The AM Forum

Well, I just picked this up last week.  Thought I would share some pic's.  I have not done any kind of testing yet, and am lacking a final (4-400) and the modulators, 2* 811a's.  But I hope to have more updates in the next year or so.  73's

(http://i50.photobucket.com/albums/f307/ukv894/VRL%20Globe%20King%20500-D/DSC_0888.jpg)

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Here is a link to the Photobucket page so you can see larger pic's. 
http://s50.beta.photobucket.com/user/ukv894/library/VRL%20Globe%20King%20500-D

Nice looking homebrew rig !

PM me if you need a 4-400A. 

I can donate one to the cause since that'll be the least of your problems with that thing.

Great on Paul offering you a 4-400A but a 4-250 is all you would really need for that rig and in a pinch, a 4-125 will work if you keep the input down to about 300 watts.

Good luck with the rig! 

Don't take this the wrong way:  that chassis that looks like aluminum with the huge Dahl iron on it in the rear no less, badly needs more support--that rack chassis won't hold it as is.  I don't think I'd even try to beef up the chassis with struts--I'd get that transformer out of there and put it in the bottom of the rack cabinet.  I'd get a 4 foot high rack and use that for the rig with the iron in the bottom.  I'm not sure I'd even want to use steel with side struts for that thing.  It looks way too huge to be on a rack chassis.  maybe the photo makes it look bigger than it is.  If it weighs as much as I think (around 60 lbs or more) pull it.  You'll probably like having the rig in a bigger cabinet, perhaps on wheels, anyway.

GL 73

Rob

PM sent, thank you.

Everything seams to be 3/16 sheet metal, I thought the same when I first seen the pics the previous owner mailed me.  It looks like its doing fine the way it is, but I will see more later on when I get inside of it. 

Thank you for your input, 73's.

Ah... The globe king copy

http://amfone.net/Amforum/index.php?topic=28525.25

Maybe yours was the prototype.

Here's the VRL $3885 Globe King:

(http://amfone.net/Amforum/gallery/25_27_08_11_2_33_44.jpg) and yours (http://i50.photobucket.com/albums/f307/ukv894/VRL%20Globe%20King%20500-D/DSC_0886.jpg)

His clearly has the 755 WRL VFO mounted to the faceplate.  The other one you posted has some kind of digital vfo. I bet this thing could be gone through and would run good on the air. It has some quality components there...

C

Ya, it has the full unit, other then the enclosure (WRL 755A) VFO.  I hope it works good!  I have build DDS units in the past for radios, but I have full plans to get the WRL VFO working 100%. 

I have not looked at the radio very close inside yet, but I will post more on it as I get her on the air.  I did try to call, and e-mail the builder of the VRL Globe Kings for schematics, but all contacts had no luck.

I'm not worried, the parts look great, I know I can get it honking.

 

Keep us updated and take some photos along the way. There are alot of guys here that can help if you get stuck

C

The advertised version had the digital dial. It's been reported that several of these were sold to amateurs in the Northeast but haven't heard anyone admitting to it.

ke7trp, I subscribed to your YouTube quite some time ago. Love your radios!  I myself have a FL-101, and FR101 I am about done with restoring, and am working on a re-caping on my FT-101E for my mobile! 

My primary rig is a FT-857D, but I LOVE tubes!  Been playing with EM' most of my life.

This radio is so clean, I bet it never worked properly or was not used.  I cannot understand why someone would spend the asking price on one of these that did not work. But from all the information, or should I say lack of...  I myself have not heard of a VRL 500-D that works.  :-(


I will be giving detailed info as I get it, even HD video on my You Tube one day. 

I am a full time father, (4 kids) so time is lacking and I work slow anymore.   Hope to catch you guys on the air! 

 

I have some 811A's I can contribute. If you need info on the 755A, I have a factory manual.
                                 Joe W4AAB                                                 

I would love that!  I have a friend that has been trying to get me into playing with 811a's for about 15 years now, KC8COM.
Here is my chance.

