"Dave" wrote in message
news.com...
Many thanks to all who replied, both here and by email.
They sound like a great tube for LOTS of purposes. My
favorite suggestion was building a regen, using each
half in place of the 6AQ5's called for in the ARRL handbook
design from the 50's!

How about an oscillator / amplifier for HF, running low
plate voltage for a relatively low RF output? Seems they
should be able to do that - and having a separate oscillator
stage it wouldn't be prone to runaway and exessive crystal
current. And it would look VERY cool!


I'd think running the 829 in parallel for a HF PA, with another
829 as a P-P modulator would be a neat project.

Pete

Lots of discussion about using the 829 for VHF power amplifiers, and
even audio amplifiers and conversation pieces. But I haven't seen
mention here of their use in pulse generators. I have a TS592A/UPM15
pulse generator that uses one in its output stage (not all my test
equipment is very new ;-), and one of the early uses of them was as a
driver in "hard tube" radar pulse modulators, developed fairly early
in WWII. They were used in "Model 3 hard tube pulsers" for example,
where the two sections were run in parallel, outputting well over a
kilowatt during the microsecond long pulse, 0.1% duty cycle. The very
similar 3E29 also get lots of mention in early radar pulser history.
Perhaps someone knows: was the 3E29 an 829 re-designed and/or
specifically tested for use in pulsers? What was the 829 originally
intended for, and when was it first introduced? Who made the first
ones, RCA or someone else?

Cheers,
Tom


"Dave" wrote in message tnews.com...
Hi all,

I just found several 829B tubes - believe it or not in my garage - I
must have got them in a box of stuff at a ham fest at one time.
A check on Ebay shows they're pretty much worthless for the sake
of dollars, but they're so COOL! With the two plate caps that are
actually just stiff pins, they look like little Martians.

I put a pair on my office credenza just to look geeky cool. Fresh
out of the box as NOS they look amazing - just like they were made
yesterday. It's a pity they have no value - maybe as a homebrew
project??

So can someone tell me what they would have been used for?
Something tells me they're a VHF power tube.

Any application as a one-tube QRP rig of any sort? Any stories
about using them in the past? I've built a lot of little rigs over the
years, but never knew about the 829

Thanks,

Dave

Lots of discussion about using the 829 for VHF power amplifiers, and
even audio amplifiers and conversation pieces. But I haven't seen
mention here of their use in pulse generators. I have a TS592A/UPM15
pulse generator that uses one in its output stage (not all my test
equipment is very new ;-), and one of the early uses of them was as a
driver in "hard tube" radar pulse modulators, developed fairly early
in WWII. They were used in "Model 3 hard tube pulsers" for example,
where the two sections were run in parallel, outputting well over a
kilowatt during the microsecond long pulse, 0.1% duty cycle. The very
similar 3E29 also get lots of mention in early radar pulser history.
Perhaps someone knows: was the 3E29 an 829 re-designed and/or
specifically tested for use in pulsers? What was the 829 originally
intended for, and when was it first introduced? Who made the first
ones, RCA or someone else?

Cheers,
Tom


"Dave" wrote in message tnews.com...
Hi all,

I just found several 829B tubes - believe it or not in my garage - I
must have got them in a box of stuff at a ham fest at one time.
A check on Ebay shows they're pretty much worthless for the sake
of dollars, but they're so COOL! With the two plate caps that are
actually just stiff pins, they look like little Martians.

I put a pair on my office credenza just to look geeky cool. Fresh
out of the box as NOS they look amazing - just like they were made
yesterday. It's a pity they have no value - maybe as a homebrew
project??

So can someone tell me what they would have been used for?
Something tells me they're a VHF power tube.

Any application as a one-tube QRP rig of any sort? Any stories
about using them in the past? I've built a lot of little rigs over the
years, but never knew about the 829

Thanks,

Dave

Tom Bruhns wrote:

Lots of discussion about using the 829 for VHF power amplifiers, and
even audio amplifiers and conversation pieces. But I haven't seen
mention here of their use in pulse generators. I have a TS592A/UPM15
pulse generator that uses one in its output stage (not all my test
equipment is very new ;-), and one of the early uses of them was as a
driver in "hard tube" radar pulse modulators, developed fairly early
in WWII. They were used in "Model 3 hard tube pulsers" for example,
where the two sections were run in parallel, outputting well over a
kilowatt during the microsecond long pulse, 0.1% duty cycle. The very
similar 3E29 also get lots of mention in early radar pulser history.
Perhaps someone knows: was the 3E29 an 829 re-designed and/or
specifically tested for use in pulsers? What was the 829 originally
intended for, and when was it first introduced? Who made the first
ones, RCA or someone else?

Cheers,
Tom


"Dave" wrote in message tnews.com...


Hi all,

I just found several 829B tubes - believe it or not in my garage - I
must have got them in a box of stuff at a ham fest at one time.
A check on Ebay shows they're pretty much worthless for the sake
of dollars, but they're so COOL! With the two plate caps that are
actually just stiff pins, they look like little Martians.

