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Restoration of an Eddystone S.750 - The section you are trying to ...

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if one or more <strong>of</strong> the gain controls, BFO variable capaci<strong>to</strong>r or switches needed <strong>to</strong> bereplaced or serviced.- On arrival, themains tr<strong>an</strong>sformerhad a piece <strong>of</strong>b<strong>are</strong> wire shovedin<strong>to</strong> the 110vtapping socket. Ireplaced this withthe correct type <strong>of</strong>insulated jumper(for some reason Ihad one in myjunk box).19- Installed aquick-blow in-linemains fuse in thepsu compartment.Also, installed a 250mA slow-blow fuse in a chassis-mounted fuseholder wired in<strong>to</strong> themains tr<strong>an</strong>sformer secondary centre tap (it had a 3 amp fast blow installed on arrival).- Checked the general electrical safety <strong>of</strong> the psu unit – checking for loose wires, poorinsulation etc. Replaced a pair <strong>of</strong> wires who’s insulation had been heat-damaged by thestabilizer dropper resis<strong>to</strong>r <strong>an</strong>d re-dressed them <strong>to</strong> avoid it happening again.- Installed a new mains lead <strong>an</strong>d chassis grommet, using a plastic cable-tie <strong>to</strong> retain thelead.- I made a replacement dial lamp holder <strong>to</strong> replace the bodged screw-thread one <strong>an</strong>dreplaced the long-bulb #47 dial lamps (pretty st<strong>an</strong>dard in US <strong>an</strong>d C<strong>an</strong>ada radios) with thecorrect small globe-type bulbs (the long-bulb #47 lamps interfered with the drive cord).20- I noticed that both the AF <strong>an</strong>d IF gainpots were non-original components: the IFgain was a 10kohm linear carbon track unit<strong>an</strong>d needed <strong>to</strong> be replaced with a wirewound (ww) unit as it carries a small DCcurrent – carbon tracks don’t like that. A‘period’ Colvern ww pot was found in myjunk box (ex-Blue Streak I think) – ittested ok <strong>an</strong>d was fitted (pho<strong>to</strong> 20). <strong>The</strong>AF gain pot tested intermittent, as well ashaving a cracked front plate, so that wasalso replaced with <strong>an</strong>other ‘period’ unit11

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