Hi,
I currently have on my bench a Racal Syncal 30 aka TRA931. I'm currently involved in looking into alternative PA transistors since good 2N5070s are nearly impossible to source these days.
I currently have a pair of 'experimental' transistors in place and the set is happily generating 20W on all frequencies with a very slight drop (about 2W below 2MHz). What is a bit alarming is that the set will happily deliver 20W (in the High position) even when AM is selected. Oddly, although the manual specifically states that the o/p is nominally 5W on AM (and understandably too), there is no mention in the circuit description of how this reduction in output power is achieved.
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Looking at the wiring associated with the Mode Switch, it looks like the Mute pin (66) on the synthesiser might have something to do with it, but poking around in that area has proven inconclusive.
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Can anyone shed some light on this?
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Regards,
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Ian, GM0UHC
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