My next transmitter project

[WQ9E]

I made a 140 mile round trip yesterday after work to pick up my next transmitter project.  It is a set of homebrew decks for a medium power AM transmitter.  The RF chain uses a 6L6 crystal oscillator with 807 buffer and 8005 driver to a pair of 808's in push/pull.  The modulator is a pair of 811's into a 250 watt transformer.  I have some matching oil filled HV caps in my junk box which will fit the HV deck (866 rectifiers with 1.5KV B+ out).  The "low voltage deck" provides 500 volts for the oscillator and buffer and 1,000 volts for the 8005 RF driver and 811A modulators.

 I need to build a speech amp and I will use a pre-war Meissner Signal Shifter for a VFO.  It came with a homebrew rack but I am going to use some cherry left over from another wood working project to build a new rack for it.  I am tempted to build in some glass viewing windows into the rack using some of the wavy glass from the original windows from my house.  Before I bought it all of the windows were replaced with new Anderson units and the originals were all stored in the barn.

When finished this will be paired with a RME-9D receiver.

Rodger WQ9E

[WQ9E]

One additional picture, the underside of the exciter deck.

[ka3zlr]

Wonderful Catch Roger it's found a good home.

73
Jack.

[Todd, KA1KAQ]

Excellent, Rodger!

This is the nice stuff to find and resurrect. Commercial gear is fine too, and yields more help from the large numbers of users. But the HB gear from this time frame is always a joy. From the design and layout, to construction techniques and materials used, seems there's always something to be learned.

Looks like the guy was a true craftsman, right down to the 90 degree bends in his wire. Is that solid copper buss wire?

Since you're going to build a rack from scratch, I can suggest a method of viewing used on one of W1PEG's old rigs I have here. Though the front panels are all solid, he used an open-frame rack, and enclosed the back with a wooden frame covered in brass screen, so that the entire rig is viewable from the sides and back while in use, yet thoroughly shielded and safer than being open. These racks still show up from time to time in decent shape, a coat of black wrinkle and away you go. But even with a cherry frame, you can still utilize the same approach. If I can locate a picture easily, I'll post it later.

I've got one of the later Meissner Signal Drifters here, will be curious to hear how you like yours.

[W2PFY]

And here are a pictures of it when it was still in rack. Hope this helps. The original seller sent these to me. I'm very happy to see it went to someone who will make it work. I was afraid it would be parted out transformer by transformer and sold to the highest bidder.  




Updated broken link. 03-22-2020 Work in progress...

[WQ9E]

Thanks for the comments. 

Jack,  it has found a good home and it has a lot of vintage company.  I have been going through my old literature and I have found some close rigs but not this one yet so if anyone recognizes the lineup from an article I would appreciate the information. It is possible it is a one of a kind design.

Todd, the wire is solid copper but most of it does have a cambric sleeve over it.  As far as I can tell, he used regular bare buss wire and then sleeved most of it.  The twisted wire is a different type but the color closely matches the sleeves on the other wire.

I like the screening idea and I would appreciate a photo if you come across one.  The screen would be nice for shielding.  I have used the Signal shifter a little bit (mostly as a driver while testing the Gates BC-250) and it seems to work OK.  The drift on 80 wasn't noticeably worse than my Ranger or Valiant.  With the 3 shielded coils it is the perfect exciter for a final that stays on one band most of the time.

Terry, thanks for the link to the photos and I downloaded them and will keep them with the other documentation that came with the rig.  It is definitely going to stay in one piece.  I have the rack that came with it but the panels (plywood) were discarded before I got it.  The rack is still in the back of the pickup since it had been stored in a warehouse that was inhabited by brown recluse spiders.  I have to spray for Japanese beetles again this morning and I am going to hit the rack with that and then hose it down later with my pressure washer.  The rack is much taller than it needs to be for this rig so I plan to do a custom rack that looks as nice as the rest of the rig.  The existing rack will probably get modified to use with some of my rack mount commercial receivers.

Rodger WQ9E

[W1AEX]

One additional picture, the underside of the exciter deck.

That is a beautiful example of point to point wiring. I'm glad this is heading into your station rather than into a landfill somewhere!

Good luck with the restoration project!

Rob W1AEX

[N3DRB The Derb]

made my day. that is awesome HB, the way it's meant to be.

dont use that wavy old glass though or your modulation will be distorted, plus you wont be able to put goverment  EnergyStar decal on it unless you use double pane viewing windows.     