It does use (2) 12ax7's for pre-driver, then a single 6L6 for a audio driver.  The audio final, or modulator uses the 811a's.

I will be replacing the 6l6 with a Grove Tubes Black plate, and have a vast collection of 12ax7's.  I think I will go with RCA's there!

The RF driver is a RCA 6146, I think that might be a keeper!

You can reach me via E-Mail if need be at (kd8piq at arrl dot net), or just QRZ for address.  FREE is for ME!  HA HA

You guys are great!  73's best wishes, de KD8PIQ

Here is a link to the Photobucket page so you can see larger pic's.  I upload new pics to this page as I get more into the radio.
There is much lack of information out there on this rig so..., here is some new for you....  ENJOY!


http://s50.beta.photobucket.com/user/ukv894/library/VRL%20Globe%20King%20500-D

Wow, a Black Plate one! I wonder how they get the Black on the plate and if the Black offers any improved performance of the tube.  Maybe during the winter I'll test some Black plated 6L6's with the non black verify if there is a difference? I also wonder if the reason for the Black plate lends itself to better cooling? I know that in sunlight, black color absorb"s the rays of the sun readily so perhaps inside a vacuum tube, the reverse is true?  The only large transmitting tubes I know of is the 813 metal anode is black but for the most part, all the rest are gray, silver to brown in color.     

I have been into musical arts for 90% of my life, along with radio.  I have tested many tubes in aspect of there sound comparison, and have found even in common tubes, such as the 6L6 just changing the brand or age of tube can change the audio minutely.  I run groove tubes in my Ampeg SVT6 Pro 1100W bass amp, and have also ran RCA's .  The black plate grove tubes seem to be smoother in response to me.  It might not matter much, but myself... I'm just picky that way with my tubes.  If they are used for sound, I love to swap them left and right until I find the sweet spot par-say.


good talk, 73's
 

 

 Scott, The hazing is starting.. Just ignore them man :)

Good to know! My son says the same thing and I have a number of audiophile friends who tell me the same thing. There must be something to it but I wonder if it's the minute spacing of the elements within the tube that makes them preform with very subtle different between brands. Like you say, it's what you hear that counts.

These things are like bad pennies that keep turning up.

-Is it Serial Number 1?   That was a very popular number; available for a special price!  ;)

Nope.  It does not have a serial number.  But the power supply/modulator deck is stamped "1005", and the other likewise.

The P.D. Co. transformers are marked "01/03/2002"

It looks very well built.  From my several months of searching online this is the best one out there. And like I have said, it all looks new.

That rig has an honest face.

Wasn't the VRL GK build/designed by W6CHR if so, I believe he is in Federal Jail...

That seems to be the same guy. Not sure.  Has a nice QRZ page.

C

It is although am not sure about the jail thing.  That is a poor design and I do hope whoever bought it reads what Larry Rau had to say about it before they spend a lot of money.  The one he spend a lot of time with never worked and the guy who owned it spent a LOT of money.  That one wound up on Ebay but didn't sell.  Not sure where it is today.  To my knowledge there were only three of them built.

What hasn't been posted is the article by Larry Rau written some years back where he documented the poor design and construction of the one I mentioned earlier.  The last I saw it was on eHam but I can't find it.  One thing I do remember is one of the power transformers does double duty in a couple of the stages.  Note in the pictures there are only two decks.  As I recall the power supply in the VRL provides all voltages to everything in the set and that didn't work too well, where as the original Globe King has a power supply for the RF deck and one for the modulation deck.

It will be interesting to see what this guy finds as he goes through it.

You probably should start one Page 1 of the link: http://amfone.net/Amforum/index.php?topic=28525.0

Here's an old link with some pictures: http://www.angelfire.com/alt/myvintageradio/

Yes Jim,  you are correct ... went searching on Larry's exhaustive treatise on the 500D problems and proposed fixes,  but could not find it.

