UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Success Stories

Notices

Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE!

Reply
 
Thread Tools
Old 7th Aug 2022, 9:48 am   #1
Gabe001
Octode
 
Join Date: Oct 2019
Location: Stockport, Greater Manchester, UK.
Posts: 1,047
Default Resurrection of a Philips BX180U

I recently acquired a Philips BX180U from ebay for the sum of £25, simply because I liked the look of it. It is a continental MW only set with built for a 220v AC/DC supply. Nothing too special or unusual about it.

From the photos it looked in pretty good condition cosmetically with some flaking from the stripes, which is to be expected. My only concern was the lack of the dial pointer evident upon scrutinising the seller's pictures. The seller assured me it was tucked away by the side of the dial and didn’t move when the knob was turned.

With some luck the set arrived (in one piece), and I got to work on it.

Cosmetically, the radio was decent. There were a few hairline cracks that were not really visible, but would need stabilising. The stripes were more “greyish” than I expected, compared to other Philips sets. I took the set apart, having some difficulty removing the grub screws, but they turn in the end. For those not familiar with Philips sets, the grub screws tend to screw into the shaft rather than the knob, meaning that rust can weld the shaft and grub screw together quite easily.

I had a quick look at the chassis and decided to leave the electrics to the end, as clearly a lot of electrical work would be required, more about this later.

The bakelite got the Brasso treatment, which brought out a nice shine, and two small hairline cracks were stabilised with epoxy. The flaking stripes were removed and repainted from scratch using a small painting palette of acrylic paints and a small paintbrush. The original colour is “grey-ish”, but I oped for the standard Philips creamy colour they use in other sets. Not original I know, but it looks much better. The water based paint is easy to use and and excess can be wiped off without affecting the bakelite. The set would need restringing, but this didn’t appear too complex and I decided to do this last


Electrically, the set would require quite a bit of work. Preliminary checks with the multimeter revealed that the rectifier (UY41) was open circuit. The dropper resistor was broken off the bakelite. The UL41 had gone soft. The OPT was open circuit (very common in Philips sets). There were the usual Philips black tarry caps that needed replacement. The tuning cap was almost seized and moved with difficulty. The resistors seemed fine. Time to get to work!


1. The dropper resistor which had broken off the supporting bakelite was re-fixed

2. The UY41 was replaced by a good one from my valve spares

3. A new tested UL41 was purchased from ebay (from france!). It only cost me 9.60 euros which is a good price I think. I do have a “hummy” one in my spares which would do as a temporary substitute.

4. The ball bearings and other moving parts got lubricated to allow the tuning cap to rotate freely

5. A new OPT was secured from this forum (thanks Horris) which I installed. It wasn’t a like for like replacement, but it fit the bill, although it required an extra hole to be drilled in the chassis and the restricted space made drilling quite awkward.

After replacement of the infamous grid coupling capacitor and the one between the mains (with a suitably rated type x cap), a new mains lead and some safety checks (neutral to chassis) it was time to give the radio first switch on with the lamp limiter……

and nothing.

The double pole on and off switch was faulty and intermittent. I gave it the servisol treatment, worked it a few times and waited for the servisol to dry, and it worked reliably afterwords.

I don’t have a capacitor reformer for smoothing caps, so my general soft start method of reforming using the lamp limiter and monitoring the voltage gives me about 50% success. They did reform but the cap was getting warmer than I would be happy to accept, so a new pair of smoothing and reservoir caps would be required.

In any case, the radio worked somewhat and I could receive the usual stations. Output was distorted but I still had a few of the tarry caps to replace, and even with the lamp limiter the voltage at the anode of the UL41 was too high, in excess of 200 volts. This was because the dc resistance of the replacement OPT was quite a bit less than the original, and also because the set was built for 220v, and my mains is 238v. Two 5W series resistors were used to bring the voltage down a notch.

Once the caps were replaced and the voltages matched those in the service sheet, the set worked much better. The smoothing and reservoir caps were replaced with slim modern versions (due to the lack of space under the chassis). The picture shows one of them temporarily tacked – in the completed version (not shown) I used a tag strip. The restringing required the cord to be pushed through 2 thin and quite long hollow metal tubes. I'm not sure what the engineers were up too, but this proved frustrating and finally the wife helped me out with a sewing needle and thread - a joint effort.

The final problem was quite a marked heterodyne whistle upon tuning into a station. Having replaced all the caps likely to be responsible, and checked the grounding, the set was finally stabilised by adding some capacitance across S6. I placed another capacitor in parallel to c13 (c13 = 115pf). I initially used 39pf but this cut the signal down too much and I decreased this to 15pf which keeps it silent without affecting the station volume significantly. Once I put the set together I realised the tuning cap was shorting at around the 450m mark, so I fixed that.