I put a pair on my office credenza just to look geeky cool. Fresh
out of the box as NOS they look amazing - just like they were made
yesterday. It's a pity they have no value - maybe as a homebrew
project??

So can someone tell me what they would have been used for?
Something tells me they're a VHF power tube.

Any application as a one-tube QRP rig of any sort? Any stories
about using them in the past? I've built a lot of little rigs over the
years, but never knew about the 829

Thanks,

Dave


Don't have answeres to all those questions but the 3E29 had a "better"
cathode to handle
the peak current requirements..

Bill K7NOM

Tom Bruhns wrote:

Lots of discussion about using the 829 for VHF power amplifiers, and
even audio amplifiers and conversation pieces. But I haven't seen
mention here of their use in pulse generators. I have a TS592A/UPM15
pulse generator that uses one in its output stage (not all my test
equipment is very new ;-), and one of the early uses of them was as a
driver in "hard tube" radar pulse modulators, developed fairly early
in WWII. They were used in "Model 3 hard tube pulsers" for example,
where the two sections were run in parallel, outputting well over a
kilowatt during the microsecond long pulse, 0.1% duty cycle. The very
similar 3E29 also get lots of mention in early radar pulser history.
Perhaps someone knows: was the 3E29 an 829 re-designed and/or
specifically tested for use in pulsers? What was the 829 originally
intended for, and when was it first introduced? Who made the first
ones, RCA or someone else?

Cheers,
Tom


"Dave" wrote in message tnews.com...


Hi all,

I just found several 829B tubes - believe it or not in my garage - I
must have got them in a box of stuff at a ham fest at one time.
A check on Ebay shows they're pretty much worthless for the sake
of dollars, but they're so COOL! With the two plate caps that are
actually just stiff pins, they look like little Martians.

I put a pair on my office credenza just to look geeky cool. Fresh
out of the box as NOS they look amazing - just like they were made
yesterday. It's a pity they have no value - maybe as a homebrew
project??

So can someone tell me what they would have been used for?
Something tells me they're a VHF power tube.

Any application as a one-tube QRP rig of any sort? Any stories
about using them in the past? I've built a lot of little rigs over the
years, but never knew about the 829

Thanks,

Dave


Don't have answeres to all those questions but the 3E29 had a "better"
cathode to handle
the peak current requirements..

Bill K7NOM

"Geoffrey G. Rochat" wrote:
in elfla.com,

[snip]

: A lot of The Radio Amateur's Handbooks of the '50s and '60s had 892B
: projects in them. The 1953 edition, immediately to my left as I write this,
: has "A 100-Watt RF Amplifier for 50 and 144 Mc." on page 405. It runs
: push-pull class-C, up to 120 Watts CW or FM, and 100 Watts AM.

Gone by the 1955 edition I have. The 1947 ed uses it in 3 2M TX circuits.

I have 3 RCA 829B and 6 or 7 slightly sturdier UK mil CV2666 equivalents,
plus some CV178A / 5894 bottles I intend to use sometime in something:-)

: And the following fellow has gone to an awful lot of trouble to use two
: 829Bs in parallel single-ended triode mode in a stereo amplifier:
:
: http://www.pmillett.addr.com/829b_amplifier.htm

These (Chinese) stereo push-pull amplifiers are commercial products:

http://www.cayin.de/amps_de/endverstarker/929D/929D.htm
http://www.cayin.de/amps_de/vollvers.../500/500mk.htm
http://www.cayin.de/amps_de/endverst...00mk/800mk.htm
http://www.cayin.de/amps_de/endverstarker/800/800.htm

They substitute Russian FU29 or GU29 or US 3E29 in some.

You can get a rough translation by copying & pasting
http://translate.google.com/translate_c?hl=en&u=
in front of the links, with no space between the two.

These seem to be out of production now by the manufacturer;
they used to be on the vaccum tube amplifier link from their English index:
http://www.sparkaudio.com/eproduct.asp

RdM
(operators certificate in 1969 at 17 - never actually got on air - one day!)

"Geoffrey G. Rochat" wrote:
in elfla.com,

[snip]

: A lot of The Radio Amateur's Handbooks of the '50s and '60s had 892B
: projects in them. The 1953 edition, immediately to my left as I write this,
: has "A 100-Watt RF Amplifier for 50 and 144 Mc." on page 405. It runs
: push-pull class-C, up to 120 Watts CW or FM, and 100 Watts AM.

Gone by the 1955 edition I have. The 1947 ed uses it in 3 2M TX circuits.

I have 3 RCA 829B and 6 or 7 slightly sturdier UK mil CV2666 equivalents,
plus some CV178A / 5894 bottles I intend to use sometime in something:-)

: And the following fellow has gone to an awful lot of trouble to use two
: 829Bs in parallel single-ended triode mode in a stereo amplifier:
:
: http://www.pmillett.addr.com/829b_amplifier.htm

These (Chinese) stereo push-pull amplifiers are commercial products:

http://www.cayin.de/amps_de/endverstarker/929D/929D.htm
http://www.cayin.de/amps_de/vollvers.../500/500mk.htm
http://www.cayin.de/amps_de/endverst...00mk/800mk.htm
http://www.cayin.de/amps_de/endverstarker/800/800.htm

They substitute Russian FU29 or GU29 or US 3E29 in some.

