[Amps] New SB-200 owner

[Peter Chadwick]

Lou said:
>Not too good, yet 85% of the trash you  will see on 
SB-200 conversions is exactly that, add on 6 meters to HF. <


Surely not! The older ARRL handbooks had a 4-250 amplifier design for 21, 28 and 50 MHz, and that's the nearest I've seen to multiband amps including 6. There were some British Army amps that covered about 30 to 50 and 50 to 70MHz using a 4-250A, and they were tuneable - but in two varieties rather than switched bands. Personally, I'd have said that trying to add 6 metres to an HF amp was a good way of asking for trouble. If you designed it from scratch with suitable mechanics to give very low capacitance switching between HF and VHF tanks, you might get away with it, but as an addition........I think we all accept that 572Bs aren't the ideal tube for 50MHz, but to try and get the thing to work on the other bands as well I would have thought required a magician rather than an engineer.
73
Peter G3RZP