Philips N4308 - belts - UK Vintage Radio Repair and Restoration Discussion Forum

WallHow · 6th May 2014, 8:19 pm

I recently started a project to clean up and refurbish a Philips N4308 / 85 reel to reel. All going well, cleaned off the black goo that all the belts had turned to, made some new clutch inserts and bought what I thought at the time was a complete set of new belts online from Germany.

When coming to fit the belts I realised that whilst the service manual identifies 4 seperate belts (parts 112, 118, 133 and 139), my belts kit included only 3! The kit includes the following round section belts:

belt 1- 175mm diameter (2.5mm thickness)
belt 2 - 80mm diameter (2mm thickness)
belt 3 - 55mm diameter (2mm thickness)

No details or instructions provided of which belt is for where - but it looks like the above belts are parts 118, 133 and 139 respectively. So it looks like I'm missing part 112 - the 75mm belt.

I'm very new to all this so apologies if this seems like a daft question - does anyone know why the kit would have been sold as just a kit of 3 belts rather than including all 4? Or are the 80mm belt or the 75mm belt for alternative set ups or are both required for operation?

Many thanks
Howard

DOFFERY · 6th May 2014, 9:21 pm

Howard,
There were four belts on the 4308 as you noted, I would presume from your description you have the flywheel 55mm belt 3, the main 175mm belt 1 & the idler 80mm (my belt 3 ,belt 4 not required), it would appear the counter belt may be missing. I attach a drawing of the various belt systems on the 4307/8.
Being the 4308 I would suggest the fig . 8 counter belt is missing, not a real problem, it is slightly smaller in dia than the idler belt 2.

Colin.

ricard · 7th May 2014, 9:45 pm

Is Phlips the only manufacturer that insists on using these figure-8 belts where the belt rubs against itself at the crossover point? The same solution is used for the rewind belt in the EL3549/3534.

WallHow · 8th May 2014, 9:34 pm

Many thanks for the response and the belt diagram Colin - very helpful. The description I had from the belt seller for the kit said it included: 1 capstan belt, 1 pick up reel belt and 1 counter belt - so I assumed it was missing the take up belt rather than the counter belt.

In any case - I fitted the 3 belts as per your diagram and all seems to be working - really chuffed to see/hear it working! As a purely temporary measure I used an appropriately sized eleastic band as the counter belt while I order a proper belt and even the counter seems to work. Just a few queries:

i) the speed change lever seem rather stiff with the new flywheel belt - is this normal with a new belt and will it slacken at all (just don't want to overstress the plastic lever and snap it!)

ii) is it OK to keep using the 80mm belt for the take up belt when the user manual states 75mm?

iii) any advice on the best type of glue for refixing the aluminium trim that's come off - would evo-stik be OK?

iv) any idea where this 'spare' part that I have left over is meant to go - it's a circular clip/collar about 7mm diameter and 4mm high! (Unfortunately struggling to attach a photo!)

Many thanks
Howard

vidjoman · 9th May 2014, 9:13 am

Quote:

Originally Posted by WallHow

any idea where this 'spare' part that I have left over is meant to go - it's a circular clip/collar about 7mm diameter and 4mm high!

Possibly off one of the knobs. Philips usually have a clip on the knob to give it added strength.

DOFFERY · 9th May 2014, 11:57 am

Howard,
Just checking the former posts, your belts ,ie. belt 3, 55mm is in fact belt no. 4 on my sketch NOT the flywheel belt, this flywheel belt is missing for your 4308, hence the tightness of the speed change, my error, I apologise. Your kit of belts was in fact for the very early type of 4307 bottom left of my sketch where the main drive belt drove the flywheel, your suppliers error if you ordered belts for the 4308. The 55mm belt you were supplied with is not required for your 4308. The idler belts for the idler & counter are very similar.
So basically you were supplied with the belts for the very old 4307, main 175, take up 55 & counter 80, you need the flywheel & idler (No3) although as you have found the latter works as the idler.If you require , either or both let me know, I have them in stock. Hence my kit includes the 5 belts to cover all variations but you only need the flywheel & perhaps the idler No 3.

Again my apologies for my error.

Colin,

WallHow · 10th May 2014, 7:52 am

Many thanks - that makes sense!

ricard · 10th May 2014, 1:47 pm

Regarding the metal trim, I usually use contact glue to refit it. The trim is very light so the glue does not have to be very strong, but it helps to have a certain resilience. I'm not sure exactly what evo-stik is, it looks like some kind of superglue which should be ok too, except that superglue tends to be rather brittle and can crack when knocked, causing the panels to come off again.

