Rega RB300 turntable...
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From: Arfa Daily on 17 May 2010 04:57 Hi all Anyone happen to know the value of the resistor in the CR network connected in the synchronous motor feed ? Looks like brown - red - brown so 120 ohms, but it's well overheated and discoloured, with a nice burn mark right around the spiral element, right in the centre. Can't get a reading from either end to the burn point. Looks at a guess to be rated about 3 -5 watts. Anybody think of a reason *not* to use a wirewound rather than the original metal film type ? Arfa
From: N_Cook on 17 May 2010 05:25 Arfa Daily <arfa.daily(a)ntlworld.com> wrote in message news:Gx7In.61132$6C.51055(a)newsfe15.ams2... > Hi all > > Anyone happen to know the value of the resistor in the CR network connected > in the synchronous motor feed ? Looks like brown - red - brown so 120 ohms, > but it's well overheated and discoloured, with a nice burn mark right around > the spiral element, right in the centre. Can't get a reading from either end > to the burn point. Looks at a guess to be rated about 3 -5 watts. Anybody > think of a reason *not* to use a wirewound rather than the original metal > film type ? > > Arfa > > Wasn't Rega tonearms only? What sort of vintage is the deck? Is it definitely for use on 240V mains ? -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://diverse.4mg.com/index.htm
From: Adam Sampson on 17 May 2010 06:55 "N_Cook" <diverse(a)tcp.co.uk> writes: > Wasn't Rega tonearms only? No, but the RB300 is indeed a tonearm, rather than a turntable. There are PDF manuals on vinylengine.com for a bunch of Rega tonearms and turntables which might help identify what the deck actually is. It's worth noting that the discussion on the page for the Planar 3 (which would be a plausible turntable to have an RB300 fitted) has some comments on replacement motor resistor values, with one comment suggesting 150 ohm 5%: http://www.vinylengine.com/library/rega/planar-3.shtml -- Adam Sampson <ats(a)offog.org> <http://offog.org/>
From: Arfa Daily on 17 May 2010 07:28 "N_Cook" <diverse(a)tcp.co.uk> wrote in message news:hsr215$lak$1(a)news.eternal-september.org... > Arfa Daily <arfa.daily(a)ntlworld.com> wrote in message > news:Gx7In.61132$6C.51055(a)newsfe15.ams2... >> Hi all >> >> Anyone happen to know the value of the resistor in the CR network > connected >> in the synchronous motor feed ? Looks like brown - red - brown so 120 > ohms, >> but it's well overheated and discoloured, with a nice burn mark right > around >> the spiral element, right in the centre. Can't get a reading from either > end >> to the burn point. Looks at a guess to be rated about 3 -5 watts. Anybody >> think of a reason *not* to use a wirewound rather than the original metal >> film type ? >> >> Arfa >> >> > > Wasn't Rega tonearms only? > What sort of vintage is the deck? Is it definitely for use on 240V mains ? > > > -- > Diverse Devices, Southampton, England > electronic hints and repair briefs , schematics/manuals list on > http://diverse.4mg.com/index.htm > Well, sort of. I guess that the full deck is probably a Rega Planar 3, but definitely a Rega-original product. There is a "Grahams HiFi London" tested sticker on the bottom with a handwritten date of '86 on it. There is a manufacturer's label on the bottom also saying "rega Made in Britain" and "Rega Research Ltd" To the best of my knowledge, it has always been used here in the UK.The motor is a synchronous type, 4 wire, and marked 110v 50Hz. Two grey wires go straight to mains neutral. Switched mains live comes back to a small (original looking) PCB in the motor compartment. It passes through the R in question to to the motor red wire. There is then a cap, 0.22u 400v polyester, between the red wire and the blue wire, so I guess that this RC combination is a phase shift / AC dropper so that the motor is happy at 240v. There is no indication on any of the labels as to the voltage specs, but the fact that it is a 50Hz synchronous motor single speed deck, and also that the mains lead is absolutely original and coloured blue and brown, would suggest that this was built for use in europe on 50Hz mains of at least 220v ?? Arfa
From: Meat Plow on 17 May 2010 08:09
On Mon, 17 May 2010 09:57:09 +0100, Arfa Daily wrote: > Hi all > > Anyone happen to know the value of the resistor in the CR network > connected in the synchronous motor feed ? Looks like brown - red - brown > so 120 ohms, but it's well overheated and discoloured, with a nice burn > mark right around the spiral element, right in the centre. Can't get a > reading from either end to the burn point. Looks at a guess to be rated > about 3 -5 watts. Anybody think of a reason *not* to use a wirewound > rather than the original metal film type ? > > Arfa Did you try a 120 and see what happens (with some current limiting in place) With things like this I usually clip in a light fuse in case the resistor was actually 1200 ohms or more :) |