Clark,  Yes,  SRI for  posting something that you had posted,  but need to up my post-count!

Pete,  Yes,  no surprise,  you are correct ... just shoot me!

Vic da LID

I can recall listening in on a QSO in the early 2000s with a station in New York, I think his name was Paul, in Long Island going on about having bought this VRL GB500, and all the problems he had with it. It wasn't working properly/at all, and he was in QSO at that time with Jaimie KF2VM, and it sounded like Jaimie was joining to try and get the tx going for him.

Al

I went back and dug up some old email.

Part of what I wrote, circa 2008 -- was that I had been researching the possibility of an article on the new Globe King.

His business partner (and website manager) confirmed to me in a phone call that Groome had no production line, no standard pattern for construction, and no inventory of parts.  Essentially he was taking orders (with substantial cash up front) and then building homebrew transmitters, each of which was cobbled together from whatever odd parts he could round up.

This same business partner told me Groome had severe health problems and would never be able to build to a deadline.  After later seeing a "new" digital VFO version of his replica "Globe King," I wondered whether claims of bad health were part of the questionable business practices as well.

He never directly returned my phone calls and I dropped the proposed coverage idea. Last contact information I had  --

Chuck's VCR & TV Shoppe
3059 Clarksville St
Paris, TX 75460-7915
(903) 784-8417

Vintage Radio Retail Store
2165 NW Loop 286
Paris, TX 75460
903-785-2077

Yeah.. Big deal. We all know they never worked. Rip it apart and fix it. Its a 4-400 and a couple 811's..  Not that big of a deal ya know?  It has good iron and some nice parts.

People are like sharks. They smell blood and they all come running!  Lets get the ropes! 

C

Huh? All I've seen is a number of members offering parts or other assistance, some comments on the original builder/seller and poor execution of the original design.


When we last flogged this dead horse a year or so back, I pointed out then that the article was gone from eHam. Someone mentioned that they do purges from time to time clearing out data. I thought perhaps it was more related to the subject matter and person of questionable character. Would be nice to have it preserved somewhere for posterity. I communicate with Larry now and then, I'll see if he still have it saved anywhere.

Larry mentioned a number of issues including the flimsy construction overall, too much weight on too thin of a chassis, parts running at or beyond their ratings, and poor design work. IIRC, the one he rebuilt was for a fellow in Long Island(likely the same guy Tim heard) who had spent a lot of money to get the rig only to be greeted by a transmitter that never worked right (or at all?), then spending a LOT more to ship it to CA where Larry reworked it and documented the process.

While I don't see it ever being rare or desirable, clearly the rig has some excellent bits for rebuilding. I wish the new owner good luck in making something good from the ruins. There's plenty to work with.

BTW, the W6 referred to was a member here briefly. He joined when N2LEN was looking for a new SX-88 bezel, miraculously offering new bezels in the Classifieds. I think he's the only member ever removed from 'fone based solely on reputation. It did not please him.


That's a very revealing thread well beyond the actual VRL topic. Wow.  ::)

 

We had a little bit of everything and "everyone" in that thread.  :D

I got the power supply deck on the work bench now for testing.  I will be checking voltages on the deck on my variac, and a 1000:1 voltage divider I built for my Fluke 114. 

Here are some "NEW" Pic's never seen before from what I can gather, other then the few that have been inside of these radios.

I am a full time father of 3, and we home school.  So I do not have much time to spend on this project, so please forgive me for my long time taken.

I hope you all enjoy these pic's!  I will have more info as I get there.



73's!  de KD8PIQ


(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0059_zps094b80fd.jpg)

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Very nice Iron!  Its fortified for sure! 

The build quality is better then I expected.  Lots of negative press by a couple old kodgers on the web about those transmitters.  I am sure you can get this going and it will be great!