Nickthedentist · 10th May 2014, 1:50 pm

Evo-Stik normally refers to a contact adhesive, i.e. one that you apply to both parts, leave to go tacky, then press together.

However, it's now used as a brand on a whole range of different products.

Nick.

ricard · 10th May 2014, 9:30 pm

Thanks Nick, tried to google it but with ambiguous results. A contact adhesive is what I'd go with in this case at any rate.

Jimmyhaflinger · 11th May 2014, 11:40 pm

Quote:

Originally Posted by WallHow

any idea where this 'spare' part that I have left over is meant to go - it's a circular clip/collar about 7mm diameter and 4mm high!

If it's an aluminum ring it's a spacer for the speaker mounting bolts

Refugee · 12th May 2014, 12:08 pm

Where did you get the rubber from to make the clutch inserts?
Could you post a link please?

DOFFERY · 12th May 2014, 1:28 pm

Any belt old or new of aprox. 1.5/2.00mm cut to size, overlap clutch disc by 1.5/2,0mm, just a press fit, no need for original shape etc. Two inserts per clutch will suffice. Just be aware the Left/Right discs differ

Colin.

WallHow · 12th May 2014, 2:20 pm

I did struggle to find something suitable that I could use - thought it would be easy to find something made of rubber about 2mm thick. I didn't have any old or new belts lying about so couldn't do as Doffrey suggests. I was going to use a large rubber washer from a sink waste but couldn't find one in my local town without having to buy the whole waste! In the end cannibalised a flexible rubber tree tie and cut the inserts out of that using a scalpel to a similar design to the originals as shown in the service manual.

I used Evo-stik (contact adhesive) for the trim seems to have worked well.

The clip/collar was from one of the control knobs - so that mystery is solved.

Cheers
Howard

Jimmyhaflinger · 13th May 2014, 12:52 am

by the way, i'm also restoring a 4308, i had to replace the speaker terminal plate as it was broken off and the wires were just soldered together and hanging in mid air, (luckily i was able to salvage one from a scrap Philips speaker)

anyway, is the speaker frame supposed to be grounded?

DOFFERY · 13th May 2014, 8:01 am

Howard, You really have gone the whole hog cutting the exact shapes for the clutch inserts , I admire you , the scalpel bothers me

?

WallHow · 17th May 2014, 9:05 pm

Well - not the exact shape! And when I say scalpel - perhaps craft knife would be more accurate.

Could I just check about the speed change lever. This still seems rather tight when turning the lever on way, but OK when turning it the other - are yoiu meant to turn the machine off completely before switching between speeds - it seems as is I am fighting against the belt drive direction.

Cheers
Howard

DOFFERY · 17th May 2014, 9:45 pm

Hello Howard,
You don't have to turn the machine off to change speeds, all the change lever does is move the flywheel belt via a lever from one pulley to another, it is possible that it may seem tight one way & less the other way but shouldn't be a problem. Have you tried turning the speed change when machine is switched off, any difference??

A drop of oil on the shaft under the speed change lever might assist.

Colin.

Jimmyhaflinger · 17th May 2014, 10:27 pm

the speed can be switched while the motor is running in these recorders, maybe you fitted a belt that's too hard, the original belts were thick but quite soft and resilient

luckily both of my N4308 recorders still have their original belts and even clutches in perfect conditions, they're both "made in holland" Mk1 machines from 1971.

astrat65 · 14th May 2015, 8:02 am

Hi there,

After reading this thread, I have obtained a set of belts for my Pye 9123 recorder, which is the same as the Philips N4308.

Having cleaned up the mess of the old goo left by the original belts, I am not sure how the new belts fit.

Does anyone have a photo or instructions on how to fit the new belts.

Thanks

6th May 2014, 8:19 pm	#1
WallHow Retired Dormant Member Join Date: May 2014 Location: North Yorkshire, UK. Posts: 5	Philips N4308 - belts I recently started a project to clean up and refurbish a Philips N4308 / 85 reel to reel. All going well, cleaned off the black goo that all the belts had turned to, made some new clutch inserts and bought what I thought at the time was a complete set of new belts online from Germany. When coming to fit the belts I realised that whilst the service manual identifies 4 seperate belts (parts 112, 118, 133 and 139), my belts kit included only 3! The kit includes the following round section belts: belt 1- 175mm diameter (2.5mm thickness) belt 2 - 80mm diameter (2mm thickness) belt 3 - 55mm diameter (2mm thickness) No details or instructions provided of which belt is for where - but it looks like the above belts are parts 118, 133 and 139 respectively. So it looks like I'm missing part 112 - the 75mm belt. I'm very new to all this so apologies if this seems like a daft question - does anyone know why the kit would have been sold as just a kit of 3 belts rather than including all 4? Or are the 80mm belt or the 75mm belt for alternative set ups or are both required for operation? Many thanks Howard

