harder to move than a truck with flat tires

[John K5PRO]

Yesterday we relocated a pristine RCA BTA250L from KRSN's studio in Los Alamos to my garage. It has an Atomic Energy Commission property tag on it, from the 1940s, after the Manhattan Project when the secret city went public. Attached are some photos of the move, before I put them on website. Aluminum was in short supply during the war, so the L was built entirely from steel, with 1/8 inch thick metal wrap around one piece shell. It is the heaviest hunk I have ever moved. Took 6 of us to get it out of the station. I was always concerned of getting flattened if we lost control, like Wyle E Coyote when the Roadrunner drops the safe on him.

Note the creative use of a come-along and chain, using the back door to pull it upright from the trailer. Lucky the wall didn't buckle or the cable didn't break...

It came with an extra modulation transfomer. The one that was connected is a 900097-1, and the spare was identical in size but marked XT-1690. On Patrick's J's BunkerofDoom page, there is a photo of his 250L with a XT-1690 in it. Did RCA have different p/n's for the same iron, like a spare part number and the original part?

[John K5PRO]

More photos of the transmitter move in Los Alamos.

[John K5PRO]

More photos of the move. Accompanying me was Bob Henry, Richard Summers, David Sutton (the station co-owner), and Brent ?. A bystander walking past was cornered and enlisted when we laid 'er down on the trailer. Not something to be taken 'lightly'.

[John K5PRO]

Now we have it out of the station, that glass door was worrisome.

[John K5PRO]

Got it on the trailer. My Tacoma sure felt the load. Note the clever way we lowered in in the garage. We were whipped, and running out of safe ideas. As long as no one was under that thing...

[John K5PRO]

Here's the scary part, using a come-along to raise it upright from the trailer. I blocked the bottom with timbers against the wall of the garage, so that it wouldn't kick out and slide.

Here is the proud owner next to a classic. For 250 watts, RCA sure over-designed it. Back then, value-engineering wasn't needed to be competitive. I was looking over the instruction manual for Broadcast Electronics 4MX-50 50kW rig, and its only slightly larger, but lighter (very little iron and no tubes).
250 Watts       85"H x 40"W x 22"D, 1360 lbs
50 Kilowatts    87"H x 45"W x 35"D, 1115 lbs

[WA3VJB]

John congratulations on the new baby !

This is one of the nicest sequences of photos I've seen of a Transmitter Rescue, thanks so much for posting.

That transmitter sure looks pretty; hasn't been messed with much, and very clean.

The property tag is an awesome bit of history too. You'll have to say you're "on the atomic transmitter" whenever you get on with us.

Did you get any history stories from the station owner?

[k4kyv]

I have used an RCA XT-1690 mod transformer in my HF-300 rig  for almost 30 years.  I have a spare one just in case, but probably will never have to use it.  Those things are indestructible!  RCA really conservatively rated it.  I have pushed mine, at 1 kw DC input, all the way up to 150% positive modulation peaks and it just kept on humming along, with no noticeable temperature rise after an old-old buzzard transmission.  It is perfectly quiet with zero talk-back. I use a UTC LS-103 (50 hy/500 ma) as modulation reactor.

BTW, has KRSN ever resolved their antenna dilemma?  I occasionally listen to their streaming audio.  Great little station, and I hope they can stay on the air and that they keep the same format.

I use the line amplifier I got from them every day.  I split it into two sections and rebuilt one of the 2 channels onto a separate chassis.  It was modified to high-Z push-pull input using a pair of high mu triodes, and I use it as the preamp for my balanced-output D-104. The other half still works fine, but it is sitting on the shelf right now. The unit was definitely homebrew, but whoever built it did an absolutely professional job. I kind of hated to touch his excellent wiring, but I had no use for both amplifiers on the same chassis. I can't wire up anything that neatly, no matter how hard I try.

[flintstone mop]

THAT ALMOST looks like a RA250.
But Roger the dead weight. I think there was competition to see who could make the heaviest 250 watt TX back then. GAWD that RA250 I had and shipped to DERB was EVIL to move!!!!
FRed

[KA2DZT]

Nice transmitter,  1360Lbs, thats not heavy.

Try moving a 4000LB milling machine.  I moved 1300Lb lathes by myself.  It can be done, but you have to think about it for a few days.

Nice pictures, you guys did a great job,  no damage to the rig and nobody got hurt.

Thats a good day.

Fred

[Steve - WB3HUZ]

Very nice looking transmitter. I'm sure it will sound just as nice!

[Bill, KD0HG]

Does it have glow-in-the-dark meters, John?

[Steve - WB3HUZ]

It has glow in the dark tubes.

[N0WEK]

It's a beauty!

Great job!

