Advice for Good BNC Cables - Page 1
Forum section: electronics / beginners

author: adpmlw
author_rank: Newbie
timestamp: August 19, 2025, 06:17:21 pm
content: Hi,I am an EE student buying my first oscope. I have landed on the MSO5074 which can be hacked to 350 MHz bandwidth and has two 25 MHz function generators. My question pertains to this: with this scope and its specs in mind, how do I know what a quality BNC cable is? For example, I'd like a couple male-to-male cables as well as alligator clips or mini-grabbers on the other end. What sets apart good and bad BNC cables? To what extent does it matter? Suggestions? Are the average cables you see on Amazon sufficient? I am completely ignorant on what to look for in regards to this and how it affects the signals.Thanks

author: edavid
author_rank: Super Contributor
timestamp: August 19, 2025, 09:03:20 pm
content: Go around the EE department labs until you find an impressive test equipment setup and check out the BNC cables they are using. Most likely they will be Pomona brand. Unfortunately they are too expensive for a student to buy new, but if you have access to ham fests, surplus stores, auctions etc. you may be able to pick some up used.Cheap cables can have all sorts of electrical and mechanical problems, but they are usually OK for non-critical use, until you can score some Pomona cables.

author: TimFox
author_rank: Super Contributor
timestamp: August 19, 2025, 09:31:57 pm
content: Pomona cables are excellent for test equipment usage.For serious RF work, my source is Pasternack: they have a wide selection of cables, but I like RG-223/U for 50-ohm applications.(Not cheap, of course.)https://www.pasternack.com/bnc-male-bnc-male-rg223u-cable-assembly-pe3087-p.aspx

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: August 19, 2025, 10:19:27 pm
content: A few EEs in the past had told me that RG 223 was perhaps the minimum cable to use for testing. You can save a lot of money by making your own cables. However this usually involves getting a good crimper for attaching a bnc. For the grabbers, I find that the cheap ones do not appear to be of good quality, so I use Pomona. RG 223 is double shielded and a bit hard to work with putting the bnc ends on. But you will have the cable length you need. Anything that is Pasternack is horribly expensive, I do have some though. Tim has more money than I do.... I think that working below 1 GHz you should not need the top line cables, but just good ones.I do not think your scope has a setting for 50 ohm input so mostly you will be using probes mostly? Using probes is safer for the scope. To have 50 ohm input you need an adaptor. You do need grabbers for the output a lot of the time.....and stuff like BNC to SMA adaptors. Perhaps someone more familiar with the scope can comment. Also search this forum for your scope. Lots of stuff here.edavid's suggestion is very good. Ask at your uni's lab and see what they buy, you probably could get an educational discount also. Sometimes it is beneficial to see what is thrown out also. A bit of dumpster diving.

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: August 20, 2025, 01:12:06 am
content: I have almost always made my own It is cheaper and done correctly just as good as most others.However do not use cheep Chinese parts, do use Belden cable and Amphenol connectors, Huber & Suhner makes a great RG-223/U cable.Check local shops for loan/help crimping cables, Mouser and Digi-Key with parts, there are some decent cheep Chinese crimpers but that's another subject. Amphenol and Pomona are also good brands for pre-made cables.Jeff

author: Vovk_Z
author_rank: Super Contributor
timestamp: August 20, 2025, 08:48:15 am
content: I'm not sure a starter needs a lot of great HF BNC cables. It depends on its area of electronics, of cause. For example, I have 350 MHz old analogue Tektronix 2465 and just one proper 350 MHz rated probe (it was used too, not new). Everything else is just random mix of quite cheap cables or self made because I don't work with high frequencies (mostly up to 1 MHz). And when I do I just use totally another instruments, like SA+VNA (Tiny SA Ultra, LiteVNA etc), and proper HF SMA or N-type cables, not that BNC rubbish.

