Good morning,
Having owned the 220 years ago, I was pleased to see 1200 watts output, key-down in the SSB position, this entirely consistent with advertized parameters. With better performance when connected to 240vAC rather than 120v AC, the amp, running in class AB1, should not produce more than 50 percent of input power plus a portion of the output power of the exciter. So, if, in full output position, i.e. SSB rather than tune, One has obtained plate resonance and has coupled to a 35 to 75 ohm output with the pi network, an accurate watt meter, assuming a 50-ohm output, might be expected to read between 1000 & 1200 with full output from the exciter.
Cheers,
Jerry VE3QSO
----- Original Message -----
From: Mark
To: [log in to unmask]
Sent: Friday, August 14, 2009 8:37 PM
Subject: Re: Heathkit SB-220 HF Amp output
Hi
I have never owned this mottle of amp but I believe that it is rated as
a 1 KW. Any thing you get above that is more then the (factory) specs. I
might be wrong about that.
God bless,
Mark
----- Original Message -----
From: "Michael Ryan" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, August 14, 2009 12:21 PM
Subject: Heathkit SB-220 HF Amp output
> Hi all:
>
> I recently picked up a Heathkit SB-220. After taken the steps
> necessary to bring it up slowly, the amp was idal for 15 years, here
> is my results.
> I use an LDG Electronics TW-1 Watt Meter to tune and here are the steps.
> 1. Placing the meter in tone mode, key down in CW, Adjusting the Tune
> control on the amp to find the highest pitch possible. That's how you
> find the plate setting.
> 2. Key down in CW, with tone mode, adjusting the load control to find
> the highest pitch possible. With 10 watts from my exciter, I see about
> 180W.
> 3. With the amp in stand by, I increase my exciter to 100, re_ingage
> the Amp in CW, adjusting the load control for yet more pitch.
> The result is approximately 1000W. Note the amp is in CW/Tune and each
> adjustment on the controls take about 10 seconds.
> When I reduce my exciter's drive to 60W, I see 800W with the amp still
> in CW/Tune. When I switch the amp to SSB, I only get another 200W.
> Total output, 1KW on SSB with 60w of exciter drive. With 100W drive, I
> won't see no more than 1300.
> Is this normal? I don't think the tubes are bad because the amp powers
> up to spec in CW/Tune.
> 100W drive =1000.
>
> TNX all & 73:
>
> Michael De VO1RYN
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