Philips EL3541 restoration

[IMSglos]

Hi all

I have a Philips EL3541 which was bought by my grandparents for my mother when she was a teenager. I would like to restore it to the best working condition achievable.

Electrically it turns on, records and plays back ok. Mechanically the tape counter belt has snapped and the transport struggles with fast forward as the spool gets fuller, and it doesn't rewind at all.

1. Where can I get replacement belts?
2. Any tips on cleaning down and re-lubricating this mechanism?
3. Any tips on making the transport work fully properly again?
4. What should I aim to do electrically e.g. re-cap - anything else?
5. Should I clean the heads, if so how and what with?

Many thanks

[DMcMahon]

Sounds like you are half way there if it records and plays back OK, that is a good start indeed.

I do not know the EL3541 or any of the other Philips units so my comments are just general.

1. There are many drive belt sellers on websites such as eBay, typically they sell a set of belts for a particular Make/Model rather than individual belts. Normally they would be advertised as "New" which in this case means they have been manufactured by someone, but not the manufacturer.

They could also be advertised as "Used", these may be OK but because of age there would be a risk that not so good.

They could also very occasionally be advertised as NOS (New Old Stock), this is an erroneous title, really it should say something like OUS (Old Unused Stock), these although unused could also be a risk due to age deteriation.

Some people find suitable drive belts by buying large lots of miscellaneous belts that people advertise and also some people make their own by using O-ring cord cut to length and the ends joined by supergluing (I have never yet done this).

2. For general cleaning I would recommend IPA (isopropanol / Isopropyl alcohol). For general re-lubricating any good quality light to medium grease, Superlube is one of the popular greases.

https://uk.rs-online.com/web/p/greases/1847967/

Be careful not to get grease on the belts, rubber idler wheels, the heads, guides, pinch wheel etc, less grease can often be better than too much.

3. Do not be too quick to rip the unit apart, R2Rs can be difficult to re-assemble, especially if you do no take lots of notes/photos of everything as you go.

First by operating under power and also manually (power removed from machine by removing mains cable not just switched off) try to see/quantify what is happening/not happening. So for example, for rewind not working there may be a belt slipping, idler wheel not making contact/sufficient contact with the Supply reel table/spool etc etc.

For any idler wheels that move on arms/linkages, the pivot point (s) may be gummed up/partially seized etc. Stripping relevant parts, cleaning and re-lubing can often help.

4. Clean the electrical switch contacts using a switch contact cleaner such as Servisol Super 10 and exercise the switch many times, also can be done on control potentiometers (pot) particularly if noise is heard on the audio when pot adjusted.

Re-capping is not an easy question, some people would strongly state to always re-cap, others would say only re-cap when required, I am toward the last statement. "Required" meaning if the capacitor looks in poor condition or measures bad or is causing a measurable problem in the circuitry. Re-capping generally is in reference to 2 main type of capacitor, paper and electrolytic. Occasionally some people say "replace all capacitors" which is a ridiculous statement to make without lots of qualifications. Paper capacitors are non polarised capacitors and are of several types, 2 most common problem types (due to age) are wax covered/impregnated (such as Wima) and plastic covered paper (such as Hunts Mouldseal).

Electrolytic capacitors are polarized capacitors of larger capacitance values and large value ones are used in power supplies for reservoir and smoothing etc, also used for additional smoothing, de-coupling, AC signal carrying etc in other parts of the circuitry. Electrolytics degrade due to age and can fail occasionally, sometimes visually obvious by a ruptured/leaking body. I would say they are less troublesome than paper capacitors.

Capacitors block the passage of DC voltage and with age naturally degrade and can electrically leak allowing DC voltage to pass. Depending upon the extent of the electrical leakage it could be serious in some parts of the circuitry such as the anode outputs of valves that connect to the next valves control grid via a paper capacitor, particularly potentially serious on the output valve as worst case the output transformer could get damaged.

A good starting place is to do a good visual check of everything, checking for any components that look in poor condition, damaged, burnt, loose connections etc.

5. Yes definitely clean the heads (often more than once required) using IPA and cotton buds/Q-Tips and/or soft cloth, do not use anything abrasive and avoid scratching the face of the heads. Inspect closely, maybe using a magnifying glass to ensure heads are really clean, they may look clean but still may have deposits.

Also clean the whole tape path, i.e. anything that comes into contact with the tape, the various tape guides, capstan shaft etc. You have to be a bit careful with the rubber pinch wheel/roller (the roller that presses the tape onto the rotating capstan shaft) as some rubber material may not react well to IPA cleaning, although I personally IPA clean them OK.

Service manuals can be downloaded free of charge from sites such as hifiengine.com

[radiotechnician]

After replacing the two belts, the next item s to remove the turntables and
check the three elastomer nubs, The turntables engage wind and takeup
by positioning the height to select what is needed.

Fine adjustment is done with plastic spacer washers.

The service manual should be on the net, otherwise if there is a portion
you wish to see, ask and i will reply under this topic.

There have been many queries, about the EL 3541, and searching them should detail the turntables.

I have repaired many of those machines, long ago and own a few in the 'pile' .

In Canada is was known as the Continental 200.

Also makes a fine amplifier for a turntable or a tuner.

Engage the button in the mike compartment to do that.

The other thing about it is the attachment for the mechanical foot switch.

[Michael Maurice]

What do you suggest we used to replace the three elastomer nubs?