author: TimFox
author_rank: Super Contributor
timestamp: August 20, 2025, 02:22:01 pm
content: Making one’s own assemblies from brand-name RG-223/U cable and BNC connectors makes perfect sense.Crimping requires a good tool, but the old-fashioned non-crimp connectors require careful dimensioning, a sharp knife, careful fanning of the braid, and a normal wrench: they are slower to assemble, which is why the commercial assemblies are crimped.

author: Bud
author_rank: Super Contributor
timestamp: August 20, 2025, 03:02:22 pm
content: You should be using generic scope probe cables. They are constructed with a special distributed resistance wire and the probe tip has low capacitance. A regular coaxial cable should only be used for RF applications where 50 Ohm impedance matching is required.

author: TimFox
author_rank: Super Contributor
timestamp: August 20, 2025, 04:23:04 pm
content: I believe that's what I said above.

author: adpmlw
author_rank: Newbie
timestamp: August 20, 2025, 10:57:51 pm
content: Thank you for the comments. I think I should add a little more context. I go to a small school so there isn't much in the way of getting anything from the department. Additionally, we frequently had issues with our equipment in lab exercises, hence the reason I want to avoid cheap equipment that will cause me headaches later.I should have been more clear from the outset on the use for these cables. I do intend to use the probes provided with the oscilloscope, and I was intending to use these cables with the function generator on the scope. The function generator is only 25 MHz, however I would not rule out higher frequency use in the (near) future.From your responses I am seeing a mixed bag of recommendations for high quality but very expensive cables as well as recommendations to make your own. So, I have a few questions:1. In regards to making cables, it seems the consensus is using RG-223/U cable along with some BNC connectors? To what extent do brands of these matter? I would not be surprised at problems with cheap ones, but are there middle of the road ones? Must they be the ones already mentioned? What problems do you expect to see with cheaply made ones? Looking for as much information as you can distill. Are there special "features" to look for in good connectors? I do own crimpers that should work for this.2. For use with the function generator, are the cables that have alligator clips or the grabbers a bad idea? If they are a bad idea, why? In lab, we'd have something like a CADET board to plug the other end into, which I don't have. So how do you guys go about handling that? Just looking to gather as much info as I can here.3. I am curious at the mention of the 50 ohm adapter. Are you saying that in regards to using a BNC cable instead of a scope probe? And commenting that the scope can't handle that by itself without an adapter? (again, wasn't planning to do that)4. Finally, any specific suggestions on cables that are premade but not overly expensive?Because I am buying the oscope with an education discount, I could add on BNC cables at $18 each, which is what inspired all these questions because I would expect big brand markup. Additionally, these are still only male-to-male.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: August 20, 2025, 11:31:04 pm
content: Good BNC and SMA connectors Brand Name. Like Amphenol. Some cheap connectors are OK but it is impossible to tell unless you buy them and try them out, problems include poor fit. The more expensive brands like Huber Schuner and Pasternak are usually better but MUCH more money, probably not worth it. If you can buy 10-20 at a good price you will be set for a while. Make sure they fit 223.For attaching to a board....what kind of connectors does the board usually accommodate?? Probably SMA??? Then you can make BNC to SMA jumper or get BNC to SMA adaptor.You can get grabber leads that go on the end of a BNC cable. I have some.I do not think there is any 223 that is not good. At least I have not seen any. On ebay you can get brand name for $2 a foot or less, I think that is good price. 223 has double silver plated shield which makes it hard to install the BNC but worth using. The center conductor is silver plated single strand copper to fit into the pin of the BNC nicely. Any decent 50 ohm coax would be fine for low freq though. Some is stiffer and some more flexible. Since most good test jumpers are 223 or better and the price is not terrible, I suggest making your own jumpers that way you can get the ends you want and the lengths you need. Having a cable with one BNC and the other end a SMA is more convenient than using an adaptor for example. You already have the crimper. There are all sorts of 50 ohm coax that would be OK or better but you have to start somewhere.... once you get used to making the crimped connections you will be OK.50 ohm adaptor is called a terminator and just goes on the scope's BNC. The scope will then read the magnitude of the signal correctly.Look up RG 223 and 50 ohm pass through terminator.

