Hi all

A few weekends ago I was at Radio Fest and picked up a few old Philips Radios and more yet to be identified!

I have worked out the model of one of them. It is a Philips 2652. I have a basic cct diagram for it but nothing on how to re string the dial pully and indicator.

I haven’t pulled the chassis out of the case yet due to the way that the tuning indicator is hooked up. It uses a push pull setup that looks like bike break cables. I don’t want to disturb this too much just in case I can’t get it back together again.

Over all the rest of the radio is a big mess. If I didn’t do this sort of thing to pass time it would just sit on a shelf somewhere!

The set has been heavily modified with a loop areal attached through the air holes in the back panel. There is a makeshift Phono Input as well as some kind of ext speaker and terminals that are yet to be worked out!

The power cord looked nice until I cut a bit of the cloth away and found that it was actually rubber coated wire and has perished. (I always check this sort of thing before starting to repair)

The speaker is interesting... There is an octal plug connecting it to the chassis and the speaker is covered by some kind of white cloth from the back. I guess this stopped dust and stuff getting into the back of it.

There was / still is a power switch that someone added to it. I am yet to decide if I will keep it in use or try and fill the hole in the Bakelite that they drilled to fit it.

So after my rant does anyone have any info on how the tuning pulley and dial string works and have a diagram in case I break it.

Thanks

Daniel

2652 on the circuit I have shows a single 6V6 OP. not PP or a tuning indicator?

The circuit indicates an electrodynamic speaker with negative feedback, hence more than four wires , on the speaker plug; If the transformer is on the speaker?

That sounds like it may have been nobled or is not what you think it is. If the OP tubes are like 6CM5 the grid cap is the plate.

Can't help with dial, need to see what we are facing? These are not normally hard to work out.

Marc

Hi Marc

Sorry for the confusion I was talking about how the tuning operates. The marker is moved by 2 cables, One at each end of the dial glass. they look like bike break cables.

I will take some photos tomorrow and link them in to show what I am playing with.

Some Strombergs & I think the PYE on the bench drive a horizontal pointer.

Some of these are double wound & others cross over. I have re-cabled a couple with no reference material.

Some sets actually do use wire and I have used parachute cord on one old one (its cordage was the same diameter).

It's incredible the number of messy ways that some concieved, to do simple things.

Marc

Ok....

Hear are the photos (Link to Photo bucket)

Philips Model 2652.

This is where I am currently upto in pulling it down. Do you have any ideas as to how to pull out the dial indicator? I think that it might be as simple as un doing the screws and the whole thing will come out in one piece, but knowing my luck that wont happen!

I have also put in the cct diagram as well if anyone is interested!

Don't see anything too strange. It's an electrodynamic speaker. AGC is switched out on SW.

Interesting that it has a three gang tuner used the way it is. More often you find that with a preceding trf ,colpitts osc, or pre amp.

Is that 9K on the audio transformer? If so that suggests voltage could be slightly higher than 250V, but knowhere over 300V as it would need screen dividers.

I would tend to use 22μF 500V caps on HT & change the cathode bypass on the 6V6. Check all of its resistors as the ones around 6V6 especially on the grid, have a high attrition rate.

The usual get rid of paper caps and check resistors as you go. I would check the mica Plate to Grid of the 6V6. Do not leave the can electrolytic, wired in. A modern 22μF 63V will mount easily on the 6V6 socket. normally pin 8 (+) to whichever of pins 2 or 7 is going to chassis (not the one that isn't)

It looks like the dial stays. It is probably done the way it is so that the chassis can be moved back a bit. There is then the possibillity that you can loosen the drum lockscrews & slip it from the shaft? After which (should you not be prepared) the cord will jump off (annoying)

Marc

Hi Marc

I removed the dial slide rod and it come out as a complete assy with the chassis. it was then easy to undo a bolt on the dial drum and slide out the 2 cables that go to the indicator. This way I don’t have to realign the dial pointer system. It looked and sounded harder that it is.

Overall the chassis is in a poor state. things were heavily modified with ext speakers tapped from the main speaker, Phono input added as well as a different set of connections for the sw antenna.

I plan to return the system to original state (or as best I can with what is left!)

I was planning to totally recap and change resistors in the radio just because it will end up at my in-laws. I want it to be reliable otherwise I won’t hear the end of it!

Just looking at the cct again... What is the point of removing AGC(AVC) in shortwave?

Also with the way that they played with the front end to add a different antenna for SW would there be any advantage of having a separate antenna for this? I don’t think it would have worked properly anyway because they had a switch to isolate the 2 coil banks. (L1 and L2 from L3 and L4)

There are also other things like components connected without support. There is a Mica that comes from a terminal with a resistor then attached then going to a valve. This doesn’t seem like a factory effort, If it was then its still dodgy because lack of support.

With the mod. There is always great risk of throwing the whole set off frequency & severely impinging on its sensitivity. Put it back to circuit: Unless it is the modification described persuant to 2652A, which is a factory mod.

I missed C19 10μF. Be careful caps like C1 should be left alone unless mechanically damaged. The Mica's like C9 rarely fail. Do not use supermarket 1/2 watt resistors on HT they will not withstand the voltage.

Relief that the dial assy comes out as a job lot.

Resistor cap sounds shonky. I have had several sets where parts have been changed & no effort taken to clear the tags. That's how things like that happen. solder wick & solder suckers, are useful. Never be afraid to add the odd terminal strip.

The converter in this looks similar to a 6A8, which is not the normal shortwave tube ECH35 / 6J8 tended to be the later choice.

If you put AGC on 6A8 on SW it can impinge on the grid bias. The changing bias can pull the valve off frequency. I would suspect this with the Philips valve as well.

Marc

Hi Marc

Thanks for that. It will be a couple of days before I can attack the chassis. I will post before and after photos of what I do.

What do you think about patching the hole on the left side front of the case. That is where the power switch was. I have never tried to repair Bakelite yet and am unsure of how to get colours and fill right.

If it is hard to get right then I will leave the switch there. (I was just going to put the power switch on the back of the chassis where it cant be seen.

Thanks

Daniel

Right... things are going slow number six satellite modem, less than a month old, appears to have gone to god, as did the other 5. Need to have words with the TIO.

Make sure the switch is not part of that mod? You can always replace the volume control with a switch pot & keep it on the front. 500K is a common value and is gettable.

I need a tapped long shaft, switch pot for a PYE and it is looking like an import job. There is a place in the US that actually repairs the old ones. Would need to know the tapping point. eg the PYE is 40K

It is difficult to get adhesives other than those like araldite to bond to bakelite, which is Formaldehyde based. The exuding Formaldehyde can be a pest as it will destroy some of the things that contact it.

True bakelite had fillers like asbestos, wood & flour.

There are people that repair it, but I would suggest pigments like that used in concrete mixed into Araldite or one of the putty types. Stain on putty might work? never tried it, lustre will be the hassle.Test before using on the cabinet.

Marc