Re: Mini PA für my uBITX #ubitx

Timothy Fidler

Reply : Some of the photos I have seen have marginal looking  OPTs on them as in things that look like longitudinally split core coaxial cores.

2.  THe fully assembled versions will have a heat sink based on something like 30 W dissip most likely.  When you look at the MRF 186 specs it is rather in efficient so 
heat,  when it is run at 90 W out continuously could be a real problem.  A modern mosfet RF Amp will be nominally 60 percent eff in class B but NOT this one.

3. Some of the units have a power supply capacitor that is marginal at 24 V supply. - It can be changed out - in fact the Ozzie Wordpress article may have mentioned that.

apart from that , no issues !  PS it would be fascinating to find out how so many of these VHF gemini pairs got left in a sack in PRC prior  to their being repurposed for current use  - I guess they were intended for some military project that was canned or a better device (higher efficiency) was found and these ones went begging.??

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