Driving the 3cpx5000a7 amp with about 500w and getting 10kw pep. I love this amp! Probably going to be on ebay in the near future. This is just a feel good video, take it easy trolls.
I got double or more out of a 3CX3000 . It wasn't a Eimac tube. It was an Econco rebuild that had a better tungsten thoride filliment . My power supply was bigger. I was also volting the filliment about 9 volts. Sold it 25 years ago, and it is still in action .
You could cook a truckload of hot dogs with that beast. Nice! Was that a new 100% triode or one pulled from medical grade swap out certification? It would be interesting to see the vent chimney system you made to accommodate that flange mounted triode.
douro20 This is how amp technology moves forward. Testing and learning. I think kf8od knows the legal limit. Old school is very bullet proof, soon it will all be solid state amps.
Bob H I built this amp about 3 years ago. It been sitting so I like to fire them up every once in a while. Power required is 240vac at 30a single phase. 73, Mike
How are you running your tube? Grounded grid, grounded cathode? Cathode driven or Grid driven? I am running one with the grid ring isolated on plexiglass and driving the grid with -200vdc bias and a 1:3 RF matching transformer. It makes a killer AB1 amp. A 5 watt carrier with forward modulation to about 12 watts drives the tube to 5000 watts. On AM it keys low watts and modulates to 5000 watts. It runs even better on SSB. It will top out about 7500 watts. This tube can’t take a lot of grid drive. I find 12 watts to be about the most drive. It has a 25 watt grid dissipation, but over 12 watts the grid current starts to exceed the 100 ma max on my tube. I’m running about 5KV on the Anode. Fun stuff. The Chinese version of this tube is only $250. 73, N1FQF.
I will be in Hawaii celebrating my 25th wedding anniversary so unfortunately I am going to miss Dayton this year. You can email me direct if you would like, Check out my website: qsl.net/kf8od. Some good information on there.
The power is not an ideas, how you can have 10 kw with a 5 kw anode dissipation tube???? You must stude the tecnic before writing stupid things (i made a 5Kw ouput linear amplifier using an Eimac 4CX5000A several years ago) I1RRT Bobby Italy.
Alexshowa Bobby, thanks you for your comment. Look at the data sheet for your 4cx5000, list the output as 16kw. The 3cpx5000a7 is actually a 3cx15000b7 with a 5kw anode made for the MRI industry. They use the tube to pulse 13kw. The size of the anode dictates the power that can be generated with a given air flow to maintain the seal temperature at a safe level. In ssb mode the tubes will generate far more. 73, Mike
jeramy duncan The plate voltage on this amp is 5500v, I have used 6500. These tubes love plate voltage, the higher the plate voltage the higher the gain.
jeramy duncan The 10kw is pep. Your tube might be a little soft. I had several that were a little low on the output. They bang the hell out of these tubes with a square wave in the MRI amps.
This is a 8" piece of stainless steel tube, welded plates top and bottom. This load is built the same way the 1500 watt load was built. It uses a carborundum 890SP 375 watt resistor. 1" X 18"long. Three gallons of mineral oil. 73, Mike
You can build a high power RF dummy load like this using a old electric oil filled heater by modifying the heater coil with RF load resistors on a copper bar, the old oil filled electric heater cavity will work perfect for RF load and is completely RF shielded and convection oil cooled.
