I'm choking ACK ACK

[N3DRB The Derb]

by request, here's pictures of the stock plate choke and the cathode chokes in the Gonset amps.

[W3GMS]

I assume the bypass caps are right at the tube socket pins?
Joe W3GMS

[W1EUJ]

Soooooo small.

[N3DRB The Derb]

Joe, yeah they are. For all the good they do. 

that plate choke. is smaller than the plate choke on a Viking 2. By a lot.

[Opcom]

by request, here's pictures of the stock plate choke and the cathode chokes in the Gonset amps.

I wouldn';t trust that little plate choke thing past a set of sweep tubes in an 11 meter mobile amp! A Gonset funny:

Boom! the smoke came out and the SET is GON!

Love the hammers..

[N3DRB The Derb]

yeah, I didnt notice at first. Slab said "those chokes are way too small."  I wuz like: "huh. yeah they are."

[The Slab Bacon]

I will always feel that those piss-poor undersized plate and filament chokes are the reason they needed a neutralizing circuit on a grounded grid amp! Not to mention that the fil chokes are individual chokes (one for each lead) instead of the typical bifilar wound filament chokes seen on every other GG amp that I have ever worked on.

Anyone else out there got any inpoot on this??

                                                                   The Slab Bacon

[The Slab Bacon]

Timmy,
          Here is another thought. since you are now "reinventing the wheel" with this project and rebuilding it from scratch. It would be a good idea to add in an "artificial center tap" to improve the AC balance on the filament, instead of grounding one leg of the fil winding. A couple of 10-15 ohm 10w resistors will do the trick nicely. If you need some, let me know and I will send them to you. This will eliminate a possible
"hum on carrier" in the future caused by an ac imbalance on the fils.

                                                                   The Slab Bacon

[N3DRB The Derb]

Timmy the Tron said thats exactly what will happen - I'll have some hum unless I do that. Go ahead and send teh rx's, I dont have any of that wattage rating in those values. All those parts are actually from the second amp. the only thing thats happened to the first is it got the tank cut out of it , the so called bandswitch, and the 2 X 500pf loading cap that requires fixed padders. I got 100 various value @ 3KV bypasses in today, the rest of my filter caps and clamps should be here soon.

right now I just wanna get the matchbox finished and put all the screws in it. Amps are next. 

[N3DRB The Derb]

that guy I got the plate chokes from also makes bifilar wound 25 and 35 amp fil chokes. I forget how much they are. maybe I should get 2 of them.

here they are:

http://www.freng.com/pages/services_rf_components.htm

[Opcom]

Ye Olde artificial CT on pair 3-500Z's in modulator. It works FB!!

Two 10 Ohm 20W resistitiators, mica cap bypass to GND.
CT goes to B- power supply terminal because the RF PA plate current meter is between there and GND.
I suggest gorssly oversized resistors so they don't heat and change value, and match a pair as close as possible if you have a pile of them.

[Vortex Joe - N3IBX]

Yo Timmy Dude,
                     That plate choke is definitely whimped out! May your first REAL plate choke in the amp be a masculine plate choke! Looks like it needs to grow a set of callognes.

Call me Joe, call me Mr. "Plate choke" if you need help with a manufactured one.
       
Mr Plate Choke,
                     N3IBX

[N3DRB The Derb]

Joe,

I went and had 2 new ones custom made for me - the  'old' ones on ebay were costing more money than new custom made jobs!!

I tell ya what you can do fer me by way of substitution - do you have any medium ceramic plate caps (that will fit on 572B tube caps ) same size as 811A i think) you can send me thru da mail? The Gonset uses National grid-grips which may be fine for grids but are quite wimped out for plate connections.

lemme know if you gotz any in the vortex - I dont think these kinda thangs are your cup of tea but you may have some anyways. I need 8 of the little bastards.