author: Fire Doger
author_rank: Regular Contributor
timestamp: August 20, 2025, 11:41:22 pm
content: Maybe it is too early to dive that deep into cables.In real world everything effects everything. If for example you slightly bend a non top quality cable it will change it's properties...But it doesn't look like your problems have anything to do with that. The problems at your school are probably result of very bad handling, maybe they did not properly crimp them, 20 cents bnc, and similar "mechanical" issues.If that's the case you could just buy the male to male bnc and create adapters like bnc female to crocs, female to hook, etc... You will get a known quality bnc and the ability of multiple adapters.When you will need a better quality cable in terms of signal integrity you will know it.If your signal exits the coaxial form i.e. crocodiles then there is no reason to compare cables. For that kind of cables I use RG316 because it's thin and flexible.

author: inse
author_rank: Super Contributor
timestamp: August 21, 2025, 05:15:48 am
content: I very much agree to Fire Dogers posting.RG223 cable is good for serious RF test setups, and low level measurement stuff like test receivers or spectrum analyzers.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: August 21, 2025, 02:56:11 pm
content: It would be great to point out what happens if OP does not invest in proper value BNC cables. What if he buys the first available cheapest RG58 and pick up 100MHz probe sets on Amazon? How much cable quality going to matter when alligator clips are in the picture? So that OP can make a trade off between the plenty of cables vs serious power and noise capabilities, for his given $$$.

author: BillyO
author_rank: Super Contributor
timestamp: August 22, 2025, 01:40:39 am
content: Quote from: dobsonr741 on August 21, 2025, 02:56:11 pmFor a lot of applications, those would be just fine. Why do we have to assume this .. student .. will ever need 20GHz capability, or more?Hey, lets advise him to buy those really nice cables from Gore or Huber & Suhner. You know, those ones that cost about $300US per meter.Yeah, cry once...If he spends his entire career developing affordable power supplies and testing them at that ridiculous 20MHz bandwidth limit, does he really need anything better than "the first available cheapest RG58 and pick up 100MHz probe sets on Amazon?" Or does he have to spend $2,000 to equip his lab with a fine, but small, assortment of bejesus cables?Yeah, let alone learning the basics at college.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: August 22, 2025, 02:06:21 pm
content: A good compromise is going with the 223 or equivalent coax, making your own cables so that you have the correct length and correct connectors. This enables you to have good cables and connectors at a pretty low price. If you do this you will be set for low MHz cables and if the need arrives, the cables will be good for over one GHz. End adaptors can then be used for grabbers, if needed. If you are just starting to build a toolbox the price of 223 and good connectors is not very much at all and it does not make sense to use poorer coax unless you maybe have some already. If you use all good 223 only you wont be looking for your one good cable when trying to measure something. All of your cables will be good. Also you need different BNC connectors for different size coax so just going with the one size simplifies the purchases. In general the prices on pre made cables are rather high with the really special ones being quite exorbitant. If you make your own, you will probably have better cables at a much lower price. You will probably have better cables than most people. Perhaps someone else can recommend a brand of BNC connectors, I kinda like Amphenol.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 22, 2025, 02:43:04 pm
content: Some standalone AWGs come with a BNC cable as standard, but not all. I don't think any of the 'scopes I've used ever came with one though : (Still, as an EE student, perhaps the OP doesn't realize that most of the time, the supplied 'scope probes are to be used, and that's not the same thing as a BNC cable and grabbers.Maybe the OP can just nicely ask his college/uni to borrow a BNC cable, since they must have hundreds lying around, and I don't recall typical lab supervisors being so stingy not to loan out a cable or two to the few that might have a need for it, since few students may have their own equipment to use them with.EDIT: Just read that's not viable:Quote

