Roberts R404 - UK Vintage Radio Repair and Restoration Discussion Forum

Mike Phelan · 13th Sep 2008, 1:04 pm

As received:
Knobs were intact, everything rather dirty, volume control would not turn. Sometimes worked, then either waveband would go off with just a quiet hiss.
First job was to remove and dismantle the VC – the spindle was totally seized due to the lubricant becoming solid. I removed the circlip and spindle, taking care not to lose the two tiny carbon brushes. Cleaning all the parts in IPA and greasing the spindle gave it a new lease of life when I reassembled it. Now for the rest of it. TR1, the mixer/oscillator (AF117) responded to tapping, so it was suffering with the usual whisker-pox. In went a BF450, and the radio came to life. After leaving it running, it became intermittent – it still worked from the VC onwards using the scientific wet finger method, so prime suspects were the IF stages.
These are in an alloy can, and it looked as quite a bit of work had been done here as the pins were resoldered, and flexing the can made the set come on. There was a lump of foam wedged between the can and chassis!

Nothing for it except getting the can out and having a look. When I did, the two transistors had been replaced with the same type – AF117. There was also a tiny crack in the print leading to the output pin that was probably the main cause of the intermittency.

I repaired the print and fitted a couple of BF450s – on reassembly and test, it worked fine, so I set up the two presets on the AF stage. Not quite R707 performance, but it sounds quite nice.
I noticed that the three rubber grommets holding the tuning gang had virtually crumbled away; fortunately they can be replaced one at a time without disturbing the drive cord and pointer, so I did that.

Now for the cabinet:
The speaker was full of dust and there was a small tear in the cone near the edge – a piece of tissue cemented to the cone was needed. A bit of panel-beating on the grille was required as well.
The chrome on ‘Roberts’ logo was a bit worn, so I took the badge off and sprayed it with Humbrol silver spray.
I then made a bit of a discovery; I am a great believer in using Danish Oil on cabinets, except for the high gloss ones. So, I gave the cabinet ends the treatment, taking care not to get any on the black rexine. Unfortunately, the mice and men won : some oil got on the rexine!

Idly, I tried to rub it off; of course that did not work.
However, the rexine took on a lovely glossy finish! So, oil went on the rest of it – after replacing the badge it looks quite a decent little set.

Darren-UK · 13th Sep 2008, 1:09 pm

Neat little job there Mike

. Danish Oil on rexine, I'll have to remember that one.

Robert Darwent · 13th Sep 2008, 3:36 pm

Hi Mike

You've done a super job there! I haven't a R404 but I have got the similar styled R303 model. They are lovely little sets when restored.

Quote:

Originally Posted by Mike Phelan

...the mixer/oscillator (AF117) responded to tapping, so it was suffering with the usual whisker-pox...

I like your terminology! I think "whisker-pox" should be officially adopted to describe the well known AF11x series affliction!

Quote:

Originally Posted by Mike Phelan

...I then made a bit of a discovery; I am a great believer in using Danish Oil on cabinets, except for the high gloss ones. So, I gave the cabinet ends the treatment, taking care not to get any on the black rexine. Unfortunately, the mice and men won : some oil got on the rexine!

Idly, I tried to rub it off; of course that did not work. However, the rexine took on a lovely glossy finish! So, oil went on the rest of it...

I haven't tried Danish Oil but I did a similar thing by accident with Teak Oil, it also brings up rexine beautifully! BTW I once tried Teak Oil on a dull bakelite cabinet and it also brought that up to a long lasting high gloss shine. Very good stuff!

An excellent result Mike, well done!

Regards

mark pirate · 14th Sep 2008, 9:48 pm

Hi Mike, nice resto, i have an almost mint r404 that is also suffering from af117 disease, reading your thread has made me decide to tackle my set as soon as i get hold of a few bf450's

Cheers
Mark

Mike Phelan · 15th Sep 2008, 7:20 am

Thanks, Darren and Robert. Mark - go for it - we'll be watching

GJR 11L · 15th Sep 2008, 9:17 am

Nice set Mike, is the little wooden shelf that should slot into the sides of the cabinet missing by any chance? I have a spare if you need one.

