UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Roberts RT7

stonehopper · 19th Apr 2009, 6:55 pm

Thanks all, and Brian for the welcome - and yes, I've visited Paul Stenning's site, and got my service sheet from there, though Geofy's talking a foreign lingo! (Appreciated though - I'll learn in time). I can only guess at the symbols on the diagram for now Geof, but I will get there.

I have taken the red lead for the battery to be positive and connected with crocodile clips in absence of the correct PP10 or 9 connectors.

This red lead connects to a tab from the 'OFF' switch.
The black lead connects to several items, C32, T1 & T2 also.
There is a wire leading from one of the T2 connections to the speaker - coloured red.
The black speaker wire connects via a track to several of the little 'torpedos' with coloured bands.
The big C32 in the corner has its red top connected to the perimeter band of solder (I'm sure there's a correct name for the soldered tracks under the board?) which in turn is connected to the metal frame, so positive earth. Fair enough.

The body of T2 shows distinct signs of melted plastic at the top on one side, a dob of wax has collected on the twisted tab holding it to the board (melted most like + gravity) and even a small smoke burn on the metal arch above it, so must consider it 'no longer with us'.

It does look like there may be other issues with items other than this T2 as has been suggested, but until I replace that - short of removing everything and testing for values - I must ask if all these bits are actually available? Where from - and how expensive? I probably paid too much in £7.50, but I'm a sucker for an ugly face.

I've taken a couple of pictures, but I'm sure you all know what toasted components look like.

What's an 'emitter' look like, and what does it do?

19th Apr 2009, 6:55 pm	#11
stonehopper Retired Dormant Member Join Date: Apr 2009 Location: St Albans Posts: 50	Re: Roberts RT7 - problem Thanks all, and Brian for the welcome - and yes, I've visited Paul Stenning's site, and got my service sheet from there, though Geofy's talking a foreign lingo! (Appreciated though - I'll learn in time). I can only guess at the symbols on the diagram for now Geof, but I will get there. I have taken the red lead for the battery to be positive and connected with crocodile clips in absence of the correct PP10 or 9 connectors. This red lead connects to a tab from the 'OFF' switch. The black lead connects to several items, C32, T1 & T2 also. There is a wire leading from one of the T2 connections to the speaker - coloured red. The black speaker wire connects via a track to several of the little 'torpedos' with coloured bands. The big C32 in the corner has its red top connected to the perimeter band of solder (I'm sure there's a correct name for the soldered tracks under the board?) which in turn is connected to the metal frame, so positive earth. Fair enough. The body of T2 shows distinct signs of melted plastic at the top on one side, a dob of wax has collected on the twisted tab holding it to the board (melted most like + gravity) and even a small smoke burn on the metal arch above it, so must consider it 'no longer with us'. It does look like there may be other issues with items other than this T2 as has been suggested, but until I replace that - short of removing everything and testing for values - I must ask if all these bits are actually available? Where from - and how expensive? I probably paid too much in £7.50, but I'm a sucker for an ugly face. I've taken a couple of pictures, but I'm sure you all know what toasted components look like. What's an 'emitter' look like, and what does it do?