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?

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