Coaxial cables - vendors and quality - Page 1
Forum section: electronics / rf-microwave

author: mio83
author_rank: Regular Contributor
timestamp: March 16, 2020, 02:37:33 pm
content: Hello,with the goal of learning more about RF and electronics in general, I have recently got a Spectrum AnalyzerBeautiful instrument. However I now realise how important it is to have decent quality coaxial cables (BNC/SMA). The few ones I have are cheap chinese cables and either get outright interferences from the outside (e.g., FM 88Mhz-108Mhz signal appears everywhere when using the crappy cables) or the signal gets distorted when I touch the cable with my hands and move it.I have looked at a respectable seller (Batronix) and the prices of good quality (made in Germany) coaxial BNC/SMA cables are crazy high. Like 29euros for 1 meter, or so.Could you recommend a good quality vendor of coaxial cables (BNC&SMA) with slightly more affordable prices, if it exists?thanks!Thanks!

author: AJ3G
author_rank: Regular Contributor
timestamp: March 16, 2020, 04:06:49 pm
content: Believe it or not 29 Euro’s for 1 Meter of quality test cable is not excessive. If you look at other companies such as Gore, and Megaphase, the price departs drastically upward for terminated cables used for this type of application.The best deals I have found come from eBay and other sources of used equipment. May want to check this out.Rich

author: mio83
author_rank: Regular Contributor
timestamp: March 16, 2020, 06:19:00 pm
content: Thanks. I will look for good opportunities on second-hand market then.

author: David Hess
author_rank: Super Contributor
timestamp: March 17, 2020, 08:40:24 pm
content: If you make your own cables, then there is a big improvement to be had by using double shielded cable instead of common single shielded cable. I like Teflon dielectric RG-400 and RG-142 but RG-223 would be where I might start.

author: El Rubio
author_rank: Regular Contributor
timestamp: March 18, 2020, 05:13:48 am
content: Are you sure your interference is from the cabling? If the FM source is strong enough to cause interference even through the cheapest RG58, then I believe it is likely saturating the SA through the antenna or whatever is attached to it. Filter on the input should help. Super expensive cables like Gore are designed to be phase stable and are not necessary for basic spectrum analyzer use.

author: Mechatrommer
author_rank: Super Contributor
timestamp: March 18, 2020, 05:32:47 am
content: Quote from: mio83 on March 16, 2020, 02:37:33 pmthats cheap! i will be willing to become permanent customer if there is easy access to buy. another cheaper solution is probably huber suhner, but still high compared to your price (i have 3x 30cm old stock minibend for ~$70). i got 2x 6' Gore Phaseflex from member here for $250 and i consider that a bargain (like new and still within spec according to seller) you can get about the same price from china used, but spec is unknown. make sure you dont have high heart attack risk when searching for those new. i will use china coax anytime for < 1GHz so i will not wear out my huber suhner and gore phaseflex sooner.

author: OwO
author_rank: Super Contributor
timestamp: March 18, 2020, 10:42:46 am
content: I tested the phase stability and match error of various coax cables at 3GHz a while ago:https://groups.io/g/nanovna-users/topic/cable_phase_stability_tested/69522569

author: DaJMasta
author_rank: Super Contributor
timestamp: March 18, 2020, 04:43:58 pm
content: The second hand market or old stock market has been my go to for getting proper RF cables. On the lower (sub 6GHz) frequency side, there's a fair bit of availability from major vendors as surplus telecom equipment, so you can get good cables and connectors from major brand names, often unused. It gets pricier as the frequency goes up, but to some degree the same can be said for test cables through 20GHz or so, there is some availability, and if you're willing to hunt down datasheets and search around, there are some much more affordable deals to be had.I ended up with some Huber & Schuner, Teledyne, Rosenberger, Times Microwave, and others for relatively affordable prices. When looking around for adapters, specifically to BNC or N connectors or that frequency range below SMA but still pretty high, I actually found Digikey to have some of the better prices on new ones in single quantities. The availability is a lot less used or old stock, and Mouser had them a bit higher while Pasternack and a couple others had still higher prices for the same stuff. Ebay and the like can still have deals, but you won't likely be able to get every adapter on your list for cheaper than the full list on Digikey.

author: OwO
author_rank: Super Contributor
timestamp: March 18, 2020, 05:17:38 pm
content: Do be careful that cables easily degrade if bent too much and are considered a consumable, so I would personally not go for the used option unless it's really cheap and/or you have the means to measure if the cable is up to spec. Currently the best cable you can get here for a reasonable price is the SS405 cable rated for 18GHz for VNA applications:https://item.taobao.com/item.htm?id=607518859769&ns=1Unfortunately I don't see anyone selling it outside of taobao, so it is difficult to get.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: March 19, 2020, 08:52:05 am
content: Quote from: OwO on March 18, 2020, 10:42:46 amthank you for doing this. I have been wanting to do something along this line for a while now, in part because I get tired of people telling me how we are wasting money on that phaseflex stuff, blahblahblah.Perhaps once the COVID19 lockdowns around here are over I can do that in a weekend. Have a few different cables I can test.Do you have any numbers on phase 'repeatability'? eg, cal cable in a specific position, move cable around a bunch, put back in original position, compare?

