Bomber 4D32 tube

[w1zzz]

While Bob (W1XYZ) was helping me repair my 32V2 transmitter, he noticed that the 4D32 tube made by Ratheon had the words "Bomber stock"  written on it.  We guess it must have come from the post-WWII era, early 50s perhaps when hen Gen. Lermay was assembling SAC bombers. Attached is a picture of me (w1zzz) with the 4D32 tube in my ham shack.

[W7TFO]

That tube is a real treasure!

73DG

[ke7trp]

really cool.

[WA1GFZ]

Very cool. Maybe it came out of Jimmy Stewart's B36

[KB2WIG]

On March 22, 1941, Jimmy Stewart was drafted into the U.S. Armed Forces. He was assigned to the Army Air Corps as an enlisted man and stationed at Moffett Field, Calif. During his nine months of training at that base, he also took extension courses with the idea of obtaining a commission. He completed the courses and was awaiting the results when Pearl Harbor took place. A month later he received his commission, and because he had logged over 400 hours as a civilian, he was permitted to take basic flight training at Moffett and received his pilot wings. During the next nine months, he instructed in AT-6, AT-9 and B-17 aircraft and flew bombardiers in the training school at Albuquerque, N.M. In the fall of 1943, Stewart went to England as Commanding Officer of the 703d Bomb Squadron, equipped with B-24s.

He began flying combat missions and on March 31, 1944, was appointed Operations Officer of the 453rd Bomb Group and, subsequently, Chief of Staff of the 2nd Combat wing, 2nd Air Division of the 8th Air Force. Stewart ended the war with 20 combat missions. He remained in the USAF Reserve and was promoted to brigadier general on July 23, 1959. He retired on May 31, 1968.


http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=1670

[W3RSW]

I really liked his cold war USAF movie where they were just bringing out B-47's and he had to convnce his wife that his duty was to stay in the AF.  She kept pushing him to get in big business.

Strategic Air Command [VHS] (1955)

[WD5JKO]

Does anyone have knowledge as to how the 4D32 tube was primarily used? I had heard it was a pulse modulator tube used in radar application. The 4D32 has a massive cathode and therefore high pervience capable of peak plate currents of over an ampere at relatively low plate voltage. I ultra-modulated one once, and was able to get > 800w PEP from a single tube from a 100watt carrier (200% modulation). With a sine wave drive the internals of that tube would light the room with a combination of red and blue. The same tube took this abuse for years without complaint...

Try that with a pair of 6146's...they won't last a minute.

Jim
WD5JKO

[Tom WA3KLR]

I’m glad to see the comments here on the 4D32, as I’ve always felt that the tube was well engineered and under-appreciated for its engineering.  It has a built–in screen bypass of about 100 p.f. as I recall.  That tells you that it was intended for VHF in the original design application.  

I don’t think it was widely used and the ham HF transmitter applications would not have required the internal screen bypass.  Perhaps some military radio guys can state in what military radios they were used.

The 4D32 came out in 1950.  It was made only by Raytheon.

As I see it:
At the time, the 6146 hadn’t come out yet and so there was a hole in the availability of newer tubes in the 100 Watt range.  When the 6146 did come out in 1952, it quickly eclipsed other tubes the commercial market.

(I'm a former 32V-3 owner.)

[KM1H]

The 4D32 came out earlier than 1950 and maybe even during WW2 when many tubes were classified and not registered until later.

The first ham use was the 1949 Viking I followed by the first 32V the same year and later the HT-20.

Then during the Korean War it was used as a pulse modulator in a USAF radar. It never received a VT or JAN designation and the ones I have for the Viking I, 32V2 and spares are marked just USAF.

Considering that a pair could easily put out a 250W carrier at low PS and RF component cost its a very underated and under utilized tube.

There is also the 4D22 with a 12/24V filament.

Carl

[WA1GFZ]

I thought he drove a B36 in the movie. 6turnin and 4 burnin

[Opcom]

The B36 and the 4D32 are both most beautiful examples of engineering. I enjoyed seeing and touching the B36 at the SAC museum near Omaha. The 4D32 served me well for years in a Viking I in the old bootlegging days. It must have suffered some abuse but never really went flat.

There's still a new spare 4D32 here but the Viking was sold some time ago. The buyer was too cheap and wanted $20 off for "no spares". (incl NOS 807's and others..) hah. silly buyer. It's a heck of a tough tube! the only thing I can think of to replace with would be a 4-65. I never liked the twin 6146's Johnson used.

Whether the 4D32 says bomber on it or not, it is a "bomber".

[w1vtp]

I thought he drove a B36 in the movie. 6turnin and 4 burnin

I got up close to one at Loring AFB as a kid.  Also. watched a test stand wind up one of those P&W's R-4360s on a test stand. What an awesome experience for a jn.  Got inside a B36 and missed getting into the cockpit by 2 kids but did get to look down through the bombay doors to the ground way down.  Included is a shot of the transmitter on a 36

Al

[Mike/W8BAC]

Frank, Your right. Here is a clip from the movie showing Jimmy and one of my favorite actors, Harry Morgan (Colonel Potter) as flight engineer during a takeoff routine in a B-36. I'm sure during Stewart's carrier he saw the inside of one of these often.

http://www.youtube.com/watch?v=VGjyH2ulsCk

Mike

[WA1GFZ]

4-65 is a high Z tube. It will not work well at 750 volts.
AF needed low voltage tubes because of corona issues when you get up high. I remember the first radar system we pulled to 60 K feet. First thing we changed was the mylar insulators under the modulator transistors. Mica worked much better. Final tube ran at 1KV.
That is why the ART13 ran low voltage.

