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Old 1st Nov 2017, 9:52 pm   #29
turretslug
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Join Date: Nov 2011
Location: Surrey, UK.
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Default Re: AR88 Low HT

Quote:
Originally Posted by Keith View Post
It's worth improving the almost non-existant fusing arrangements. I put the spare fuse holder on the rear apron to use in the centre tap of the HT winding (I think I used a 150mA part). This was a "stable door bolting" measure having just had the mains transformer burn out due to capacitor failure!
There's quite a bit of chassis space under the mains transformer- as a safety weenie, I made a bracket secured by the 3x 0.25uF bath-tub fasteners featuring 4x 1.25" fuse-holders for mains, 2x FW rectifier anode and 6.3V protection, as the rectifier heater registered 5.4VAC with a a calibrated Fluke, it got a 0.1 ohm fusible film in series. Some countries (UK, US) seemed quite blasé about the amount of power involved around HT transformers, others really went to town on protection (Scandinavia).
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