6th May 2014, 9:21 pm	#2
DOFFERY Retired Dormant Member Join Date: Aug 2004 Location: Blackpool, Lancashire, UK. Posts: 1,488	Re: Philips N4308 - belts Howard, There were four belts on the 4308 as you noted, I would presume from your description you have the flywheel 55mm belt 3, the main 175mm belt 1 & the idler 80mm (my belt 3 ,belt 4 not required), it would appear the counter belt may be missing. I attach a drawing of the various belt systems on the 4307/8. Being the 4308 I would suggest the fig . 8 counter belt is missing, not a real problem, it is slightly smaller in dia than the idler belt 2. Colin. Attached Thumbnails Last edited by DOFFERY; 6th May 2014 at 9:24 pm. Reason: inclusion

7th May 2014, 9:45 pm	#3
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Philips N4308 - belts Is Phlips the only manufacturer that insists on using these figure-8 belts where the belt rubs against itself at the crossover point? The same solution is used for the rewind belt in the EL3549/3534.

8th May 2014, 9:34 pm	#4
WallHow Retired Dormant Member Join Date: May 2014 Location: North Yorkshire, UK. Posts: 5	Re: Philips N4308 - belts Many thanks for the response and the belt diagram Colin - very helpful. The description I had from the belt seller for the kit said it included: 1 capstan belt, 1 pick up reel belt and 1 counter belt - so I assumed it was missing the take up belt rather than the counter belt. In any case - I fitted the 3 belts as per your diagram and all seems to be working - really chuffed to see/hear it working! As a purely temporary measure I used an appropriately sized eleastic band as the counter belt while I order a proper belt and even the counter seems to work. Just a few queries: i) the speed change lever seem rather stiff with the new flywheel belt - is this normal with a new belt and will it slacken at all (just don't want to overstress the plastic lever and snap it!) ii) is it OK to keep using the 80mm belt for the take up belt when the user manual states 75mm? iii) any advice on the best type of glue for refixing the aluminium trim that's come off - would evo-stik be OK? iv) any idea where this 'spare' part that I have left over is meant to go - it's a circular clip/collar about 7mm diameter and 4mm high! (Unfortunately struggling to attach a photo!) Many thanks Howard

9th May 2014, 11:57 am	#6
DOFFERY Retired Dormant Member Join Date: Aug 2004 Location: Blackpool, Lancashire, UK. Posts: 1,488	Re: Philips N4308 - belts Howard, Just checking the former posts, your belts ,ie. belt 3, 55mm is in fact belt no. 4 on my sketch NOT the flywheel belt, this flywheel belt is missing for your 4308, hence the tightness of the speed change, my error, I apologise. Your kit of belts was in fact for the very early type of 4307 bottom left of my sketch where the main drive belt drove the flywheel, your suppliers error if you ordered belts for the 4308. The 55mm belt you were supplied with is not required for your 4308. The idler belts for the idler & counter are very similar. So basically you were supplied with the belts for the very old 4307, main 175, take up 55 & counter 80, you need the flywheel & idler (No3) although as you have found the latter works as the idler.If you require , either or both let me know, I have them in stock. Hence my kit includes the 5 belts to cover all variations but you only need the flywheel & perhaps the idler No 3. Again my apologies for my error. Colin,

10th May 2014, 7:52 am	#7
WallHow Retired Dormant Member Join Date: May 2014 Location: North Yorkshire, UK. Posts: 5	Re: Philips N4308 - belts Many thanks - that makes sense!

10th May 2014, 1:47 pm	#8
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Philips N4308 - belts Regarding the metal trim, I usually use contact glue to refit it. The trim is very light so the glue does not have to be very strong, but it helps to have a certain resilience. I'm not sure exactly what evo-stik is, it looks like some kind of superglue which should be ok too, except that superglue tends to be rather brittle and can crack when knocked, causing the panels to come off again.

10th May 2014, 1:50 pm	#9
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,864	Re: Philips N4308 - belts Evo-Stik normally refers to a contact adhesive, i.e. one that you apply to both parts, leave to go tacky, then press together. However, it's now used as a brand on a whole range of different products. Nick.

