Recapping an AR88 - best (cheapest!) source of axial polyester caps?

[Martin G7MRV]

Title says it all really, im restoring an AR88 for RAF Snaith museum, and need to source replacement caps for the bathtubs and micamolds inside.

I've priced these up so far with Cricklewood and I'm up to just over £70!

Can someone direct me to a cheaper source, and/or recommend a low cost suitably rated type?

Cheers
Martin G7MRV

[G6Tanuki]

I've always gone for the Vishay yellow capacitors; even at RS prices it's not too painful!

[am doing the same with a BC-348 at present]

[RadarAl]

I usually buy capacitors from Mouser, they have a good range of high voltage and can be quite large to enable easy fit.

[Techman]

Originally Posted by Martin G7MRV

I've priced these up so far with Cricklewood and I'm up to just over £70!

That sounds about right to me. I think you're either going to do the job properly or you're not, although it brings the price of parts up to about what the radio would be worth as a max if it were to be sold on the open market. Cricklewood are very good and I can certainly recommend them. However, there's an ebay seller I think called something like 'dunkuk' (or similar) who I've used for capacitors on a number of occasions and have found the quality equal to any others that I've used, but at half the price of those others.

[HamishBoxer]

I have bought good quality caps off Ebay and possibly the mentioned Dunkuk. Always a fair price.

[Horris]

Try Rapid Electronics part no 08-1321 for 100nf. Very economic and very good. I have used lots of these caps in all values and found them very reliable.

Dave

[turretslug]

The restoring/recapping debate is potentially endless- but I like to say that the valves and wound components of the day were highly developed components, but now stifled by their accompanying decoupling capacitors (particularly) and deserving of modern equivalents in order to show just how well they can perform. Also, there's a question of perspective- whilst the AR88 was a high-performance and state-of-art radio in its time, it was also a value-engineered, mass-produced commercial product using relatively mundane passives. In other words, it deserves the respect of being fitted with at least half-decent capacitors (not stub-lead no-name salvage miscellany!) but without going full audiophool on it. As I'm not an OEM looking to save a penny per unit, I like to add touches like 2W metal oxide/film resistors as oscillator anode loads and so on- maybe it doesn't make so much odds as regards minimising drift and noise, but doing my best costs not a lot, and I don't have an accountant leaning over me anyway.

[Martin G7MRV]

Thanks everyone,
Im going to check prices with the big trade suppliers like mauser and digikey etc and see whats on offer.

My main consideration here is to get the set working for live demonstration at the museum, so it doesnt have to be done to peak performance, but at the same time im wanting reliability - id prefer a single effort and not have to keep doing running repairs. I myself am rather strapped for cash, and although im sure I could go cap in hand to the museum for funding I personally find that rather cheeky! The set was kindly donated, and I volunteer, my ethos here is that my time and if necessary money are part of that - the only thing i take from the museum is free cups of tea!

Im considering swapping the high value resistors as well for better rated parts, but this might be a job for the '2nd pass' once the critical issues are covered.

Still, the museum is now closed for the winter - although lots of work going on behind the scenes espacially to renovate the building - and we next open to the public in spring, so ive plenty of time. I might do one capacitor an evening...

Edit = looking on Mauser now, looks like the dubilier parts might be the way to go

[Silicon]

The capacitors that 'HamishBoxer' mentioned have the advantage of thicker and longer lead out wires.
They are also physically larger than others.

These factors can affect the mounting method.
Have you decided how you will replace the small 'metal cans'?

[Station X]

Originally Posted by Silicon

Have you decided how you will replace the small 'metal cans'?

Did you mean the bath tubs? I restuffed mine. I cut the backs off with wire cutters (don't try to unsolder them or you'll melt the feed throughs) and peeled back the soldered seams. The back's not needed and no one will be able to see it's gone.

[greenstar]

Not wishing to relieve Ebay of any business, but I found Dunkuk there. He appears to be a UK seller with an interest in valve electronics. Unless he is a complete liar he appears to take some care:
Dunk's Shop
Duncan Haskell
6 Grantley Drive
Fleet
Hampshire
GU52 7SA
United Kingdom
Email: duncan.haskell@gmail.com

Example from listing:
47nf / 0.047uf 5% 630volt Rated polypropylene Axial Metal Film
These look similar to the polyester ones from China but they are a better specification being made of the more desirable, more stable polypropylene material. They are well finished with epoxy end caps and good quality wire. These are actually a lot better made than the Vishay ones I have been buying from Farnell!

The 2nd photo in the listing shows a 100nf capacitor from the same range being tested, I cant guarantee they are all this precise but they are certainly a cut above the average.

Great for building or repairing valve radios, amplifiers and also good for in car electronics or anywhere where you need the best reliability and quality.

[David G4EBT]

I've bought those polypropylene caps from Duncan for some years now - never a moment's trouble. He stocks a wide range of values of axial 630V ones. Low P&P, and speedy delivery too.(A registered eBay Business seller since June 2004).

[Martin G7MRV]

Originally Posted by HamishBoxer

I have bought good quality caps off Ebay and possibly the mentioned Dunkuk. Always a fair price.

I've finally found this seller (seems the mobile app won't allow a search by seller, had to wait until I was on the laptop) and saved him.

Thanks