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Old 11th Dec 2017, 1:04 am   #18
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Join Date: Jun 2006
Location: Chard, south Somerset, UK.
Posts: 6,193
Default Re: 'Kalmus' wideband RFPA: info.?

This Kalmus amp. & it's reliability. In my hands, over a period of about 12 years, it hasn't been used for extended periods of time delivering substantial power (40 - 50 W.) into 50 Ohms. It gets used very occasionally: typically when I need a higher output voltage than my HP 8640B will produce - or other R.F. generating sources I have. OTOH, in a past employment, I regularly used an AR amp. of similar spec.: that was often blowing O/P transistors.

As for "fixing it", I'm not yet convinced that it actually needs fixing. The max. O/P is 50-W. (approx.) and the waveform looks O.K. too. Although the O/P power varies substantially with freq., since it doesn't have ALC, I suspect that that variation is simply a characteristic of the design.

"Your idea is crazy! But the question is this: is it crazy enough . . . . to be true?" (Niels Bohr)

Last edited by Skywave; 11th Dec 2017 at 1:10 am.
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