Philips 206A restoration - UK Vintage Radio Repair and Restoration Discussion Forum

Charles Wallis · 8th Jul 2022, 10:29 pm

Further to my recent request for help with the rectifier here is how it turned out. I received this 1940's 4 valve AM radio after it had been a non runner in an attic for about 40 years. The valve line up is ECH35, EF39, EBL31, AZ31. It was in a dreadful state, filthy dirty and most of the rubber (pre plastic?) insulation on the wiring was crumbling away. Clearly not a set to apply power to any time soon with the 2 core mains cord itself cloth covered and looking very dangerous indeed. The Trader sheet 478 had the wrong valves but I managed to get the Service Data sheet with all the correct data as this was a different version.

I checked all the transformer DC resistances and they were OK. I disconnected and labelled all the grotty wiring around the mains transformer I then applied mains via a bulb limiter to the 245V primary winding and checked AC on the secondaries. The 4V, 6.3V and 495V HT secondaries all seemed OK. The rectifier valve was missing and I took advice from this forum and acquired a new one rather than use diodes. I did some preliminary rewiring of the rectifier circuitry with a new smoothing cap and the AZ31 valve delivered 300V without load, so I had HT power at least.

An eagle eyed member (thanks Jerry) spotted on a photo that the top cap of the output valve was missing, a common problem, so I acquired one of these as well. I then set about a complete rewiring and recapping of the set, a fairly time consuming but rewarding activity. I replaced both decouplers C1 and C2 under the chassis leaving the remaining can on top for visual effect only. There were a large number of horrid waxies and black tar caps, all of which I replaced with polyester yellows.
With all that done and double checked, I plugged in the other 3 tubes and checked the heaters; all good. With a speaker wired in I then put in the rectifier and switched on; silence! The EBL31 was only luke warm but again with sound advice that it might be a poor connection on the base, that was fixed and it began to get hot and make some hum and a lot of motorboating. Further advice and the problem was the earthed screen on the EF39 IF amplifier valve. Apparently common on this type. With a bit of fiddling this was solved and the set burst into life. Victory! The reception seemed reasonable on SW, MW and LW.
With a working set I now put in a proper new mains lead and rewired all the wiring from the voltage selector to transformer.
Then I restrung the tuning system using cord from a fabric shop and a Biro spring as tensioner.
Lastly I polished up the Bakelite cabinet with T cut car polish. Only then did I realise what a stylish looking set it is, having been totally focussed on whether it would actually work or not!
All in all a very satisfying project and thanks again to all who helped on this forum.

Sideband · 9th Jul 2022, 6:28 am

These are good sets. You were lucky with the output transformer. I had two of these sets and both had O/C output transformers! Like you, I had to do a rewire although only partly as some wiring was rubber covered and the rest was PVC. I was able to make one good radio out of the two. One of the sets I had was so bad it was only any good as a parts donor anyway. I replaced the smoothing can on mine with a new double type bought from 'Ask Jan First' in Germany. I used an output transformer from yet a third parts donor set (although a different model).

Well done persevering and getting a successful result. It sometimes is amazing how the tattiest and most poor condition sets bounce back and perform really well.

Phil G4SPZ · 9th Jul 2022, 6:28 pm

Nice job, well done!

telstar · 11th Jul 2022, 2:55 pm

Hi. What a good restoration. I have one of these radios, as well as a Mullard MAS82 of a similar circuitry (the latter will be restored later.
I had problems on my Philips with the I.F can fittings, they were very loose on the chassis.
Cheers
Mike

Gabe001 · 12th Jul 2022, 9:20 pm

Well done with this set, a very good end result. It seems like you had your work cut out with the wiring and electrical work.

You were lucky the OPT was good. My Philips 462a had an o/c OPT. Same with the bx180u. Only the 371a didn't need the OPT replaced. Looks like it's a common Philps issue.

Charles Wallis · 13th Jul 2022, 9:42 pm

Thanks for the replies. Another problem I encountered was a broken coil in the front RF stage. The winding was very fine like a human hair. Intitially there was no reception, then I spotted the broken wire. I think I might have broken it when cleaning the waveband switch which is very close by. I managed to solder a single strand to bridge the gap and it worked!

silver ghost · 14th Jul 2022, 12:45 am

Have you tried to connect a DAB converter or something like a modern record player to the radio set? I guess you need a RIAA stage for the newer cartridges to work. I have noticed a lot of the old radios have banana plug-in option for record players and even extra loud speaker some times. It is a silly questoin, but I wonder how the sound turns out on old sets like this.

