Philips 374 Radio Cassette Recorder - UK Vintage Radio Repair and Restoration Discussion Forum

dan.mih · 8th Nov 2019, 1:08 am

Hello,

I have found a very good looking radio cassette player Philips 374. It has a great sound, it feels like your are near a modern soundbar

.

Unfortunately, the cassette player is defective. One gear (orange, indicated by arrow) has many teeth missing. The plastic is very fragile, the teeth fall if you touch them.

I have asked if a 3D print can replace the wheel, but I have received answers about uncertain results. The gear may be subject to rapid wear due to forces applied.

In this situation I am asking:
1) Is this a common design of Philips cassette players? If yes, can somebody give more details about what models were fitted with this unit?
2) I have disassembled a few parts of the cassette player. What is the purpose of the contact around the gear that turns the cassette?
3) Does somebody have a service manual of this type of cassette player?

cmjones01 · 8th Nov 2019, 1:21 am

That's a splendid looking machine, proper Philips distinctiveness. I've certainly heard of gears in cassette decks falling apart, but I don't know what to do about this one. However, the contacts around the takeup spool are probably for sensing that the tape is moving correctly, and activating the auto-stop mechanism if the spool stops rotating. I once had a Philips car cassette player which used the same method, and it had a solenoid-operated stop mechanism.

Chris

Maarten · 8th Nov 2019, 3:57 am

Indeed a very common problem, as Philips used some kind of polyurethane to dampen the noise on some gears. Polyuretehanes (brought to you by the makers of sticky rubber goo and glazed pinch rollers) aren't the most stable materials. Luckily, mfbfreaks.com has hard plastic replicas for some of those gears. If you can't find it on their site, you could mail them or ask on their forum.

P.S. the polyurethane doesn't really crumble from the forces, but due to chemical instability. It seems to be accellerated somewhat in damp environments, with the polyurethane even giving off some slighly corrosive byproducts when it falls apart completely if the environment is really damp.

camtechman · 9th Nov 2019, 7:45 am

Grundig C400 series cassette machines have a similar problem; (the gears turn to a jelly consistency).

unitelex · 10th Nov 2019, 6:57 pm

If you can remove the gear without it completely falling apart, you might be able to find somebody skilled with a small milling machine and lathe who could copy it. A material such as Delrin/Acetal/Nylon is easy to machine and would be reasonable durable.

But there would need to be enough of the gear remaining so that the diameter, tooth pitch and axle sizes could be measured.

ben · 10th Nov 2019, 8:13 pm

whilst you are in there, check/change the pinch roller and erase head (the latter tends to fall to pieces and may leave sticky residue on tapes!)

8th Nov 2019, 1:08 am	#1
dan.mih Triode Join Date: Aug 2019 Location: Toplita, Romania Posts: 11	Philips 374 Radio Cassette Recorder Hello, I have found a very good looking radio cassette player Philips 374. It has a great sound, it feels like your are near a modern soundbar . Unfortunately, the cassette player is defective. One gear (orange, indicated by arrow) has many teeth missing. The plastic is very fragile, the teeth fall if you touch them. I have asked if a 3D print can replace the wheel, but I have received answers about uncertain results. The gear may be subject to rapid wear due to forces applied. In this situation I am asking: 1) Is this a common design of Philips cassette players? If yes, can somebody give more details about what models were fitted with this unit? 2) I have disassembled a few parts of the cassette player. What is the purpose of the contact around the gear that turns the cassette? 3) Does somebody have a service manual of this type of cassette player? Attached Thumbnails

8th Nov 2019, 1:21 am	#2
cmjones01 Nonode Join Date: Oct 2008 Location: Warsaw, Poland and Cambridge, UK Posts: 2,677	Re: Philips 374 Radio Cassette Recorder That's a splendid looking machine, proper Philips distinctiveness. I've certainly heard of gears in cassette decks falling apart, but I don't know what to do about this one. However, the contacts around the takeup spool are probably for sensing that the tape is moving correctly, and activating the auto-stop mechanism if the spool stops rotating. I once had a Philips car cassette player which used the same method, and it had a solenoid-operated stop mechanism. Chris __________________ What's going on in the workshop? http://martin-jones.com/

8th Nov 2019, 3:57 am	#3
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,199	Re: Philips 374 Radio Cassette Recorder Indeed a very common problem, as Philips used some kind of polyurethane to dampen the noise on some gears. Polyuretehanes (brought to you by the makers of sticky rubber goo and glazed pinch rollers) aren't the most stable materials. Luckily, mfbfreaks.com has hard plastic replicas for some of those gears. If you can't find it on their site, you could mail them or ask on their forum. P.S. the polyurethane doesn't really crumble from the forces, but due to chemical instability. It seems to be accellerated somewhat in damp environments, with the polyurethane even giving off some slighly corrosive byproducts when it falls apart completely if the environment is really damp.

9th Nov 2019, 7:45 am	#4
camtechman Nonode Join Date: Jan 2008 Location: Milton Keynes, Bucks. UK. Posts: 2,552	Re: Philips 374 Radio Cassette Recorder Grundig C400 series cassette machines have a similar problem; (the gears turn to a jelly consistency). __________________ When I die, please don't let my Wife sell my collection for the amount I told her I paid for it!

10th Nov 2019, 6:57 pm	#5
unitelex Hexode Join Date: May 2005 Location: Greater Manchester, UK. Posts: 496	Re: Philips 374 Radio Cassette Recorder If you can remove the gear without it completely falling apart, you might be able to find somebody skilled with a small milling machine and lathe who could copy it. A material such as Delrin/Acetal/Nylon is easy to machine and would be reasonable durable. But there would need to be enough of the gear remaining so that the diameter, tooth pitch and axle sizes could be measured.

10th Nov 2019, 8:13 pm	#6
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: Philips 374 Radio Cassette Recorder whilst you are in there, check/change the pinch roller and erase head (the latter tends to fall to pieces and may leave sticky residue on tapes!) __________________ Regards, Ben.