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.

(Mike Andrews) wrote:

: In .com (rec.radio.amateur.homebrew), Dave wrote:
:
: 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....
:
: On the transmitter for the AN/ARC-3, the plate leads just had push-on
: clips with a little bit of spring-loading, much like the contacts in a
: tube socket.

In the RSGB Amateur Radio Handbook 3rd Ed. they went so far (full
construction details) as to give details of a drilled and tapped (for grub
screw) 3/4" x 5/16" brass rod, for QQV06-40 / 5894 (has thicker pins)!

You might consider using the brass inserts from terminal connector blocks,
which already have grub screws and come in at least a couple of sizes.

Since the anode tank circuits then often used flexible copper strip to
possibly more brass rod in these British circuits, a bit of heat-sinking
would be taking place as well, I think. May as well use a heavy contact.

The 829B needs external neutralising, unlike 5894 with it built-in.

I could scan the few pages of the 1947 ARRL I have showing 829B, but you
might want to find the few years following for more, maybe improved ones.

(Mike Andrews) wrote:

: In .com (rec.radio.amateur.homebrew), Dave wrote:
:
: 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....
:
: On the transmitter for the AN/ARC-3, the plate leads just had push-on
: clips with a little bit of spring-loading, much like the contacts in a
: tube socket.

In the RSGB Amateur Radio Handbook 3rd Ed. they went so far (full
construction details) as to give details of a drilled and tapped (for grub
screw) 3/4" x 5/16" brass rod, for QQV06-40 / 5894 (has thicker pins)!

You might consider using the brass inserts from terminal connector blocks,
which already have grub screws and come in at least a couple of sizes.

Since the anode tank circuits then often used flexible copper strip to
possibly more brass rod in these British circuits, a bit of heat-sinking
would be taking place as well, I think. May as well use a heavy contact.

The 829B needs external neutralising, unlike 5894 with it built-in.

I could scan the few pages of the 1947 ARRL I have showing 829B, but you
might want to find the few years following for more, maybe improved ones.

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