[Amps] SB-220: 1,800 Watts Output

[Jim Barber]

I was thinking 100 watts carrier/400 watts PEP AM, actually.
That would allow me to use the Flex 5000A at roughly the same output 
level as my old Johnson Viking Valiant.

I'm not a "10 minute club" member, but have occasionally been known to 
go 2 minutes keydown on juicy topics. Assuming 2 minutes 'on' and 5 
minutes standby in a round table it doesn't sound like I'd be stressing 
the PS or tube all that much, although I'm a bit suspicious of the 
cooling from that single 5 1/4" muffin fan.

FWIW, when the SB1000 was last in regular use I loaded it to around 800 
watts out and only drove it as hard on SSB as it took to get that. (as 
measured by a  peak-reading meter) That seemed to work at the time.

BTW: I recently tried using one of the PA77's to get that same 100/400 
output on 75M and found that it was too difficult to get my 25/100 watt 
rigs trimmed down far enough. The 3KA has less gain so is probably a 
better candidate, but I haven't tried it yet.

Good info all, thanks.

73, Jim N7CXI

Bill, W6WRT wrote:
> ORIGINAL MESSAGE:
> 
> On Mon, 30 Nov 2009 11:54:20 -0800, Jim Barber <audioguy at charter.net> wrote:
> 
>> Then that begs the question - Marketing claims aside, what would be an 
>> appropriate max output power to run with a SB1000/AL80 ?
>>
>> It's a timely question for me, at least. I have a nice SB1000 that's 
>> been in the storage room for 5 years or so and was thinking about 
>> getting it out and putting a tube in it. It has 160m, which my 3KA and 
>> PA77's have not. It also doesn't cause gale force winds in the shack... ;-)
> 
> REPLY:
> 
> I have an SB-1000 which I ran on HF for several years and then converted to six
> meters. It will give 1 kW out on CW or SSB but should be limited to about 600
> watts on  RTTY or FM. The limiting factor for RTTY or FM is the power
> transformer. You could run it for brief bursts (chasing DX) but for extended
> periods such as RTTY contesting at 1 kW the transformer will overheat. 
> 
> 73, Bill W6WRT
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