[WD5JKO]

. I remember the first radar system we pulled to 60 K feet. First thing we changed was the mylar insulators under the modulator transistors. Mica worked much better. Final tube ran at 1KV.
That is why the ART13 ran low voltage.

A quote from rec.audio.tubes:


The 3E29 was used as a RADAR modulator. Discharge a charged lumped constant (LC) transmission line into a magnetron & get a nice steep edged pulse of RF. The faster the edge the better the resolution of the system.


I wonder if the 4D32 did the same thing as the 3E29 (pulse version of the 829B)?

Jim
WD5JKO

[Todd, KA1KAQ]

The 4D32 came out earlier than 1950 and maybe even during WW2 when many tubes were classified and not registered until later.

The first ham use was the 1949 Viking I followed by the first 32V the same year and later the HT-20.

Actually the 32V-2 came out in 1949 along with the Viking I. The 32V-1 came out in 1946, clearly pointing to the WWII years as the source of the 4D32.

Was probably used in in some wartime RADAR and/or countermeasures set up. It certainly has that pulse-tube design look to it.

Great shot of the ART-13 in the B-36, Al. It doesn't appear to be hooked down to anything, though. Wouldn't want that thing flying around in the cabin if the plane hit turbulence. The B-36 was out of service when I was a kid, but I recall hearing them referred to as the Flying Cigar. Definitely a lot going on with one of those beats. Pretty amazing to think of it all coming together for controlled flight.

[WA3VJB]

B-17.

They rool !

I posted this last year; still feel lucky to have taken the flight.


 http://www.cnn.com/2008/US/04/11/usaf.flyover/index.html?iref=allsearch

On the "bomber" tube, I once saw a 4D32 with a ceramic base. And I have a JAN type with red paint rather than etched. Date code into the 1970s.

[KE6DF]

Searching the ARRL pubs archive, the first mention on the 4D32 is March 1946 in a brief article about recently introduced tubes.

No doubt it was a WWII development, but may have made it onto the market a few months after the war ended.

[DMOD]

Wow, great find.

I purchased a spare 4D32 for my Viking 1 as backup and it too was a Raytheon tube.

The paperwork had the serial number of the tube and said it was tested in March of 1952, but no bomber markings, dang it.   

Phil - AC0OB

[KC2ZFA]

in terms of tube capacitance, one 4d32 is like two 6146's in parallel. So, rf-wise, the 4d32 is a drop-in (after some hacking and some rewiring).

peter

[WA1GFZ]

or install a pair of 4D32s and run them light so you have plenty of peak emission for monkey swingage

[KC2ZFA]

or install a pair of 4D32s and run them light so you have plenty of peak emission for monkey swingage

mmmm...so, if one puts two of them into, say, a dx-100 then the only
change IN THE DRIVER portion (one would have to redesign the pi-net for the humongous power) would be changing C45 (see below) to 22pf ?

[Jim, W5JO]

Does anyone have knowledge as to how the 4D32 tube was primarily used? I had heard it was a pulse modulator tube used in radar application. The 4D32 has a massive cathode and therefore high pervience capable of peak plate currents of over an ampere at relatively low plate voltage. I ultra-modulated one once, and was able to get > 800w PEP from a single tube from a 100watt carrier (200% modulation). With a sine wave drive the internals of that tube would light the room with a combination of red and blue. The same tube took this abuse for years without complaint...

Try that with a pair of 6146's...they won't last a minute.

Jim
WD5JKO

The 4D32 were just as scarce as hen's teeth until a few years ago when the government sold their stock that was warehoused.  Price went from over 70 per tube down to less than half that, about 5-10 years back.  I recall the early days of eBay when guys would advertise them as a Collins part.  The tube was introduced in 1950 and the military bought most of the production I was told.  For what I don't know, but when they sold them  to surplus dealers the price took a real dive.  Now guys buy them in pairs to have a spare.

6146s might not take what you did but the 6293 might @ 350 volts at 3 amps peak.  They, too, were beam power pulse tubes for radar.  If you use them in place of a 6146, they will last a good long time with a lot of  abuse especially if you cool them.  They have a hefty plate and cathode.

[K9PNP]

I thought he drove a B36 in the movie. 6turnin and 4 burnin

You're both right.  Started out in 36's and ended up in 47's in the movie.  We [ARADCOM] did a lot of work with SAC.  Knew some good guys there.  Now we are both history.  Before I get to where I can't travel easily I hope to get to Wright Patterson AFB to see the B-36 there.  And some of the other types that I talked to on the UHF.

An old Raytheon Special Purpose tube manual [no date] shows Vmax on plates as 750, Imax 300 ma.  50W dissipation.  135 W output.  For the RK4D32.

[WA1GFZ]

B47, was that the Northrup flying wing?