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Old 16th Feb 2015, 11:00 am   #3
David G4EBT
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Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 4,393
Default Re: Trio 9R-59DS communications receiver (1970)

I look upon the 9R59DS with fond affection. It was my first short-wave receiver, bought pristine but second-hand in 1971, and luckily, it came with the now rare matching loudspeaker as there isn't a built in speaker - just a phone socket.

Most of the limitations were well known back then, and there was a series of modifications in the much lamented Radio Constructor Magazine to improve the performance and to add features. As to poor image rejection, it isn't of course unique to the 9R59DS - it's something that all single superhets have in common on the higher frequencies. It does at least have bandspread.

Some of the mods included fitting a crystal calibrator and voltage stabiliser, fitting a smoothing choke and re-positioning the OPT away from the mains transformer, to reduce hum levels, improving the IF stage, and so on. I did most of the mods on mine. They're ideal to work on as they're so large, which means that the internal layout of components isn't cramped.Inevitable that as they approach their 50th birthday, the usual problems are starting to develop, and I dare say that of those that do turn up from time to time, they'll often have been 'got at'.

Beauty is in the eye of the beholder, but I always liked the appearance of the set, and still do. There was one at the NVCF last May which was unmarked and un-tampered with, compete with speaker, at a giveaway price. I was sorely tempted and nostalgia almost overcame common sense but I'm in 'de-cluttering mode', so I passed on it. It wasn't there long.

Enjoy the set Phil.
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