You can get a rough translation by copying & pasting
http://translate.google.com/translate_c?hl=en&u=
in front of the links, with no space between the two.

These seem to be out of production now by the manufacturer;
they used to be on the vaccum tube amplifier link from their English index:
http://www.sparkaudio.com/eproduct.asp

RdM
(operators certificate in 1969 at 17 - never actually got on air - one day!)

On Sun, 08 Feb 2004 14:11:12 +1300, Ross Matheson
wrote:

"Geoffrey G. Rochat" wrote:
in elfla.com,

[snip]

: A lot of The Radio Amateur's Handbooks of the '50s and '60s had 892B
: projects in them. The 1953 edition, immediately to my left as I write this,
: has "A 100-Watt RF Amplifier for 50 and 144 Mc." on page 405. It runs
: push-pull class-C, up to 120 Watts CW or FM, and 100 Watts AM.

Gone by the 1955 edition I have. The 1947 ed uses it in 3 2M TX circuits.

I have 3 RCA 829B and 6 or 7 slightly sturdier UK mil CV2666 equivalents,
plus some CV178A / 5894 bottles I intend to use sometime in something:-)

There used to be a *relatively* popular surplus rig that used three of
them. I remember they were lined up and as I recall the final had a
tuned line output link coupled to the antenna.

Don't remember what it was called. That was nigh onto 40 years ago.

snip

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On Sun, 08 Feb 2004 14:11:12 +1300, Ross Matheson
wrote:

"Geoffrey G. Rochat" wrote:
in elfla.com,

[snip]

: A lot of The Radio Amateur's Handbooks of the '50s and '60s had 892B
: projects in them. The 1953 edition, immediately to my left as I write this,
: has "A 100-Watt RF Amplifier for 50 and 144 Mc." on page 405. It runs
: push-pull class-C, up to 120 Watts CW or FM, and 100 Watts AM.

Gone by the 1955 edition I have. The 1947 ed uses it in 3 2M TX circuits.

I have 3 RCA 829B and 6 or 7 slightly sturdier UK mil CV2666 equivalents,
plus some CV178A / 5894 bottles I intend to use sometime in something:-)

There used to be a *relatively* popular surplus rig that used three of
them. I remember they were lined up and as I recall the final had a
tuned line output link coupled to the antenna.

Don't remember what it was called. That was nigh onto 40 years ago.

snip

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

William Donzelli wrote in message
om...
(Tom Bruhns) wrote in message
om...

Lots of discussion about using the 829 for VHF power amplifiers, and
even audio amplifiers and conversation pieces. But I haven't seen
mention here of their use in pulse generators.

Or CRT drivers (in the AN/APS-44 aircraft radar, and I think some of
the Navy PPI repeaters).

Perhaps someone knows: was the 3E29 an 829 re-designed and/or
specifically tested for use in pulsers?

Probably. 3E29 was used in the Mk III IFF interogators, circa 1943. I
don't know of any other major uses for the 3E29 (AKA 829A). Real 3E29s
are getting quite scarce, but 829Bs still can be found in biblical
quantities.

What was the 829 originally
intended for, and when was it first introduced? Who made the first
ones, RCA or someone else?

1943, probably RCA, although National Union was apparently an early
second source. 832 was the model for the 829.

William Donzelli

I've seen references to the fact that the 829B was used in MIT's Whirlwind
computer as core memory drivers, definitely a pulse application. I don't
have any documentation on that, but I do remember some dual plate 829B-like
tubes in the Whirlwind fragments that used to be on display at the
now-defunct Boston Computer Museum. They could have been 3E29s, though, or
even 832s.

The Univac I used 829Bs, as documented here (5/8ths of the way down the
page):
http://ed-thelen.org/comp-hist/BRL61-u3.html

With that complement of tubes you could make one heck of an all-modes
transceiver!

William Donzelli wrote in message
om...
(Tom Bruhns) wrote in message
om...

Lots of discussion about using the 829 for VHF power amplifiers, and
even audio amplifiers and conversation pieces. But I haven't seen
mention here of their use in pulse generators.

Or CRT drivers (in the AN/APS-44 aircraft radar, and I think some of
the Navy PPI repeaters).

Perhaps someone knows: was the 3E29 an 829 re-designed and/or
specifically tested for use in pulsers?

Probably. 3E29 was used in the Mk III IFF interogators, circa 1943. I
don't know of any other major uses for the 3E29 (AKA 829A). Real 3E29s
are getting quite scarce, but 829Bs still can be found in biblical
quantities.

What was the 829 originally
intended for, and when was it first introduced? Who made the first
ones, RCA or someone else?

1943, probably RCA, although National Union was apparently an early
second source. 832 was the model for the 829.

