Mt Washington Wx CAM
Heathkit SB-200 Amplifier 6-Meter Conversion
Heathkit SB-200 Amplifier 6-Meter Conversion:
The original Heathkit SB-200 Amplifier was an 80 through 10 meter amplifier that sold for around $400 as a kit. The SB-200 uses a pair of 572B tubes, which can put out a nice solid signal approaching 600 watts (output) with 100 watts of drive on CW. When these amplifiers were sold the rules stated power input as the legal power. This amplifier was rated at 1000 watts INPUT, not output. The current drain is 8 amps at 240 VAC or 16 amps at 120 VAC. This amplifier was on the market for over 20 years, as was its big brother, the SB-220.
My SB-200 has been converted to 6 meters only. The band switch has been bypassed and and only runs on six meters. If I drive it with 100 watts CW, I can get 750 watts out, but I usually run it at about 500 watts output on CW. I have been running this amp on 6 meters for over 11 years and it still performs well and I have not had any issues whatsoever.
I have only used this amplifier with my Icom IC-706 MKIIG. I am going to run some tests with my Icom IC-756 Pro III and with the old venible Yaesu FT-625RD. The Yaesu only puts out 25 watts, so I do not know if it will be enough power to drive it to a useful power level. I have a Bird Wattmeter, so I have a good instrument to measure the power with. I am going to run tests into a dummy load so that I can have the same reference with all three radios. Results will follow!
Running 500+ watts really helps out during openings, but really helps when the band is not open. This gives me over 6 db more output than most of the other people on the band. I have good reason to believe that it really works well. Back in November of 2001 I worked JH8DBJ on 6 meter CW and was the only station east of the west coast that he heard that day. Japan is my best DX on 6 meters. This contact was made over a 6,244 mile path. This is three (3) F2 hops on 6 meters! Needless to say, I have had a lot of fun with this amp on 6-Meters. Hope to work you on the Magic Band!
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