Correct fitting of fan & pulley to Collaro Conquest Motor?

[Old Sparky]

Hopefully, the attached photographs will show clearly how I've refitted the pulley & fan to the motor shaft of a Collaro Conquest Autochanger after I'd removed the armature to clean & relube the bearings.
According to the service manual the top of the pulley boss should be 13/32" above the top of the top bearing, and the spring under the stepped pulley shoul 'locate the slot in the fan boss'.  No way will the end of the spring locate in the slot, and I'm sure it wasn't when I removed it (didn't take a picture 'before', though!)  Can somewone more familiar with Collaro Autochangers confirm if I've reassembled these items correctly.  After refitting the turntable, and rotating it by hand there doesn't appear to be an drive from the motor to the TT, although I have removed both idlers, cleaned & relubed the shaft of the 'jockey pulley' one, and checked that both idlers are OK(which they are!).  The deck is from an EAR 'Music Maker' Record Player, and is wired in series with the Valve heaters, so, AFAIK, it runs from nominally 150v (Valves are UY85/UL84 which need nominally 90v).  There are only two wires coming from the motor field coils, a black, which connects to 240v 'live' via the on/off switch, and yellow, which connects to the UL84 pin 4, and, in the absense of a variac or step-down transformer, I cannot power the motor until I've wired back up to the amp!

[Old Sparky]

Looking at pictures of the 'Conquest' deck on Vinyl Engine, it appears that the AC53 Motor fitted to the Conquest originally had a voltage selector panel fitted on one side of it, plus a motor on/off switch mounted on the deck chassis. Since the EAR Music Master is a 'live chassis' design, with the valve heaters fed from the motor winding , obviously the motor supply isn't seperately switched, but presumably the lack of a voltage selector switch, and the two-wire direct connection between the motor gfield coils and the amplifier was a factory mod. carried out by EAR at the time of Manufacture (around 1957/58)

[Old Sparky]

I 've sorted the deck & motor/fan set-up in the Conquest deck, which is now running beautifully. The Motor has only the two leads, as stated, black goes to mains via the player's on/off switch, thus receiving the full AC, measured at 240v here, whilst the yellow goes to the valve heaters (UY85 & UL84), and reads about 88v on my DMM. However, the player in which all this is fitted is proving to be a ****** problem!, mainly due to excessive mains Hum, which is really loud, despite having replaced the reservoir/smoothing can, cathode bypass cap. & resistor, 10K resistor between Res. & smoothing Cap. (The UL84 screen grid supply), and mains lead. I've never had so many problems with a simple record player as with this EAR Music maker! The X5H cartridge, which was in the player when i received it, is working fine, once I;d replaced the original, brittle lead in the PU arm with a PU lead set removed from a scrap BSR autochanger.

[Terry]

I'd check the earth rail for a high resistance joint somewhere or, assuming it is on a PCB, damage to the track.

With only one valve, I doubt an earth loop will be the problem but it might be worth checking to see if any wiring has changed from the original.
Sudden thought!  You have eliminated a heater/cathode leak in the UL84, I trust?

Another thought - could one of the replacement smoothing caps be faulty? (Ignore the cathode by-pass: it only affects the gain.)

[Old Sparky]

The EAR Aplifier is 'hard wired' on a small metal chassis, Terry. I changed the UL84, using one which works OK in a PYE Table radio I borrowed it from, so, AFAIK, the cause isn't a heater/cathode leak, unless the replacement valve has just developed one. The odd thing is, that several days ago, when I first tried the player with the replacement valve, there was only a small amount of hum at vol.control setting of ca. 75% and above.
Possibly faulty capacitors or a high resistance earth could be the cause. I'll have to check further.

[Old Sparky]

               
Since the above post I've discovered that the tone correction capacitor's lead had fractured close to it's body, which may/may not be the cause of the loud hum.  The pictures show the player after rewiring, etc.

[Old Sparky]

I also realised that I'd wrongly connected the leads from the pickup to the volume control. Having fitted a 5-way tagstrip to which, with some difficulty I soldered the very fine wires from the pickup arm, I then connected said tagstrip to the i/p points on the control panel, using a 'figure of eight' twin screened lead terminated in small 'spade' connectors (the twin brown lead visible in some of the pictures) However, I connected the inners of the two screened leads to either side of the volume control via 2n2 Class 'Y' caps. So far, so good, but I then connected one of the inner cores of the screened lead to the 'spare' tag (i.e. that which would have the second channel of a stereo cartridge attached) of the tagstrip. This meant that one side of the X5H mono cartridge was connected to the 'hot' side of the V/C, but the other was, via the screens of the twin brown lead, connected to the control panel chassis. Having corrected that error by connecting the inner core of the screened lead to the other side of the cartridge, I was rewarded with decent quality sound, or at least as good as I'd expect to get from a one-valve amplifier, but the hum level, although reduced, is still, to my ears, too high. It varies with the setting of the volume control, but is still noticeable with a record playing. I'll replace the unscreened leads in the PU arm with a length of miniature twin screened wire, and may also reroute the mains lead so that less of it is in the cabinet. BTW, originally there was no isolating cap. between the Live mains lead & chassis, only one on the neutral side, so I fitted a 2n2 from the Live side to chassis as well. Ws that a good idea?

[Old Sparky]

I removed the isolating cap. between Live & Chassis, and rerouted the mains lead along the LH side of the player, as viewed from the front. This resulted in much reduced mains hum.

[Refugee]

I removed the isolating cap. between Live & Chassis, and  rerouted the mains lead along the LH side of the player, as viewed from the front.  This resulted in much reduced mains hum.

That is looking like a clue that the mains lead is connected with the live to chassis.

[Old Sparky]

The circuit ia astandard UY85/UL84 'live chassis' design, in which the Neutral mains lead is connected to the metal chassis of the amplifier via one pole of the on/off switch, whilst the 'Live' (when did 'Line' become the approved term, btw?) lead connects to the motor via the on/off switch. The Motor, which runs from ca 150vac, then supplies the two valve heaters in series(It's a Collaro Conquest Autochanger, but with only a black and a yellow wire(no voltage selector-presumably EAR specified the this way) The Volume & Tone Controls are on a seperate metal panel, which is isolated from the amp. chassis, so the Class 'Y' caps (as it now is )goes to the DC Negative line from Mains 'N'.