William Donzelli

I've seen references to the fact that the 829B was used in MIT's Whirlwind
computer as core memory drivers, definitely a pulse application. I don't
have any documentation on that, but I do remember some dual plate 829B-like
tubes in the Whirlwind fragments that used to be on display at the
now-defunct Boston Computer Museum. They could have been 3E29s, though, or
even 832s.

The Univac I used 829Bs, as documented here (5/8ths of the way down the
page):
http://ed-thelen.org/comp-hist/BRL61-u3.html

With that complement of tubes you could make one heck of an all-modes
transceiver!

Hi,

The 3E29 may share a similar appearance, and the same pin out as the
829, but it certainly is not interchangable. To quote the RCA TT5
manual:

3E29: Heater-cathode type containing two high-perveance units used
as retangular-wave pulse modulator. Modulator Service maximum
CCS plate dissipation (per tube) 15watts.

Further down, it shows the plate supply voltage as 5000V, and the
instantaneous plate voltage as 5750V.

829: Heater-cathode type having midtapped heater used as af power
amplifier and modulator and as rf power amplifier and oscillator.

CCS dissipation is shown as 30W with natural cooling, and 40W with
forced air cooling.

It is pretty clear to me that the 3E29 was rearranged for high plate
voltage, and was used as a radar modulator tube. It is designed to
put out high voltage square waves.

-Chuck Harris

William Donzelli wrote:
(Tom Bruhns) wrote in message om...


Lots of discussion about using the 829 for VHF power amplifiers, and
even audio amplifiers and conversation pieces. But I haven't seen
mention here of their use in pulse generators.


Or CRT drivers (in the AN/APS-44 aircraft radar, and I think some of
the Navy PPI repeaters).


Perhaps someone knows: was the 3E29 an 829 re-designed and/or
specifically tested for use in pulsers?


Probably. 3E29 was used in the Mk III IFF interogators, circa 1943. I
don't know of any other major uses for the 3E29 (AKA 829A). Real 3E29s
are getting quite scarce, but 829Bs still can be found in biblical
quantities.


What was the 829 originally
intended for, and when was it first introduced? Who made the first
ones, RCA or someone else?

Hi,

The 3E29 may share a similar appearance, and the same pin out as the
829, but it certainly is not interchangable. To quote the RCA TT5
manual:

3E29: Heater-cathode type containing two high-perveance units used
as retangular-wave pulse modulator. Modulator Service maximum
CCS plate dissipation (per tube) 15watts.

Further down, it shows the plate supply voltage as 5000V, and the
instantaneous plate voltage as 5750V.

829: Heater-cathode type having midtapped heater used as af power
amplifier and modulator and as rf power amplifier and oscillator.

CCS dissipation is shown as 30W with natural cooling, and 40W with
forced air cooling.

It is pretty clear to me that the 3E29 was rearranged for high plate
voltage, and was used as a radar modulator tube. It is designed to
put out high voltage square waves.

-Chuck Harris

William Donzelli wrote:
(Tom Bruhns) wrote in message om...


Lots of discussion about using the 829 for VHF power amplifiers, and
even audio amplifiers and conversation pieces. But I haven't seen
mention here of their use in pulse generators.


Or CRT drivers (in the AN/APS-44 aircraft radar, and I think some of
the Navy PPI repeaters).


Perhaps someone knows: was the 3E29 an 829 re-designed and/or
specifically tested for use in pulsers?


Probably. 3E29 was used in the Mk III IFF interogators, circa 1943. I
don't know of any other major uses for the 3E29 (AKA 829A). Real 3E29s
are getting quite scarce, but 829Bs still can be found in biblical
quantities.


What was the 829 originally
intended for, and when was it first introduced? Who made the first
ones, RCA or someone else?

For the 829B picture and some "Beautiful Tube Pin-ups " SEE URL:


http://www.dogstar.dantimax.dk/tubes...ups/pinups.htm


--
73- Cambio - Keyboard To You (:-)
"Bill Turner" wrote in message
...
On 8 Feb 2004 21:44:55 -0800, (William Donzelli) wrote:

but 829Bs still can be found in biblical
quantities.

__________________________________________________ _______

Now there's a picture! Made my day.

--
73, Bill W6WRT

For the 829B picture and some "Beautiful Tube Pin-ups " SEE URL:


http://www.dogstar.dantimax.dk/tubes...ups/pinups.htm


--
73- Cambio - Keyboard To You (:-)
"Bill Turner" wrote in message
...
On 8 Feb 2004 21:44:55 -0800, (William Donzelli) wrote:

but 829Bs still can be found in biblical
quantities.

__________________________________________________ _______

Now there's a picture! Made my day.

--
73, Bill W6WRT

Chuck Harris wrote:
in rec.radio.amateur.boatanchors40283c62$0$3200$61fe ,

: Hi Ross,
:
: It certainly could be that they are very similar inside.
: I have used the 829B, but I have never had my hands on a 3E29.

Ditto. (Well, I haven't actually *used* them yet - they're still NIB! :-)

: Purely speculation on my part, but I would guess that the 3E29 has
: fewer sharp edges inside to help prevent arc over and other funny
: stuff at the 6x increase in plate voltage. I would guess that the
: cathode is made of much sterner stuff, and the vacuum is purer.

