Roberts RP28 - UK Vintage Radio Repair and Restoration Discussion Forum

Andrew Humphriss · 18th Feb 2017, 8:25 pm

I picked up a very clean Roberts RP28 radio and told it worked having paid £12.
The radio works in the background of what seems to be the radio oscillating.
Any idea on where to look, having no circuit diagram?
Andrew 2E0NDZ

Nuvistor · 18th Feb 2017, 8:36 pm

Have you confirmed it's not interference?

Andrew Humphriss · 19th Feb 2017, 5:25 pm

It appears to be like white noise with a signal hidden in it and very distorted
Any ideas
Andrew

FIXITNOW · 20th Feb 2017, 8:21 am

its probably going to be a faulty capacitor ,it will need striping fault finding and repair
,is this something you feel you can do ?

Radiocruncher · 20th Feb 2017, 4:14 pm

It could be the audio IC. These sets don't like reverse polarity so that may have happened in the past and caused the issue. I've found the capacitors in these to be pretty reliable.

Good luck

Graham

Andrew Humphriss · 22nd Feb 2017, 2:11 pm

Thank you for the leads, does anyone have a circuit diagram for this Roberts RP28, I was surprised by the mdf used inside.
Can anyone confirm how to get the chassis out?
It sounds like an AF issue but until I get it out of the cabinet who knows?

73s
Andrew

Nuvistor · 22nd Feb 2017, 2:24 pm

I have looked online for a circuit but nothing found, hopefully one of the forum members may have one.
Frank

FIXITNOW · 22nd Feb 2017, 3:58 pm

Roberts RP28 radio circuit diagram there are 2 it depends on you serial number

what is your serial number ?

only have some basic stuff but 2 big to upload

18th Feb 2017, 8:25 pm	#1
Andrew Humphriss Pentode Join Date: Jan 2009 Location: Stratford upon Avon, Warwickshire, UK. Posts: 127	Roberts RP28 I picked up a very clean Roberts RP28 radio and told it worked having paid £12. The radio works in the background of what seems to be the radio oscillating. Any idea on where to look, having no circuit diagram? Andrew 2E0NDZ

18th Feb 2017, 8:36 pm	#2
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Roberts RP28 Have you confirmed it's not interference?

19th Feb 2017, 5:25 pm	#3
Andrew Humphriss Pentode Join Date: Jan 2009 Location: Stratford upon Avon, Warwickshire, UK. Posts: 127	Re: Roberts RP28 It appears to be like white noise with a signal hidden in it and very distorted Any ideas Andrew

20th Feb 2017, 8:21 am	#4
FIXITNOW Octode Join Date: Feb 2007 Location: Ely, Cambridgeshire, UK. Posts: 1,976	Re: Roberts RP28 its probably going to be a faulty capacitor ,it will need striping fault finding and repair ,is this something you feel you can do ?

20th Feb 2017, 4:14 pm	#5
Radiocruncher Hexode Join Date: Dec 2013 Location: Torrington, Devon UK. Posts: 446	Re: Roberts RP28 It could be the audio IC. These sets don't like reverse polarity so that may have happened in the past and caused the issue. I've found the capacitors in these to be pretty reliable. Good luck Graham

22nd Feb 2017, 2:11 pm	#6
Andrew Humphriss Pentode Join Date: Jan 2009 Location: Stratford upon Avon, Warwickshire, UK. Posts: 127	Re: Roberts RP28 Thank you for the leads, does anyone have a circuit diagram for this Roberts RP28, I was surprised by the mdf used inside. Can anyone confirm how to get the chassis out? It sounds like an AF issue but until I get it out of the cabinet who knows? 73s Andrew

22nd Feb 2017, 2:24 pm	#7
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Roberts RP28 I have looked online for a circuit but nothing found, hopefully one of the forum members may have one. Frank

22nd Feb 2017, 3:58 pm	#8
FIXITNOW Octode Join Date: Feb 2007 Location: Ely, Cambridgeshire, UK. Posts: 1,976	Re: Roberts RP28 Roberts RP28 radio circuit diagram there are 2 it depends on you serial number what is your serial number ? only have some basic stuff but 2 big to upload