tuner before amp

[w9cll]

Be careful with the input as said, that is a great amp but jamming on it on AM will kill it quickly. Personally I wouldn't feed it with anything over 80w AM.

 

[552fl]

alright give 80 watts a try and see what it will do on output.

 

[552fl]

That BBI amp Builder is getting a lot of Watts out of them stock sb220 .. but he is using 200 plus Watts drive though very interesting huh..

 

[Shadetree Mechanic]

That BBI amp Builder is getting a lot of Watts out of them stock sb220 .. but he is using 200 plus Watts drive though very interesting huh..

The tubes won't last long at all doing that. There are a few modifications that need to be done to the 220 for AM. Otherwise don't plan on getting full rated power out of it. How long do you want the tubes to last?

 

[w9cll]

That BBI amp Builder is getting a lot of Watts out of them stock sb220 .. but he is using 200 plus Watts drive though very interesting huh..

I get the feeling you like to see the watt meter peg over but be gentle on this old girl and she will last forever.

 

[552fl]

No I was just letting y'all know what I seen on YouTube.. already spent for the harbach mods capacitors and metering board and fan so I think next would be the tubes. I'll be as happy as long as it will do 1200 pep

 

[w9cll]

Just keep all this in mind. On AM its 50% duty cycle so no long keydowns.

 

[w9cll]

I'll be as happy as long as it will do 1200 pep

I think you will get that output but not for long. Personally, I would run it at 700-800 watts, it will run all day long at that output.

 

[552fl]

30 year old tooth must be still good then because it will do that no problem..

 

[552fl]

Tubes

 

[w9cll]

30 year old tooth must be still good then because it will do that no problem..

Tubes will last a long time if you don't jump on them.

 

[Road Squawker]

BTW, the chart in post #22 is INPUT power

 

[552fl]

I wonder how ameritron gets 1000 Watts out of there one tube amp with the 3 500 Z tube

 

[543_Dallas]

I wonder how ameritron gets 1000 Watts out of there one tube amp with the 3 500 Z tube

They exaggerate the rating. It has to be driven hard, overcoupled to keep the grid current down and they use that bs dynamic bias to improve efficiency. That amp also has a good ALC circuit that connects to the radio. The alc circuit monitors grid current and will throttle back the radio to protect the tube.

The al80b is only good for 125 to 150 watts carrier on AM and 600ish pep. I never run mine above 750 pep on ssb. It will do the advertised kw but that's ridiculous. Ameritron put enough power supply in the al80b to take full advantage of the tube. Heapshit did not. Also remember the al80b and most HF amps make less power on 10, 11 or 12 meters. I know a few cbers that were dissatisfied with their new ameritron.

You have to look at more than the tubes to determine what an amplifier is capable of. The sb220 will deliver 1200 pep on ssb without hurting anything as long as you tune it right. Compare the power supply and cooling system to an ameritron al82 or an old Henry amplifier that uses 3-500z tubes. The sb220 is light duty at best.

 

[552fl]

almost bought one and found out that they don't do what they say so everyone talked me into buying this Heathkit what you call Heap s*** I'm starting to agree with you you hit the nail on the keep Heap s***