I have seen mention of harder vacuum and tolerances in pulse-rated tubes.

Ned, in a 1997 r.a.t post, compares a pulse-rated 4PR65A to a 4-65A, itself
already having a higher vacuum than your average receiving tube, and notes
that the latter wouldn't sub for the former. [http://tinyurl.com/3c5wx]
Elsewhere he mentions 4-400A and 4PR400A. Eimac numbers, I think.

: They make a special point of saying that the 3E29's mu will always
: be within 10% of the spec'd value. That tends to indicate that more
: care was taken with internal tolerances, particularily cathode to
: control grid spacing.

Quite possibly. I hadn't heard the 10%. Top of the bell curve selection?

: The part I find odd is usually when RCA is listing a similar tube
: they will say something like plate curves match 6L6, or some such.
: There is a total absence of mention of the 829B in the 3E29 spec
: sheet.

Exactly my point with the 6146 equivalent examples, all from TT5.
All listed as sharing 6146 data except for that very alike pulse tube 6293.

Yet, again, the ARRL Handbook data section has 3E29/829B sharing.

That German audio retailer with the Chinese amps has them using 829B, 3E29,
or GU-29, implying AF similiarity. There's a clear picture of the GU-29 at:
http://ly1dq.hypermart.net/gu-29.htm (and a simple 2M TX example at
http://ly1dq.hypermart.net/exam/gu-29_01.gif , to stay slightly on topic:-)

: What do you want to bet that the 3E29 also cost 3x the 829B?

(:=}) Quite possible, since military or other radar the likely application.
Plus it likely wouldn't do to say "Just use our 829B, it'll work fine" ;-)

They must have at least been "selected" or perhaps built to better specs.

It wouldn't make sense to be building an essentially identical tube too
differently. A subtly different cathode coating, perhaps, for the different
pulse current requirements? (like starting batteries vs storage) (total
speculation on my part!) and a longer time on the vacuum pump would be easy
to arrange on the same production line, with the build otherwise identical.
Perhaps harder vacuum plus statistical selection alone would be enough?

Ah! I've been scrolling through my files, and found some text on 829B/3E29
I'd saved from the Joenet archives (someone building an amp with one or two)
in which Gary Longrie says "Same tube, but the 3E29 is pulse rated, can hold
off 5kv, being built with ceramic parts."

I don't know how true this is ...

I notice that the UK mil CV2666 has a completely extra top mica disc above
the plates, extending all the way to to the glass, with ceramic inserts, as
well as the bottom metal disk with ceramic inserts like the RCA 829B.

It just occurred to me to do an image search on 3E29. Sure enough,
http://www5b.biglobe.ne.jp/~tritium/rca3e29-1.jpg
http://www5b.biglobe.ne.jp/~tritium/rca3e29-2.jpg
http://www5b.biglobe.ne.jp/~tritium/rca3e29-3.jpg

http://home.snafu.de/appelt/tubes/3E29.jpg

It looks the same as the RCA 829B that I have here, as far as I can see.

Hmm. http://hereford.ampr.org/cgi-bin/tube?tube=3E29
-
"Maximum Ratings (Design Center Values)

Plate Voltage ................................. 750 Volts
Grid No. 2 Voltage ............................ 240 Volts
Plate Dissipation ............................. 40 Watts
Grid No. 2 Dissipation ........................ 7 Watts

For other characteristics and typical operation, see 829B"
_

http://www.r-type.org/exhib/aaa0174.htm shows 829B (& "=" 3E29)

Commentary mentions the superior European double tetrodes, which

"made the 829B and 832 obsolete, and offered greater output power.
This valve type would not have been the valve of choice by 1950.
Currently, designs exist to use all of the VHF double tetrodes as audio
amplifiers, these are physically beautiful devices and deserve to be seen."

: Anybody have a 1950 price sheet?
:
: -Chuck Harris

That would be interesting, too.

RdM

[obviously with too much time on his hands right now, but likes his 829B!]

Chuck Harris wrote:
in rec.radio.amateur.boatanchors40283c62$0$3200$61fe ,

: Hi Ross,
:
: It certainly could be that they are very similar inside.
: I have used the 829B, but I have never had my hands on a 3E29.

Ditto. (Well, I haven't actually *used* them yet - they're still NIB! :-)

: Purely speculation on my part, but I would guess that the 3E29 has
: fewer sharp edges inside to help prevent arc over and other funny
: stuff at the 6x increase in plate voltage. I would guess that the
: cathode is made of much sterner stuff, and the vacuum is purer.

I have seen mention of harder vacuum and tolerances in pulse-rated tubes.

Ned, in a 1997 r.a.t post, compares a pulse-rated 4PR65A to a 4-65A, itself
already having a higher vacuum than your average receiving tube, and notes
that the latter wouldn't sub for the former. [http://tinyurl.com/3c5wx]
Elsewhere he mentions 4-400A and 4PR400A. Eimac numbers, I think.

