E.A.R. DeLuxe record player.

[parlourtw73vs]

I forgot to mention that when attaching the probes to the output transformer I got a scratching noise from the loudspeaker when I touched the probe to the the terminals on both left and right of the centre terminal. Is this a good sign?

[ms660]

Looks ok to me.

Lawrence.

[Station X]

In the third picture where you're testing the output transformer you have the meter set to the 200R range which is OK, but you might like to try the 2k range. In pictures 4 and 5 you're using the diode range which is no good for measuring output transformers.

[parlourtw73vs]

As you've suggested Graham here are 2 images with the meter set to 2k. As the readings are comparatively the same does this imply the transformer is OK?

[Station X]

That's fine. The transformer is OK. 199 ohms for one winding and 216 ohms for the other. The slight difference is because the outer winding will be longer than the inner one even though the number of turns is the same.

You might like to try the neutral test using the 2k range.

[parlourtw73vs]

OK Graham, as suggested here are 2 images of the results in the 2k range for the mains neutral test. If it's ok by you it seems easier for me to upload images of readings and the probe positions to eliminate any possibly erroneous interpretations which I may make. This time the readings seem to imply that the wiring to the chassis is correct, is that so? If all now seems in order with the mains neutral and output transformer I'll proceed to the further tests advised by the various contributors.

[Station X]

That's good. Plug wired correctly. Short circuit (zero ohms) neutral to chassis and 460 ohms live to chassis. The 460 ohms will be made of up the resistance of the valve heaters, the 3.3k parallel resistor and the resistance of the motor.

One last thing to check is that the plug is fitted with a 3 amp fuse.

Try testing the rectifiers next using the various resistance ranges. See post #67.

[parlourtw73vs]

Thanks for that confirmation Graham, rest assured I'll be installing a 3amp fuse before this unit is put into service. I've taken photos of the rectifier readings and will post them next, but first I'd like to put up 4 images of the earth connections underneath the deck and also at the on/off switch as requested by Lawrence earlier. There are a total of 10 images so they'll appear in 2 posts. For clarity I've picked out the marker on the rotating switch of my meter then it's obvious which setting it's on. You'll see that I was only able to get readings on the 20m setting, when I switched to the 200k setting I got the 1 again. This happened with both rectifiers but I've only uploaded an image of the first. The readings for both rectifiers are very similar as you suggested but you'll have to tell me if they are within specification. Cheers, Malc.

[parlourtw73vs]

Continuation of images.

[Station X]

The tests on the rectifiers are inclusive, so when you order capacitors you might as well order a 1N4007 diode at the same time so you can replace them. You'll need to check all the writing on the smoothing capacitor can as there'll be more than one cap inside it.

I'll leave the earthing arrangements for the forum's safety experts to comment on.

[parlourtw73vs]

Graham, when you say the tests on the rectifiers are inclusive is that a re -iteration of your earlier post wherein you said that a check on one was a check on both? Are these rectifiers out of specification or are you suggesting that the replacement diode is a desirable procedure for extending the usable life of this record player?

[Techman]

Originally Posted by Station X

I'll leave the earthing arrangements for the forum's safety experts to comment on.

You made me chuckle there, Graham

As regards fitting a 3 amp fuse before putting into service, I'd advise fitting a 3 amp fuse immediately, as if there's a fault condition while under testing and taking measurements, you've got virtually no protection against damage with a 13 amp fuse - if that's what's fitted now?

[Station X]

Originally Posted by parlourtw73vs

Graham, when you say the tests on the rectifiers are inclusive is that a re -iteration of your earlier post wherein you said that a check on one was a check on both? Are these rectifiers out of specification or are you suggesting that the replacement diode is a desirable procedure for extending the usable life of this record player?

What I'm saying is that there isn't a reliable method of testing metal rectifiers using a DMM. I have been able to test them using an analogue (moving coil) meter though. A 1N4007 will cost pence so you might as well get one and fit it.

[parlourtw73vs]

As Requested:-

[Techman]

It's true what Graham says. I think that if you're serious about repairing these sort of items, then an analogue meter such as an AVO is a 'must have' piece of test gear - I couldn't work without one to use along side my DVM. There are people on the forum that collect AVOs and keep buying them up, which I personally think is a shame as there are many members who don't have one and they'd be better off on a work bench (or kitchen table) being used for what they were intended for. The down side is that an old AVO is likely to have faults of its own. I've got a number of them and I can honestly say that not one of them is fully functional on all ranges and I pick one for whatever particular test I'm doing, rather than getting one fully serviced and working, which is what I really should do!

[Techman]

Hey, well done on that 3 amp fuse - looking good!

[Techman]

I guess that earth connection to the lug on that pot which will earth that section of metalwork, has no electrical connection to the neutral connected chassis of the main amplifier?

[parlourtw73vs]

With regard to the rectifier I'll do as you suggest Graham. With the measurements I've given of the various components where else do I need to look to determine what components need replacing. Are any of the capacitors whose photos I posted earlier of any use to me? I've posted images of the large metal hunts capacitor which I presume is a 3 in 1 unit. I think the ratings are visible on it, is it possible to check this with my DMM?

[ms660]

Cheers for those extra photo's earlier, it confirms the arrangement in the schematic so far.

Re: photo's in general: Still not convinced of a proper connection between the -ve of the reservoir capacitor that's now fitted and the amplifier chassis....Anyone?

Lawrence.

[Techman]

I'm not sure without going back and studying all the previous pictures. A continuity check with the DVM would confirm that connection from negative side of capacitor to chassis.