author: BillyO
author_rank: Super Contributor
timestamp: August 22, 2025, 02:55:04 pm
content: Quote from: adpmlw on August 19, 2025, 06:17:21 pmFor working 350MHz and lower these cables will get you started without breaking the bank.https://www.aliexpress.com/item/1005006173259490.htmlI have a few of these at various lengths and ends. I tend to use them more often than my "better" cables, jut because they do the job and I'm always trying to "save" my "good" cables.Are they the best cables in the world? No, not even close. Are they good enough for f < 350MHz? Yes, they do just fine.Now, let's hear from all those that have never used these come on out and tell us how horrible they are.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: August 22, 2025, 03:23:22 pm
content: Really good price and I have made up some like this. They are OK. I just do not like the fact that you can kink them more easily and also the connection at the BNC connector really needs to be reinforced with shrink wrap quite a bit. We had trouble with this at the radio shop where the coax gets abused badly.. However thanks for putting this up. 316 cables are just fine even though they have higher losses. Losses are not important in just a few feet normally. Freq response if just fine since we are talking lower than one GHz. And these are really cheap. Shielding factor is far less than 223. I still prefer the 223.... But the 316 has Teflon inner insulator making soldering easier. That is, if you make your own or repair one you bought, If you have purchased these particular cables can you comment on the quality of the BNCs?

author: shabaz
author_rank: Frequent Contributor
timestamp: August 22, 2025, 03:39:57 pm
content: Quote from: BillyO on August 22, 2025, 02:55:04 pmIt's a fair point, it's OK to consider cost.I purchased low-cost custom cables from this supplier in China:https://www.rfsupplier.com/customcable.html(admittedly, not as extremely low cost as the ones you mention, but not so far apart).RG-223 1m BNC cable is about $16 there.(I've usually gone for "RG-316 Double Shield" which is still single-digit, about $9).Here's a quick review of that supplier:I like the service, price, and the fact I can choose the cable and conector type. The construction seems consistent. The downsides for me are:(1) they use thin heatshrink, I wish they'd use the double-wall stuff, or at least make it a purchaseable option. Still, even some high-end custom cable suppliers only offer thin heatshrink on their web-based order form (i.e. you'd need to contact them for fully bespoke).(2) there's no option to select high-quality connectors. It would be nice if they had a slightly more premium option with a known brand connector, granted at more cost, if the customer clicked to select that.In summary, at the low cost, so far I'm still happy with this supplier, but for when I want high quality (e.g. with a VNA) often I make my own cables, and that way I get to string ferrites on them if required before attaching the connector, use thicker heatshrink and so on, as desired).I have considered to purchase a solder bath one day for making decent flexible cables with particular coaxes which benefit from that, but tool clutter and costs add up, and realistically I'd use it so rarely, so for now I don't think it is worth it for my needs.

author: BillyO
author_rank: Super Contributor
timestamp: August 22, 2025, 03:47:30 pm
content: Quote from: Wallace Gasiewicz on August 22, 2025, 03:23:22 pmMiddle of the road. Not as good as the Amphenol crimp on ones I use to make my own cables, but much better than the really lousy stuff that has accumulated around here over the years. They cam in nice and positively and fit with only a tiny amount of wiggle room.

author: BillyO
author_rank: Super Contributor
timestamp: August 22, 2025, 03:51:52 pm
content: Quote from: shabaz on August 22, 2025, 03:39:57 pmThanks for posting this!

author: MarkF
author_rank: Super Contributor
timestamp: August 22, 2025, 04:02:31 pm
content: I bought this set on Amazon. They are flexible, have a nice feel, 50 ohms,and at 25MHz and lower freq a good starter set for the money.https://www.amazon.com/dp/B07FZV589P?ref=ppx_yo2ov_dt_b_fed_asin_title

author: Bud
author_rank: Super Contributor
timestamp: August 22, 2025, 04:45:35 pm
content: Quote from: BillyO on August 22, 2025, 03:51:52 pmDo not know about other connectors but the "gold" plating on SMA connectors from this supplier is junk. Wears off quick and turns grey-ish. For prototyping they are ok but I would not use them in a final product.

