Can anyone please tell me if the side grills are supposed to be covered in cloth ?
I have put cloth over the speaker however the other side grills are open and you can see all the insides of the radio.
Thank you for any help.

Mine has fabric covering the sides.


Ben.

Last one I repaired had them covered. I replaced it with synthetic awning as it was in the sun in the office of a heavy equipment repair & sales dealer.

I would be careful with it. The rectifier was a weak one & I replaced it with a 6X_ with a bit more current handling. I am however, convinced that it was a needle that actually caused the one in it to vaporise, internally. As this unit had near a packet of needles inside it.

Apart from replacing the usual suspects, do a very thorough inspection for needles in amongst the wiring. The side covers do discourage the fauna, from crawling inside

Thank you Ben and Marcc.
I will cover the side opposite the speaker ,which I already covered and leave the back uncovered to give it some cooling.
I have got it working well , however the pickup transducer which is a 2000 ohm Garrad needs replacing , very low output. It initially had no output I managed to free it up it now works but only just have placed a wanted in the sales and wanted section.
Regards Jim.

It is somewhat unlikely that you will get a functional original as many of them had rubber in them and it deteriorated.

There are several purveyors of cartridges, but there are traps. There are Magnetic & Crystal types. I recently had a Sonotone 9TA with a broken yolk & a genuine one is an arm & a leg. The trap was finding a sub with enough OP. Its around 400mV.

I ended up getting the correct stylus for it (part of the problems) and used Loctite 401 to fix the yolk.

This is why I have issues with record changers, invariably the kids or some other malfunction, will cause a pile of records to land on top of the tone arm and neither record, or cartridge, fare well. This is what I believe happened to my fixer one.

Marc

Hello Ian and Marc.
Thank you both for your replys I can see this is going to be a challenge. Yes it is all there the armature was stuck over one side on the perished rubber .Managed to prise it of and the armature returned to its middle position wiggled it from side to side and it now works on very low output. I do not want to put a modern replacement in there because I want to retain originallity. I guess Iam lucky to get any output from it. Any advice will be greatly appreciated . I thing Marc, what you were talking about was to transplant another cartridge and somehow intergrate the old to the new.
Ian any help you can offer on alignment will be greatly appreciated. The annoying part of this this is I had another complete gram that was a mess and sold it off cheaply , not intending to get another one down the track. When I was in primary school there was one of these in the class room and I always liked it so I have some sort of silly sentimental attachment to them . Anyway what else would we be doing , need to have projects and challenges to keep the remaining grey cells going. My background is electronics which also had a large mechanical component to it.
Regards Jim

I can vaguely recall fixing one of these when I was a kid. The trick was replacing the rubber (I think I used bicycle inner tube) and getting the gap on the pole pieces to be as small as possible without hitting the poles on loud passages.

It was a very long time ago but I can remember it being successful. There's an adjustment screw???

There are traps. What I have seen with a Philips is that the magnetic cartridge floated and the set was back biased.

Important are the caps. It would be useful to know what this cartridge is viz Magnetic / Crystal. If the set has old wax paper caps and a Magnetic unit the leaking caps can significantly impinge on the bias of the valve as they have to block the DC path via the cartridge. Leaking wax paper caps will have a significant negative effect on the set as will out of spec resistors.

One mistake in the Philips was that bare metal electrolytic caps had been installed and tied to ground? That effectively shorted out the "back bias" which will exacerbate poor performance.

Thanks again Ian and Marc.
The caps have been changed and the radio woks well , if I remove the cartridge and touch the relevant pin in the tone arm there is plenty of amplification.
I will have another go at the cartridge, I would suspect it is magnetic and not crystal its stated impedance is 2000 ohm. I can see a coil in there with a lot of turns on it.
Regards Jim.

The wiring diagram will be the other clue. As pointed out, the magnetic cartridge needs a capacitor in series with it, which may be quite small in value. It may also be fed to a voltage divider? The magnetic cartridge puts out quite a lot of voltage.

No, magnetic cartridges don't put out a lot of voltage. However, that type (called a "rock crusher" pickup) were designed to be compatible with the "pickup" terminals of period radios and 500mV RMS output would be typical. You would turn the volume control up a bit higher than you would for the radio.

It's highly doubtful that any DC that could be applied to the pickup coils by, say, a leaky cap could have any significant effect because it would be swamped by the field from the permanent magnet in the pickup. Remember that these things were commonly connected directly across a radio's volume control when used as an add-on to your console radio. The low impedance would shunt the detector's output and the pickup would endure a DC current from the AGC. If that didn't kill the radio signals, you would simply tune the radio off the station! Crude, but that's the way it used to be....

As I recall, the needle carrier connects to a rocking armature which may or may not have a small magnet in it. The needle has to move (rock) this armature in the magnetic field in which the 2000 ohm coil is located, to generate an electrical output from the coil. It's possible that in freeing up the needle you've broken the bond with the rocking armature.

As a kid I also used to fix clocks and the degree of skill required to dismantle and re-assemble one of these pickups is about the same as you'd need to fix an alarm clock.

Thanks again Marc and Ian.
The device has a permanent magnet horse shoe shape and works pretty well as Ian has described.
I had another go at it and adjusted it so the armature was back in the middle it now works reasonably well . I dought if it will work for long however all the rubber suspension pieces are in a sorry state. But at least it is working with reasonable volume and I am greatfull for that .
I would still like a replacement . I may be able to cobble a modern one in somehow.
Regards Jim.

You may be able to use black RTV silicone to replace the rubber parts......

Hello Ian.
While. It works I will leave it , I have the shakes very bad so do not want to risk destruction .

I have repaired many old magnetic pick-ups using rubber valve tubing used in old school Woods/Dunlop bicycle tyre tube valves. You can find the rubber valve tubing in cheap $2 shop bicycle tube repair kits