The only major difference in modern caps, made & rolled like the old wax papers is the dielectric and its breakdown voltage and time. The styro is a poly styrene plastic and the styrene monomer is one we used to make the harder floor polishes, binders. One issue with them is soldering time other than that they are fairly stable.

Where you need to be careful is with the pulse grades. A hard plastic will not tolerate to much of that. Consider that the pulse grade in the electric fence, which is basically a capacitor discharge system, is charging & discharging at around 1 second intervals and running 24/7.

I note that in America a few are replacing electrolytic caps with a non polarised film type as there are less issues, with "form". Often the metal is printed onto the dielectric & some still use paper.

Technology has really changed the the tolerances to much tighter; specificity of application; life & reliability of the caps, from what we saw & delt with when we started (and are now tossing).

Interesting reading: https://www.electronics-notes.com/articles/electronic_components/capacitors/metallized-plastic-film.php

Marc

I cant comment to the capacitor discussion, a bit beyond my years and experience. Fascinating reading though!

The changer is indeed a BSR ua25, I should have mentioned that! I Have managed to glue it together, it came apart right where the tone arm spring anchor goes, a weak spot I suppose. I repositioned the anchor down 5mm so there is less stress on the repair. It might do, time will tell. I'll still hunt around for a spare, I may have found one from Multisonics in Thornbury.

Cheers!

A thin strip of aluminium for reinforcement and araldite makes a permanent job.
JJ

Wesley, occasionally there is a debate over whether to keep certain types of capacitors (also known as condensers) in a radio or replace them. It will pass soon enough.

If you happen to start restoring a few radiograms and/or tablegrams, it may be worthwhile to acquire a small number of turntables from each of the common brands, BSR, Collaro and Garrard. Sometimes, depending on the cartridge and stylus originally fitted, you may have to replace these even if the rest of the turntable is in working order.

Replace all the capacitors and resistors in the power supply, these always fail. Check the output transformers are ok, these have a high failure rate when the set is used with a bad power supply. The rest should be ok.

The 6M5s can go bad and pull the HT voltage down . Check the 10k and 100k resistors , these can be as high as 20k and 150k . As a rule I replace these , seems Kriesler and Philips used some cheap quality resistors .

Cheers
Vic

Your unit is much too new to have the issues Vic is referring to. By the time they built this at Cawarra Rd Caringbah, Kriesler had lifted their game and component technology had improved markedly.

It has the later generation output transformers, with polyester insulated wire on nylon bobbins. These were developed to overcome the reliability issues Kriesler and others had with speaker transformers. The resistors in your unit are mostly all 1W Ducon or Morganite, over-spec'ed for the job they have to do so as to improve reliability. That generation of blue Ducon electros are also normally OK.

Just replace the 4 wax paper caps and you are good to go. Trust me!

Thanks everyone for the ongoing discussion

Hey Ian you linked a 0.01μF and a 0.047μF capacitor, On the service sheet there are 4 paper caps at 0.047μF and 2 at 0.02μF. Cant see any rated at 0.01μF. Should I go the 0.02μF as indicated?


Cheers!

Sorry that's meant to be 0.022μF

Thanks to your nice high-res pictures I zoomed in closer and found that what I had taken to be 0.01μF caps are actually 0.0022μF 1kV caps. Sorry about that. Anyway, the search functions on that site are excellent, you should be able to find what you need.

Actually, I just tried and it wasn't so easy. It's actually quite difficult to find high voltage caps these days. And they ain't cheap when you do!

https://au.element14.com/cornell-dubilier/dppm10d22k-f/capacitor-polypropylene-pp-film/dp/1610815?st=2.2nF%201000v

Some of the parts listed as paper could have had polyester caps substituted in production. I can only see 2 x 0.047μF papers in that chassis.

Thanks for that Ian, I still managed to be out by a decimal point, for clarity there is:

2 x 0.047uF
2 x 0.0047μF
2 x 0.0022uF

on the service sheet. But perhaps the 0.0047μF are not paper as you indicate.
Cheers, Wes

Yes Wes that looks like it.

You could probably get away with less than a 1kV rating on the .0022μF caps - they are 1kV to allow for the possibility that the amp is accidentally run without the speakers connected. But they are available so grab them while you can.

Photo uploaded to Post 37.