[WQ9E]

Tim,

Instead of the energy star decal I thought with the age of the rig a WWII gas rationing sticker will be more appropriate.  Or maybe we will get electricity rationing decals soon.   This morning I was about 10 minutes into my operation as net control for the Midwest Classic Radio net and just after I hit the PTT for the Ranger/Desk KW the lights flickered and went out.  Fortunately power was back on in about 2 seconds but at first I thought I had a major "zorch" event.  I have a sneaking suspicion it has something to do with the new "wind farm" that just went online a few miles away.  This is the third intermittent power interruption since they spun up the generators 2 weeks ago and all events have happened during clear weather.

I finished up my RME-9D tonight with the final steps being a meter movement transplant and alignment.  This receiver will be a great match for the "new" rig so I am highly motivated to get it going as soon as possible.   My first classes are on Monday but I think after teaching a couple of sections of international marketing I will spend some quality time working on a purely domestic rig 

[K5UJ]

that's cool Rodger; I posted a link a day or two ago to some Thordarson plans for pre WWII gear, and among them a speech amp so you may have a look at it to get ideas? 

Heard Don K4KYV booming in on 3886 an hour ago with Jack K9ACT and one or two other guys.   Was listening on my new 1/4 w. 75 m. vertical but too hot and too late in the shack to fire up some tubes and butt in.

[K5UJ]

oh yeah, the post with the http link was over in the books and printed matter section.

73

Rob K5UJ

[W1UJR]

Hi Rodger,
Couldn't be in better hands OM!
I've seen your past work, you're a first rate craftsman, and I greatly appreciate the effort you put into it!

The home brew stuff is extra cool as you know that some now old buzzard put his heart and soul into it.
Wonder if you got any documentation on the rig?
Once you get it back together, you can almost imagine his excitement, after months of building, turning the power switch on and watching for smoke. Please send over photos of the process and final product, I'd be delighted to see how it goes together.

I like the chassis, nicely, well laid out, the Masonite front panels remind me of the rig I picked up from Carl 1KPD a few years back, see photo below. Now just add a nice cherry wood rack frame and you're all set!

Looks complete, but let me know if you need any parts.

-Bruce

[WQ9E]

Bruce,

Thanks for posting those photos!  That is a neat looking piece of gear.  I was thinking about using masonite panels for this rig also since the original (discarded by the "interim" owner) were made of plywood.  The masonite suree looks good on that rig.

The person I bought it from got it from the estate of W8UWI and he noted that there was no documentation with it.  The seller had spent some time around broadcast gear and he put together some very useful documentation during the time he had it. 

He thinks that originally there was a separate power supply for the modulator but that was missing and he planned to run the modulator from the same supply (1,000 volt) that also supplies the 8005 driver tube.  That is a decision I will make during rebuild, whether to build another power supply deck for the modulator or borrow power from the existing supply.  I have to go back to my UTC catalogs to get the ratings for the S-74 transformer; the power supply uses both sets of secondary taps to provide a 500 volt supply for the 807 buffer and 1,000 volts for the 8005 driver.  The plate supply is used only for the 808 tubes and uses a UTC S-49 (300 mil rated) to supply 1,500 volts.  I do have a suitable transformer and set of chokes for a separate 1,000 volt supply but they aren't the nice matching S series UTC so I hope that the existing 1,000 volt supply is large enough to handle the modulator load.  Otherwise, the new supply will be built in the same style but hidden at the bottom. 

Looking at the tube data, it looks like a pair of 808's were designed for 300 to 400 watts input in plate modulated service.  Hopefully the 808's included are good, otherwise I have 3 NOS Eimac 100TH tubes that hopefully are good and will fit the socket but will require a different filament transformer.

I will document the rebuild and testing complete with photographs.  It will be fairly easy to test it one deck at a time as I go through them.

Rob, thanks for the link to the speech amp.  I also have a couple of boxes full of never used UTC audio transformers I picked up at a hamfest for a grand total of $5.  Among them are an LS-55 and LS-57 output transformer; I could use one of them in the speech amp and make some of the audiophiles cringes at such a lowbrow use of a linear standard series output transformer

Rodger WQ9E

[WQ9E]

And a photo of the RME-9D.  It is running currently with a substitute S-meter until I find a correct replacement.  The entire meter was missing when I got the receiver and the current one has the guts out of a Simpson movement coupled with the scale from a spare RME-45 meter.  I also need to dig through my knob collection to replace the incorrect one that is on the antenna trimmer.