: They make a special point of saying that the 3E29's mu will always
: be within 10% of the spec'd value. That tends to indicate that more
: care was taken with internal tolerances, particularily cathode to
: control grid spacing.

Quite possibly. I hadn't heard the 10%. Top of the bell curve selection?

: The part I find odd is usually when RCA is listing a similar tube
: they will say something like plate curves match 6L6, or some such.
: There is a total absence of mention of the 829B in the 3E29 spec
: sheet.

Exactly my point with the 6146 equivalent examples, all from TT5.
All listed as sharing 6146 data except for that very alike pulse tube 6293.

Yet, again, the ARRL Handbook data section has 3E29/829B sharing.

That German audio retailer with the Chinese amps has them using 829B, 3E29,
or GU-29, implying AF similiarity. There's a clear picture of the GU-29 at:
http://ly1dq.hypermart.net/gu-29.htm (and a simple 2M TX example at
http://ly1dq.hypermart.net/exam/gu-29_01.gif , to stay slightly on topic:-)

: What do you want to bet that the 3E29 also cost 3x the 829B?

(:=}) Quite possible, since military or other radar the likely application.
Plus it likely wouldn't do to say "Just use our 829B, it'll work fine" ;-)

They must have at least been "selected" or perhaps built to better specs.

It wouldn't make sense to be building an essentially identical tube too
differently. A subtly different cathode coating, perhaps, for the different
pulse current requirements? (like starting batteries vs storage) (total
speculation on my part!) and a longer time on the vacuum pump would be easy
to arrange on the same production line, with the build otherwise identical.
Perhaps harder vacuum plus statistical selection alone would be enough?

Ah! I've been scrolling through my files, and found some text on 829B/3E29
I'd saved from the Joenet archives (someone building an amp with one or two)
in which Gary Longrie says "Same tube, but the 3E29 is pulse rated, can hold
off 5kv, being built with ceramic parts."

I don't know how true this is ...

I notice that the UK mil CV2666 has a completely extra top mica disc above
the plates, extending all the way to to the glass, with ceramic inserts, as
well as the bottom metal disk with ceramic inserts like the RCA 829B.

It just occurred to me to do an image search on 3E29. Sure enough,
http://www5b.biglobe.ne.jp/~tritium/rca3e29-1.jpg
http://www5b.biglobe.ne.jp/~tritium/rca3e29-2.jpg
http://www5b.biglobe.ne.jp/~tritium/rca3e29-3.jpg

http://home.snafu.de/appelt/tubes/3E29.jpg

It looks the same as the RCA 829B that I have here, as far as I can see.

Hmm. http://hereford.ampr.org/cgi-bin/tube?tube=3E29
-
"Maximum Ratings (Design Center Values)

Plate Voltage ................................. 750 Volts
Grid No. 2 Voltage ............................ 240 Volts
Plate Dissipation ............................. 40 Watts
Grid No. 2 Dissipation ........................ 7 Watts

For other characteristics and typical operation, see 829B"
_

http://www.r-type.org/exhib/aaa0174.htm shows 829B (& "=" 3E29)

Commentary mentions the superior European double tetrodes, which

"made the 829B and 832 obsolete, and offered greater output power.
This valve type would not have been the valve of choice by 1950.
Currently, designs exist to use all of the VHF double tetrodes as audio
amplifiers, these are physically beautiful devices and deserve to be seen."

: Anybody have a 1950 price sheet?
:
: -Chuck Harris

That would be interesting, too.

RdM

[obviously with too much time on his hands right now, but likes his 829B!]

Chuck Harris wrote:

: The part I find odd is usually when RCA is listing a similar tube
: they will say something like plate curves match 6L6, or some such.
: There is a total absence of mention of the 829B in the 3E29 spec
: sheet.

Oddly, after all my previous post, I hadn't looked at an RCA 3E29 spec.
This old one (TT?) from 1946, does say " Similiar to type 829-B, but
intended particularly for pulse modulator service."
http://www.mif.pg.gda.pl/homepages/f...049/3/3E29.pdf

Still unclear on what makes the difference, though.

Chuck Harris wrote:

: The part I find odd is usually when RCA is listing a similar tube
: they will say something like plate curves match 6L6, or some such.
: There is a total absence of mention of the 829B in the 3E29 spec
: sheet.

Oddly, after all my previous post, I hadn't looked at an RCA 3E29 spec.
This old one (TT?) from 1946, does say " Similiar to type 829-B, but
intended particularly for pulse modulator service."
http://www.mif.pg.gda.pl/homepages/f...049/3/3E29.pdf

Still unclear on what makes the difference, though.

Well to answer the replacement question - according to GE Industrial Tube
Products Guide - (Dated 9-79)

You can replace an 829 with an 829B.

You can replace an 829A with an 829B or an 3E29.

You can only replace an 829B with another 829B.

Why? I don't know, that's what GE says.


Now what an you use an 829B for? Well I got one, it was a spare from a GE 6m
Prog Repeater our club had on the air. The replaced it with a nice Moto. The
Prog was up for grabs but no one wanted it and was about to be hauled to the
landfill so I took it.

