I'm not happy with that meter modification, you can get a dip in cathode current when adjusting the tune variable, but you can't read plate (anode) current with screen current added to it. It would also be nice to read screen current after all those mods to be sure it's the proper value, at least until operating conditions are settled on and everything is proper. At the end of the day (except for neutralization that may be needed now) you can throw away the manual and write a new one, that's no longer a Johnson ANYTHING you have there, more like a KA2PTE Firedrake (fire breathing dragon). If you can make a sticker, or better yet a decal and put this in that blank spot above the tuning control it would make a mean finishing touch. JIGGITY JIGGITY! Yeah, in addition to an airline pilot Glenn Quagmire is a ham fond of boat anchors with tubes in his basement. Heh, Godzilla finally set King Ghidorah on fire! ('->)

I see the metering change, confusing at best, I can't make sense out of what it was originally, the switch selects "screen" & HV, but in Class AB1 it was originally set up for max screen current is 28mA for 2 tubes, but why measure it? I'm used to tuning the grid circuit, so grid current was metered, I'm lost here. Then there's a watts scale on M2 lower scale with plate current on the upper, why I have no idea because to get plate DC input you multiply the upper scale by M1 lower scale (KV) provided calibration is correct and that depends on R101-105 being all within 1% so there could be no more than 5% from nominal worst case scenario. Would Johnson spring the bux for precision resistors when they cheap out on everything else? Collins on the other hand used a single 1% multiplier in the 20V I repaired, but there's a gulf as wide as The Grand Canyon of Mars here. (;->) You can't have enough bypass caps though, the Ranger and Valiant had them up the wazoo and there was a shield can on the meter, but when they designed the Valiant they cheaped out on the most critical parts, the modulator and final. Mod iron on both was puny, and the Valiant used 6146s that suck as audio tubes when 807s shine. Then they paralleled 3 6146s in the final and at the voltage and current it ran at the plate impedance is only around 500 ohms. That leaves a 10:1 typical transformation ratio in the pi network, not high enough to adequately tune out harmonics and spurs, plus it was a BITCH to neutralize, more shit going up the pipe to the signal spitter. UGH! That's where my Drake TVI filter came into play, without it my TV went nuts, likely the neighbors' too. Oh, if your TV goes BSOD when you key up the Firedrake there is another Drake that can fix it, they made a KW filter too. Cathode resistor bypass caps? No, there are no cathode resistors, it's not cathode biased, it's an RF output amp, not an audio power output stage.

OH RATS! The music stopped, the bloody WiFi disconnected AGAIN! Since "they" added several more mobile laptops to this already overloaded wireless network it has been acting funky. Then instead of upgrading it like should have been done a long time ago the cheap bastards changed several channels around and made it much worse. They've also created a medical situation in the process, the nurses' meds carts mobile laptops aren't working, oh lovely. I wish they would do like I do, I have an iron clad rule; IF YOU DON'T KNOW WHAT YOU'RE DOING DON'T F***K WITH IT!!!

There, finally I got it connected again, and just in time for one of my favorite songs on one of my favorite albums, I Talk To The Wind on the King Crimson Court of the Crimson King. It's such a beautiful song and in my key too, I loved harmonizing to Robert Fripp before I lost my voice. I'm pretty sure you'll like Radio Caroline too, Europe's top pirate radio ship gone legal; http://www.radiocaroline.co.uk/#home.html Rant mode off, so ON WITH THE SHOW.

"While I was in there saw one of the terminals the control grid goes to on one tube was not soldered, and was really loose
so fixed that."
Keep looking, again you were reminded of the value of close visual inspection. If I found a terminal without solder in a Collins 32V2 transmitter (the sweetest audio I ever heard in CB in our AM Gangstas group) I was repairing I can't imagine how many you'll find in a Johnson. (;->) At least your job is pretty easy, Collins is infamous for being technician and broadcast engineer unfriendly.

"C10 was an original Sangamo molded mica, 2500WV / 5KV max. It was mounted inside the fan compartment, so maybe they thought the heat on the tube sockets would shorten its life and they went overkill?"
No, just a convenient place to mount it. I had dozens of those things and put them to good use replacing fixed loading caps in those miserable Johnsons. I've heard the expression among hams "Happiness is a big Johnson" and I'm sure they mean the ones they were born with.

"I like using a doorknob for it. Yes way overkill but since this is no longer factory plate voltage and is AB1, I rather have higher rated in case of a catastrophe."
You're in love with those TV doorknobs, but I'm sure you'd like a cat ass trophy addition to your shack, you can order one on line. (;->)
https://www.etsy.com/market/cat_ass_trophy
Jim N2EIY, W2RXR, and whatever he changed it to now, overkill is his middle name. I needed a power supply so he gave me one he had kicking around, a Tripp Lite 12V regulated 60A unit that could run 3 2M FM rigs transmitting continuously without getting warm, overkill. Then there's the bracket scrounged from an old computer, an octal plug in relat, and MORE DOORKNOBS, overkill. One of my favorite scrounge spots was behind the local TV repair shop and besides tubes that I tested and added to my collection, quite naturally I collected doorknobs. When I built a medium size Tesla coil I saved lots of work making the HV capacitor out of glass plates, aluminium foil, and glue I wired al of my doorknobs in parallel.They sorted themselves when I turned it on, some had a defect or another and exploded like the one in the ATU.

"I read neutralization was rarely needed on the Tbolts, but as I am into new territory here, would be worth looking into
and try to avoid the parasitics."
It's not a matter of new to the territory, I'm more of an egg spurt than an ex spurt, it's a matter of the amp no longer being a Thunderbolt, Arthur Pendragon had a wizard named Merlin who changed it into a Firedrake. How's that for a new kingly tale a bored knight named Lance A Lot came up with? Don't mind me, this f***ed up WhyFry is driving me mad...........

Here's a thought to ponder, there's a grounded grid mod for the wee beastie. With a grounded shield between input and output you don't need neutralization, just 80-100W to drive it vs. IIRC 5-10W grid drive two tubes.

Family Guy Glenn Quagmire ham.jpg

Firedrake.jpg