Bomber 4D32 tube

[Opcom]

4-65 is a high Z tube. It will not work well at 750 volts.

The 4-65 will work well at 750V. Its not a perfect substitute in a Viking but don't count it out too quickly.

[KE6DF]

B47, was that the Northrup flying wing?

Nope,

it was a 6 engine bomber built in the late 40's / early 50's to drop nucs on the Soviets.

A precursor to the B-52.

There were about 2000 B47s built.

I have a friend who served on them as a bombadier.

I don't think the flying wing ever made it into production.

Dave

[KM1H]

I once saw a pack of B-36's and B-47's fly over the house in Valley Stream NY during a show at Mitchell AFB. I think I had an orgasm    The 47's were a regular flyover.

As far as the 4-65 the efficiency tanks at LV, do the math on that chart. I never could get one to play well at around 800V in a Henry driver stage for a 3CX3000A7 industrial amp built for Perkins Elmer, and there was a big difference between NOS tubes. At 1600V ( went to a doubler) it did well and all tubes acted the same.

Carl

[w1vtp]

4-65 is a high Z tube. It will not work well at 750 volts.

The 4-65 will work well at 750V. Its not a perfect substitute in a Viking but don't count it out too quickly.

Patrick

At first, I dismissed your 4-65 comment but then - - - I thought - "yeah! that would be a perfect choice for my EICO 720!"  But, I have to figure out where I would cut the peek-a-boo window.  117 ma would be handled quite well by the 720 PS.  I'd probably have to gut out the clamper and install a bias supply.  I like it! But not for my Vikings.

Al

[w1vtp]

B47, was that the Northrup flying wing?

Nope,

it was a 6 engine bomber built in the late 40's / early 50's to drop nucs on the Soviets.

A precursor to the B-52.

There were about 2000 B47s built.

I have a friend who served on them as a bombadier.

I don't think the flying wing ever made it into production.

Dave

I seem to recall some B-47s at Loring AFB when I was up there in the 50's

[w3kmp]

I once saw a pack of B-36's and B-47's fly over the house in Valley Stream NY during a show at Mitchell AFB. I think I had an orgasm    The 47's were a regular flyover.

As far as the 4-65 the efficiency tanks at LV, do the math on that chart. I never could get one to play well at around 800V in a Henry driver stage for a 3CX3000A7 industrial amp built for Perkins Elmer, and there was a big difference between NOS tubes. At 1600V ( went to a doubler) it did well and all tubes acted the same.

Carl

Carl,

I grew up in Garden City. I remember my Dad taking me and my younger brother for a car ride around Mitchell Field, seeing the German POW camps, and  also going to the air shows.  If I remember, I think that they landed a B-36 there one time. I also remember being at Roosevelt Field with a friend, who's Dad worked as an A&E mechanic for Texaco.

Boy, long time ago!

Ken
w3kmp

[KM1H]

This will put the B-36 in perspective; thats a B-29 next to it!  The wing span is almost a half wave on 160.

Ken, I had several relatives at Grumman, Sperry and elsewhere building planes and parts during the war plus 2 uncles flying B-17's out of the UK and remote cousins in the Luftwaffe. I had to learn to kick ass at a young age because of my heritage

Carl

[w3jn]

The B-36 is THE most impressive piece of Communist-fighting iron ever constructed.  There's one at the USAF Museum in Dayton, OH.

Here's a clip from the classic movie "Strategic Air Command" starring Jimmy Stewart (as mentioned earlier), with an engine start, taxi, and takeoff with 6 turnin' and 4 burnin'.  Later in the movie Jimmy Stewart transitions from the B-36 to the Boeing B-47.

http://www.youtube.com/watch?v=3wvEzhyY9F4

[KE6DF]

I happened upon an article about the Univac I tube based computer developed in the early 1950s:

"UNIVAC I used 5,200 vacuum tubes,[6] weighed 29,000 pounds (13 metric tons), consumed 125 kW, and could perform about 1,905 operations per second running on a 2.25 MHz clock. The Central Complex alone (i.e. the processor and memory unit) was 4.3 m by 2.4 m by 2.6 m high. The complete system occupied more than 35.5 m² of floor space."

And it used 4d32s:

"The vacuum tubes used in the UNIVAC I were mostly of type 25L6, but the machine also used tubes of type 6AK5, 7AK7, 6AU6, 6BE6, 6SN7, 6X5, 28D7, 807, 829B, 2050, 5545, 5651, 5687, 6AL5, 6AN5, 6AH6, 5V4, 5R4, 4D32, 3C23, and 8008."

A typical PC is 1 million times faster.

[KX5JT]

I thinking to myself... why all these different tubes in the UNIVAC?  What on earth would a 4D32 be doing in a digital computer where surely almost the entire lot of tubes are used as logic gates and registers?  Seems pretty inefficient to use an rf power tube in there.  I know I am missing something... my mind is a little foggy though.. I just woke up from a really surreal dream.