[IMSglos]

Thanks for all your advice!

Originally Posted by Michael Maurice

What do you suggest we used to replace the three elastomer nubs?

Good point - I think from memory (haven't looked for a good long time) but I am almost certain the nubs are worn on at least the rewind spool. I need to look but assume at this point they will need replacing with something.

[DMcMahon]

Not familiar with the elastomer nubs, cannot see them on this drawing section.

[Leon Crampin]

They're not shown separately on your diagram, but you can see the three circular pads in each lower turntable. I had some success using pencil erasers for this - but I have to say it's a rather poor design.

Because the turntable drops on fast wind, the spooling is poor, and the grip tends to be inadequate when pulling at a large radius. Other than that, it's a well made machine. I seem to remember that the electronics are recent enough to use Philips polyester capacitors, rather than paper. I think you will have little or no work to do restoring the electronics.

Leon.

[IMSglos]

If I'm talking about the same thing as Michael Maurice (apologies if not) they sit in the three little holes on the spokes on parts no. 89, which are shown in the diagram as circles just within the outer circumference. They poke upwards and I believe they touch the underside of parts 94/95 when FF/RW is engaged. I've always presumed this is some sort of friction clutch mechanism.

[DMcMahon]

Looking at the English service notes I think I understand now that they are spacer pads fitted between the Reel Disks (94/95) and the Coupling Wheels (89) for coarse adjustment, referred to as vulcolan pads.

[DMcMahon]

Thank you Leon, that make sense now, I see in older posts in the Forum some people refer to them as cork (maybe they previously have been repaired with cork).

Lucky if he has no paper capacitors to worry about, that is a bonus !

[DMcMahon]

Originally Posted by IMSglos

If I'm talking about the same thing as Michael Maurice (apologies if not) they sit in the three little holes on the spokes on parts no. 89, which are shown in the diagram as circles just within the outer circumference. They poke upwards and I believe they touch the underside of parts 94/95 when FF/RW is engaged. I've always presumed this is some sort of friction clutch mechanism.

Thank you all clear now.

[paulsherwin]

As an alternative to using IPA as a solvent cleaner, which can be difficult to find (especially at the moment), you can use ordinary methylated spirits (meths) from a DIY or hardware shop. It was standard BBC practice to clean tape heads and guides with meths back in the analogue era.

[DMcMahon]

The nubs/pads sound basically the same as the rubber type reel table clutch pads (that get replaced by cork for DIY repairs) on my Tandberg 6000X and other Tandbergs.

[garry71]

Originally Posted by paulsherwin

As an alternative to using IPA as a solvent cleaner, which can be difficult to find (especially at the moment), you can use ordinary methylated spirits (meths) from a DIY or hardware shop. It was standard BBC practice to clean tape heads and guides with meths back in the analogue era.

My Ferguson service sheet says to use meths on the heads and pinch roller as well.

[Lucien Nunes]

I have done a few of these now and the elastomer nubs are always the trickiest part. Very few alternatives to the original material seem to work as well, I did make some notes on which rubber grade gave the best results but don't have them to hand. I purchased a selection of materials in the form of thick o-ring cord of suitable diameter (8mm?) cut slices of them accurately square on a mitre box, pressed them into the pockets and then ground the surface of the three flat and true together. Obviously they have to project the correct distance otherwise you can't shim the reel heights to give sufficient travel to engage / disengage positively while remaining aligned with the tape path. One of my machines had been quite badly mauled when someone had apparently tried to improve the wind / rewind by scoring grooves in the table and bending the linkage instead of adjusting the shims. I expect your machine has been treated rather better.

Other minor problems that showed up were an intermittent muting contact on the output socket, and difficulty adjusting the R/P switch bowden cable(s) where someone again had tried to fudge it and bent something. IIRC the oscillator was intermittent on one unit, which was down to the tank cap. It was the only traditional black Philips pitch component, the rest being mustards. I had difficulty sourcing the correct main belt at first. I think I got a better fitting example from a chap in Luton.

[DMcMahon]

Originally Posted by paulsherwin

As an alternative to using IPA as a solvent cleaner, which can be difficult to find (especially at the moment), you can use ordinary methylated spirits (meths) from a DIY or hardware shop. It was standard BBC practice to clean tape heads and guides with meths back in the analogue era.

Paul,

I have not used Meths for anything for a very long time, how does it compare to IPA for head cleaning ?

David

[TIMTAPE]

I think I read that meths has a higher percentage of water than IPA and could be a problem where the moisture doesn't evaporate quickly enough such as on tape heads. A more likely problem I've seen is corroded tape head faces due to leaving Sticky Shed tape goo on tape heads for a long period. The goo is hygroscopic so the moisture eventually pits the head surface. I recently had to give an A77 head a mild relap to remove the corrosion.

[ricard]

I've used meths for years for cleaning tape paths and haven't seen any issues. It evaporates fast enough. It is said that it dries out rubber though, not sure why it would do that more than IPA; hopefully someone with a better grasp of chemistry than me can explain!

[Radio Wrangler]

Vulkollan is a brand name for a family of polyurethane elastomers. Hard ones appear as tyres for industrial castors, softer ones as aftermarket suspension bushes for landys. It might be possible to still buy something that could be cut down to make substitute friction pads, but it would likely involve experimentation.

David

[IMSglos]

Thanks for all your help and advice everyone