Over the years, at events such as the NVCF, Golborne Swapmeets etc, for nominal sums I’ve bought a number of KB FB10 ‘spares or repair ‘Toaster’ radios with damaged Bakelite cabinets, have restored the electrics and repaired and re-sprayed the cabinets in various colours. At the recent Golborne event, on Mike’s ‘A fiver or less’ pile I found yet another Toaster with a damaged cabinet. Knobs, dial and base were all intact, and at a fiver, it’s not much of a gamble even if it’s a non-worker.
The earlier MW/LW FB10 had a frame aerial – the FB10 MK2 (from Serial Number 110,001) had a ferrite rod aerial and a different valve line-up but they also seem to have variations in the valve line-up with a mixture of B9, Octal and B7G valves. This one has a ferrite rod aerial, so is a MK2, the valve-line up of which is stated as:
V1: 6BE6 (B7G)
V2: 6BJ6 (B7G)
V3: 6AT6 (B7G
V4: 6BW6 (B9A)
V5: 6V4 (B9A)
The line up of the earlier version was:
V1: 6BE6 (B7G)
V2: 6BA6 (B7G)
V3: 6AT6 (B7G)
V4 6V6GT (Octal)
V5 6X5GT (Octal)
The set had no serial number and the line-up was a mixture, in that V1, V2 & V3 were MK2 valves, but V4 was as the earlier version - a 6BW6. V5 initially posed a mystery as it had an octal valve-holder on the chassis, but had a neatly made adaptor consisting of an Octal plug and a B9A holder, plugged into the holder, presumably fashioned by a former ‘custodian’ of the radio. The B9A valve that was plugged into the adaptor had lost its markings so was something of a mystery. I checked the cross-wiring of the adaptor which seemed to indicate that the B9A valve was a 6V4. It worked fine so I left it in place. (I assume that the octal valve would have originally been a 6X5GT).
The adaptor reminded me of one that I’d made some years ago when I couldn’t find a genuine EBL31 valve (double diode-pentode) to fit into my Ekco A22. I made an adaptor to enable an EL84 to be used along with two germanium detector diodes till a genuine EBL31 came along.
All but one of the waxy caps had been replaced, so I replaced that one. Everything looked in order so I tried the set on my lamp limiter and it worked fine. I switched it to be powered direct from the mains, checked the voltages and all were close to spec. The alignment was spot on.
A neat feature of this compact set is that it uses an auto-transformer rather than a dropper, so it keeps the heat down, but of course it means that the chassis may be live, so live chassis precautions needs to be taken. One oddity was that the two parallel resistors from the auto-transformer to the rectifier anodes are stated on the service data as being 150 Ohms each, (hence, 75 Ohms in parallel) but the markings on them clearly show that they’re 330 Ohms each, (165 Ohms in parallel). They actually only measure 65 Ohms. Rather unusual for carbon composition resistors to reduce in valve with age, but it does mean that they’re close to the stated spec, so I left them in place. They appear to be 5 Watt resistors, so share the load to the rectifier anodes, (which are strapped together).
The ferrite rod aerial was lathered in a thick coat of wax to such an extent that anyone could be forgiven for mistaking it for a mains dropper.
I filled the crack on the cabinet with epoxy car body filler, sanded the cabinet with 220G wet and dry, primed it with acid etch primer, and finished it in Wlko ‘Duck-Egg’ blue gloss. Excellent paint at only £4.00 for a 400 mL aerosol can, which comes in a range of colours:
https://www.wilko.com/en-uk/wilko-en...00ml/p/0466173
Sadly, with FB10s, the bright green silk speaker fabric fades over time and looks shabby, so I found a piece which didn’t look out of place as a replacement.
Total expenditure was £9.00 – a fiver for the radio, £4.00 for the paint (lots left in the can).
A little bit of effort, a lot of fun and a nice end result. (The last one I restered was given a red ‘overcoat’).
Pic 1 below is a rear view of the set as found, showing the V5 adaptor in place, and the ferrite rod aerial looking rather like a mains dropper.
The small autotransformer is below the aerial, and to the right, are the two carbon composition (5 Watt?) resistors, R14 & R15 in parallel.
Pic 2 is a close-up of the neatly fashioned octal/B9A adaptor.
Pic 3 is a sketch of the cross-wiring of the plug and socket of the adaptor.
Pic 4 shows R14 & 15, clearly marked as 330 Ohms each.
Pic 5 is of the faded speaker fabric.
I'll attach some pics of the cabinet in another post
Hope that’s of interest.