2x Roberts R600s ca 1972/3 from Wootton Bassett auction £2

[howard]

Hello again,

These two Roberts R600s, one in black and the other in red, were originally on the Bring & Buy table at the last Wootton Bassett event marked £7 each but they didn't sell and ended up in the auction and I bid and won them both for £2. Neither was complete, missing knobs and aerial, broken handle, the red one had a bashed in grille and neither worked. Both had good cases though. This first account is of the restoration of the black one which was relatively straightforward, the restoration of the red one will follow when I've finished reassembling it and that one has had work done on both its Mullard modules.

This black R600 s/n 88713 was built around 1972 and has an oblong metal badge and no 'Local Radio' on its dial. It was dirty, its aerial was missing, one large knob had lost its trim and its handle had two splits in it and was about to break. I keep a few spare aerials and knobs and had spares for an R600 so I fitted those. When attached to a battery the set did nothing, not even through its earphone socket so I passed it onto Ron Bryan to take a look at.

The earphone socket was found to be faulty so that was bypassed and then the quiescent current was found to be very low so the bias and mid-point were reset on its output transistors and away it went, working well on all wavebands. The set was then realigned and returned to me to complete.

I didn't have a spare black handle for it so I placed an ad for one on the forum and Pete 'morecider' had one and very kindly sent it to me. I then dismantled the set, gave it a good clean with upholstery cleaner, touched in one or two tiny nicks on the grille, polished the dial with Safecut, polished the side panels with Topps dark scratch polish, and then replaced the handle, and reassembled the set. Finally it was all polished with Mr. Sheen.

This has come up a nice example of an R600, it works well and sounds quite good. There's not much I can do about the earphone socket, Roberts still keep a socket to fit the R600 and the R707 but it has a square chrome trim (as on Hackers) rather than a round trim. It's also almost impossible to get the earphone socket off these Roberts sets without damaging it and the dial so best left alone. However if anyone knows a source of original looking earphone sockets for the R600 please let me know.

My thanks to Ron and Pete.

Restoration of the red R600 to follow shortly.

Howard

[howard]

Hello again,

This is the second of the £1 Roberts R600s from the last Wootton Bassett auction. This late red one s/n 170447 had a duff earphone socket as well so when switched on nothing came out of the loudspeaker, but with an earphone plugged in it was found hardly working on FM and a bit insensitive on AM. The tuning control was very stiff too. Apart from a bashed in front grille, the set was in quite good cosmetic condition, and has a factory fitted PSU socket and an indelible BWBF label on the back. The last rod on the telescopic aerial was missing so I fitted a new aerial and then passed the set onto Ron Bryan to take a look at.

First the wires to the earphone socket were shorted out so that the set could be heard working through its loudspeaker. The LP1169 FM tuner module was removed which entailed removal of the dial, its blue aluminium background under it, and the tuning spindle cord pulley (parked as in pic below) to gain access to the three screws which hold it in place. The tuner was then dismantled - unsolder screening can, unsolder spindle bracket, untwist tabs fixing spindle bracket to base plate, remove spindle + bracket + anti-backlash gears + spring, undo 2 tuning cap screws, pull screening can and pcb and tuning cap from base plate and unsolder pcb from screening can. The BF195 transistor inside was replaced and also the nylon tuning spindle which had a badly worn pinion gear, with a brass spindle from a scrap R707 FM tuner module. The FM module was put back but as the set wasn't working a lot better on FM, attention was then focussed on the LP1171 IF module. It is possible to remove this without taking out the switch panel - four of the module leads pass out through a slot in the switch PCB and using an extra long slim bit on the soldering iron, these leads can be disconnected from the four tinned copper switch wires via the slot and cleaned up with braid (solder-wick) - and then the remaining module connections unsoldered and straightened and the module can be lifted out. The AF114 and 2x AF115 transistors were replaced with AF124 and 2x AF125s inside the LP1171 IF module, the module reassembled and reconnected, the AM and FM RF circuits realigned and the set then worked perfectly.

The set then came back to me for cosmetic repairs. The existing grille was lifted off with the aid of a hairdryer, the surface underneath cleaned and then blackened with Kiwi Scuff Kote, and then a brand new grille fitted and stuck on with Pritt Stick dipped in water. The case was cleaned with upholstery cleaner and polished with Mr Sheen. The side panels which were unmarked were treated with a light coat of Topps medium wood Scratch cover. The dial which was still loose from Ron's repair was polished with TCut as it was quite worn and then polished with Mr Sheen. The blue aluminium piece under the dial was stuck back on with double sided sellotape, the dial put back in place and the aerial socket reconnected. The set was then reassembled.

It is amazing how well this R600 works with all new transistors in its LP1169 FM tuner and LP1171 IF modules ! It picks up everything on all wavebands, and Classic FM which is a weak station here, it picks up with ease. Also the VHF waveband extends beyond 106 MHz on the R600 so one can tune into a few more stations than most sets of its time. Cosmetically it's also excellent, and the R600 looks rather nice in red leathercloth.

Howard

[howard]

And pics of the LP1171 IF module ...

[geofy]

Two excellent restorations as usual Howard. Well done. I would not have picked on the BF195 though, they tend to be very reliable.

Regards

Geof