Nickel plated phosphor bronze ribbon

[k4kyv]

I was looking through a 1935 catalogue, and found the classic EF Johnson coil clips listed, designed to fit onto standard 1/4"-wide turns of edgewound coils.  They sold for a few pennies each, and according to the description, were made from nickel plated phosphor bronze. The outfit that bought Cardwell Condensers (they also manufacture some of the old EF Johnson line) has the clips for sale, but they want $19.95 apiece for them, with an 8-week waiting period!  They obviously don't keep them in stock, but manufacture them upon demand. They would be very easy to make if one had a source of the ribbon stock.

I measured the dimensions of one of mine, and the ribbon stock is 0.375" wide and 0.041" thick.

I tried to find a source of this ribbon on line, but most of the nickel plated phosphor bronze I could find was in wire form, sold for use as banjo strings.  I did find some sources of ribbon and sheet stock, all from India and China, with a minimum order of something like 1000 kg. You would think it would be available in more reasonable quantities and sizes, since it is still widely used for switch contacts, plugs, sockets, etc., but I was unable to find a source of raw stock.

[WBear2GCR]

I would buy the phosphor bronze stock from a place that sells such metal specialty items, like McMaster Carr, etc... and then either have it plated or form it then have that plated. I'd ship it to a plating house, unless you know one close by anyhow.

Nickel plating is well within the range of bench top DIY work.
Give it some consideration.

It has all sorts of beneficial applications in radio hardware!

Of course for most metals, you hit them with copper first, then nickel on top. Chrome is put on top of the nickel if you go for chromium. Chromium of course is not a DIY thing, afaik. Silver, otoh, is fine at home... copper then silver on top.

                    _-_-bear

Plenty of online info on plating...

[Opcom]

I've used PB as 'finger stock' around a RF door. It was not plated but it is springy and certainly worked well. It is also good formed into a cylinder such as 1" dia. and 1/2" tall, to press against a flat contact for a high voltage connection as a drawer is slid in and out of a cabinet.

[k4kyv]

P.B. was widely used for antenna wire in the 1920s.  It was standard practice for those old flat-top and cage antennas.  But its electrical conductivity is rather poor, compared to pure copper.

IACS = International Annealed Copper Standard, a unit of electrical conductivity for metals and alloys relative to a standard annealed copper conductor; an IACS value of 100% refers to a conductivity of 5.80 × 107 siemens per meter (58.0 MS/m).

http://www.copper.org/applications/industrial/designguide/conductbronze02.html

[KM1H]

The USN used PB for antenna wires well into the 60's and maybe later because they didnt corrode in salt air.

And nickel is a horrible RF conductor