Another Bush Reborn - UK Vintage Radio Repair and Restoration Discussion Forum

mark pirate · 12th Dec 2011, 7:09 pm

I did this little set as a test to see how long it would take to fully restore an average DAC90A to a high standard, as I have been asked to restore a couple.

This particular set is a later version, sporting a gold dial and perspex backed knobs.
The date on the smoothing cap is august 1956, amazingly, the DAC90A stayed in production until late 1959, being the most successful set Bush ever produced.

After a quick inspection I powered it up slowly via my variac and it crackled into life. Shortly after, I could hear the mains filter cap fizzing away, so switched it off quick!

On removal of the chassis, it was clear that no repairs had ever been done since new, a point to note here, the knobs are usually held on with grub screws accessed via two holes underneath the set, in this case, the knobs are of the pull off type.

After removing the dust with a paintbrush and vacuum, the chassis was cleaned using a rag wetted with WD40. The dial diffuser was removed and the light tray was given a good clean. The spewed mess that was the mains filter cap was removed, then time to tackle the re-capping.

These little sets are a joy to work on, all 10 waxies are easily accessed, most being on a tagstrip. I replaced all caps under the chassis with nice new ones, the resistors were checked at this point and all were within spec.

I then replaced the tone correction cap on top of the output transformer and replaced the mains filter cap with an X2 type, modifying the original clamp to hold the new cap in place.

All the valves had their pins cleaned, and the holders were given a dose of Servisol, along with the wavechange switch and volume pot.

I fitted new dial bulbs and refitted the diffuser. Then a drip of oil on the tuning pulleys, time to power up the chassis.

I ran it up via the variac, and all was well, this set really can rattle windows!

Leaving the chassis merrily playing away, I turned my attention to the cabinet. This was just a bit grubby, but no cracks or chips, it was cleaned using Fairy Liquid and cold water. It cleaned up well despite all the little paint spots that were gently scraped away using a fingernail.

The cabinet was left to dry, so on to the speaker grille. I have found Flash kitchen spray works wonder on these, gently scrubbed with an old toothbrush.

The knobs were cleaned with Fairy Liquid and cold water, the dial glass was very carefully cleaned, as the markings on the underside can easily come away.

The cabinet was then polished up with T-cut, then polished using neutral wax polish, the set was then reassembled, the knobs fitted and given a final polish with a soft duster.

Well, I can report that the total time taken was just under five hours from start to finish, and around £6 in new parts.

It really performs well, with plenty of volume, no hum at all, and the speaker on this set is perfect. The set really looks as good as it sounds, the only downside is some staining of the bottom of the dial but it is 55 years old!

Mark

mark pirate · 12th Dec 2011, 7:11 pm

And the finished set....

Lloyd 1985 · 12th Dec 2011, 7:27 pm

Great work there

Certainly easier than the DAC90, I find those a bit fiddly with the tag strip mounted vertically. I think I spent something daft like 2 months on my DAC90! it was a mess though

I've set myself a task for the winter to rebuild a DAC90a from spare parts! Started with an empty case, then got the remains of a chassis thats been butchered for spares! The case looks good so far, and I threw the most disgusting chassis in history straight into the ultrasonic cleaner. Doesn't look as good as yours yet though!

regards,
Lloyd.

Boom · 12th Dec 2011, 8:19 pm

That has come up well. Nice one

I don't know why but one of my DAC90As has a silverish loudspeaker grill rather than the usual gold. I can't see any damage to the coating so assume it is a variant but it is the only one I have ever seen.

HamishBoxer · 12th Dec 2011, 8:57 pm

Mint! Gerry Wells used claim 15 minutes to sort.

David

Mark the Mender · 12th Dec 2011, 9:44 pm

Nice one Mark, well done.

cheers Mark

mark pirate · 12th Dec 2011, 9:47 pm

I am quite pleased with this set, it is still belting out 'gold' as I type. I wish all restorations were this easy

Quote:

Gerry Wells used claim 15 minutes to sort.

I don't think I could change more than half the caps in that time!

Quote:

I've set myself a task for the winter to rebuild a DAC90A from spare parts! Started with an empty case, then got the remains of a chassis thats been butchered for spares!

Well Josh, I have the same idea, mine has also been robbed of a few bits, and the cabinet is a bit more than cracked!
But I feel a custom paint job is in the offing......
Is yours really as bad as this?

Mark

Ever-HMV · 13th Dec 2011, 12:11 am

What a fantastic restoration

I'm totally impressed!

I rarely restore the chassis cosmetically, although I'll happily spend ages on painting, polishing, cleaning and repairing the case etc.

Perhaps on my next restoration I'll have a go at the chassis too.

Rob

HamishBoxer · 13th Dec 2011, 11:54 am

Hi Mark,no i couldnt change more than halve the caps either in that time!