C

I agree!
It's pretty cool to see that the Dahl iron tags actually say VR Globe King...
Thanks for sharing all these pictures. You are right, it's great to actually see the real idea really up close!

Nice pieces, and great looking iron! The high voltage bleeder resistor bottom might be marginally insulated. See picture attached.

Jim
WD5JKO

Yes; it might find more insulator when I get into her.  Thank you for pointing that out!

de KD8PIQ

I removed the resistor from the deck, and cut (2) pc of MSHA HV isolation sealing tape and layered them over each other, then poked a hole through
for the mounting stud (all-thread). 

Then at the top, added (2) separate insulators for added spacing from the terminal junction.   

(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0035_zps95b1edd7.jpg)  (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0036_zps3b55a9d5.jpg)

The Dahl transformers are nice.

I'm curious to see some close ups of the RF deck when you have the chance to take some. I know that some of the components in the WRL GK 500s were marginal, especially anything that had any modulated B+ voltage on it.

Al VE3AJM

At least the parts are new-ish and should not have problems. It should be done to your liking regardless of anything else.

I wonder about this conclusion Al.  What makes you think this?

After the power supply/modulator deck pass my requirements, I will then pull the RF deck.  I will be sure to keep this thread noted with information, and HD pic's.  You will also find video later along the project.

Take care!!
73's, de KD8PIQ

Put her on the Yack tonight, after putting a 1 ohm, 20W shunt in series with the main AC power input
to read if there is an abnormal reading in excessive current draw with my DMM.

So far so good.  You can clearly see in the pic, the amp draw is less then an amp at this point.
Check out that nice warm velvet glow from the VFO's Oa2!

 I did find the 6l6 had a bad grid leak, so removed it; and wanted to test w/o the 811a's.  I do have a few extra 6l6 tubes,
and plan more testing with tubes installed soon.

(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/1_zps901f3f59.jpg) (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/2_zps9d2d67b3.jpg) (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0039_zps353a8182.jpg) (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0042_zps1098de69.jpg)

Jim, I owned a Globe King 500A a few years back and have built a few HB txs in the 500 watt class. My GK500A needed a lot of work and I sold it to a buddy of mine who kept me appraised of his repairs/improvements to the transmitter.

Looking at the RF deck.. the bandswitch/bandswitch contacts,, the final tank coil itself, the phenolic material that the coil was wound on, the size and spacing of the plate tuning capacitor all appeared to be what you might expect to see in a 100 watt output class transmitter, not a 500 watt dc input plate modulated AM rig, especially the plate tuning capacitor.

I have a Johnson Viking 500 for comparison. The tank circuit components are massive in contrast to the GK500. The Viking isn't a perfect tx either of course. 

Al VE3AJM

Ok Al, I understand your conclusion now.  I have one that I have used for the past 10 years without issue.  Granted the components cannot stand very high voltages they are, however adequate for the power level stated.

Where one would really have trouble is if you suddenly lost an antenna or tried to transmit into an open.  That would cause a lot of problems.  Not only would the tune cap arc but it is very possible to puncture one or more of the fixed mica caps in the output circuit.  Mine puts out about 325 or so watts on 160, 75 and 40 with good modulation and I have never had a problem.  It is not a broadcast transmitter but it will do the job within the expected parameters.

The one KD8PIQ has may be a different story.  The power supply section is different than the original in that the HV transformer supplies both the RF deck and the modulator deck as I recall, unless it has been modified.  The original design was for a SS VFO and Chuck could not get it to work because of low output so he found and incorporated a 755 in this one.

As already posted, Larry Rau spend a lot of time attempting to make one like it work and wasn't successful but there are a lot of the original out there that work fine.

Hi Jim

I'm glad that yours hasn't had any problems. My GK500A had signs of being overheated/abused by a previous owner, and it would blow fuses especially on unkeying the tx. My friend Ken VE3MAW used a bunch of solid state relays in his, amomgst other mods, and its working well for him now.

I'm very curious to see what they did with the VRL 500 in the RF deck too.