I am not sure how long the receiver was out of service but it didn't require a lot of work.  I replaced all of the old wax paper caps and found only 3 resistors significantly out of spec.  I cleaned and lubricated the tuning capacitors and switches and replaced a weak 24A BFO tube.  The alignment was surprisingly close and the IF alignment was still perfect.

The receiver plays nicely and seems pretty stable on the lower bands.  It is the only receiver I have where the parallel mode of the crystal filter is actually useful-I guess I need to go back and investigate my other receivers that have this series/parallel filter choice to see what I missed during repair.  The photo was snapped while it was copying K9ACT in QSO with W4FMS on 3880.  Both stations were good copy and at the time the antenna was a 20 foot piece of wire sitting in the basement since I had the outside antenna disconnected because of approaching thunderstorms.

Rodger WQ9E

[W1UJR]

And a photo of the RME-9D.  It is running currently with a substitute S-meter until I find a correct replacement.  The entire meter was missing when I got the receiver and the current one has the guts out of a Simpson movement coupled with the scale from a spare RME-45 meter.  I also need to dig through my knob collection to replace the incorrect one that is on the antenna trimmer.
Rodger WQ9E

Oh man, is that BEAU-TI-FUL, you lucky dog you! 
Love those round dials, thought the RME-69 looked pretty, that takes the cake!

[WQ9E]

Oh man, is that BEAU-TI-FUL, you lucky dog you! 
Love those round dials, thought the RME-69 looked pretty, that takes the cake!

Thanks Bruce but I still don't think it compares to some of the neat rigs you have posted lately.

I live about 25 miles from the original Peoria factory so I like acquiring the gear.  I am still looking for one of the setups with the RME-69 receiver and the preselector that were built into the same cabinet.  I believe they also made a model that included the VHF converter which would have been a really long receiver.  That and the WWII era Meissner transmitter with built in signal shifter would make a nice combo.

[Todd, KA1KAQ]

Sweet receiver, Rodger. Not many of those around, the 69s being much more plentiful. My 69 hit the road back in the 80s sometime which I regretted a bit for losing the cool looks, but it required the external preselector to get decent performance out of it. I've seen the all-in-one version you mentioned on a couple occasions, one with half-moon windows and one with rectangular windows. RME....89? Can't remember.

Snapped a few quick shots of the HB rig in the open frame rack with screened rear cover. Not a lot of detail but I'll get some additional ones to you soon. I have some out-of-town business on a communications/construction project I've been consulting on that I need to be on hand for, seems some of the drawings and procedures are beyond the grasp of a few. The first clue was when they mentioned using a crane to pick a Rohn 45 tower with all equipment left in place. 

[W1UJR]

Thanks Bruce but I still don't think it compares to some of the neat rigs you have posted lately.

I live about 25 miles from the original Peoria factory so I like acquiring the gear.  I am still looking for one of the setups with the RME-69 receiver and the preselector that were built into the same cabinet.  I believe they also made a model that included the VHF converter which would have been a really long receiver.  That and the WWII era Meissner transmitter with built in signal shifter would make a nice combo.

Hello again Rodger,
Going to AWA this week, will keep my eyes open for you.

I have not seen the RME-69 with the preselector built into the same cabinet, must be a rare bird indeed.
Ed Gable K2MP, the former curator of the AWA Museum is a RME fan, he gave a talk on RME a few years back at the Conference.

I've always appreciated the lack of labels on the early RME's front panel controls, and recall hearing something about RME not having alignment instructions with their sets, and a line stating something to the effect that if you need the instructions, then you have no business inside a RME. 

Some day I'll make it out your way, my business is affiliated with Robert Bosch, which is based in Broadview, IL. Time permitting, I always try to add in a ham radio visit or two when I travel.

When, if, you get a chance, I'd love to see some inside shots of the RME-9.

[WQ9E]

Todd,

Thanks for the photos and I do like the screen look.  The insides of some of these old rigs are just too pretty to hide and I may overcome my prejudice against MV rectifiers so I can watch the pretty blue flashes from this one.  I hope I don't end up regretting that choice.

I have some similar skirted dials to the ones on your transmitter in my box of knobs and I hope I have enough for this project.  They really look sharp. 