[Vortex Joe - N3IBX]

I tell ya what you can do fer me by way of substitution - do you have any medium ceramic plate caps (that will fit on 572B tube caps ) same size as 811A i think) you can send me thru da mail? The Gonset uses National grid-grips which may be fine for grids but are quite wimped out for plate connections.

lemme know if you gotz any in the vortex

DerbMeister,
                I should be good for at least 4 of them. If I can come up with all eight, then you'll get all eight, or whatever number I have. I can put them in the snailmail to you. I'll check over the next few days and let you knw either way. Please let me know if your current on QRZed.com.

Just to recap things, you're after eight ea. of the non-"National" branded steatite/ceramic plate caps? I'm curious as to why you don't want the "National" branded ones? From my own experience, they're every bit as good as the "Millen" varieties or other ones out there. I have some brand new unmarked ones by a unnamed manufacturer that may not be as good as the "National" branded ceramic plate caps.

I'm curious why you think the National 811A/sized plate caps would be sub-standard for your 572B's? Regardless, I'll give you whatever megotz.

Best Regards,
                  Joe N3IBX

[N3DRB The Derb]

joe,

National grid grips don't have any ceramic in them - they are more like spring clips than plate caps. I've seen too many of them have almost no tension left after 40 years to rely on them for a HV anode connector. if you try to re tension them, they go out of round. Just dont like em for a connection carrying big amounts of RF and/or DC.

Here's a pic of them. After they get squished down many times, they get pretty loose. I think they are called grid grips for a reason. 

I'm pretty sure 811 and 572B caps are the same size. The 572's have a ceramic seal.

[Vortex Joe - N3IBX]

joe,

National grid grips don't have any ceramic in them - they are more like spring clips than plate caps. I've seen too many of them have almost no tension left after 40 years to rely on them for a HV anode connector. if you try to re tension them, they go out of round. Just dont like em for a connection carrying big amounts of RF and/or DC.

Here's a pic of them. After they get squished down many times, they get pretty loose. I think they are called grid grips for a reason. 

I'm pretty sure 811 and 572B caps are the same size. The 572's have a ceramic seal.

Tim,
      I appreciate the pics and description of what and why! I fully understand where you're coming from OM! Yes, a standard spring clip made from "Belleville" type steel looses it's resileniency after a few times and won't always "spring" back into place. It's a common problem with some grid caps as well.

To my knowledge, the 811/A, 572-B,TZ40,T55,and 866/A, etc all take the same diameter plate caps. National did make nice ceramic jobs, much the same way James Millen , etc did. There are also some no-name Chinese jobs floating around that can "stand the gaff". The ceramic plate caps were the extra cost jobs.

I should (hopefully) be able to fill your requirement from my stash of plate caps. You know me, I save EVERYTHING; in case someone somewhere could use it sometime for something - hi! I'll check and let you know how I make out.

Regards,
           Joe N3IBX

[N3DRB The Derb]

ok Joe sounds good. They do have the chinese ones on ebay -  but I thought someone on here might have hundreds stashed away in some corner . I'm getting to where I hate buying chinese stuff anymore.

[Vortex Joe - N3IBX]

ok Joe sounds good. They do have the chinese ones on ebay -  but I thought someone on here might have hundreds stashed away in some corner . I'm getting to where I hate buying chinese stuff anymore.

Timmy,
         Hundreds of 'em stashed away in a corner somewhere? You never know what you'll encounter. I came into (of all things) a very large-ecsent stash of neutralization caps. I had a few of them kicking around here for future projects, etc, but never in my life did I see so may of them in one place at one time. As it turns out, the SK, former owner of them was Hammy-Hambonin since 1933 and  had all sizes shapes and configurations from his projects.

Regards,
          Joe
         

[Vortex Joe - N3IBX]

Tim - I sent you a email with pics of eight plate caps I dug up for you today. Five are bakelite, the other three are metal, of a different variety than what you have. All should be FB for your application. Let me know if you want any of them, and I'll send them your way.

Best Regards,
                  Joe Cro N3IBX

[N3DRB The Derb]

Joe, sent ya mail back. I went ahead and gave the lousy chinese some money. Thanks for lookin.