The only difference is in the diameter of the plug shaft, but the shape of the tip contact may have an influence as well.
It looks like the industry tried to make a compromise plug to fit both 1/8" and 3.5mm jacks. After all, they are only about 0.01" different. However, that assumes that the contact springs in the 3/5 mm jacks have enough travel to reliably contact the slightly smaller 1/8" plugs. That appears to not always be the case. Of course, it has to do with the actual design of the leading end contact that is tapered for smooth insertion. Differences in that shape might be the cause for many intermittent fits. Too many variables, Hi! As I reported earlier, I have found the RS plugs marked 1/8" / 3.5 mm are actually closer to 3.5 mm and work FB. I bought a bunch a few years ago. Maybe the next time they will have switched vendors and they won't work. Who knows? As Jim, K9YC, reported, you can go to the major brands on line. He reports absolutely consistent results with them. Sometimes the "higher priced spread" is worth the money. 73, Ron AC7AC -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Carl Clawson Sent: Tuesday, January 03, 2012 10:07 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Speaker Plug I could infer from this discussion that 3.5 mm and 1/8 inch are two different types of connector but I find no evidence of that. The terms are used interchangeably by manufacturers. Switchcraft, for instance, titles their products as 3.5 mm but goes on to say "all products are 1/8 inch." On their drawing you'll see the plug diameter given as 0.14 inch +/- 0.01. That's 3.56 mm +/- 0.25. They're also not cheap, but I recently bought some to try as I too have found this type of connector to be generally unreliable. The one that I went to the trouble of measuring showed poor sleeve contact. Maybe it's a corrosion problem. Lightly polishing the sleeve has helped with some of mine. Others remain incorrigible. I have not been able to find any industry standard for these connectors. 73, Carl WS7L K3 #486 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
