William Donzelli wrote: In the early 60's a machine control my employer used on a can-end making stamping presses (think pull-top beer cans) was built using IBM "wire" relays. The IBM sourced chassis had an array of sockets for the relays with a wirewrap (?) backplane. The chassis was connected to the machine with a large multi-blade connector very similar to the Jones connectors that have been talked about, although smaller in size, they were larger in contact count. The connector was always described as the "North plug". Our BOM system says it was sourced from North Electrical. The "wire" relays were quite simple. They consisted of multiple Form C contacts. The moving contact was a wire tack welded to the armature. By my time they had pretty much been replaced by a CD4000 based digital logic system. Stories were told about the tack weld fatiguing and the wire contact shorting things in arbitrary ways. Not a desirable feature for a stamping press control. I have been curious about the relays since I found a cannibalized chassis about 10 years ago, which I still have. I thought that the technology might have been used on tabulating machines, but I never did any research. I can take pictures of it to jog memories. Anybody (Mr. Donzelli) recall IBM equipment like this? -chuck

Yes, pictures please. -- Will

----- Original Message ----- From: "Charles H Dickman" <chd_1 at nktelco.net> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Saturday, May 23, 2009 3:19 PM Subject: Re: Anyone heard of a North Plug or IBM wire relays ... Re: Jonesplugs, or similar sorts of plugs Hi Chuck, describe, including the crimp terminal plugs. And yes, they did come in different widths depending on how many poles were required at that point in the logic. My experience with them was in the early 60's and most of the ones I encountered were silver rather than gold though. You should be able to easily slide the wires out for inspection and just as easily slide them back into place. With the silver ones we sometimes slid all the contact wires out just enough to clear the contact posts and them ran a little flat burnishing tool between all the posts to "clean" them. Some thought this was counter-productive, and I can't really recall ever fixing a problem that way. Unless a short occurs somewhere and actually destroys the wires and/or contacts due to too much current, they seemed very reliable. There was also a variant with two coils. When the main coil pulled the relay in the armature became mechanically latched in that position. Then some time later the smaller coil could be activated momentarily to unlatch and allow the contacts to return to the normally closed position. Nice if you needed it activated for long periods and didn't want to have to keep current flowing through the main coil. Greener as well, before we even knew what green was. :) Later, Charlie Carothers -- My email address is csquared3 at tx dot rr dot com

----- Original Message ----- From: "Mike Loewen" <mloewen at cpumagic.scol.pa.us> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Sunday, May 24, 2009 7:50 AM Subject: Re: Anyone heard of a North Plug or IBM wire relays ... Re:Jonesplugs, or similar sorts of plugs I had not seen that document before; thanks for the reference. What beautiful illustration drawings - reminds me a lot of the early Amateur Scientist ones in Scientific American magazine. Later, Charlie Carothers -- My email address is csquared3 at tx dot rr dot com

[ Video connector with pins like this : o o o o o o o o ] s/had/have/ in my case :-). Getting replacement heads is decidedly non-trivial, but you can modify the head beam to take Betamax head tips (take them off a Betamax head disk, although where you find those now is another matter). As a totakl OT aside, the portable reel-to-reel Sony VTR I have (which doesn't have one of these connecotrs...) has a nesty design flaw. The head beam mounts on a disk on the main motor sindle, the heads rotate in slot between the upper and lower drums (which are fixed). The problem is that the nut holding that disk to the motor spindle is a normal right-hand thead, with the result the nut can work loose in normal operation, When this happens, the disk wobbles all over the place, the head tips hit the edge of the upper drum and break off. Had they used a left-hand thread, I would have not had to rebuild said head beam. Much as the Microribbon connecotrs are called 'Amphenol plugs' in some books,. I guess. To make this marginally more on topic. I have an NEC RGB monitor that used to have such a connector on the back. Years ago I modified it to take RGBI (CGA) video and replaced the connector with a DE9. I probably still have the 8 pin connecotr I removed, just don't expect me to find it any time soon. -tony

Yes, that conenctor (We generally call them PL259s and SO239s (plug and socket respectively) over here) was quite common on video equipment at one time. I have no idea why, it's not even close to constant impedance, and it's very easy to make a right mess of soldering the plug to the cable. The BNC connecotr is a lot nicer. There was a popular monochrome monitor over here in the late 1970s/early 1980s. I think it was a Nitachi, the case was grey-painted metal with a black plastic front panel, it was almost cubical in shape, and came in 9" and 12" versions. I came across them used with Apple ][s, RML380Zs, etc. Anyway, that used SO239s as the input connectors. -tony

On 24 May 2009 at 12:34, Dave McGuire wrote: They're ancient (1930s) and go back to a time when "UHF" was 30 MHz. and up. "Microwave" was anything shorter than 1 meter. Given the materials and technology of the time, their survival has been nothing short of remarkable. Cheers, Chuck

On 24 May 2009 at 13:18, William Donzelli wrote: I'm not certain, but I think the Navy designation came about after they'd been introduced into the commercial market. I'll have to go look at a 1939 radio handbook to see if I see them mentioned anywhere. Nevermind, I found a mention on ERT: "The UHF connector, also sometimes known as the Amphenol coaxial connector was designed in the 1930s by a designer in the Amphenol company for use as an RF connector in the radio industry. The UHF connector was initially intended for use as a video connector for radar equipment, but it later became used in a variety of RF applications." Regardless, consider that they are almost as old as (modern) coaxial cable (1929, US Patent 1835031). --Chuck

