[Ron Ramirez]

Hi folks,

I have noticed that several of you are now using film capacitors such as the Solen Fast caps sold by Antique Electronic Supply as replacements for electrolytic caps in various old Philco sets.

This is something I have not done as of yet, but have been wanting to for some time now. I am now working on a vintage Philco instead of a Fisher, for a change, and wanted to ask:

Do you only use these as the input filter, or do you replace as many electrolytics as you can with these?

This particular Philco has some multi-section cans and it is going to be pretty difficult, if not perhaps impossible, to restuff those with multiple film caps.

So let me know your thoughts.

Thanks.

[morzh]

I use it as the input filter (not sure Solen or not...could be). Maybe once used it as the input and the second cap after choke.
Makes no sense to use it elsewhere- too expensive.

[Arran]

Ron;
  Any non polarized cap will work, if the voltage rating, and capacitance is right, I've even heard of people using motor capacitors for filters. As you mentioned the main issue is space, even the more modern caps are still more bulky the the equivalent electrolytic, though that four section unit under a 18/118 chassis might be a candidate for it since they are lower value and lower voltage then the filter caps in the power supply, which generally makes them smaller and cheaper, try Mouser's search engine for ideas.
Regards
Arran

[Ron Ramirez]

Thanks guys. Input filters it shall be, conventional electrolytics for the rest.

[Arran]

Ron, Mike;
  This is one of those things that I have been contemplating for some time now, substituting non polarized (usually poly film) in place of conventional electrolytic caps where ever possible. In radios such as my Radiola 18, Canadian Marconi XII, or Philco 96 they didn't use electrolytics at all because they either were not available (with the Radiola 18, Marconi XII), prohibitively expensive (with the 1929-1930 models), or simply not considered trustworthy. But thanks to the proliferation of devices with capacitive droppers and switch mode power supplies the number of high voltage, high value caps on the market, in more compact sizes, seems to be much more extensive then it was a few years ago, so it's not really that impractical to stuff an old Mershon (or any wet electrolytic can of suitable size) with a number of poly caps in parallel. But the number of non polarized caps of high values has also been increasing at the other end of the scale, so you can use those types as a substitute for the smaller electrolytics found in transistor radios, caps in the 1 to 10 uf range, if you have enough space, so I think I will be giving those a go too.
Regards
Arran

[Phlogiston]

Values of 8, 10 and up to 15uf will fit in many of the pre-1940 cans. The 15uf @630V is too large for most of the early cans that were 8uf and smaller.

The big 3 advantages are NP - don't worry which end goes where, 630V rating and the fact that you will never need to service the filter again. - - and a lot of little things like ripple current ratings.

I've been using them for around 10 years now.

[Bob Andersen]

I've used them both for the main filter caps and smaller valued electrolytics. For example the 18 chassis has a 3 section electrolytic with values of only 1, 1 and 2 uF. I think this is a good place to consider using film caps.

I also like using these polypropylene AC motor run caps when the original cans are missing becuase they fit very nicely in the original mounts
[Image: https://farm2.staticflickr.com/1462/2476...a387_z.jpg]

[EdHolland]

I used similar film based motor caps for the 16X. They had all metal cases, and I set them up with connections below the chassis. This looked quite reasonable in place. I had to make a clamp, as original hardware was long gone along with the original caps, but it worked out nicely, and the set plays beautifully hum free.

[Bob Andersen]

These have two lugs below for chassis connections. The nut on top is just for mounting and has no electrical connection.

$4.20 for a 10uF
https://www.mouser.com/ProductDetail/Arc...TIZSgv0%3d

[Ron Ramirez]

Thanks Bob (and Ed, and Russ). Bob, I agree regarding model 18 - if film will fit, they should be used.

OK folks, this is a 38-690 so appearance counts. No caps with studs on top - they need to be stuffed inside original cans. The Solen Fast 10 uF, 630 VDC caps have a smaller diameter than the Arcotronics/Kemet 10 uF, 630 VDC yellow film caps from Mouser. Any reasons why I should not pick the Solens?

Solen - 1.07" D x 1.88" L
Kemet - 1.36" D x 2.28" L

Links:

https://www.tubesandmore.com/products/ca...ylene-fast

https://www.mouser.com/ProductDetail/Arc...aZdPERw%3d

[Arran]

These look promising, if one wants to maintain the aluminium can look and isn't crazy about the look of the plastic ones. https://www.mouser.com/ProductDetail/KEM...kG6JxGA%3d
Regards
Arran

[morzh]

Ron

Use the cheapest that fits.

BTW aren't there dual caps there? Forgot, has been almost a year. Single will fit.

[Phlogiston]

10 years, maybe 1000 radios using the Solens - 0 failures.

There may also be a 12uf that is the same diameter as the 10uf.

I have frequently put 2 of the 10uf caps in one can either to get 20uf or 2 10s as original. Yes it can be tight.

[tbone]

I started using film caps exclusively on 2015. What started me on it was that the radio I was working on was going to someone who might only use the radio a few times a year. I didn’t want the radio to come back because a cap failed. Plus any radio that has an 80, 5X4, 5Y4, etc is subject to high B+ Levels until the rest of the tubes conduct. One could argue that a inrush limiter on the AC line would solve that problem, but I’ve just never done it.

I used all solen fast caps on my 38-690 last fall. The only cap that would not fit in the old can was the 18uf. It’s under the chassis. I stuffed all the cans on both chassis. I believe I was forced to put one cap in the other multi can on the amp chassis as there was no room for the three. Ran new cloth wire out of the cans that matched the original color.

The one radio I had trouble with was my GE E-101. The radio called for a couple of 30uf units and there was no room in the cans or under the chassis. I used 500 V electrolytics there.

[Phlogiston]

Yep, in later radios or those with values over about 20uf we are still stuck with electrolytics. You know there is a series of Nichon caps that are about as thin as a pencil. you can easily get 3 or more in an old can.