David

Jonster · 13th Dec 2011, 12:04 pm

Nice, that's come up well and should give enjoyment for many years to come!

SeanStevens · 13th Dec 2011, 12:55 pm

A very tidy restoration

I have two DAC90a (s) - one is SO LOUD it is shocking. The other is in terrible electrical condition and rather quiet. It is odd how they vary so much.

SEAN

ThePillenwerfer · 13th Dec 2011, 9:00 pm

My first successful restoration was a brown DAC90a and agree that they are fantastic sets both to work on and in terms of performance.

I too have a desire for a smashed one that can be 'Customised.'

- Joe

Phil G4SPZ · 13th Dec 2011, 10:39 pm

Lovely job, Mark. I'm also impressed with how well the chassis looks after the WD40-and-rag treatment. Well done!

I haven't restored one of these but I did something close, an AC91 which has an autotransformer and short wave coverage. It's incredibly sensitive and sounds very nice. Pity the "Bush" brand has become so devalued, these were really high quality sets.

mark pirate · 14th Dec 2011, 10:22 am

Quote:

I haven't restored one of these but I did something close, an AC91 which has an autotransformer and short wave coverage. It's incredibly sensitive and sounds very nice.

Hi Phil, i have the console version (sug 3), I would like an ac91, i do have a real liking for bush sets, i never turn one down, even total wrecks!

I agree, they do vary in performance, i have five, this one has loads of volume & the best looking UL41 i have seen, it looks as new, none of the usual brown stains on the glass, i don't think this set has seen much use, it certainly shows that a full recapping works wonders.

Quote:

I too have a desire for a smashed one that can be 'Customised.'

Hi Joe, i have most of the bits i need to rebuild my wreck, but it will be modded to my own spec, as for the cabinet, i am thinking gloss black with a silver grille & knobs

Hopefully, there will be another success story soon, as i have a 1947 dac90 on the to do list.

Mark

tedzed1 · 14th Dec 2011, 4:06 pm

Hello Mark, looks a cracking set now, wish I could get all my chassis looking like that.
Brilliant, Well Done.

Lloyd 1985 · 14th Dec 2011, 7:12 pm

Quote:

Originally Posted by mark pirate

Well Josh, I have the same idea, mine has also been robbed of a few bits, and the cabinet is a bit more than cracked!
But I feel a custom paint job is in the offing......
Is yours really as bad as this?

Mark

Think you might have me mixed up with another forum member there

My cabinet was cracked, but not anywhere near as bad as that! The chassis was beyond disgusting, it had gone dark brown!
So far I'm short of an output tx, speaker, aerial coils, dial bulbs, wavechange switch, back cover, dial and knobs

Not too much to find! I do have a spare dial from a DAC90, which I could use, and I'm sure I could copy the knobs in resin or something. I'll have to find a picture of the chassis before I cleaned it, it really was yuck!
Good luck with the DAC90, the one I recently finished sounds great, they kick out far too much heat though.

Regards,
Lloyd.

12th Dec 2011, 7:09 pm	#1
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Another Bush Reborn I did this little set as a test to see how long it would take to fully restore an average DAC90A to a high standard, as I have been asked to restore a couple. This particular set is a later version, sporting a gold dial and perspex backed knobs. The date on the smoothing cap is august 1956, amazingly, the DAC90A stayed in production until late 1959, being the most successful set Bush ever produced. After a quick inspection I powered it up slowly via my variac and it crackled into life. Shortly after, I could hear the mains filter cap fizzing away, so switched it off quick! On removal of the chassis, it was clear that no repairs had ever been done since new, a point to note here, the knobs are usually held on with grub screws accessed via two holes underneath the set, in this case, the knobs are of the pull off type. After removing the dust with a paintbrush and vacuum, the chassis was cleaned using a rag wetted with WD40. The dial diffuser was removed and the light tray was given a good clean. The spewed mess that was the mains filter cap was removed, then time to tackle the re-capping. These little sets are a joy to work on, all 10 waxies are easily accessed, most being on a tagstrip. I replaced all caps under the chassis with nice new ones, the resistors were checked at this point and all were within spec. I then replaced the tone correction cap on top of the output transformer and replaced the mains filter cap with an X2 type, modifying the original clamp to hold the new cap in place. All the valves had their pins cleaned, and the holders were given a dose of Servisol, along with the wavechange switch and volume pot. I fitted new dial bulbs and refitted the diffuser. Then a drip of oil on the tuning pulleys, time to power up the chassis. I ran it up via the variac, and all was well, this set really can rattle windows! Leaving the chassis merrily playing away, I turned my attention to the cabinet. This was just a bit grubby, but no cracks or chips, it was cleaned using Fairy Liquid and cold water. It cleaned up well despite all the little paint spots that were gently scraped away using a fingernail. The cabinet was left to dry, so on to the speaker grille. I have found Flash kitchen spray works wonder on these, gently scrubbed with an old toothbrush. The knobs were cleaned with Fairy Liquid and cold water, the dial glass was very carefully cleaned, as the markings on the underside can easily come away. The cabinet was then polished up with T-cut, then polished using neutral wax polish, the set was then reassembled, the knobs fitted and given a final polish with a soft duster. Well, I can report that the total time taken was just under five hours from start to finish, and around £6 in new parts. It really performs well, with plenty of volume, no hum at all, and the speaker on this set is perfect. The set really looks as good as it sounds, the only downside is some staining of the bottom of the dial but it is 55 years old! Mark Attached Thumbnails