It lasted about two days in my house working fine. Then I put it out of it's
misery and parted it out. It had lots of juicy power transformers, tubes and
sockets, XTAL holders and so on. Most ended up in other projects or repaired
rigs except for the 829B.

What to do with it ???

I decided to build a one tube 40 Meter CW transmitter.

Nothing special about that - all of us have built 6L6's or 117L7GT, 6V6,
6C4, 6GW8 or you name it peanut whistlers. Nothing more than an oscillator
connected to a string (antenna) blasting out a few watts.

But how about a SINGLE tube transmitter pumping out 100 to 115 Watts !!!

With minimal parts count to boot!

I got the idea from QST - June 1940 (page 26) in which Fred Sutter W8QBW
describes a transmitter using -TWO- 6L6's in push-pull supposedly outputting
100 watts to an end-fed Zepp.

I'd take the 100 Watt claim with a little grain of salt... but it's still
not too shabby for 12 parts and 2 tubes not counting the power supply.

The 829B can replace the two 6L6's and the circuit can be adjusted
accordingly. The output tank circuit will be PI instead of link which was
common back then. I also have a nice power transformer that looks like it
can do 700 mils at 750 VAC so I have plenty of head room to crank out more
power if it can handle it and the XTAL doesn't shatter.

I'll use forced air cooling because the 829B socket is already designed for
it. Was gonna go with a fancy blower but I noticed the XYL is not using the
small Dirt Devil handVac I gave her for her birthday. Will cut a small hole
in the chassis and placed a PVC pipe and attach the air hose to that. RCA
Manual says the MAX glass temp is 235 F so hopefully, the plastic vac can
handle it.

For a Glass Chimney, I took a drinking glass and cut off the bottom with a
glass cutting wheel. I was rinsing out the dust in the sink when she spotted
me. I told the XYL I had just taken out the glass from the hot dishwasher
and poured a little bit of cold water and the glass cracked and the bottom
fell out. I hoped she didn't notice the ends were nicely smoothed.

You should have seen her face. Classic...

It's the same look I get when I bring in another hamfest surprise and
promise it's the last radio I'll ever buy because my radio collection is
complete - excuse.

Well anyway - A single Tube 100 Watt CW Transmitter - that's my 829 project.

Have all the parts - now waiting for the weather to warm up so I can get to
work in the Garage.

You just know if she sees that tube chimney and her Dirt Devil, I might just
have to sleep there too.


-Biz WDØHCO

I posted a picture of my 829B on alt.binaries.pictures.radio for those who
have never seen one.

Well to answer the replacement question - according to GE Industrial Tube
Products Guide - (Dated 9-79)

You can replace an 829 with an 829B.

You can replace an 829A with an 829B or an 3E29.

You can only replace an 829B with another 829B.

Why? I don't know, that's what GE says.


Now what an you use an 829B for? Well I got one, it was a spare from a GE 6m
Prog Repeater our club had on the air. The replaced it with a nice Moto. The
Prog was up for grabs but no one wanted it and was about to be hauled to the
landfill so I took it.

It lasted about two days in my house working fine. Then I put it out of it's
misery and parted it out. It had lots of juicy power transformers, tubes and
sockets, XTAL holders and so on. Most ended up in other projects or repaired
rigs except for the 829B.

What to do with it ???

I decided to build a one tube 40 Meter CW transmitter.

Nothing special about that - all of us have built 6L6's or 117L7GT, 6V6,
6C4, 6GW8 or you name it peanut whistlers. Nothing more than an oscillator
connected to a string (antenna) blasting out a few watts.

But how about a SINGLE tube transmitter pumping out 100 to 115 Watts !!!

With minimal parts count to boot!

I got the idea from QST - June 1940 (page 26) in which Fred Sutter W8QBW
describes a transmitter using -TWO- 6L6's in push-pull supposedly outputting
100 watts to an end-fed Zepp.

I'd take the 100 Watt claim with a little grain of salt... but it's still
not too shabby for 12 parts and 2 tubes not counting the power supply.

The 829B can replace the two 6L6's and the circuit can be adjusted
accordingly. The output tank circuit will be PI instead of link which was
common back then. I also have a nice power transformer that looks like it
can do 700 mils at 750 VAC so I have plenty of head room to crank out more
power if it can handle it and the XTAL doesn't shatter.

I'll use forced air cooling because the 829B socket is already designed for
it. Was gonna go with a fancy blower but I noticed the XYL is not using the
small Dirt Devil handVac I gave her for her birthday. Will cut a small hole
in the chassis and placed a PVC pipe and attach the air hose to that. RCA
Manual says the MAX glass temp is 235 F so hopefully, the plastic vac can
handle it.

For a Glass Chimney, I took a drinking glass and cut off the bottom with a
glass cutting wheel. I was rinsing out the dust in the sink when she spotted
me. I told the XYL I had just taken out the glass from the hot dishwasher
and poured a little bit of cold water and the glass cracked and the bottom
fell out. I hoped she didn't notice the ends were nicely smoothed.

