I wouldn't worry about that, you see full output on CW, I wouldn't think
when you're doing something continuous like keying in CW, even with the amp
in SSB, I wouldn't think you'd see full power, most amps will put out
considerably more when you're actually using SSB than when you just put a
carrier in to it. My SB-200 for example will where I usually run it, show
about 490 watts when I check in CW. Yet when I change the radio to SSB, my
TW1 says less than that, but I put a peak reading meter on it and find it's
around 650 actually if not more on peaks. I wouldn't worry about your
numbers at all but if you want to tell if the tubes are going soft anyway,
noting it will be down from what you see on 40, 20, 75, check it on 10
meters if you can. If it's way down there, then it might be something to
think about but I'm talking way down, it's going to be a little down no
matter what on that band. Assuming of course that amp will go there but
since it was a kit, I'd doubt there's anything in there to stop it. I think
your numbers are just fine though. Also, your supply voltage can have a
little effect on that too. I'm not sure what you have where you are.
----- Original Message -----
From: "Michael Ryan" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, November 10, 2009 2:36 PM
Subject: Heathkit SB-220 pwr out questions.
> =20
>
> =20
>
> Hi all:=20
>
> =20
>
> I've been running a Heathkit SB-220 HF amplifier for the past 5 months =
> and the overall output #s, aren't on par with a couple of other 220s =
> that are in operation in my area.=20
>
> My Amp is bone stock and original tubes. I don't know if the other amps =
> are because I don't know the operators personally., only one.=20
>
> The #s they claim are 100W in =3D 1KW CW, 100 in =3D 1800/2KW SSB.
>
> I use an LDG Electronics TW-1 meter.=20
>
>
>
> Here's my amplifier tune up procedure with my antenna tuned to a 1 to 1 =
> SWR.=20
>
> =20
>
> 1. Set the Exciter drive at 10W, CW, on desired band.=20
>
> 2. Place the Amplifier in the CW/Tune position on same band.=20
>
> 3. Key the exciter and amplifier, adjust the tune control to increase =
> the pitch of my meter, about 10 seconds of key down, return to receive.=20
>
> 4. Key the exciter and amplifier, adjust the load control to increase =
> the pitch of my meter further, about 10 seconds of key down, return to =
> receive.=20
>
> Key the exciter and amplifier to get a reading: 10W in =3D 170 out.=20
>
> 5. Place the amp in stand by and increase the exciter's drive to 100W.=20
>
> 6. Key the exciter and amplifier, adjust the load control, increasing =
> the pitch of my meter to its maximum, about 10 seconds of key down, =
> return to receive. =20
>
> Key the exciter and amplifier to get a reading: 100W in =3D 1030 out.=20
>
> 7. I switch the amp to SSB, leaving the exciter in CW, key the exciter =
> and amp to take a reading,=20
>
> 100W =3D 1237 out.=20
>
> As my meter requires a continuous carrier to function, this is why I =
> leave my exciter in CW and switch the amp to SSB for the final reading.=20
>
> I reduce the drive to 75W, with the exciter in CW and amp in SSB, I see =
> about 1KW out.=20
>
> LDG Electronics claim that there is about a 5 to 10 percent inaccuracy =
> on the measurements.=20
>
> Should I be concerned about these figures, are they normal, should I =
> consider replacing my power supply components and or tubes?=20
>
> =20
>
> Thanks & 73:=20
>
> =20
>
> Michael De VO1RYN=20
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