author: El Rubio
author_rank: Regular Contributor
timestamp: March 19, 2020, 01:40:56 pm
content: I have several RG142 cables and find they are very durable. If you make it up yourself, I recommend three layers of heatshrink tubing at the base of the connectors. I do this with all cables I make up and it really makes that stress point at the base of the ferrule last much longer. The RG142 has a silver plated solid steel center conductor as well as silver plated copper double braid shielding. It's not cheap, but you can get bulk cable for <$2 per foot on the auction site. I have a lot of LMR 240 laying around and usually make up jumpers and test cables using that. It holds up fine on the bench, and pretty good as in the field. I will add, I have broken every type of cable, but the three layers of heat shrink method really extends the life of any cable.

author: tkamiya
author_rank: Super Contributor
timestamp: March 19, 2020, 05:14:18 pm
content: From your description, it sounds like to me, your problem is more of connectors/assembly than cable itself. With spectrum analyzers, wiggling cables or connectors shouldn't affect display. Unless you live right next to transmitter site, FM signal shouldn't be showing up either. That tells me you have an incomplete connection somewhere.First, I'd connect a terminator to your SpecAn's input and verify FM signals don't show up. Then buy a good quality cables, but not super crazy price ones. I use Times Microwave (TLR-195) kind and have zero issues. Don't skimp on adapters if you are using one. Mini-Circuits have good ones at reasonable prices.By the way, what's the maximum frequency you'll be using? Above set should be good to at least 4GHz.

author: TeddyPython
author_rank: Contributor
timestamp: March 19, 2020, 11:15:03 pm
content: Quote from: OwO on March 18, 2020, 10:42:46 amDo you have a single blog or website with a collection of your work/projects/measurements? You always seem to have done some cool stuff.

author: Mechatrommer
author_rank: Super Contributor
timestamp: March 19, 2020, 11:37:49 pm
content: impedance test on china RG174 and RG402 (semi rigid)https://www.eevblog.com/forum/projects/performance-of-china-50-ohm-coaxial-cable/?topicscreenlook how funny the RG174 is beyond 500MHz... RG402 is fantastic but... its semi rigid...

author: mc172
author_rank: Frequent Contributor
timestamp: March 19, 2020, 11:46:01 pm
content: +1 on the "coaxial cables are consumables" bit.A while ago I had to run some tests at the request of a customer, while they visited our site at great expense (and looking for an excuse to confirm that we are idiots). The results looked really, really good, abnormally good - so good that it was even outside the performance of the next class of product, including competitors. My company was well chuffed - we smashed it! The test was easily 20 dB clear of the limit line. Happy days, yeah?We were using very expensive but quite old HP cables and it turned out that the region between the crimp ferrule and the immediately adjacent flexible section of the coax braid had gone open circuit due to fatigue so the results were all over the place.On the face of it, the cables never looked like a suspect. They had individual serial numbers, HP branding on them and were ridiculously expensive. Well, there you go.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 24, 2020, 03:37:32 am
content: +1 for Times Microwave

author: Lord of nothing
author_rank: Super Contributor
timestamp: April 02, 2020, 12:51:30 pm
content: Is there an European Distributor who can make Cable with connector who are rugged and sturdy?I got some from an Amateur /CB Radio shop with 1cm diameter. One Plug got loose and thankfully I could fix it.But I want to add some more VHF, UHF and HF Antenna who need some propper Cable.Can someone say anything about the Cable:https://www.delock.de/produkte/G_1619_Antennenkabel.htmlI buy a lot (via my Distributor) from that Company.The have no Datasheet for UHF and VHF Freqs.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: April 02, 2020, 01:00:24 pm
content: Quote from: Lord of nothing on April 02, 2020, 12:51:30 pmTo me, no datasheet would already be a indicator that I don't want to be using them.

author: Lord of nothing
author_rank: Super Contributor
timestamp: April 02, 2020, 01:35:23 pm
content: QuoteWhy?I got many products from that Company and the are good (Chinese) Quality.When I compare it with my Ebay Products from China.

author: charliedelta
author_rank: Regular Contributor
timestamp: May 02, 2020, 04:53:49 am
content: The only quality brands left these days is Habia and Suhner and maybe Commscope(Andrew and Times Microwave) Everything else is just Chinese junk. I have made up some spectrum analyzer patch leads with the MESSI & PAOLONI cable and that seems decent. The cable are very well shielded.Its really had to find to decent connectors, the Chinese stuff is really awful and so many vendors are switching to chinese manufactured with their brand name on it. It would be great if we could all get together and do a group buy for some quality connectors. I will never connect a Chinese made N connector to my Rohde Spectrum analyzer they are so terrible I always use Suhner on the test equipment end.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: May 15, 2020, 01:28:36 am
content: Generally, I'm with those recommending western manufacturers with an established reputation. Although there might be an exception: when I announced my intention to remove all Jyebao components from our products, they arrived shortly later with a delegation of three guys from Taiwan, the EMEA sales guy and the guy from their representative. They provided me with a specially adapted N connector within a rather short timeframe. And they have a catalogue program of RF test components and test grade cables. I'm willing to give them a chance in that department when I have to flesh out my own or the company lab next time. It's try or get fleeced, after all.

author: Electro Fan
author_rank: Super Contributor
timestamp: May 15, 2020, 03:25:30 am
content: +1 for Times Microwave cables and connectors

author: breakerbreaker
author_rank: Newbie
timestamp: September 23, 2020, 02:41:33 am
content: well said. There a plenty of suppliers out there that would offer quality uhf connectors. The problem is that majority of uhf connector and cable manufacturers have now moved their production to China and thrown QC out of the window. I am located in Australia and i have been using this suppliers for years for all of my uhf connectors and coaxial cables.https://connectvk.com.au/product-category/uhf-connector/uhf-connectors/page/2/