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Re: 4 Tube 811 Amplifier.
You dont need matched tubes -- just put some resistance in the cathodes and they self match -- rich knows more about how to get the right values of resistance -- im still learning Steven Grant W4IIV
By Steven Grant <w4iiv@...> · #252 ·
Re: 4 Tube 811 Amplifier.
Very good English Anyway I had a Ameratron (sp) AL 811H This was a 4 tube 811 amp. Try researching it for CKT diagrams and ideas. I think the schematic is on the Ameratron web page. la3pna wrote:
By KR4DA <kr4da@...> · #250 ·
4 Tube 811 Amplifier.
Hi group. I'm Thomas, La3PNA and I'm in the progress of starting to build an HF amplifier with 4 811A tubes. I'm gone to use 4 of them because, I got the tubes, sockets and Plate caps for 4. I have
By la3pna <snknutse@...> · #249 ·
Re: Calculating Grid dissipation revisted
I increases. ### agreed. ### Those 253 lb Dahl's are a bargain..... on SSB because one of his 68-pounders will do 15k out. 8910/4cx15,000J. ### I find that hard to believe !... but I may well be
By pentalab <jim.thomson@...> · #248 ·
New file uploaded to ham_amplifiers
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the ham_amplifiers group. File : /LA3PNA 811 Amplifier/811.jpg Uploaded by : la3pna
By ham_amplifiers@... · #247 ·
Re: plate xfmrs... hypersil.. Dahl... etc.
them too! other very good companies who make some gem dandy transformers, and for a way better price. I'll dig up a couple of address for you later today. ### someone listed on 'amp's.. think it was
By pentalab <jim.thomson@...> · #246 ·
Re: Tubing/strap for RF
all ### The way around that problem on 10/12m is this.....[a] Use a 10-1000 pf ceranic vac cap for 160-10m.... the other cap is a 12- 500 pf jennings... also good.... IE: use a low min C cap. ### [b]
By pentalab <jim.thomson@...> · #245 ·
Re: Calculating Grid dissipation revisted
RMS cathode-grid potential multiplied by - meter indicated - DC grid current is an okay approximation. The actual dissipation calculation involves integral calculus. Drive And degree of loading
By R L Measures · #244 ·
Re: Tubing/strap for RF
Tom gets some things pretty much right. However, VHF parasites isn't one of them. A Q of 15 on 10m is quite common.
By R L Measures · #243 ·
Re: Calculating Grid dissipation revisted
wrote:
By craxd <craxd1@...> · #241 ·
Re: How to Getter a 3CX-3000A7 / 6000 / 10,000 , etc !
So Tom was just blowing Smoke. He and his faithful followers are good at that.
By R L Measures · #242 ·
Calculating Grid dissipation revisted
Lemme get this straight To calculate Grid diss..... we take RMS cathode V x DC grid current ??? If that's the case..... that equates to 1.2 KW of drive to a 3CX-6000A7..... to just max out the grid
By pentalab <jim.thomson@...> · #240 ·
Re: Tubing/strap for RF
wrote: 15 and a tube such as the 8973. (18v, 650A filament) #### Nobody in their right mind [except Tom Rauch] is ever gonna run a loaded tank Q of 15 ! Using the 'new' formulae for calculating tank Q
By pentalab <jim.thomson@...> · #239 ·
Re: How to Getter a 3CX-3000A7 / 6000 / 10,000 , etc !
filament only? nothing to getter the tube? ### Correct ! 0-48 hr- 48 days on a new 3-500Z will NOT getter the tube..... from fil heat. There are NO heat activated getter's on a 3-500Z. On a 3-500Z....
By pentalab <jim.thomson@...> · #238 ·
Re: Trim, please!
Another problem is missing or incomplete quoteback marks. R L MEASURES, AG6K. 805-386-3734 r@...
By R L Measures · #237 ·
Re: Water Cooling A GS-35
A problem with TFE is cold-flow under the pressure of a hose clamp. Silicone rubber does not have this problem.
By R L Measures · #236 ·
Re: Regarding Henry SS amplifier
Phil Clements escribi: Yes, Phil, I'll do that; I always heard the owner was called Ted Henry, is this ok?. The answers in all cases were signed by a man called Ted Shannon Henry, so I guess if not a
By GGLL <nagato@...> · #235 ·
Re: Water Cooling A GS-35
so what species of raptor do we plan on cooking?? Steven Grant W4IIV
By w4iiv@... · #233 ·
Trim, please!
Please guys, do some trimming when quoting messages in your replies. Recently there have been posts with as many as four levels of quotes with replies interspersed which are virtually unreadable as a
By Bill Turner <dezrat@...> · #234 ·
Re: Amplifier Content
ORIGINAL MESSAGE: wrote: ------------ REPLY FOLLOWS ------------ Nope. Bill, W6WRT
By Bill Turner <dezrat@...> · #232 ·