The AM Forum

I have a 7-foot rack Class B/C transmitter using 810 finals and modulated by 805's.  The power supply deck weighs around 200-300 pounds; HV is 4000VMT and supposedly 1 or 2 amps; filament transformers are 10V and appear to be 20-40 pounds in weight each.  The modulation transformer is a T-11M77? at 125-300 watts.  Built in the 1930's or 40's.

Is this a saleable item as a resoration project or better off parted out?  What would it be worth?  I have no idea but thought some of you might have suggestions on what the market looks like for an old homebrew boat anchor that must weigh a total of 700 pounds.

It is a bit dusty but I have some photos on Imageshack if you want to look at them: 
http://imageshack.us/g/43/015copyl.jpg/

Thanks!

Russ
WA1JFX

That looks to be a well-built, classic design transmitter. 

By all means, I'd clean it up and get it going.  The necessary tubes and parts are available without too much trouble.

If you don't want it, many out here would.

Please don't break it up.

73DG

I agree, try to find a good home for it intact.

The panel layout, the needle knobs, the verniers, shown in your photo below, are all classic construction design, authentic to the style of the era.

My first "big rig" came to me the same way I am hoping yours will go to someone.  I found it posted on an index card at a HAM radio shoppe in Laurel Maryland in 1976.  The guy who started building it in the early 1950s abandoned the project for SSB, and he died in 1975.

His friends, settling his estate, posted the card thinking someone might be able to cannibalize the RF deck to make an amplifier, with no thought given that anyone would want to finish a high level plate modulated AM rig.  SO there I was. 

Had a lot of help, but got it on the air over Christmas break, right about this time of year, and it's been running well on 80, 40 and 10 meters ever since.

PLEASE consider passing that along to someone, with any history and storytelling you happen to know about the rig's builder and operator.

Other than for the layer of dust, it looks in great shape for a homebrew rig its age. Once cleaned up, it should be easily restorable.  Usually when you find a rig like that, it's been cannibalised and half the parts are missing, inevitably the hardest to replace.

It would be a shame to break it up for parts. Working specimens of that style of construction are becoming ever more rare.

Not sure what it would be worth, but I'd say a few hundred bucks at least.

Why not try to get it running and on the air? Even if you still decided not to keep it, that would make it greatly appreciate in value, if it was known put out a good quality signal.

As others have said, I would definitely not break it up for parts.  The construction is done well and just needs a lot of cleaning.  When these old homebrew transmitters are gone, that's it, their gone.  Preservation is certainly a worthy thing to do and this is a good candidate.   

Selling it is not going to bring tons of money.  I would think $300.00 would be a fair price.  If you part it out, you will likely get a little bit more, but then the transmitter is destroyed and gone forever.

It's yours so you will have to make the choice, but I am glad you asked for opinions. 

I am curious what your connection is to the transmitter?  A bit on its history would be interesting. 

73,
Joe, W3GMS

Gentlemen,

The rig was built by W1HJP, Doc Hewson, now SK.  Originally the rack was over 8 feet tall.  There is a homebrew transmitter, receiver, antenna tuner, and a tube type speech processor that goes with the rig.  I believe the design came out of an old QST.  Doc was an engineer, so he was not intimidated by metal work or electronics.

The rectifier tubes were mercury-filled.  I would think those are scarce and maybe dangerous to have in the shack, considering the health risks with mercury.

I don't have the expertise to get this rig up and running.  I would have to have a lot of help.  Maybe I should start a museum...

I appreciate the comments and concurr that the rig is a fine piece of work that should stay intact.

Russ

What a treasure.
Too bad I am in California, I would jump on that immediately. It seems you East Coasters
have more of that stuff floating around. I wish you luck in finding a good home.

I'd love to have a rig like that. But there is no way to get it to California.

Better try to find it a home as is.

Dave

That is a very cool rig...Don't part it out...don't worry about mercury rectifiers....$200-$300 would be a fair price...Good Luck....

Nice old transmitter and I see on Google Earth that you are in an area of Maine where you can get there by car ;D ;D ;D

If your going to offer it up for sale, please try to make sure it won't go to an eBay flipper. If it were mine, I would want to trade it for a working transmitter that you may have been looking for. That way you'll feel more satisfied and you would know that it went to a good home.

There are people here on AMFone who live in Maine who could probably help you get it going.

That's a nice looking old buzzard transmitter. It would be a shame to break it up for parts. It reminds me of the 812 rig in my shack. You can get that one going again with a bit of work and caution. It would be worth the work to anyone here who appreciates that type of construction.

Bill KA8WTK

I wouldn't worry about that.  Probably good ol' 866As or maybe 872As.  Not dangerous to have in the shack unless you allow them get broken and let the mercury contaminate something you eat, drink, breathe or soak into your skin. Many of those who post here on this board still use them in operating rigs.  I must have a couple of bushels of new and used ones in my tube collection, and have at least 9 operating MV rectifier tubes in my homebrew transmitters.