Al VE3AJM

I preformed HV testing today.

The plate voltage for the 811a's read 2kw, along with the plate for the 4-400.

That is kinda high for a 811a, so I have e-mailed The Perter Dahl Co. for information regarding what the voltage taps should read on the custom build transformers.

I have replaced the 6l6 with a very nice NOS Sylvania.  The plate voltage for the 6l6 tested 325, and the data sheet reads 450 max, so that should be fine.  The old tube had a bad grid leak..

I still have not put the 811a's in the deck, I'm not sure about 2kw on the plates...

Any input on this one?

-Scott

Scott, does this unit use the same HV for the final and the 811As?  If so  you may have troubles with it.  The modulator deck should have a power supply for the 811As separate from the HV for the final.

Scott,

The Viking 500 was designed with the 811A modulators running at the same plate voltage as the 4-400A final, 2,000 volts under load.  Supposedly the Johnson design engineer got the official "OK" for this from RCA and they do run fine in the 500.  You need sufficient bias to set the proper idle current but the tube has no problem...At least with good quality U.S. production tubes.  Some of the Chinese brands may not stand up to this voltage level.

The HV power seems to come from the same xfmr, but separate winding's.

I read just shortly ago from here: http://amfone.net/Amforum/index.php?topic=16744.0 (http://amfone.net/Amforum/index.php?topic=16744.0)
about the Johnson running the 2kw on 811a plates....

I have also just measured negative 12.5 vdc on the grid pin (3) on both 811a sockets.

I do have a very nice matched pair of NOS Made in USA for the US ARMY/US NAVY Sylvania tubes in the boxes.
My very favorite uncle in CA shipped me not too long ago for this project.  (WB6SLC)

I'm going to cross my piggies, and plug them in and power her up....

-kd8piq
  

It might be only 23 degrees outside, but my shack is heating up!

(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0040_zpsed42f9a7.jpg) (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0041_zpsc1d34c60.jpg) (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0042_zpsd1699c59.jpg) (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0043_zps5b7bc7ac.jpg) (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0044_zpsfbc81e93.jpg)

From the pictures, I can't see a choke in the HV power supply. Perhaps its capacitor input configuration as opposed to choke input? Curious.

Al VE3AJM

The big gray box is a oil cap, tied into the 2kw, then grounded.  I do not know its value, the metal strap has it covered and down too far to see.

Yes, I can see  8) the oil filled capacitor with the strap, I can't see any choke. If it were there, it would take up a lot of real estate on the chassis.

Al VE3AJM

I thought that was a choke to the right of the oil cap, or is that a transformer?

I think it is.  The deck is running right now, and I don't want to flip it over to look.  :-)

RF Deck, just opened.


(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0039_zpsd9ae1c9b.jpg) (http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0041_zps2fb30282.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0042_zpsf62777af.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0044_zps7a928eb8.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0046_zpsca0c2065.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0047_zps6c2d3703.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0049_zps30768a50.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0050_zpsa9ffe485.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0052_zps912fd603.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0053_zps34b739b0.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0054_zps333a4b81.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0055_zps35b13d3e.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0056_zps9cc78eb6.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0057_zps92616472.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0058_zps632fbe0a.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0059_zpsd28746d5.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0060_zps47636cf3.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0061_zps91e2c3d6.jpg)(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0064_zps2568ae68.jpg)

There were 3 pics of Dahl iron from the PS chassis that we could see, and that we had closeup pics of. Plate, modulation,and a modulator filament transformer topside. So that transformer by the oil cap would be the filament transformer.

I guess we'll find out for sure in the course of time. Did this transmitter come with any documentation and or schematics?

Al VE3AJM

No information, no paper work.  You guys have the same information at this point, that I do.

I see 4 transformers on the PS chassis: the HV and modulator transformers, the one by the big cap, and the other one in front of the modulator tubes.