Hmmm...are yopu/they/we confusing this with the earlier UHF connector, the 93M? Those are indeed late 1930s. -- Will

On 24 May 2009 at 21:50, William Donzelli wrote: A little browsing on the Amphenol web site turns up: http://www.amphenolrf.com/products/CatalogPages/unf_catalog.pdf "Invented in the 1930's by an Amphenol engineer, E. Clark Quackenbush for use in the radio industry..." I wonder about this, however. Quackenbush's name appears on US patent 2,422,982 (1947), but it deals with T- and L- UHF adapters. And his full name (on the patent) is "Edward Clarke Quackenbush"--not "Clark" as Amphenol would have it. However, the connector *was* pre-war. See patent 2,335,041, Bruno, 1942 "Right Angle Electric Connector". That is *definitely* a 239- type connector shown in the drawings, but no patent references are given. Does anyone have a very old SO/PL 239 with a patent number on it? As an aside, patent 477,951, Menger, 1892 shows what amounts ot a coaxial cable, but its purpose was for electrical distribution and no mention is made of RF applications (understandably). Frustrating--I know the patent for the thing has to be out there, but finding it isn't going to be easy. Maybe I should join the fray and offer my opinions of Microsoft products...it requires less thought and goes better with beer... --Chuck

On 26 May 2009 at 12:10, William Donzelli wrote: I wrote them asking for clarification on their claim. Let's hope they have a company archivist who knows his/her stuff. At any rate, I'll let the list know if I find out anything. --Chuck

On May 24, 2009, at 12:53 PM, William Donzelli wrote: You mentioned GR-874s...I've never put one on a network analyzer, but I use them all the time in DC metrology applications. They're wonderful in that world. -Dave -- Dave McGuire Port Charlotte, FL

Interesting that most amateur radio equipment still uses them as standard. I have an IC-706MKIIG (two antenna connections: one for HF + 50MHz, another for 144 and 440MHz) with a pair of SO-239. I don't remember any rig with N connectors on the back, although I'm pretty sure I've seen it. In other side, it is not hard to find antennas with N-female connections, even because they are waterproof (!). My GP-98 has a N-female on its butt.

On May 24, 2009, at 12:58 PM, bfranchuk at jetnet.ab.ca wrote: I think "F" connectors are truly the worst. -Dave -- Dave McGuire Port Charlotte, FL

Tony Duell wrote: Many years ago, I worked in a calibration lab, and after (actually) ranting about how crappy a connector an "F" type was, I tested one to make a point.... and the damned thing was very clean. Weird. And, they're very easy to put together, relative to BNCs, for example. That the electrical characteristics are almost identical to BNC connectors is something I still don't quite understand, although I believe the instruments... (all HP equip. <Grin>) Warren

It is very common on portable TVs and that small LCDs from Casio and RS.

On Sun, 24 May 2009 12:34:19 -0400, Dave McGuire wrote: Show me a connetor design from the 30s that will take RG8 low loss coax and handle several KWs of RF power without arcing and sparking. You will not do it with a BNC. PL259s are easy to terminate with a little practice and a good soldering gun! To get closer to being on topic, try soldering 3 or 4 pieces of coax to a DB9 connector to use as a RGB video feed and look at it on an analyzer, it makes a PL259 look like a real clean option. I agree the PL259 is overkill for 1v composit video, but they do have their uses. The other Bob

How much is the impedance mismatch, when the termination (or source) is immediately next to the connector? Not much, in the real world. Problems abound when using these anywhere in between. -- Will

PL-259oids are much cheaper to make than Ns. They also adapt easily to lots of types of coax, provided one uses the proper nut is used on the rear (which many people just leave off anyway). Ns have lots of picky little bits. -- Will

On 24 May 2009 at 21:57, Tony Duell wrote: N connector is 1940s vintage. I think the difference boils down to materials. Nylon was first produced in 1935 and first found commercial application in 1939, after the UHF connector had been deployed. (The UHF connector uses a rigid phenolic insulator, which was a mature technology, dating from about 1908). I suspect that coax of the 1930s was rubber insulated covered with cotton or silk-- hardly a low-loss medium. Materials make a big difference. How many young engineers even know what "DCC" (as in "#18 AWG DCC) stands for? But then, why should they need to? :) --Chuck

I asusme this is due to a different diameter central pin -- small pin in large socket causes a bad connection, large pin in small socket wrecks th socket. I've heard this claimed of BNCs too, but I've seen measurements made on new, good-qulaity BNC plugs (Amphenol, Greenpar, etc) which indicate the central pins are the same diameter and there is no possiblilty of damage by using the 'wrong' plug. Has anyone got measurements for N connectors? -tony

There are two types of N connectors, one for 50 Ohms and one for 75 Ohms. The N connector is controlled by MIL-C-39012. 50 Ohm N type connector center pin - 0.0650 ? 0.0005 75 Ohm N type connector center pin - 0.0355 ? 0.0005 Plugging a 50 Ohm male connector into a 75 Ohm female will damage it. Plugging a 75 Ohm male connector into a 50 Ohm female will provide a crappy connection. Best regards, Steven ----- Original Message ----- From: "Tony Duell" <ard at p850ug1.demon.co.uk> To: <cctalk at classiccmp.org> Sent: Monday, May 25, 2009 10:57 AM Subject: Re: Jones plugs, or similar sorts of plugs