubt they have shared some engineering.
I'm gonna snap some internals of this 6GT5A here in a
few... Next break, or possibly after work if things get
too busy to squeeze into a regular break period.
I just got back from Tektronix, where I was learning a
little about MATLAB and how to connect to Tek's stuff.
Though it seems more likely I'd be using Labview, as
we already have made the investment.
I need to find a list of common "skippy" commands.
Might decide to build the curve tracer from scratch,
rather than risk high volts getting into our Keithley
or Agilent GPIB sourcemeters...
I can sorta program an AVR, so thats where I might
lean toward giving a new piece of test gear some
crude the ability to communicate (by RS232 or GPIB).
There is no doubt they have shared some engineering.
I'm gonna snap some internals of this 6GT5A here in a
few... Next break, or possibly after work if things get
too busy to squeeze into a regular break period.
I just got back from Tektronix, where I was learning a
little about MATLAB and how to connect to Tek's stuff.
Though it seems more likely I'd be using Labview, as
we already have made the investment.
I need to find a list of common "skippy" commands.
Might decide to build the curve tracer from scratch,
rather than risk high volts getting into our Keithley
or Agilent GPIB sourcemeters...
I can sorta program an AVR, so thats where I might
lean toward giving a new piece of test gear some
crude the ability to communicate (by RS232 or GPIB).
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