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3cx1200a7 amp
- Thread starter Sm7tvj
- Start date
You are going to build an amp using two 3CX1200A7 and you have to ask how much power output it will have? :sad: 5000 volts is pretty near the maximum rating for that tube. Typical class AB operation uses about 3500-4000 volts at 0.7 amps. With 85 watts drive this will deliver 1500 watts output. Two tubes with 120 watts drive should deliver an easy 3000 watts without a problem. More output is possible however signal quality will suffer.
What is the legal limit in Sweden any way?
P.S. Good luck tomorrow in the gold medal final. We plan to show mercy.
What is the legal limit in Sweden any way?
P.S. Good luck tomorrow in the gold medal final. We plan to show mercy.
The problem is you don't know the efficiency until AFTER the amp is build and tweaked. At that point all you need to do is read the watt meter. :laugh:
RatsoW8
Supporting Member, W9WDX ARC Member - WD8T
http://www.g8wrb.org/data/Eimac/3CX1200A7.pdf
Ok so you can look up the tube specs and make your decision on what you can expect out of a pair of tubes.
http://www.g8wrb.org/data/Eimac/3CX1200A7.pdf
The spec sheet should give the efficiency CK, of course if there is a decent tuned tank circuit and tuned input.
Ok so you can look up the tube specs and make your decision on what you can expect out of a pair of tubes.
http://www.g8wrb.org/data/Eimac/3CX1200A7.pdf
The spec sheet should give the efficiency CK, of course if there is a decent tuned tank circuit and tuned input.
The actual efficiency will depend on the tank circuit to a degree. Small coil equals lower eff. Also the actual operation class will determine that as well. Class B? Class AB1 or AB2? Even poor construction techniques such as the tank coil being too close to the cabinet etc can affect overall eff.
With 5000 volts and 2 amps, a pair of 3CX1200A7's are not the correct choice in terms of both reliability and cost. They cost almost as much per tube as a 3CX3000A7 and there is no comparison between the capabilities a pair of 1200's has to one 3000. 10 KVA of power supply is inappropriate for 2400 watts of plate dissipation.
It takes more than three 1200's to equal the dissipation a single 3000 has and even with that, the durability of 3 small tubes is miles away from what you get with a single tube that can handle the entire plate supply. The ONLY reason to build a pair of 1200's would be if you already had the tubes.
It takes more than three 1200's to equal the dissipation a single 3000 has and even with that, the durability of 3 small tubes is miles away from what you get with a single tube that can handle the entire plate supply. The ONLY reason to build a pair of 1200's would be if you already had the tubes.
by the time your done building the amp 120 watts of drive should give you around...... 1.21 jigawatts i think maybe 1.22 if your flux capacitor is set right
M
Mr Fix it
Guest
If you already own the tubes and they work I would suggest selling them. You can probably fetch at least 500 per tube . I would then suggest you buy a new econco 3cx6000a7 for 1100 bucks. 73
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