BNC patch cables - Page 1
Forum section: electronics / beginners

author: calin
author_rank: Regular Contributor
timestamp: December 04, 2012, 05:30:15 am
content: I am looking to get a few BNC male to male patch cables, adapters and terminators to use with my func gen and scope. While I am pretty much clear that 50 ohm is the good choice for general use I am not sure: RG58/U or RG147/U. It is just hobby work if it goes to 100Mhz what my scope can do fine (but I think that is a moot point - most coax-es can go in Ghz range easily)Looking at these - both have stranded core so are flexible:RG58 nice with strain releif and 2ft long:https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&pa=256743&productId=256743RG147 - nice & thin at 3ft:https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10001&pa=111473&productId=111473What you guys use ? Do you think something else in the under 10/20$ will be better ?

author: free_electron
author_rank: Super Contributor
timestamp: December 04, 2012, 05:57:46 am
content: Real men use hardline bent at correct radiusses and tightened with a torque wrench to specification.

author: calin
author_rank: Regular Contributor
timestamp: December 04, 2012, 06:07:05 am
content: indeed true. I tend to hit the coax resonance frequencies in the cables I make and that affects the north north -west side of my brain ... really complex formula .. and that induces laziness.So I guess I am not that "real" to make my own

author: joelby
author_rank: Frequent Contributor
timestamp: December 04, 2012, 06:12:06 am
content: If you need more than a couple, I've had very good service fromrfsupplier.comfor RF cables. They'll build them to your specifications - cable type and length, and connector type.

author: calin
author_rank: Regular Contributor
timestamp: December 04, 2012, 06:19:54 am
content: Wow .. nice find that site, bookmarked, they have the whole "soup" in BNC terms. Need maybe 3-4 so not worth the hassle; I just want something "factory made" - you know you handle these things day in and day out and crappy connectors or inflexible junk cable is just down right annoying.

author: joelby
author_rank: Frequent Contributor
timestamp: December 04, 2012, 06:40:34 am
content: I don't think the shipping was unreasonable, so if you're not in a hurry it might still be cheaper than your local electronics distributor.I used to make my own coax cables but it would take me 30 minutes to do each one satisfactorily, and then the centre pin would fall off after a few minutes. Never again!

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 04, 2012, 07:20:31 am
content: Quote from: calin on December 04, 2012, 06:19:54 ama good friend of mine adviced me this site...http://www.amphenolconnex.com(*) but since i'm not a yank i didnt take it. i got a bunch of bnc/coax stuffs from chinarf ebay seller, probably a rfsupplier chain, some adapters (tee, terminator etc) are dead or loose connection you need to scratch your head many times why you got distorted signal. i still have many feets of good RG174 coax from them though, i bought 50ft i did many things with it already.

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: December 04, 2012, 11:04:44 am
content: RGB-174 coax has an interesting property. The center conductor is copper-plated steel. Since. The steel is relatively stiff, this can lead to a condition known as a shield short on a cable subject to a lot of bending. The steel center conductor cuts through the dielectric and shorts to the shield.This is a difficult condition to isolate as every movement of the cable can clear a short or create a new one.No fun, especially when instrumenting a project on short notice.

author: free_electron
author_rank: Super Contributor
timestamp: December 04, 2012, 04:34:25 pm
content: Rg174 is not meant for bench use..... It is intended for fixed install in a machine where it will not be subject to vibration.As for cable sources : pasternack.

author: calin
author_rank: Regular Contributor
timestamp: December 04, 2012, 04:57:54 pm
content: RG147 indeed looks like is solid core.I have an OWON SDS1702 scope and the probe cables are really nice - they are flexible and thin but at the same time the cable does not twist and kink. 0really like them; I wonder what type of coax did these guys used - that will indeed make for some nice patch cables.And thanks to all for the nice sites ...BTW .. u wanna have a good laugh look @ thishttp://www.newark.com/tektronix/012048200/coaxial-cable-3ft/dp/11B2576...I bet the core of that cable is solid 24K gold shielded with diamonds.

author: SeanB
author_rank: Super Contributor
timestamp: December 04, 2012, 06:03:50 pm
content: A cable specially intended for use on government orders, as it allows for a fudge factor to cover cost increases on other items. Probably there is a big discount on the cable after ordering, enough to cover price increases on the rest of the order during the 5 months between quote and confirmation, and with another 6 months before payment......

author: T4P
author_rank: Super Contributor
timestamp: December 04, 2012, 07:05:17 pm
content: I'll bet RG-316. The next thinnest coax and have much better propertiesCode:Stranded copperclad steel wires, silver coated 7 x 0.17Should be correct, i guess

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 04, 2012, 08:24:42 pm
content: Quote from: calin on December 04, 2012, 04:57:54 pmRG147 doesnt register in my brain but the RG174 that i got, got stranded copper wires core inside, not solid and the dielectric is so hard i dont think the strand will have a chance to poke through. and i believe when its mentioned "flexible coax" that doesnt mean we can take it for granted and make a hard starboard bend 90 degrees it will screw the char-Z to some extend so bend with care. YMMV.

author: calin
author_rank: Regular Contributor
timestamp: December 16, 2012, 05:23:37 am
content: So for those interested .. i figured out what cable Owon has used for the scope test leads - it is RG174 with stranded core and TPR jacket (the key is the TPR jacket which is much more flexible than PVC). The only place I found some is here:http://www.cdint.com/catalog/category/Cables/BNC/to+BNC/RG174+flexibleThey also have it bulk. I got few from them .. sweeet flexible and nice !!!

author: SeanB
author_rank: Super Contributor
timestamp: December 16, 2012, 05:39:34 am
content: Must remember next time i buy BNC crimp connectors to buy the boots as well. Works well enough ( and i remembered how to crimp them, last time was when I was doing netware cabling in coax about 15 years ago) but looks better with the boots on. Ah well, self amalgamating tape works in a pinch, and as these are going outside they will be wrapped in it. Still have the crimp tooling for the cable.

author: Unknown
author_rank: Unknown
timestamp: December 16, 2012, 01:20:32 pm
content: Owon uses 50 ohm Z0 coax for probe cables? Then performance will be terrible. Even cheap $5 probes use proper lossy coax.