1973 Roberts R707 - 'new in box' and butchered inside

[howard]

Hello again,

Here's another radio won at the last Wootton Bassett auction, a Roberts R707 complete with its original box and guarantee card which was described as not working but externally showed no signs of any use and apart from a tiny nick in the leathercloth above the badge and another in one of the trims across the front appeared as new. Ron Bryan very kindly offered to repair this one and indeed did all the repairs to it.

Later that evening Ron called about the set which he had taken a look at inside .... it had been butchered, its LP1164/1 IF module had been cut open with a circular cutter or hacksaw, wires had been singed, wires cut and soldered back together again, solder splattered everywhere etc ... and this set had been put into the auction with a reserve by its previous owner and I know who that was cos I saw him bring the set in .....

There was absolutely no hope of repairing the IF module but fortunately I had a scrap R707 with an original IF module in it so Ron took that out and replaced its almost certainly duff AF114, AF115 and AF116 transistors with new AF124, AF125 and AF126 transistors. The switch assembly and the damaged module were then removed and the PCB within the module was found to be broken in half, and one of its IF transformers was found to be o/c which probably had been the cause of its original failure. The repaired module was then fitted, new wires fitted around the switch assembly (as the originals had been cut and untidily soldered back together) and the switch reinstated. The set was then found to be working, quietly on FM but not at all on AM so Ron spent a very long time figuring out what had gone wrong and discovered that during cleaning of the PCB in the repaired LP1164/1 module a tiny speck of solder had got lodged next to one of the transistor leads and was causing a short circuit. That was cleaned off and at last, for the first time in 34 years, this R707 was in perfect working order.

My thanks to Ron who did a fantastic job repairing this set. It really is like a new set in operation this R707, the volume pot and switches all work and feel like new.

Howard

[howard]

And more pics of the damage, and the repaired module.

Howard

[Colin]

Looks great Howard. A nice little 'time capsule'. Pity you and Ron had to go to all that trouble.

By the way Howard, Ron is a wonderful 'wing man' he really deserves a pat on the back for this one!

Well done Ron ...

[Steve_P]

God that is terrible. Someody hasn't told the truth there - and that set had that done to it years ago by somebody and was then left. Don't necessarily blame the person it came from for this.....

Good job though as always, and in a way you've got a virtually new radio out of that.

Cheers,

Steve P.

[Tim]

Another good one Howard. I wish I had your talent(and the time!!!) for restoring radios. A particularly spendid example of this splendid Roberts. I have a soft spot for these-and own several. Only one works properly though!

[GJR 11L]

Another of my very favourite sets there! Tell me Howard, do you know when Roberts themselves started fitting the module with AF12* in place of AF11* devices? I fitted a fresh module to one of mine and, since the module was easy enough to work on before fitting commenced, I opened it up to check for AF11*s only to find 12*s in there, and clearly it had been built that way, yet the newest 707 I have is totally as it left the factory and has 11*s in its module, my mind still bears the scars of that marathon session of remove, check, find nothing wrong, bang head on desk, refit.......

So was it only later replacement modules that had the more reliable transistors inside, or were there some sets made to that spec from the off?

[howard]

Originally Posted by Colin

By the way Howard, Ron is a wonderful 'wing man' he really deserves a pat on the back for this one! Well done Ron ...

Ron does indeed deserve all the credit for the repair to this R707 ....

Originally Posted by Tim

Another good one Howard. I wish I had your talent(and the time!!!) for restoring radios...

Thanks Tim. With this one however as with many others it was Ron who demonstrated his talent.

Howard

[howard]

Originally Posted by GJR 11L

......... So was it only later replacement modules that had the more reliable transistors inside, or were there some sets made to that spec from the off?

I don't know the answer to that. This is the second R707 with a faulty LP1164/1 IF module that Ron has repaired and both had AF11s in them. This one s/n 63878 is also the latest set I have (the highest serial number that Paul King has recorded at the Roberts Radio Group is 80378). These modules appear to be dated, the original one was stamped 73 41 (year week number ?) and the replacement module which came from a slightly earlier R707 is similarly stamped. It's a shame Mullard continued to use the AF11* transistors well into the 1970s as I'm sure that the fault with them was by then well known ...

Howard