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Kinda like a journal entry at this point but here goes another. Upon HVPS rebuild I found my plate current metering was faulty. I did not need a meter shunt. Stupid mistake # 173. Affects all prior plate current readings by making them too low, by a lot. Better late than never :rolleyes...

4cx300a amp w/ Tetrode boards: Awaiting delivery on new caps for HVPS. Going from 180uF to 330uF @ 450v Also scrapped the entire Tank circuit / band switch for a small La Pointe roller plus the separate Eldico 10M coil on the Tune side. The switch to FWB and new plate transformer increased...

Cannot escape Amps x Volts = Watts Need more Iron. Good lesson learned.

Amp seems happier with the FW bridge (instead of doubler) and new tranny (Heathkit 54-30 1800vac @ 400mA). Amp still on worktable and I must close it up & move it to operating location for more testing. Noticeably lighter without the 16A filament winding despite having 6 separate transformers...

Found it. I see the Rectifier & Cap boards currently listed on CTR are separate. EDIT: I got the HVPS board out today. I cannot justify not re-using it because it's just what I need and in great shape. I can also see that it's set for FWB if I add the remaining diodes. I had an extra 2...

It's been a few years since I made a doubler from the 1st board. If it's the same board, I'll strip the board down and reinstall diodes & caps. I attempted to find the board on your website but did not locate. Quality board thick plating that withstands re-soldering mistakes lol. CTR...

My 4cx300 tubes are starved for plate current. After years of working on this, I may as well do it right. I'm replacing the entire HVPS. Voltage Doubler replaced with a FWB driven by a different transformer rated for 1800v @ 400mA (Heathkit 54-30). No more combo trannies so I also ordered a 6v...

Thanks for your time to comment. I need to re-read your first para a few more times to fully understand it but I will do so. The very idea of a transformer for RF is fascinating. I looked at the Pride input on paper but could not decipher the diagram. Think I need to see the part, visual...

Been winding Baluns, tidying messy wires & tweaking this & that. Replaced the small core with 1-1/8" core (still mix 43). I'm focused on the RF Input section now. Changes take time to try and what works on a DL is not always good on an antenna. The attached "now" pic file is a diagram of...

$160 for a new Cantenna?? I'm on my 3rd can from a 1980's Heath Cantenna. I use Baby Oil and it smells OK.

I noted the minimal nature of the Screen supply design of the Tokyo HyPower 4cx diagrams when compared to the rest of their circuit. I'm learning less is more efficient when it comes to RF.

PRESS FIT PTFE INSULATED FEED-THRU TERMINALS on eBay at https://www.ebay.com/itm/363996444302?mkcid=1&mkrid=711-53200-19255-0&siteid=0&customid=link&campid=5336136228&toolid=20001&mkevt=1 20 for $13 including delivery. Cambion brand with datasheet. .22" insert diameter. Several Sellers. The...

Last few days rewired the input section. It was very sloppy, too many parts. I'm surprised it worked at all. What's that saying about a monkey with a typewriter composing Shakespeare? Deleted a paragraph about input tuning. All progress stopped a week at least. Small feed-throughs on blower...

Some hand from above reached down to adjust the market. Sounds about right. Internet held such promise in the early '90's.

Applied power today after rebuilding Tank & band switch. Revisions included new plate choke (series resistance drop of almost 4 ohms), new Load cap and a band switch/pi rebuild/revisions. The resultant optimal Tune and Load settings for max PO on 28.340 into DL are improved to the extent that...

For the life of me I cannot find that Item again. The paragraph above was a cut & paste from the listing itself. Found it late last night browsing ads. It ws cheap <$200 and had switched inputs for each band. Homebrew but small and finished in blue/silver. Something I'd never seen before...

Interesting Homebrew at: https://www.ebay.com/itm/334888084436?mkcid=1&mkrid=711-53200-19255-0&siteid=0&customid=link&campid=5336136228&toolid=20001&mkevt=1 The base amplifier here is an “ST” DB-2933-54 test bed for it’s RF POWER amplifier using 2 x SD2933 N-Channel enhancement-mode lateral...

I think I understand: The efficiency of swamping makes an auto tuner impractical. My bad, I keep trying to re-invent the wheel.

Thank you for your reply. For chuckles I added 2 tiny ferrite beads near the plate choke. I'll find out if the Ohmite choke can take the voltage soon. It measured 2.5 ohms while the old choke was 7ohms. My antenna system cannot handle 80 so that's a no go area for me. Waiting for the 5w...

Rebuilding Eldico band switch. Picture is of the contact connecting switch rotor to coax. Note the lump of silver on tip.