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HEATHKIT SB-200 Info required Please.

LightFoot

Member
Dec 28, 2008
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My buddy just recently acquired an SB-200 real clean. Its wired for 110 ac. Is it normal for him to just see 300 peak watts at 110 v. I know that it can be wired for 220 volts. Will it produce double at that voltage? Thanks Just Curious. Best regards and wishes to all reading and posting in this Thread..........(y)
 

No he will not see twice the output wired for 220 volts. When the amp is run near it's maximum rated power he will see a bit higher output but no where near twice. You didn't say what he was driving the amp with for a radio or how much power he is driving the amp with. that amp should put out about 600 watts when wired for 220 volts and maybe about 500 watts on 120 volts when driven with about 100 watts.
 
Hi Captain Kilowatt. The box was modded for straight 11 meters. He is using a RCI 2985 Dx Radio 1 1/2 swinging 35 watts and only producing actually closer to 350. With 1 1/2 watts he is keying 50 watts and peaking 350. We tried it with a baby driver just under 100 and even adjusted for 75 then 50 watts dead key and only produced higher dead key but nothing over 350. HV IS READING AT 2300 AND JUST DIPS TO 2100V when load is applied. Plate at 100 and grid at 50. Swr moves a hair. Maybe tubes? But then 150 more watts probably wont make much a difference to the receiving end. Also is using a hand trigger to key her up. Thanks for the reply and best to you............(y)
 
Thanks for the input 359 Just wasnt sure. Thought that perhaps it should of had more output Ive heard people saying that they are seeing 600 plus so was curious to ask. :pop:
 
He is using a RCI 2985 Dx Radio 1 1/2 swinging 35 watts and only producing actually closer to 350.
With 35 watts of peak drive, it sounds right and the plate voltage is right on. I used to drive mine with ~50 watts peak and get around 375 out. I drove it with my 101e a few times and doing a little over 100 pep and would get 650 out, but are you swinging 100 into it, or keying 100 out?
 
Hi again with 100 watts dead key in it keyed 300 watts and swung 350. Nothing more. Wish I could see 600. Thats why i thought maybe tubes going flat but does the plate reading and grid reading indicate the condition of the tubes or that the box is tuned correctly at the specific readings? Thanks again. :D
 
Hi again with 100 watts dead key in it keyed 300 watts and swung 350. Nothing more. Wish I could see 600. Thats why i thought maybe tubes going flat but does the plate reading and grid reading indicate the condition of the tubes or that the box is tuned correctly at the specific readings? Thanks again. :D

The plate voltage sounds spot on and won't change from tuning. The grid current needs dipped when tuned properly.

Outside of that, there does seem to be a problem though, are you dipping the grid during modulation or with a carrier?
 
I drive mine with 13 to 15 or so watt dk. 100 pep. 100 watt dk 550 or so out the amp. I would not drive it any harder. Great little amps if driven right. Mine is 110v. 100 or 150 watts max on dk. 100 is more easy on it. Transformers are alittle wimpy as they were built for SSB.
 
Hi 359 were dipping the grid on dead carrier. I thought the output was low. Could it be the tubes are not at 100%? I have a tube tester but for sweep tubes and not for the 572b pin style. Would be nice to test them.

Hi there Mr Clean the Heathkit are nice amps. They look like their built like a tank. By the way want to wish everyone a Happy 4th of July to come..............:pop:
 
And while you're 'grinning', just remember that modulated tone/tones must be at a constant input level. You can't do it by voice, or by using a microphone, too much extraneous noise for accuracy. What would the result be? Oh, something like twice the -apparent- output of doing the same thing with a carrier. The key word in that is 'apparent'... :)
- 'Doc
 
Dip the grid?

GG linears should be tuned for rated output with rated drive while not exceeding grid current.

Nothing gets dipped. The plate should dip somewhere near max output but some design's neutralization is less than perfect and the dip doesn't coincide with max out.
 
You're right, I'm not sure why I was talking grid current dip on a grounded grid design.

But if the tubes are not neutral, one side of the dip will be steeper or sharper than the other, but shouldn't max out still happen at the plate current dip?
 

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