In general, the set looks really good with its curved sides, red speaker cloth and cream stripes, and works reasonably well with a small 1.5m aerial. There is no aerial socket, so the aerial is hard wired. The bulb value isn’t stated on the service sheet (philips just put the part number). I used a 6v 150ma, then a 12v 150ma and this is still perhaps a bit too dim (or the diffuser is too opaque), but otherwise I’m very happy with how things turned out.

Note that the service sheets has v2 as a UAF41, when it is actually a UAF42.


Photos :

1. underchassis almost complete: still to do the smoothing and reservoir caps which I later added on tag strips, and the 15pf cap across s2 still not in situ

2. Inside with back removed

3. completed, outside

4. Area where extra capacitance was added to stabilise set

5. comparison with other philips sets for size. This set is tiny.
Attached Thumbnails
Click image for larger version

Name:	IMG_20220719_201839.jpg
Views:	99
Size:	134.5 KB
ID:	262330   Click image for larger version

Name:	IMG_20220719_201807.jpg
Views:	102
Size:	102.5 KB
ID:	262331   Click image for larger version

Name:	IMG-20220703-WA0001.jpg
Views:	128
Size:	93.2 KB
ID:	262332   Click image for larger version

Name:	Screenshot_20220807-095927.jpg
Views:	97
Size:	30.1 KB
ID:	262333   Click image for larger version

Name:	IMG_20220723_142712_038.jpg
Views:	114
Size:	67.6 KB
ID:	262335  

Gabe001 is offline   Reply With Quote
Old 7th Aug 2022, 4:19 pm   #2
Tim
Dekatron
 
Tim's Avatar
 
Join Date: Jan 2003
Location: Bradford on Avon, Wiltshire, UK.
Posts: 3,100
Default Re: Resurrection of a Philips BX180U

I think the UAF41 and 42 are pretty much interchangeable anyway.
__________________
"Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."
Tim is offline   Reply With Quote
Old 7th Aug 2022, 4:46 pm   #3
Sideband
Dekatron
 
Sideband's Avatar
 
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 6,893
Default Re: Resurrection of a Philips BX180U

Traditionally odd numbers are vari-mu. Not sure if that applies to the B8A's though.
__________________
On Spike Milligan's headstone......I told you I was ill...
Sideband is offline   Reply With Quote
Old 7th Aug 2022, 5:36 pm   #4
Gabe001
Octode
 
Join Date: Oct 2019
Location: Stockport, Greater Manchester, UK.
Posts: 1,047
Default Re: Resurrection of a Philips BX180U

Quote:
Originally Posted by Tim View Post
I think the UAF41 and 42 are pretty much interchangeable anyway.
One has an internal connection that the other hasn't got. I'm not sure if this would have made a difference in the circuit for this set.
Gabe001 is offline   Reply With Quote
Old 9th Aug 2022, 7:03 am   #5
cathoderay57
Octode
 
Join Date: Oct 2017
Location: Bristol, UK.
Posts: 1,943
Default Re: Resurrection of a Philips BX180U

Hi Gabriel, nice work; a job well done and good account of the work required. I did chuckle about the tuning cord; Philips sets often contain something to challenge the restorer.... Jerry
cathoderay57 is offline   Reply With Quote
Old 9th Aug 2022, 9:55 am   #6
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 24,496
Default Re: Resurrection of a Philips BX180U

Very attractive little set. The tuning scale looks interesting - could you post a closeup picture?
paulsherwin is online now   Reply With Quote
Old 9th Aug 2022, 1:07 pm   #7
Gabe001
Octode
 
Join Date: Oct 2019
Location: Stockport, Greater Manchester, UK.
Posts: 1,047
Default Re: Resurrection of a Philips BX180U

Paul, will do when I get home
Gabe001 is offline   Reply With Quote
Old 9th Aug 2022, 4:09 pm   #8
Gabe001
Octode
 
Join Date: Oct 2019
Location: Stockport, Greater Manchester, UK.
Posts: 1,047
Default Re: Resurrection of a Philips BX180U

Paul , see attached
Attached Thumbnails
Click image for larger version

Name:	IMG_20220809_164936.jpg
Views:	74
Size:	48.1 KB
ID:	262533  
Gabe001 is offline   Reply With Quote
Old 13th Aug 2022, 10:35 am   #9
slidertogrid
Octode
 
slidertogrid's Avatar
 
Join Date: Apr 2005
Location: Peterborough, Cambridgeshire, UK.
Posts: 1,634
Default Re: Resurrection of a Philips BX180U

Nice job ! A very attractive little set!

Rich
slidertogrid is offline   Reply With Quote
Old 13th Aug 2022, 10:43 am   #10
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 24,496
Default Re: Resurrection of a Philips BX180U

Quote:
Originally Posted by Gabe001 View Post
Paul , see attached
It looks as if it may have been made for the Scandinavian market.
paulsherwin is online now   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 6:57 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.