author: BillyO
author_rank: Super Contributor
timestamp: August 22, 2025, 05:02:34 pm
content: I guess they don't offer stainless steel? That seems to be what the best ones use.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 22, 2025, 05:36:18 pm
content: Quote from: Bud on August 22, 2025, 04:45:35 pmI'm assuming this isn't a thread about production, purely prototyping.I've probably purchased around 30 BNC cables from this supplier, not needed to throw any out so far.Although OP mentions BNC, for SMA cables, there's a decent supplier on AliExpress; Zeenko store, but main downside is that their cables are one length only (short). But great quality for the price, although I still make my own too. For prototyping, not selling to others.Good quality, custom SMA cables _can_ be easy to DIY at low cost (for prototyping), but it really depends on the connector and coax type. Some SMA connectors require an expensive $1k+ set of tools. Right-angle SMA cables in particular are easy on the tooling, with a basic hex crimper and not much else.

author: tooki
author_rank: Super Contributor
timestamp: August 22, 2025, 06:01:13 pm
content: Quote from: adpmlw on August 19, 2025, 06:17:21 pmBad cables have poorly made connectors that can make intermittent contact. The cable itself may be of low quality, perhaps not meeting impedance specs. Cheap cable tends to be stiffer than good quality. And if the connectors aren’t attached well, they are more liable to break off. Cheap connectors may introduce impedance discontinuities that cause reflections, etc.It is your choice whether to prioritize low loss (attenuation at high frequency), noise rejection/shielding, thinness, and cost. “Low-loss” cables tend to be stiffer. Generally speaking, thicker cables have lower loss, and of course that also makes them stiffer. Better shielding rejects noise better, but costs more.However, bear in mind that at typical benchtop test lead lengths, it doesn’t really matter that much at the low frequencies you’re interested in. For example, RG-174, which is fairly lossy because it’s so thin (around 2.5mm) still only has around 0.4dB loss per meter at 200MHz. Loss drops dramatically with frequency. Inexpensive, lowly RG-58 is significantly lower loss, around half as much.Different cable types are good up to different maximum frequencies. But any of them do more than enough for your 350MHz.This German cable vendor has a great overview of the cable types, and datasheets for everything to see the details (it’s available in English):https://www.koax24.de/en/coaxial-cable-50-ohm.htmlDon’t overestimate the utility of alligator clip or minigrabber cables: you are limited to very low frequencies with those (like 10MHz). Remember that your oscilloscope probes come with grabber attachments, which let you use the full probe bandwidth.Quote from: adpmlw on August 19, 2025, 06:17:21 pmAre they sufficient? Probably. But given that quality cables are still quite affordable, why bother? Quality cables last a long, long time if cared for.For example, on Digikey, ~3 foot/1m cables start at around $9. Nice Amphenol, Pomona, Molex, Cinch, and TE cables are all available for under $25:https://www.digikey.com/short/9dmrqd3t(The only brand they carry that I would categorically refuse to buy is Adam Tech; I’ve been appalled by the quality of some of their other products…)I’d suggest getting a couple of 3 foot cables, some 6 foot, and some 18-24 inch ones.The other thing I suggest getting is an assortment of BNC adapters like couplers and tees (3-way splitters: get some with 1 male and 2 females, and some with three females).

author: dobsonr741
author_rank: Frequent Contributor
timestamp: August 27, 2025, 07:50:22 pm
content: Given OP is an EE student, we might be missing to point out that the biggest possible learning opportunity on this thread is how to make good tradeoffs. IMO that’s want engineering is about.

