sb-221 Question

[2RT307]

hes been in and out sick for awhile and up had had a stroke
and unable to do much, going to be in rehab for awhile
and thats not looking good either

Hope your friend is getting better. Was this amp recently for sale at the Cowtown Hamfest?

73,
Brett

 

[WA8ZYT]

Using an oscilloscope to measure power output is a PITA as you must first convert peak-peak voltage to something a bit more useful and then compute the power based on true load impedance which must be measured and not just assumed even if using a dummy load.

Easier way is to hook a watt meter in series with the scope and compare power readings on the meter to scope deflection. So, in this case put a CW signal at 1200 watts through the wattmeter and scope and set the vertical deflection to a reference graticule on the scope face. Then switch to SSB and you will see your actual voice peaks, and more than likely see they are at the 1200 watt level you saw on the CW signal.

Actually. this is all spelled out rather nicely in the SB-220 and SB-200 manuals.