Philips 291U / 15 Radio

[bobhowe]

Hi thanks to David for kindly providing me the circuit diagram and advising me what capacitors to replace before switch on I removed the chassis from the set and it has 2 issues one is the mounting posts in the cabinet is broken easy fix by gluing but unbelievable this set has has the same shocking Bodge repair by replacing the smoothing with the incorrect type and value taped up and insecure a long time ago . Is there an issue with the make of capacitors in Philips radios as 60 oldjohn featured a Philips 291U on the UKVRRR forum on Sept 18TH 2016 his set had been replaced with the correct type and value Radio Spares smoothing capacitors pictures of my set to follow kind regards Bob

[Geordie McBoyne]

More pictures of the insides of the Philips 291U.
The HT electrolytics are in need of replacement and note the damage to the cabinet, picture No.1

Geordie McBoyne.

[bobhowe]

Hi David thanks for posting pictures the same horrible bodge job as my Philips V5A in another thread ( what are the chances of having the same make radio different model ) glad I did not take a chance and plug it in . Next step is to remove the HT electrolytics and poor wiring and locate a 25MM capacitor clamp and a 2.2K 3watt HT soothing capacitor resistor as the wire has broken off . Good points the loudspeaker is in good condition and so is the dial chord kind regards Bob

[bobhowe]

Hi last night I decided to do a few checks to see if there are any hidden issues with the Philips 291U I temporary made the set safe by snipping out the mains filter capacitor and removing the poor wiring from the smoothers and temporary connecting 1 16UF capacitor without 2.2K 3 Watt resistor . Powered up the set nothing after various checks found that the UL41 valve had an open circuit heater replaced that and got a lot of mind hum and 1 weak station on MW Talk Sport . kind regards Bob

[Geordie McBoyne]

Done some more work on the Philips 291U replaced the smoothing capacitor and decided to solder the capacitor clamp to the chassis instead of drilling in case i manage to locate later the correct bolt through type . Replaced C15 snipped out tone corrector and mains filter capacitor and Talk Sport at very low volume the audio output stage seems ok as if i touch the volume pot wiper you get a loud buzz . i am getting a HT voltage from the UY 41 is 154 Volts and 110 Volts on the UL41 Anode . Could a waxy cap be leaking ? and I changed the UY41 any advise would be appreciated  here is some pictures of the smoothing capacitor on the chassis.   

  Kind regards Bob

[Mike Watterson]

All waxy/paper caps will be leaky. Any on g2 pins will reduce volume/gain, especially check caps on . Some paper caps don't use a card and wax sleeve. Especially replace C15 47,000pF = 47nF. C19 should be replaced. Also C23, 39nF.
All the caps less than 1000pF should be OK, as they are likely not paper dielectric.
The "tone corrector" is a snubber and damps high voltage spikes when V3 is suddenly turned off by negative noise spike on the grid. I usually use a 1kV ceramic part. Tolerance and value isn't critical.
C8 and C14 should also be replaced. 150nF and 100nF

[bobhowe]

Hi Mike thanks for reply & advise I have changed C15 47NF I will change C8, 14,19, 23 as you have advised will report back when I have changed them kind regards Bob