Just got this E-Mail.  1/27/2013

Hi Scott,
Unfortunately, I can't find any info in my files on those units. They must have been special units Peter made for a customer or the design files were lost in the transfer when I took over. Either way, I do not have the design files or wiring diagrams for those units.

Jeff

Jeff Weinberg
Harbach Electronics, LLC

That transformer just doesn't have the size to be a HV smoothing or swinging choke rated for at least 2 KV, 5 H or so, and 500ma lets say, which would be needed in either or both the HV power supplies if they were choke input.
It doesn't look like a Peter Dahl unit. I wonder what the HV reading will do when there is a load on the HV power supply, from both the modulator and the final?

The use of that edge wound inductor in the final tank circuit was an improvement over the tank used in the WRL GK500s though.

Al VE3AJM

I wonder if the VRL keys the high voltage transformer primary like the GK-500 did as a PTT, or if they just key the high voltage DC? Another possibility is they just use grid blocked keying, or some variation thereof.

If VRL has a common supply for modulator and RF PA, with appropriately sized parts, this is not a problem. Many broadcast transmitters use a common supply. When running AM, the RF deck acts like a huge bleeder so the power supply regulation can be quite good. Going to CW might be a different story however.

If I were to re-do the high voltage in my GK-500, I'd use a common supply, full wave voltage doubler or Full wave bridge, large amount of capacitance, and a safety bleeder; NO CHOKE. I'd key the high voltage with a 5KV rated relay which means the B+ is there all the time...up to the relay.. The RF final will provide the load, and the modulator will pull from there at an audio rate.

Jim
WD5JKO

A lot of ham gear uses a common HV supply for the modulator and final, both of Johnson's higher power rigs (500 and Desk KW) use a common supply. 

Although a well designed choke input supply certainly provides better regulation once SS rectifiers became available and cheap the high power choke input supply was on its way out.  Tube rectifiers, MV especially, couldn't withstand the high repetitive surge current from capacitor input filtering but that isn't a problem with adequately sized silicon rectifiers as long as the transformer is also designed to handle the repetitive peak charging current.

I haven't looked over the pictures that closely but I would pay close attention to HV insulation, adequate RF current capacity for switches and capacitors in the RF output circuit, and whether tube operating points (proper bias and screen voltage) and protection is addressed.

At the least you have some good quality iron and depending upon what you paid for this if it doesn't perform well you can always build a rig of your design incorporating the useful parts from this one.

For sure, cap input common supplies can work in a plate modulated AM tx, if the tx etc is designed/built with the approprate components, etc. We'll find out if the VRL unit fits into that category, with how it was constructed.
Should be interesting.

Al VE3AJM

I am afraid that he is going to find that the parameters you guys have so well stated are not met in this transmitter therefore the reason no more were produced.  I think he will find that the voltage sag under modulation will affect both the modulator deck and final.  I am curious too.

That is the problem that was addressed by others in attempts to repair these things.  I hope it works but we shall see.

2000 volts is fine on the 811's but wont run class B as in the GK500. They will be AB1 and will run hot hot hot. But they seem fine in my Johnson 500 even with no fan.

There must be a bias supply there if the voltage is 2K.  I see in the photo that you have some idle current on the 811's meter so that is great. Looks like its working.

No reason you cant stick in 572B's for fun if you have a pair. 

The RF deck looks like an upgrade over the GK500C.   The GK500 used two coils. one addative coil under the deck. Remember that the Loading cap does not need to be wide spaced, Its working at 50 ohms. Even the one in my big transmitter is very closed spaced high value/range cap and its fine.  The tune cap is where you need the spacing.

I am seeing some good construction and good parts.  The GK500 used a modulator power supply.  Are you saying this one has a single supply?

I would probably axe the Screen supply and use a Dropping resistor from the B+ line to the screens for the 4-400. This really made a big difference in my GK500. There was no question it sounds alot better this way and the wave form is much cleaner.  However, Get it running first, Then play around with things like that.