From what I learned the original owner used this exclusively on 20 meters and the output coil included is a BC-610 20 meter coil.  I hope that in my box of large plug-in coils I have one for 80 (and hopefully even 160) with the same jack arrangement-otherwise I will be on the lookout for coils also.  I have recently had to acquire coils for an SW-3, FB-7, and a Comet Pro and to think I used to believe that finding the proper knobs was a pain.

The tower project sounds interesting and remember we sometimes do things differently now that you are in the south    I have a friend in MS who swears he remembers (when he was a young child) watching his grandfather shinny up a pipe mast to fix the connection on his TV antenna so as not to miss the Ole Miss vs Bama game.  Although a lot of folks have hand stacked 25G I knew a guy (now an SK) who in his prime could easily hand stack 45G.  Personally I really like gin poles and a crane would be even better.

Rodger WQ9E

[Todd, KA1KAQ]

Couldn't agree more on the MV rectifiers Rodger, although new examples work pretty well. The way I overcame my prejudice while still maintaining the spirit of the original design was to replace them all with drop-in Xenon replacements - 3B28s for the 866s and 4B32s for the 872s. They glow quite nicely as well, not as bright but bright enough, and they don't have the arc over issues. As soon as I swapped out the 872s in the KW-1, 99.% of the crapout issues vanished. The last 1% ended up being a bad wire-wound rheostat in the overload relay circuit. The only drawback to me, and it's minor, is the envelope shapes: 4B32s are available exactly like the 872s, but 3B28s all seem to have a more 'modern' shape. Big deal?

The HB rig pictured is a straight 80/40 dual band CW rig. The builder was also one of Raytheon's top engineers back in the day, so the attention to detail is exquisite. The screened frame on back is no exception, with aded corner braces and an additional shield added on one side. Eventually I'm going to pull the units from the rack, give it a good cleaning and reassembly. I figure it spent 60-70 years earning the character marks it now has, last thing I want to do it sterilize it. That would be different if it was flaking paint or otherwise damaged.

I have a bunch of those skirted knobs, if you end up needing some just let me know the sizes and I'll check. Most seem to be the medium-sized variants, but there are some small and large ones as well. he question is - which box, and is it here?

I'm fine with lifting the tower with a crane, once all the joints are checked for tightness. I'm more concerned with the fact that they don't want to remove any of the antennae from it, including a large yagi on top. All it needs to do is twist the wrong way a bit and things start to snap. The pick point is important too. But they've also changed the floor plan of the addition as well as the comms center, so there are some layout issues that need to be redressed. Being tied in with the the feds makes it that much more...interesting? 

[W9GT]

Hey Rodger,

Really nice old buzzard rig and beautiful RME receiver!  I'm sure you will really enjoy getting that stuff back on the air. 

I have been fortunate to have a couple of vintage home brew rigs given to me that I hope to have on the air one of these days.  One was built in the late 40's and has a pair of 4-125As in the final with the classic PP "Handbook" amplifier using B&W HDVL plug-in coils and swing link along with a huge bread slicer variable cap.  I even got a 160M HDVL coil with it.  I'm planning to replace the finals with 4-250s or 4-400s.  The modulator presently has a pair of TZ-40s in it, which I plan to change out to a pr of 4-250s or 4-400s and use an old mod xfmr out of a Bauer 707 BC rig.  It is about 90% complete and should be on soon.  Should be a strapper.  I'm trying to keep it looking pretty buzzardly, with lots of meters and the original screen-covered tube viewing windows and old Coto "steering wheel" knobs.

The second rig is really interesting, although not high power.  It has an 829B in the final modulated by an 815 (pp tetrode).  It uses all plug-in coils and classic mid 40s- style construction.  MV rectifiers in the power supply and lots of vintage iron.  It takes up a whole 48" short rack, and is certainly a monster for the power level.  Probably be a stretch to get a hundred watts out of it, maybe more like 75, but it is a work of art.  Beautiful vintage style construction and also lots of meters and controls.  Built by a craftsman!

These old rigs really deserve to be preserved and returned to where they belong....ON THE AIR!  Best of luck with your project Rodger.  Hope to hear that rig on soon.

73,  Jack, W9GT

[KB5MD]

Congratulations on the acquisition....I anguished over bidding on that transmitter but finally decided it was too far away....That is a fine looking rig.
Best of luck with it...