[John K5PRO]

I don't think the meters glow, but there is a neat light that illuminates the front controls from underneath the upper flap. Only one tube (8008 Hg-vapor rectumfinder) had a loose plate cap sealing, a bit of JB weld seems to have fixed that. The newest tubes in it have 1962 written on the bases. I will pursue the history, but I am almost "sure" the station went public over the air around 1947. Read that somewhere a long time ago. Before that they were carrier current in the secret city, probably a smaller homebrew rig, but then again, maybe they had the 250L then. Man named Burns sold the station a decade ago, and it went through several owners, the first one bankrupted it. The second one (David) got it after it was dark. He and his wife are newcomers to broadcasting and they have had to learn a lot. I diddle around there occasionally, when they need help, that their engineer can't handle or won't. Mostly moral support.

Don, they finally got their antenna relocation through zoning, and it will be on county land near a golf course. Ron Nott may supply tower, which is just under 200 feet; I think they got out of needing a top beacon. The new location for TX will happen after winter, and that will free up another big rig, a mouse-infested hacked up ITA1000 (spoken for) that is trapped behind their MW1 backup. Their Harris DAX1 is about size of a little apt. refrigerator and works like a top.

Studio will relocate first, to a cheaper rent location, they are finally getting the knack of cutting expenses to stay on the air. The present landlord is a pain, as they cannot put up their Marti STL antenna, which I already tested on the roof to reach the TX tower pickup antenna. So they are paying telco for some sort of wireline every month. New site will be LOS, so they can put STL back up and save another $250 a month....

Thanks for the info on the mod transformer. RCA made some good stuff back then.

[John K5PRO]

Right on about the RA250 comparison. I thought the same thing seeing all those meters. I helped relocate a RA250 at WUVT in 1979.
But the package size of the 250L is more like the size of the RA1000.
I stripped the carcass of one of those 5 years ago in Roswell, and it was similarly overdesigned and beefy.
Does that make me an ol' buzzard? No, not until I get one of these monsters moved to 160 or 75 and plugged in....

Life is too short, too much to do, what next?

[ke7trp]

Boy you guys had all the right tools and man power.  Did not look to bad.  I Just cant imagine why they would build that big ass transmitters for 250 watts    However, It is one of the coolest looking rigs I have seen!!   


C

[Todd, KA1KAQ]

It's a beauty, John. Has a very strong Art Deco flavor to its design. And the conditions looks excellent overall, which just adds to the coolness.

It would be interesting to do a side-by-side with the RA-250, they are indeed quite similar looking. RA-1000 is half-again as wide, nearly twice as deep, and weighs in around 2400 lbs. Collins 300G is in the same class as the other 250s, weighs in at "approximately 1370 lbs" according to the manual. Guess they didn't want those 810s getting out of control and taking over the studio so the built a fortress around 'em.

First thing I did with the 300G was add 6 casters to its base while the side panels were off and it was on its side(TNX W2ILA for the repeated nudges). Collins police be damned, practicality rules. Wonder if you have plans to do the same John, or will install it with plenty of room all around so moving later won't be necessary??

[WBear2GCR]

They built it big because IF they built it small and light it COULDN'T POSSIBLY  BE GOOD OR HAVE ANY POWER!!.   And then they couldn't sell it for the right money, or even sell it at all... times have changed.

                   _-_-bear

[John K5PRO]

Todd, definitely considering casters. Big ones. Unfortunately, that thing is easy to tip forward since it is thin and top heavy. So I may even have outrigger casters that provide some stability. Would hate to be rolling it, hit a crack in the floor and have it fall on top of me! Wow, didn't remember that the RA1000 was that heavy, but I guess so, since it had oil/tar potted transformers throughout. I still have a couple of pieces from it.

[W3SLK]

Heh, heh! I remember when Duane, KK4AM (sans KN0R), got a RCA 250 from a station. He figured if we pulled out the mod and plate iron, that JUST him and I could move the transmitter onto his Dodge, (Mutsubishi) Ram pick-up. We started to lay it down when I convinced him that if we got it down, we wouldn't be able to get it up again. Eventually he hired 4 guys/gorillas, to muscle this thing out of the basement of the station. If we would have put that thing in his pick-up, the front wheels would have been off the ground LOL! I should have bought it off of him. If memory serves me, you can add an extra 810 to that box with little effort.

[Opcom]

John, I'm really glad you got that TX. That is the most weight per watt I bet of any 250W TX. There is another guy in NM that just bought my non-working 'spare' one, I hope he will post up here. The BTA-250 is one of the most beautiful transmitters ever made. No expense was spared on fit and finish. I hope downloading the manual pages worked out. If not I can create a PDF.

[Steve - WB3HUZ]

When did you make the move? I was in your area last week John.

[Mike/W8BAC]

Nice rig John, I love the chrome! I look forward to hearing that beast on our bands.

Mike
w8bac.com

[John K5PRO]

Steve
I moved it Saturday. Sorry, missed you.

BTW, I have a scanned article for the AM Window technical information, a Carl Smith paper on the use of short vertical antennas, circa 1947.
While it is beyond AM itself, there are many AMers playing with vertical resonators, towers, and this is classic stuff, on skirts, top loading, grounding efficiency, with plenty of real measurements in the MW band. Let me know via PM how to get it to you for posting.