Thanks for posting the pictures and good luck. 

C

The HV comes from a single tap point on the VERY large "Multi" xfmr. Then through a rectifier and has the large oil cap filtering to ground.

From the cap, there are (2) wires that go to the "CUST. P/N 500 MOD XFMR".

 There are (2) inputs, and (3) outputs.  They all read 2kw.

The three outputs are as:  
One goes to the HV output on the back of the deck for the plate on the 4-400.
The other 2 are for the plates on the 811a's.


PS;
 I did just note an unused tap on the large multi xfmr, it reads 900VAC.  Might I have any problems in drop, I could try to use that point with a second rectifier and filter for the plate caps on the 811a's. Just a thought...

900 wont be enough to modulate the rig fully. 811s are just enough as it is.  The single supply is fine.  The idle current looked good on the meter.

C

The 572B's would give you twice the plate dissipation in the modulator. I did a mod for a ham who had a Gonset GSB-101 which used 4 as RF amps. The 811A's needed minus 4.5 VDC bias, but I was able to ground the grids of the 572B's. Worked much better. I am not sure that running the 811A's from the other tap would work well enough. The voltage on the modulators should be equal to or higher than on the amplifier tubes.I am running an original GK500, and I have had no issues with it, except I need to replace some HV caps as I have a hum issue.First, I need to get my antenna back up after the ice took it down.
                                                     Joe W4AAB

The 811A modulators in my Viking 500 run class B with 2kv on the plates, with a no signal current of about 35ma. They don't run red hot, and from the pics posted here of the VRL 500 with 2kv on the plates, its modulators are idling at approx. 25ma. The plates aren't showing any colour from the pics.

If one has 572B tubes, sure use them. I have used them in my Viking 500 modulator. Idling the modulators at about 35ma, I wasn't gaining anything though. Those tubes are running very conservatively though.

There appears to be a Peter Dahl choke underside chassis connected to the screen of the final tube. The screen could self-modulate that way.

Al VE3AJM

The GK500 should have 1500 volts on the plate of the 811s.  Did  you really measure 2000 volts?  Interesting.

I see the self modulating screen choke and that is how the GK runs. However, It produces distortion. If you modulate the screen in phase with the plate, the rig will work better and there is a very good difference in sound and signal quality.  It was a modification suggested by Robert W0VMC and it worked great.


C

It is best to think of the VRL Globe King as a partial replica that has some similarities but many differences from the original.  The cosmetic styling has similarities but the design, components, and layout are quite different.  Using documentation or even expectations about the original will likely be more misleading than helpful in getting this one in running order.

It would be similar to trying to use a factory service manual for an original car while working on a kit "repli-car".

I measured the B+ voltage on the 811a modulators in my GK500A at just under 1100 VDC, and the final at about 1850 VDC which is in line with what the schematic shows in the manual, give or take a bit.

Maybe yours has a different plate transformer in there or something?

I don't get bumping up the B+ voltages on the modulator and final in the VRL unit, but continue to use a VERY undersized plate tuning capacitor for the final. Thats just asking for trouble with arc overs etc. across the plates of that cap. And unlike the GK500, there is space on the chassis to accomodate a larger air variable plate tuning cap.

Al VE3AJM

If I was to tackle this project, the first thing I would do is to retrace every wire and part and create a schematic of what I had. I would not rely on some 60 year old design criteria when it can't be verified the builder even followed it.

Thats good advice to think of this as its own transmitter wQ9e.

VE3AJM-My modulator plate supply was changed. The original was bad.  Sorry. i forgot about that. Mine has 1550 volts on the 811s. I had to get my notes out. Mine also has the 500 volt LV supply taken off the main supply as the replacement modulator power trans did not have a 500 volt tap on it.  My idle is about 50MA.  Its been like that for 5 years now.  Sorry for any confusion on the voltages.

