I have seen a few home brew “3” 3-500z made to work as intended 15-160 meters. But I never seen some one using 6 or 8 811A’s or 572B’s to get legal limit. I relies there are other tubes out there to do the same with 2 tubes, but for a home brew project why not.
 
 I ask this out of curiosity more than anything,

An all tube radio, Hybrids don’t count. And to me the Kenwood TS-820 or Drake twins just barely make it in the boat anchor class. Think separate transmitter and receiver. The Drake would be the last of the boat anchors.

To save cost in my amplifier project “3” 3-500z amplifier. I have thought about connecting “2” identical plate transformers in parallel for the extra current capabilities. They would be Heathkit SB-220 plate transformers. Then I would make my voltage doubler circuit.   Any potential problems with this plan. 

I am starting my amplifier project and it may take a year to build. I am taking my time and will ask lots of questions. This will be a 3 tube amp“3” 3-500z 10-160 meter amp
Power supply:
  A string of “8” 500v @ 350uF electrolytic or “1” 60uf @ 4000 v oil filled.

Transformer: AMP SUPPLY #LK-500F-3 FIL & CONTROL FOR 3 EA 3-500Z TUBES
CORE) EI-175 X 2 STYLE #) 04 E-I LAMINATED CORE
PR) 115/230 VAC 60 HZ 1 PH
S1) 5.5 VCT @ 50A CCS
S2) 0-10-18 VAC @ 2A CCS
DM) HT = 5.250 WT = 4.375 DT = 4.205 MD = 3.125 MW = 3.500 WEIGHT) 14 LBS

Plate Transformer:
2600/2400/1800 VAC @ 2A CCS PLATE XFMR FOR 4 EA 3-500Z'S
CORE) A-0525/ C-CORE STYLE #) 10 HIPERSIL C-CORE PR)
 0-220-230-240 VAC 60 HZ 1 PHASE
S1) 0-1800-2400-2600 VAC @ 2A CCS
DM) HT = 10.769 WT = 9.825 DT = 9.188 MD = 5.000 MW = 6.437 WEIGHT) 86 LBS

I bought electrolytic caps form just radios last year to rebuild my Kenwood TL-922A P/S and they seem fine.
Do not know who is good to buy oil filled caps from
If you think I should use a different transformer say so?

Transformer will come from harbach whatever I buy.

I would not worry about the 3-500z tube, they will last 30 years. If anything a retro fit to a ceramic tube is possible maybe a GI-7b.
A sign to look for is when Ameritron, QRO, and Ten-Tec all suddenly stop using the tube, like overnight.
That would be a sure sign the manufacture has notified them of the pending end of production.   

I have always used a full wave bridge on power supplies. I can get a ct transformer but if a plate transformer is NOT center tap what do you do? I want 1200-0-1200 for 2400 x 1.414 to get about 3393 volts, the transformer must be at least 1.5 amps to supply “3” 3-500z tubes. But if no CT what?

If I am not in the shack, all coax, rotor, and remote switching cables are disconnected.
In Oklahoma if it rains it will lightning, With some exceptions from November – February.
All my cables go through PolyPhasers, that will help prevent static build up, but will do nothing on a direct strike.

I made a contact on 10 and 12 meters today. I think the 12 meter contact was my first ever. Haven’t checked my logs yet, Very disappointed so far in this cycle. I just knew that 10, 12, 15 would be hot. 

I agree some ham retail shops have poorly designed web sites. Texas Towers has an excellent well designed site. 

On my web page it tells you how to ID the traps on the CL-33 this may help.

http://www.ka5row.com/mosley.htm

3-500Z Tubes.
Amperex or RF Parts
At almost twice the price is the quality, average life expectancy, and holding up under a load worth the extra cost? 

Every things works fine now.    I went back thru every thing step by step looking of a error that I may have made, I did re solder a place or two and fired it up. Works just like new.

I think what happened, I started this project just before Thanksgiving worked on it for a hour then a week later a little more. Mail order parts then two weeks later work some more, skip a week again.
 If I had ordered  all the parts at one time, and in one day did the project every thing would have gone by without a hitch.

Kenwood TL-922A Grid Current

I just rebuilt my Kenwood amplifiers power supply. Every things works I have high voltage, Filaments work fine, relays key when transmitter closes the relays. Just no grid current.

This is what I did.

Replaced all Caps.
Replaced all bleeder resistors with 10 watt 50 k ohm from 7 watt 47 k ohm. also replaced all the .01 ceramic disk. The only difference I went with 1000 volt instead of the factory 500 volt value of disk Kept the same .01. value.

Replaced every component on the rectifier board. went from 800 piv to 1000 volt piv at 2.5 amps
Replaced / changed the 500 volt .01 ceramic disk with 1000 volt .01 and new 1/2 watt equalizing resistors at the same value.

Replaced a 33uf 160 volt cap at the filament transformer.
Replaced a 100 uf 16 volt cap at the zener diode.
Replaced "4" .01 500 volt ceramic disk on the bottom of the 3-500z tubes. The Grids

any suggestions. I will open it back up in the morning and re look at all on the ceramic disk.

That is a very good reason to stay away from the 10k radios. 

Looking for a Ham, Greg Gifford ? who lived on Bonita Dr in Garland, Texas in the 1960's.
I remember he gave me a toy fire truck when I was 4 or 5 years old. Mom and dad said something about once in a while they could hear CW on the TV.