12th Dec 2011, 7:11 pm	#2
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Another Bush Reborn And the finished set.... Attached Thumbnails

12th Dec 2011, 7:27 pm	#3
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,819	Re: Another Bush Reborn Great work there Certainly easier than the DAC90, I find those a bit fiddly with the tag strip mounted vertically. I think I spent something daft like 2 months on my DAC90! it was a mess though I've set myself a task for the winter to rebuild a DAC90a from spare parts! Started with an empty case, then got the remains of a chassis thats been butchered for spares! The case looks good so far, and I threw the most disgusting chassis in history straight into the ultrasonic cleaner. Doesn't look as good as yours yet though! regards, Lloyd.

12th Dec 2011, 8:19 pm	#4
Boom Retired Dormant Member Join Date: Jan 2007 Location: Westbury, Wiltshire, UK. Posts: 2,451	Re: Another Bush Reborn That has come up well. Nice one I don't know why but one of my DAC90As has a silverish loudspeaker grill rather than the usual gold. I can't see any damage to the coating so assume it is a variant but it is the only one I have ever seen.

12th Dec 2011, 8:57 pm	#5
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Another Bush Reborn Mint! Gerry Wells used claim 15 minutes to sort. David

12th Dec 2011, 9:44 pm	#6
Mark the Mender Retired Dormant Member Join Date: Apr 2008 Location: Warrington, Cheshire, UK. Posts: 421	Re: Another Bush Reborn Nice one Mark, well done. cheers Mark

13th Dec 2011, 12:11 am	#8
Ever-HMV Retired Dormant Member Join Date: Dec 2009 Location: Milton Keynes Posts: 144	Re: Another Bush Reborn What a fantastic restoration I'm totally impressed! I rarely restore the chassis cosmetically, although I'll happily spend ages on painting, polishing, cleaning and repairing the case etc. Perhaps on my next restoration I'll have a go at the chassis too. Rob

13th Dec 2011, 11:54 am	#9
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Another Bush Reborn Hi Mark,no i couldnt change more than halve the caps either in that time! David

13th Dec 2011, 12:04 pm	#10
Jonster Heptode Join Date: Apr 2008 Location: Eastbourne, East Sussex, UK. Posts: 671	Re: Another Bush Reborn Nice, that's come up well and should give enjoyment for many years to come!

13th Dec 2011, 12:55 pm	#11
SeanStevens Octode Join Date: Sep 2009 Location: Bath, Somerset, UK. Posts: 1,033	Re: Another Bush Reborn A very tidy restoration I have two DAC90a (s) - one is SO LOUD it is shocking. The other is in terrible electrical condition and rather quiet. It is odd how they vary so much. SEAN __________________ There are only 10 types of people, those who understand the binary system, and those who don't.

13th Dec 2011, 9:00 pm	#12
ThePillenwerfer Octode Join Date: Mar 2011 Location: Sheffield, South Yorkshire, UK. Posts: 1,453	Re: Another Bush Reborn My first successful restoration was a brown DAC90a and agree that they are fantastic sets both to work on and in terms of performance. I too have a desire for a smashed one that can be 'Customised.' - Joe __________________ "Experts are only good at one thing: explaining why something will not work!"

13th Dec 2011, 10:39 pm	#13
Phil G4SPZ Dekatron Join Date: Apr 2005 Location: Bewdley, Worcestershire, UK. Posts: 4,748	Re: Another Bush Reborn Lovely job, Mark. I'm also impressed with how well the chassis looks after the WD40-and-rag treatment. Well done! I haven't restored one of these but I did something close, an AC91 which has an autotransformer and short wave coverage. It's incredibly sensitive and sounds very nice. Pity the "Bush" brand has become so devalued, these were really high quality sets. __________________ Phil Optimist [n]: One who is not in possession of the full facts

14th Dec 2011, 4:06 pm	#15
tedzed1 Hexode Join Date: Dec 2009 Location: Tamworth, Staffordshire, UK. Posts: 320	Re: Another Bush Reborn Hello Mark, looks a cracking set now, wish I could get all my chassis looking like that. Brilliant, Well Done. __________________ Cheers Paul.