We've had all the bodges on here now! Brasso on wood, Danish Oil on rexine, what next?

I have a complete 404 "to do" as well as a fairly wrecked one that works but whose cabinet is in four distinct pieces. Must sort one out soon.

Well done Sir!

Mike Phelan · 15th Sep 2008, 1:48 pm

Thanks, John - Kim and Aggie have nothing on us!
PM on way in a few minutes.

13th Sep 2008, 1:04 pm	#1
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Roberts R404 As received: Knobs were intact, everything rather dirty, volume control would not turn. Sometimes worked, then either waveband would go off with just a quiet hiss. First job was to remove and dismantle the VC – the spindle was totally seized due to the lubricant becoming solid. I removed the circlip and spindle, taking care not to lose the two tiny carbon brushes. Cleaning all the parts in IPA and greasing the spindle gave it a new lease of life when I reassembled it. Now for the rest of it. TR1, the mixer/oscillator (AF117) responded to tapping, so it was suffering with the usual whisker-pox. In went a BF450, and the radio came to life. After leaving it running, it became intermittent – it still worked from the VC onwards using the scientific wet finger method, so prime suspects were the IF stages. These are in an alloy can, and it looked as quite a bit of work had been done here as the pins were resoldered, and flexing the can made the set come on. There was a lump of foam wedged between the can and chassis! Nothing for it except getting the can out and having a look. When I did, the two transistors had been replaced with the same type – AF117. There was also a tiny crack in the print leading to the output pin that was probably the main cause of the intermittency. I repaired the print and fitted a couple of BF450s – on reassembly and test, it worked fine, so I set up the two presets on the AF stage. Not quite R707 performance, but it sounds quite nice. I noticed that the three rubber grommets holding the tuning gang had virtually crumbled away; fortunately they can be replaced one at a time without disturbing the drive cord and pointer, so I did that. Now for the cabinet: The speaker was full of dust and there was a small tear in the cone near the edge – a piece of tissue cemented to the cone was needed. A bit of panel-beating on the grille was required as well. The chrome on ‘Roberts’ logo was a bit worn, so I took the badge off and sprayed it with Humbrol silver spray. I then made a bit of a discovery; I am a great believer in using Danish Oil on cabinets, except for the high gloss ones. So, I gave the cabinet ends the treatment, taking care not to get any on the black rexine. Unfortunately, the mice and men won : some oil got on the rexine! Idly, I tried to rub it off; of course that did not work. However, the rexine took on a lovely glossy finish! So, oil went on the rest of it – after replacing the badge it looks quite a decent little set. Attached Thumbnails __________________ Mike.

13th Sep 2008, 1:09 pm	#2
Darren-UK Retired Dormant Member Join Date: Apr 2003 Location: Blackpool, Lancashire, UK. Posts: 4,061	Re: Roberts R404 Neat little job there Mike . Danish Oil on rexine, I'll have to remember that one.

14th Sep 2008, 9:48 pm	#4
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Roberts R404 Hi Mike, nice resto, i have an almost mint r404 that is also suffering from af117 disease, reading your thread has made me decide to tackle my set as soon as i get hold of a few bf450's Cheers Mark

15th Sep 2008, 7:20 am	#5
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Re: Roberts R404 Thanks, Darren and Robert. Mark - go for it - we'll be watching __________________ Mike.

15th Sep 2008, 9:17 am	#6
GJR 11L Heptode Join Date: May 2004 Location: Ellington, Northumberland, UK. Posts: 815	Re: Roberts R404 Nice set Mike, is the little wooden shelf that should slot into the sides of the cabinet missing by any chance? I have a spare if you need one. We've had all the bodges on here now! Brasso on wood, Danish Oil on rexine, what next? I have a complete 404 "to do" as well as a fairly wrecked one that works but whose cabinet is in four distinct pieces. Must sort one out soon. Well done Sir! __________________ John.

15th Sep 2008, 1:48 pm	#7
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Re: Roberts R404 Thanks, John - Kim and Aggie have nothing on us! PM on way in a few minutes. __________________ Mike.