The AM Forum

Thought everyone might like to see the beginnings of my new project. Decided to build a copy of the Vernon Chamber 813 rig described in the 1954 Handbook (which happens to be the year I was born, that had a little to do with it). I was talking to Bob W2ICQ on his Chambers 813 and became intrigued with it, so started collecting all the parts. Bob had alot of great info on the rig since he built 3 of them. I plan to modulate the rig with 811's, you can see some of the parts laid out for mock up. Here are a couple of pictures so far. Still looking for Cardwell PL-6043 dual 140 uuf and Cardwell PL-7006 single 365 uuf caps and a Johnson N-250 neutralizing cap.

Looks like an FB start, and congrats on scoring/scrounging/saving the parts! :D

73DG

Is that a neutralizing cap to the right of the 813 in the bottom photo? I've never seen one like that.

I have one of those transmitters with the power supply which I picked a number of years ago. Power supply is so heavy, I can't lift up on to the work bench. The builder was a CW guy so there was no modulator.

Make sure you read the QST article October 1956, pp. 33-38 that provides supplementary information.
All the QST articles are on the ARRL AM page: http://www.arrl.org/am-phone-operating-and-activities

 FB looking stuff there Joe!  ;)

I know you will faithfully replicate the transmitter down to parts and placement, etc. Based on the original article, it looks like you're well on the way! Have fun

https://dl.dropboxusercontent.com/u/17340243/Vernon%20Chambers%20813%20rig.pdf

https://dl.dropboxusercontent.com/u/17340243/Vernon%20Chambers%20813-more%20about.pdf

Yes, that is a neutralizing cap to the right of the 813, it is out of a desk KW....that is not the one I want to use, but I'm looking for the smaller Johnson N-250. also looking for a B&W 3905-1 coil and 3015. I am hopefully going to get an old Globe King 500 cabinet that I plan to mount it all in.

Off to a good start!

Hopefully? I thought that was taken care of?

Hi All,

A few people were asking for updates on my 813 rig I started, here are some pictures of the chassis as all the metal work is now done. Holes for all tube sockets and other components, front panel done for mounting meters and tuning dial, bracket for under the chassis bent and installed.

Here is the front panel and the enclosure fitted and done. Now the mounting of componenets and wiring will be the next step. I would be further along, but with two little ones, it's hard to get into the shack to do any work.

Joe, 

Really nice work,  give us more updates and pictures as you move forward.

Fred

That is very nice sheet metal work...Do you have a shear and brake? 

Nice project Joe!

What sets this apart from the rest is it uses an onboard  VFO and low level circuitry to drive the 6146/813.  All of that will certainly require skill to get it all stable, neutralized, etc. I've built quite a few tube VFOs and found it is no picnic to get them rock stable.

It looks like this was a 500w CW rig. I'm sure you've considered the plate component  ratings since you plan to plate modulate it.

The metalwork looks primo and it should be a work of art when you're done.

Keep the pictures coming, OM.

Did you ever start that 4X1  X 833As rig yet?

T

Hi Joe,
      That is just sweet, I'm curious with Steve Kl7of, you have the goods to make that wonderful
sheet metal work?  I am building a 813 rig to ( or a linear ) locals here have a post of toms, yes thats you! K1jj's 813 rig of yesteryear.

73 deano

Joe, I have a cabinet about the size of a Glob Queen which you can have.  Paint is flaking off, and not sure if it's as deep as you might need.  Let me know the dimensions if you're interested.

Nice work Joe! 

I talk to Bob almost ever week on the AWA AM net I host and many times he does use the Chambers rig.  It always founds excellent and I know you will be very happy with the rig.  Even though I have not heard Dave-KA2J on in months, he sometimes runs his Chambers rig.  I think Bob-ICQ wins the contest for building multiple Chambers rigs.  I know the one Dave has was redone by Bob.  I believe that one came from Bob Raide and Bob-ICQ may have built that one years ago but not sure. 

I do have one, but it has not gotten on the air as of yet.  Need to build a power supply and modulator for it. 

Hope all is well with you and the family.

Joe-GMS

After having a really nice time at Nearfest this past weekend, a number of people were asking me about my 813 project, so I thought I would share a few picture of the work with everyone. I have completed the VFO section and applied voltage with plenty of output, played with the coil to get the correct bandspread, so that section is ready to go. Next step is to complete the rest of the driver stages and test them for proper operation.

For those who had asked, yes, I do have a bending brake, shear and lathe which really helps when making parts. But one of the most challenging parts of this project was finding the parts spelled out in the '54 handbook as I was trying to duplicate the rig as close as possible. I am incorporating all the updates that were published in the October 1956 and June 1954  QSTs.

The only changes I am making is to the metering circuits as I am using 1 ma. meters and have to change the meter shunt values. I will be building the 811 modulator and power supply section as soon as I finish the RF deck.......Have to come up with a color scheme for the rig.

Joe,
Progress on the Chambers rig looks great.  Its nice to see all the small details when they come together.  Keep up the pace!
Joe-GMS

Joe,

You're probably one of only a handful of hams that can build something that perfect looking.  I can build but not anywhere near as nice as your work.

Keep up the great work,

Fred

Pro-grade. Can't wait to hear it on the air.

And very buzzardly too.
Great stchuff!

When all done, we'd like to know what each deck weighs.

(All of us baby boomers ain't getting any younger!)

Gasp, thats beuutyyful Joe!!!

Hi Joe,

Consider engine turning and a clear finish.

https://www.youtube.com/watch?v=97RbG4JkY4o (https://www.youtube.com/watch?v=97RbG4JkY4o)

https://www.youtube.com/watch?v=341mObTmk2k (https://www.youtube.com/watch?v=341mObTmk2k)

this disk I like the best. https://www.youtube.com/watch?v=341mObTmk2k (https://www.youtube.com/watch?v=341mObTmk2k)

I think you probably don't have a cnc plasma machine but you get the idea.

Mike

Here is the completed RF Deck....all wiring is done and test voltage applied. You can see in the front panel picture that there is drive to the 813 shown in the left hand meter and the right hand meter showing cathode current in the 40 meter band. The second picture you can see the 813 with filaments lit and another shot of the tank circuit. Haven't yet decided the color scheme for the front panels.

This is a few shots of the underside of the chassis and the rear of the chassis. Next big push will be to build up the modulator and HV power supply decks.

NICE JOB

Well done Mr. Joe! Ifn you need anything make sure you let us know.

Hi Joe,
I am sure it will work as good as it looks!  Very nice job and can't wait to work you with it.  Maybe next year I will have mine ready to go.
Joe-GMS
 

Very well done!

Great looking transmitter Joe! I guess it won't be ready for the HMR on the 4th? I am going to try to make it but it depends on the weather on Saturday? The forecast may say one thing, but the Adirondacks have a mind of their own  :o :o :o


de W2PFY

Wow, you're doing great work. The pictures are beautiful transmitter porn.  ;D

Absolutely gorgeous!  You are very talented!