You should have seen her face. Classic...

It's the same look I get when I bring in another hamfest surprise and
promise it's the last radio I'll ever buy because my radio collection is
complete - excuse.

Well anyway - A single Tube 100 Watt CW Transmitter - that's my 829 project.

Have all the parts - now waiting for the weather to warm up so I can get to
work in the Garage.

You just know if she sees that tube chimney and her Dirt Devil, I might just
have to sleep there too.


-Biz WDØHCO

I posted a picture of my 829B on alt.binaries.pictures.radio for those who
have never seen one.

(Forgot to add this ear;ier:)

: I notice that the UK mil CV2666 has a completely extra top mica disc above
: the plates, extending all the way to to the glass, with ceramic inserts, as
: well as the bottom metal disk with ceramic inserts like the RCA 829B.

Like this Mullard version found on the web; it looks identical:
http://www.tnbstore.com.tw/photo/mullard/mu-829b.jpg

"alll the way to the glass" is not quite precise -
little metal fingers actually contact the glass at the edge.

(Forgot to add this ear;ier:)

: I notice that the UK mil CV2666 has a completely extra top mica disc above
: the plates, extending all the way to to the glass, with ceramic inserts, as
: well as the bottom metal disk with ceramic inserts like the RCA 829B.

Like this Mullard version found on the web; it looks identical:
http://www.tnbstore.com.tw/photo/mullard/mu-829b.jpg

"alll the way to the glass" is not quite precise -
little metal fingers actually contact the glass at the edge.

Greetings- I have one in a high level transmitting mixer I built in about
1960. The mixer took about ten watts in on 14 mhz from my HT-32B, mixed it
with the output of a crystal oscillator, drove the grids of the 829B ,and
the output was 144 mhz ssb, enough to drive a 4X-150A amp. The circuit was
designed by Don Stoner, W6TNS, and published in CQ mag., as I recall. The
tube was used in VHF military gear . It has a little brother, the 832A.
Jim, K8JL .
Dave wrote in
message news.com...
Hi all,

I just found several 829B tubes - believe it or not in my garage - I
must have got them in a box of stuff at a ham fest at one time.
A check on Ebay shows they're pretty much worthless for the sake
of dollars, but they're so COOL! With the two plate caps that are
actually just stiff pins, they look like little Martians.

I put a pair on my office credenza just to look geeky cool. Fresh
out of the box as NOS they look amazing - just like they were made
yesterday. It's a pity they have no value - maybe as a homebrew
project??

So can someone tell me what they would have been used for?
Something tells me they're a VHF power tube.

Any application as a one-tube QRP rig of any sort? Any stories
about using them in the past? I've built a lot of little rigs over the
years, but never knew about the 829

Thanks,

Dave

Greetings- I have one in a high level transmitting mixer I built in about
1960. The mixer took about ten watts in on 14 mhz from my HT-32B, mixed it
with the output of a crystal oscillator, drove the grids of the 829B ,and
the output was 144 mhz ssb, enough to drive a 4X-150A amp. The circuit was
designed by Don Stoner, W6TNS, and published in CQ mag., as I recall. The
tube was used in VHF military gear . It has a little brother, the 832A.
Jim, K8JL .
Dave wrote in
message news.com...
Hi all,

I just found several 829B tubes - believe it or not in my garage - I
must have got them in a box of stuff at a ham fest at one time.
A check on Ebay shows they're pretty much worthless for the sake
of dollars, but they're so COOL! With the two plate caps that are
actually just stiff pins, they look like little Martians.

I put a pair on my office credenza just to look geeky cool. Fresh
out of the box as NOS they look amazing - just like they were made
yesterday. It's a pity they have no value - maybe as a homebrew
project??

So can someone tell me what they would have been used for?
Something tells me they're a VHF power tube.

Any application as a one-tube QRP rig of any sort? Any stories
about using them in the past? I've built a lot of little rigs over the
years, but never knew about the 829

Thanks,

Dave

"Dave" wrote in message tnews.com...

What sort of plate caps were used? There are just pins, and
it looks almost as if there would have been a ceramic gizmo
like a tube socket to have bridged the two of them....

Fahnestock clips work fine, and they're easy enough to find (e.g.
Mouser), and they even add a bit of heat-sinking. BTW, to connect
both plates in parallel, put a clip on each plate, line them up
together and run a connecting wire through the screw holes, then
solder the whole thing (quickly) and you'll have a perfectly-fitting
dual plate cap.

73,
Mike, KK6GM

"Dave" wrote in message tnews.com...

What sort of plate caps were used? There are just pins, and
it looks almost as if there would have been a ceramic gizmo
like a tube socket to have bridged the two of them....

Fahnestock clips work fine, and they're easy enough to find (e.g.
Mouser), and they even add a bit of heat-sinking. BTW, to connect
both plates in parallel, put a clip on each plate, line them up
together and run a connecting wire through the screw holes, then
solder the whole thing (quickly) and you'll have a perfectly-fitting
dual plate cap.

73,
Mike, KK6GM