10th May 2014, 9:30 pm	#10
ricard Octode Join Date: Mar 2006 Location: Lund, Sweden Posts: 1,632	Re: Philips N4308 - belts Thanks Nick, tried to google it but with ambiguous results. A contact adhesive is what I'd go with in this case at any rate.

12th May 2014, 12:08 pm	#12
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,554	Re: Philips N4308 - belts Where did you get the rubber from to make the clutch inserts? Could you post a link please?

12th May 2014, 1:28 pm	#13
DOFFERY Retired Dormant Member Join Date: Aug 2004 Location: Blackpool, Lancashire, UK. Posts: 1,488	Re: Philips N4308 - belts Any belt old or new of aprox. 1.5/2.00mm cut to size, overlap clutch disc by 1.5/2,0mm, just a press fit, no need for original shape etc. Two inserts per clutch will suffice. Just be aware the Left/Right discs differ Colin.

12th May 2014, 2:20 pm	#14
WallHow Retired Dormant Member Join Date: May 2014 Location: North Yorkshire, UK. Posts: 5	Re: Philips N4308 - belts I did struggle to find something suitable that I could use - thought it would be easy to find something made of rubber about 2mm thick. I didn't have any old or new belts lying about so couldn't do as Doffrey suggests. I was going to use a large rubber washer from a sink waste but couldn't find one in my local town without having to buy the whole waste! In the end cannibalised a flexible rubber tree tie and cut the inserts out of that using a scalpel to a similar design to the originals as shown in the service manual. I used Evo-stik (contact adhesive) for the trim seems to have worked well. The clip/collar was from one of the control knobs - so that mystery is solved. Cheers Howard

13th May 2014, 12:52 am	#15
Jimmyhaflinger Heptode Join Date: Feb 2007 Location: La Spezia, Italy Posts: 834	Re: Philips N4308 - belts by the way, i'm also restoring a 4308, i had to replace the speaker terminal plate as it was broken off and the wires were just soldered together and hanging in mid air, (luckily i was able to salvage one from a scrap Philips speaker) anyway, is the speaker frame supposed to be grounded?

13th May 2014, 8:01 am	#16
DOFFERY Retired Dormant Member Join Date: Aug 2004 Location: Blackpool, Lancashire, UK. Posts: 1,488	Re: Philips N4308 - belts Howard, You really have gone the whole hog cutting the exact shapes for the clutch inserts , I admire you , the scalpel bothers me ? Last edited by DOFFERY; 13th May 2014 at 8:01 am. Reason: inclusion

17th May 2014, 9:05 pm	#17
WallHow Retired Dormant Member Join Date: May 2014 Location: North Yorkshire, UK. Posts: 5	Re: Philips N4308 - belts Well - not the exact shape! And when I say scalpel - perhaps craft knife would be more accurate. Could I just check about the speed change lever. This still seems rather tight when turning the lever on way, but OK when turning it the other - are yoiu meant to turn the machine off completely before switching between speeds - it seems as is I am fighting against the belt drive direction. Cheers Howard

17th May 2014, 9:45 pm	#18
DOFFERY Retired Dormant Member Join Date: Aug 2004 Location: Blackpool, Lancashire, UK. Posts: 1,488	Re: Philips N4308 - belts Hello Howard, You don't have to turn the machine off to change speeds, all the change lever does is move the flywheel belt via a lever from one pulley to another, it is possible that it may seem tight one way & less the other way but shouldn't be a problem. Have you tried turning the speed change when machine is switched off, any difference?? A drop of oil on the shaft under the speed change lever might assist. Colin.

17th May 2014, 10:27 pm	#19
Jimmyhaflinger Heptode Join Date: Feb 2007 Location: La Spezia, Italy Posts: 834	Re: Philips N4308 - belts the speed can be switched while the motor is running in these recorders, maybe you fitted a belt that's too hard, the original belts were thick but quite soft and resilient luckily both of my N4308 recorders still have their original belts and even clutches in perfect conditions, they're both "made in holland" Mk1 machines from 1971.

14th May 2015, 8:02 am	#20
astrat65 Retired Dormant Member Join Date: May 2015 Location: Taunton, Somerset, UK. Posts: 2	Re: Philips N4308 - belts Hi there, After reading this thread, I have obtained a set of belts for my Pye 9123 recorder, which is the same as the Philips N4308. Having cleaned up the mess of the old goo left by the original belts, I am not sure how the new belts fit. Does anyone have a photo or instructions on how to fit the new belts. Thanks