Those wonderful, miraculous, environment-friendly, energy saving CFLs that are supposed to replace incandescent lamps are filled with mercury, too, as are the old fashioned long fluorescent tubes we have seen in use for many decades. Nobody seems to be concerned about those.

    Black Wrinkle :P

Hmm, methinks shipping to the UK is going to be a request too far :(

I would give this a home without a second thought - I really do live the wrong side of the pond!

He said  Black Wrinkle.


klc

Nice old xmtr, looks to be well built and designed.  Needs a major cleaning and going over before it should be fired up.  All the wiring should be carefully checked.

Well worth saving.

Fred

By all means, keep it intact. Concur with all responses. Items like that are hard to find. I have a small rig in black wrinkle I am going to restore when I retire. Thanks for sharing the photos!!

Anything with a steering wheel for the power supply is worth keeping. That means it has more power than you can imagine.

Do you live near Larry NE1S (he's in Gray)?

Larry's RETIRED now, so might have time to help you with it...and he knows a lot about rigs like that.  I am too far away, else I would help you with it.  The modulator is a bit underpowered for my personal liking, but it should play reasonably.

810s are not bad at all.  A pair modulated by a pair would be rather awesome - maybe that would be a reasonable thing to do.  If the mod transformer would handle it, a pair of 810s will run close to a KW input in class C, particularly with a good high voltage on them.

You could keep the basic structure of the transmitter and include some modern upgrades such as a direct coupled solid state audio driver, and a stable VFO/RF driver.  You'd end up with a top-notch, old-style HB transmitter!

This is EXACTLY the sort of thing I'm looking for. too bad I'm in Southern Nevada. A little closer and I would drive out to get it!!

sigh...

Dave

Keep it and put it back together. That's too classic to part/scrap!

Please do not part it out.  You have some good ideas posted here.  What possible harm could MV rectifiers cause? -- That is unless they are dropped.  I've worked with MV rectifiers since I was 15 - I'm going on 75 now and am in good health and reasonably alert (engineer at Raytheon).  I always knew even back in '52 when fearing mercury was not fashionable that it was bad to drop 866s so always handled them with great care.

This grand old piece of technology is worth some TLC

Al

If you are worried about MV rectifiers, just swap them out for 3b28s or 4b32s and you are good to go. Then you are still in hollow state.

But if it were me, I wouldn't worry about it.

All of us that are over about 40 probably had someone stick a mercury thermometer in our mouths a few hundred times when we were kids. And that didn't kill us.

You come in contact with stuff worse than mercury every day.

Looking at his intro to this topic, he does not want to tackle getting this working.
So someone here make an offer and then you can be a part of history.
I see an entire Winter of clean-up and documenting the electronics. Control circuitry, power supply voltages, tube line-up, what's in and what's out.
The major pieces are there and probably some $$$ needed to get it back to good health.
I'm not a restorer type and do not have a junque box to try something like that myself. I did it once for a 1950's TX and that was in my rich days.
Fred

I hear the sentiments/philosophy about preserving the old timers work from the old days when AM was on the maturity curve just prior to SSB.  In looking at old buzzard gear on eBay and elsewhere, there are are many variations.  Old Wrinkle must have been a phase/fad...  Wow, I didn't realize the history and technology is so revered my many still today.  Thank you!

I took a couple more photos.  Note the white spots on the wrinkle finish in one photo.  Can this be removed without harming the originalality?

What is that iron candle-looking "thing" next to the 810 final?

Russ

I think you are referring to the neutralizing cap. These were used to reduce the possibility of parasitic oscillations. You want the final amplifying the frequency you want, not oscillating by itself on other frequencies.


Bill KA8WTK

Its not something that interests me as I already have enough old iron but I hope somone on here goes for it.

Id be interested in learning more about the receiver and might want to take a go at that.

Carl

I see WW2 military transmitter parts in it, so it is a post-war build.

73DG

Those are two completely seperate things and treated differently.

Neutralization is to keep the amp from becoming a TPTG oscillator somewhere within the range of the tuning caps due to the tubes Cgp allowing a feedthru path. To compensate a sample of the plate RF is sent back out of phase to the grid effectively acting as a notch filter to cancel the feedthru.

A parasitic is a VHF oscillation caused by a combination of tube structure and its internal capacities and the circuit between the anode and the output network. It is normally suppressed (Its called a parasitic suppressor naturally) by a few turns of wire around a carbon resistor. Its purpose is to suppress the parasitic from even occuring and sbsorbs very little power if designed correctly.

Carl

Restoring black wrinkle is really easy, unless it's flaking off.  Pull the meters and other stuff off the panel, get some Westley's whitewall cleaner, and wet the panel down with water in a sink.  Then spray the hell out of it with Westley's, scrub with a brush, and rinse well. 

If all the crap's not gone, then get some black satin spray paint.  Dampen a lint-free rag with mineral spirits, spray a bunch of paint into the rag, then apply to the front panel like you would be waxing it - circular motions, keep moving.  Add paint and thinner to the rag as necessary and even the paint out.  It'll look brandy=new when you're done.

I'd like it but no room and no $$ since my truck just ate $1500 last week.