[KE6DF]

What on earth would a 4D32 be doing in a digital computer where surely almost the entire lot of tubes are used as logic gates and registers?  .

I'm thinking maybe a clock driver for that 2.25 MHz clock??

Seems like you would need quite a bit of drive to clock 5000 logic tubes. Probably several 4D32s.

Another question is:

Why use a 25L6 as the primary logic tube? Seems to me a physically smaller dual triode like a 12AU7 would cut the number of logic tubes you would need in half.

[KX5JT]

I suppose that makes sense, especially since the 4D32 was a new and exciting tube at the time the UNIVAC was being developed.  As for the dual triodes i.e. the 12au7 etc... well maybe they had a great bulk deal on the 25L6!

[Mike/W8BAC]

Maybe it's my eyes? In that picture you posted Carl, I see the 6 prop engines but no jet engine nacelles. Maybe a B-36 variant?

I wonder what sort of piston engines they used? In the youtube video I see the blue smoke and sound of piston engine exhaust but the housings don't look large enough for radials. Possibly an in line V-12 Merlin or Allison?

Are any of those Univac I tubes 12 volt?

Mike

[KE6DF]

The B36 was first produced with only the 6 prop engines. Then, in a later varient (B36E?), they added two pods of two jets for a total of four jet engines.

Then I think they went back and added jets to some (but not all) of the earlier B36s.

According to an article I read, there were problems with the rear pointing prop engines not cooling properly -- not enough airflow -- and some engine fires.

[w3jn]

Maybe it's my eyes? In that picture you posted Carl, I see the 6 prop engines but no jet engine nacelles. Maybe a B-36 variant?

I wonder what sort of piston engines they used? In the youtube video I see the blue smoke and sound of piston engine exhaust but the housings don't look large enough for radials.

R-4360 radials.  The nacelles may not look big enough, but that's because the whole plane is ginormous.  The wings are thick enough the flight engineer can crawl thru them to maintain the engines in flight.

[The Slab Bacon]

I have always found radials to be fascinating. Just a wierd design that kinda defies a lot of what you think you know about engines in general. Also they always had an odd number of cylinders swinging off of a single crankpin. Just stack a few more in front of each other if you needed more horsepower. The "camshaft" (kind of hard to call it that) was an engineering nightmare. But they managed to get it all to work reliably.

With today's engineering and labor costs, it would be interesting to see what it would cost nowadays to develop such a power plant. Production costs killed the original Chrysler Hemi. (and a few other interesting power plants)

And then there was the Gnome, it just defied everything..............

[KM1H]

Did some of the early ones use JATO before the conversions? I vaguely remember something about them having to fly out over the Atlantic on takeoff.

The B-36 has to be one of the best looking bombers ever built. The B-52 is completely ungainly but sure is capable.

[WA1GFZ]

As nukes got more efficient the airplane got smaller to deliver Dr. Teller's surprise.
Boeing has a giant conventional bomb that weighs 20,000 pounds. Imagine the hole it can bore if dropped from 50K feet. It fills both bays of the B1.
Frank every time I go to P&W I crank the carb on the wasp display.
beautiful design. My Dad used one to generate cross winds during jet engine tests.

[Opcom]

The prop engines are the "Wasp Major" engine. 28 cylinders. Fires were an issue due to poor cooling.
http://en.wikipedia.org/wiki/Pratt_%26_Whitney_R-4360

[The Slab Bacon]

The prop engines are the "Wasp Major" engine. 28 cylinders. Fires were an issue due to poor cooling.
http://en.wikipedia.org/wiki/Pratt_%26_Whitney_R-4360

If you look at the cut-away for that engine, that thing has bazillions of moving parts
Makes you kinda wonder how they achived the reliability factor meeded for aircraft certification (and safety) that was a lot of stuff flying around. I guess that is why they called for 600 hour overhaul intervals. (not to mention the garbage that they use for oil in airplane engines)

[The Slab Bacon]

Here is one that will leave you scratching your head. This engine just seems wrong by all that you are used to.     

http://en.wikipedia.org/wiki/Gnome_et_Rh%C3%B4ne

or

http://en.wikipedia.org/wiki/Gnome_Monosoupape

And watch it run here   

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

[WA1GFZ]

I knew a B17 driver who blew a bottom jug off when he lost a ring and it filled up with oil. He had the piston sitting on his desk that held his smoking pipes.

[w1vtp]

10,000 HP on wheels!  What's with the water buckets at the end?

http://www.youtube.com/watch?v=s3iyOvLXxF0&NR=1&feature=endscreen

Al

[WA1GFZ]

Frank I think the logic was it ran cooler. Imagine trying to take a high speed turn with that spinning mass.
did the french ever build a good car?

[W2PFY]

Imagine trying to take a high speed turn with that spinning mass.

Actually it could out maneuver a fighter at altitude because of it's massive wing size and additional jet engines, where a fighter of the time would go into a stall. Just read that two days ago so it has to be true!