[Amps] SB-200 Low output power on 80M - edited to fit screen

[Glen Zook]

With what are you driving the SB-200?

If a solid-state unit I would bet that the drive is actually falling off due to a mismatch in the input.  The SB-200 is not famous for having a true 50 ohm input.  Remember that with a wattmeter you have to subtract the reflected power reading from the forward power reading to get the true power.

Note that the grid drive is less on 80 meters than on the other bands.  This is why I suspect an "SWR" problem with the input.

Glen, K9STH

Website:  http://k9sth.com


--- On Sat, 9/12/09, Ian Hill - K8MM <ihk8mm at charter.net> wrote:

I have an SB-200 that putting out less than expect power on 80M. Tuning was done in accordance to Heathkit's instructions....basically for maximum smoke and reduce the drive a bit if the grid current goes over 100mA. I expected the RF output power to be equal to or great than the power output on 40M and 20M, and then start falling off as you go higher in frequency. This has been my experience with other amplifiers with a pair of 572B tubes.