8th Jul 2022, 10:29 pm	#1
Charles Wallis Triode Join Date: Mar 2021 Location: Edinburgh, Scotland, UK. Posts: 45	Philips 206A restoration Further to my recent request for help with the rectifier here is how it turned out. I received this 1940's 4 valve AM radio after it had been a non runner in an attic for about 40 years. The valve line up is ECH35, EF39, EBL31, AZ31. It was in a dreadful state, filthy dirty and most of the rubber (pre plastic?) insulation on the wiring was crumbling away. Clearly not a set to apply power to any time soon with the 2 core mains cord itself cloth covered and looking very dangerous indeed. The Trader sheet 478 had the wrong valves but I managed to get the Service Data sheet with all the correct data as this was a different version. I checked all the transformer DC resistances and they were OK. I disconnected and labelled all the grotty wiring around the mains transformer I then applied mains via a bulb limiter to the 245V primary winding and checked AC on the secondaries. The 4V, 6.3V and 495V HT secondaries all seemed OK. The rectifier valve was missing and I took advice from this forum and acquired a new one rather than use diodes. I did some preliminary rewiring of the rectifier circuitry with a new smoothing cap and the AZ31 valve delivered 300V without load, so I had HT power at least. An eagle eyed member (thanks Jerry) spotted on a photo that the top cap of the output valve was missing, a common problem, so I acquired one of these as well. I then set about a complete rewiring and recapping of the set, a fairly time consuming but rewarding activity. I replaced both decouplers C1 and C2 under the chassis leaving the remaining can on top for visual effect only. There were a large number of horrid waxies and black tar caps, all of which I replaced with polyester yellows. With all that done and double checked, I plugged in the other 3 tubes and checked the heaters; all good. With a speaker wired in I then put in the rectifier and switched on; silence! The EBL31 was only luke warm but again with sound advice that it might be a poor connection on the base, that was fixed and it began to get hot and make some hum and a lot of motorboating. Further advice and the problem was the earthed screen on the EF39 IF amplifier valve. Apparently common on this type. With a bit of fiddling this was solved and the set burst into life. Victory! The reception seemed reasonable on SW, MW and LW. With a working set I now put in a proper new mains lead and rewired all the wiring from the voltage selector to transformer. Then I restrung the tuning system using cord from a fabric shop and a Biro spring as tensioner. Lastly I polished up the Bakelite cabinet with T cut car polish. Only then did I realise what a stylish looking set it is, having been totally focussed on whether it would actually work or not! All in all a very satisfying project and thanks again to all who helped on this forum. Attached Thumbnails

9th Jul 2022, 6:28 am	#2
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,571	Re: Philips 206A restoration These are good sets. You were lucky with the output transformer. I had two of these sets and both had O/C output transformers! Like you, I had to do a rewire although only partly as some wiring was rubber covered and the rest was PVC. I was able to make one good radio out of the two. One of the sets I had was so bad it was only any good as a parts donor anyway. I replaced the smoothing can on mine with a new double type bought from 'Ask Jan First' in Germany. I used an output transformer from yet a third parts donor set (although a different model). Well done persevering and getting a successful result. It sometimes is amazing how the tattiest and most poor condition sets bounce back and perform really well. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

9th Jul 2022, 6:28 pm	#3
Phil G4SPZ Dekatron Join Date: Apr 2005 Location: Bewdley, Worcestershire, UK. Posts: 4,748	Re: Philips 206A restoration Nice job, well done! __________________ Phil Optimist [n]: One who is not in possession of the full facts

11th Jul 2022, 2:55 pm	#4
telstar Octode Join Date: Dec 2003 Location: Leeds, West Yorkshire, UK. Posts: 1,592	Re: Philips 206A restoration Hi. What a good restoration. I have one of these radios, as well as a Mullard MAS82 of a similar circuitry (the latter will be restored later. I had problems on my Philips with the I.F can fittings, they were very loose on the chassis. Cheers Mike

12th Jul 2022, 9:20 pm	#5
Gabe001 Octode Join Date: Oct 2019 Location: Stockport, Greater Manchester, UK. Posts: 1,640	Re: Philips 206A restoration Well done with this set, a very good end result. It seems like you had your work cut out with the wiring and electrical work. You were lucky the OPT was good. My Philips 462a had an o/c OPT. Same with the bx180u. Only the 371a didn't need the OPT replaced. Looks like it's a common Philps issue.

13th Jul 2022, 9:42 pm	#6
Charles Wallis Triode Join Date: Mar 2021 Location: Edinburgh, Scotland, UK. Posts: 45	Re: Philips 206A restoration Thanks for the replies. Another problem I encountered was a broken coil in the front RF stage. The winding was very fine like a human hair. Intitially there was no reception, then I spotted the broken wire. I think I might have broken it when cleaning the waveband switch which is very close by. I managed to solder a single strand to bridge the gap and it worked!

14th Jul 2022, 12:45 am	#7
silver ghost Triode Join Date: Nov 2009 Location: Bergen, Norway Posts: 39	Re: Philips 206A restoration Have you tried to connect a DAB converter or something like a modern record player to the radio set? I guess you need a RIAA stage for the newer cartridges to work. I have noticed a lot of the old radios have banana plug-in option for record players and even extra loud speaker some times. It is a silly questoin, but I wonder how the sound turns out on old sets like this.