A schematic would be nice to have for this transmitter. It think once the bugs are worked out its going to probably produce a solid 400 watts and sound great.

Can someone please tell me the name of this female receptacle; and the name of the male plug that mates to it.

It is for the interconnect cable from the Power supply deck, to the RF deck.

I hope to order male ends from http://www.mouser.com (http://www.mouser.com) to fabricate a new cord.

Thank you for your time! 

-KD8PIQ

(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20Power%20Supply/DSC_0064_zps40154751.jpg)

I believe that is the 5 pin Amphenol socket.  A google search for 5 pin amphenol plug will return vendors on auction sites and websites

http://store.triodestore.com/86cp5.html

C

Not quite, but close.  These I have are 6 pin.  I'm searching around on the web.

Clearly thats a 5 pin.. Unless you are saying the Center is a pin also.. I think I can see there is a contact there.  I have never seen that style of that is what it is.. Maybe someone else can comment.

C

Plugs originally made by Amphenol as the 91MPM3L (3 pin), 91MPM4L (4 pin), 91MPM5L (5 pin), and 91MPM6L (6 pin). No longer manufactured.

I wrote this in 2006:
Lafayette, and probably others, used the five pin version on their early tube CB's. Lots of time you can find the matching mike with the five pin plug on it at a hamfest. If you line up the five pin plug with your 4 pin socket, you can see quickly which pin to cut off. Lafayette HE-15, HE-20A/B/C, HB-111, 200, 222, 333, HE-35(I think), HE-45 series all used the 5 pin version. The 3, 4, 5, and, there was a 6 pin version, were also used on some 50's and 60's audio equipment.

The Thunderbolt requires the 4 pin version.

Personally, I would find a male and female plug/socket that are currently made and available and that can roughly fit the hole. It would be scary to run any kind of high voltage through that old plug/socket combination.

I think that is the best way for me to go.  Thank you for the great info though.
73's
-Scott, de kd8piq

I saw a Millen HV type connector mounted on the centre back of that chassis as well. So apparently B+ and modulated B+ would be routed through that connection. I think I saw the cable in a pic on page 1 of this thread.

Al VE3AJM

And if you need those HV connectors you can get them at a good price from Ted at Henry.  Just email him.  He will include the HV/old style spark plug wire.

C

I have the cord for the HV.  Thank you!

Made my own interconnect for the decks today with some spar parts.
Fist time I have had the final lit up.  The final is used, but I will still let it burn in for a few before further testing.

(http://i50.photobucket.com/albums/f307/ukv894/Globe%20King%20RF%20Deck/DSC_0826_zpsefffa5de.jpg) (http://s50.photobucket.com/user/ukv894/media/Globe%20King%20RF%20Deck/DSC_0826_zpsefffa5de.jpg.html)

I let the tubes burn in all night, and most of the morning.  I now have both decks on the bench, preforming alignment procedure on the WRL 755A VFO.

I had to drill a few extra holes in the power/mod deck under the 755A to gain access to L3, and C6.  Holes already exist for L4, and C3.

I use a 1k Resistor in series with my receiver ant. from the VFO output; for Zero Beat tuning.
Obtaining Zero Beat on 1.8mc, and 7mc was a breeze.
2.0mc, and 7.4mc did not seem to show.  I tuned C6, and C3 for best RX of short wave I heard. 

I stopped at this point for this post.  I hope a wise ham out there will tell me whats up.   

Thank you!
de kd8piq 

From what I am seeing in the construction of this transmitter, is that the layout and wiring and placement of components looks very nice. Wherever the weak spots are in electronic design, find them and make it work. It's just an Amplitude modulated transmitter using tubes. No computers or microprocessors involved.
You probably have one of the few of those TX's that works. Or you get the bugs out and it happily makes AM RF for on the HAM bands.
I think you did ok in this deal.
Thanks for the nice detailed pics. Good luck with 4 kids...I am 67 dealing with one 7 yr old...toooo much energy!!!
Fred