Noisy Philips sets. - UK Vintage Radio Repair and Restoration Discussion Forum

29th Jun 2004, 10:52 pm

The Philips 170A is a big octal valved 1946 radio with an RF stage. My set would tend to become very noisy on LW only, after about 10 minutes operation. The set is full of those splendid Philips "beehive" type trimmers with rotatable caps, sealed (undisturbed from new) with a blob of yellow wax.

In the case of this set, the wax had been applied when too hot, causing it to run down the central spiral stem inside the trimmer, giving rise to an intermittent contact with the trimmer rotor when warmed up. Cleaning off and re-aligning the set cured this fault, and restored its excellent performance. These sets have no lack of gain, despite having no audio pre-amplifier.

Does anyone have any suggestions for a suitable locking compound for this type of trimmer? Silicone rubber does not look very authentic!

ajgriff · 16th Jul 2004, 11:23 pm

Candle wax?

high_vacuum_house · 17th Jul 2004, 8:01 am

How about red tamper proof paint, the type used on the heads of screws?
Christopher Capener

paulsherwin · 17th Jul 2004, 11:06 am

Nail varnish?

Paul

17th Jul 2004, 10:25 pm

Thanks for all of your suggestions, everyone. In fact, after a bit of experimentation on a scrap trimmer, I have settled on making very small felt washers which push over the pointed central stem. I then applied yellow wax as normal, covering the washer completely, locking the trimmer rotor as Philips did.

Surface tension ensures that the wax soaks into the felt, but does not go right through it, preventing it from running down the stem.

No doubt any snags with this scheme will show up after another 50 years.

Regards, Leon.

jim_beacon · 17th Jul 2004, 11:19 pm

Anti-tamper varnish is available in red and green from Farnell.

Jim.

Sideband · 18th Jul 2004, 8:43 am

Hi Leon.

Your idea sounds quite good. I normally use nail varnish (having a 20 year old daughter helps here)! Clear is good and neutral of course but as there are so many outlandish colours available now you could probably find yellow available somewhere.

Rich

29th Jun 2004, 10:52 pm	#1
Leon_Crampin Guest Posts: n/a	Noisy Philips sets. The Philips 170A is a big octal valved 1946 radio with an RF stage. My set would tend to become very noisy on LW only, after about 10 minutes operation. The set is full of those splendid Philips "beehive" type trimmers with rotatable caps, sealed (undisturbed from new) with a blob of yellow wax. In the case of this set, the wax had been applied when too hot, causing it to run down the central spiral stem inside the trimmer, giving rise to an intermittent contact with the trimmer rotor when warmed up. Cleaning off and re-aligning the set cured this fault, and restored its excellent performance. These sets have no lack of gain, despite having no audio pre-amplifier. Does anyone have any suggestions for a suitable locking compound for this type of trimmer? Silicone rubber does not look very authentic! Last edited by Paul Stenning; 27th Dec 2004 at 12:27 pm. Reason: Fix link or code for vBulletin

16th Jul 2004, 11:23 pm	#2
ajgriff Nonode Join Date: May 2004 Location: Halifax, West Yorkshire, UK. Posts: 2,587	Re: Noisy Philips sets. Candle wax? Last edited by Paul Stenning; 27th Dec 2004 at 12:28 pm. Reason: Fix link or code for vBulletin

17th Jul 2004, 8:01 am	#3
high_vacuum_house Octode Join Date: May 2003 Location: Belper Derbyshire Posts: 1,935	Re: Noisy Philips sets. How about red tamper proof paint, the type used on the heads of screws? Christopher Capener __________________ Interests in the collection and restoration of Tefifon players and 405 line television

17th Jul 2004, 11:06 am	#4
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,940	Re: Noisy Philips sets. Nail varnish? Paul

17th Jul 2004, 10:25 pm	#5
Leon_Crampin Guest Posts: n/a	Re: Noisy Philips sets. Thanks for all of your suggestions, everyone. In fact, after a bit of experimentation on a scrap trimmer, I have settled on making very small felt washers which push over the pointed central stem. I then applied yellow wax as normal, covering the washer completely, locking the trimmer rotor as Philips did. Surface tension ensures that the wax soaks into the felt, but does not go right through it, preventing it from running down the stem. No doubt any snags with this scheme will show up after another 50 years. Regards, Leon.

17th Jul 2004, 11:19 pm	#6
jim_beacon Retired Dormant Member Join Date: Mar 2003 Location: Bishop's Waltham, Hants, UK. Posts: 939	Re: Noisy Philips sets. Anti-tamper varnish is available in red and green from Farnell. Jim. Last edited by Paul Stenning; 27th Dec 2004 at 12:29 pm.

18th Jul 2004, 8:43 am	#7
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,567	Re: Noisy Philips sets. Hi Leon. Your idea sounds quite good. I normally use nail varnish (having a 20 year old daughter helps here)! Clear is good and neutral of course but as there are so many outlandish colours available now you could probably find yellow available somewhere. Rich __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....