author: David Hess
author_rank: Super Contributor
timestamp: August 27, 2025, 10:39:45 pm
content: Most oscilloscope applications do not require good BNC cables, at least up to beyond 200 MHz. I am usually more interested in reliability and flexibility; my 0.1 inch diameter RG174 and RG316 cables get the most use.Now if you have a GHz+ sampling oscilloscope, cable type matters.Double shielding is required in sensitive RF applications where otherwise signals can leak around attenuators, and double shielding also makes for a more reliable cable where it terminates into its connectors. I have a number of nanosecond calibrated cables made from RG400.Quote from: shabaz on August 22, 2025, 03:39:57 pmThanks, I will have to try them out if the tariffs are not too difficult to deal with, but I worry about the quality. Every connector I have ordered from China has been wrong in every dimension.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 28, 2025, 01:13:59 am
content: Hi David,I've been curious how good/bad the physical construction was, I took a look, and I've got some SMA cables from rfsupplier (usually I make better ones, or buy elsewhere, but they were not for any critical purposes, just prototyping use; plus they were very short specific sizes, so not as easy to buy off-the-shelf as part of a component order from Farnell/Mouser etc). If I make a cable, it will easily cost tenfold or more, due to current costs of connectors and cables in low quantities from the Farnell/Mouser, and I can't always justify it.I took one of the rfsupplier cables, it's supposed to be 15 cm, but it's slightly vague how they measure that, they measure to where the heatshrink ends I think; and it was a few millimeters longer.In conn-pin-view.jpg, I tried to compare the inside with a Huber & Suhner SMA adapter. It seemed visually OK.Then I took the heatshrink off, and the hex crimp around the braid looks acceptable too.I dremelled off the crimp and exposed the internal metal; I don't know what metal/alloy it is, but at first glance the color looks consistent through it, although I didn't examine in detail. The steel-colored BNC connector in the photo is just for simple visual color comparison.The center pin wasn't soldered, they have used a DMC-like indenter/crimper, although it's a flat crimp, so it's some clone crimp tool perhaps. So far I think everything is very acceptable for the low price.Next, I peeled back the braid. The photo shows the rfsupplier double-shielded RG-316 coax on the left, and a high-end double-shielded RG-316 coax on the right side (I don't know the manufacturer, but it's basically telecoms-level of quality, and would have cost a lot).You can see that the braid is extremely tight on the right high-end cable, and not so tight on the left, but again I think this is not too bad considering the high-end coax would not be viable in a lower-cost cable assembly. And you get to choose the type of cable, so for better performance people may choose other than RG-316 anyway.It's possible to buy semi-rigid coax custom cables from rfsupplier too (I bought some of them, but also just bought short lengths of just the coax from them too, so I can assemble with more expensive connectors) so if better shielding is needed, there is that option too).I tend to use RG-316 as a general-purpose cable, but keep a few lengths of semi-rigid coax SMA cables too, to the specific shapes/sizes to use with VNA/test jigs etc. This is all low-cost hobby stuff, no org would buy these no-name cables of course (or I hope not!). I have for sure used the rfsupplier semi-rigid cables with a few VNAs (not beyond a few GHz) and they were fine for sure, but I've taken hours making my own ones for that purpose, so I keep the rfsupplier ones as part of a little portable kit for my NanoVNA (the blue cables in the photo are semi-rigid from rfsupplier).In summary, to me it looks like they did a good job, I can't excessively fault much from what I've seen so far (which is a small sample for sure considering the range of connectors and coaxes they offer), and I get fair use out of the cables. The cables are not a bargain as such, you get what you pay for, but the price-versus-quality looks like a good match to still get a lot done. Anyway, I hope this helps to rule in or rule out this supplier depending on application.

author: BillyO
author_rank: Super Contributor
timestamp: August 28, 2025, 01:22:04 am
content: That kit you have in teh last picture, do you have a link to where you got that?

author: shabaz
author_rank: Frequent Contributor
timestamp: August 28, 2025, 01:53:02 am
content: Hi Bill,The case isMuji code 4550344907504(PP Pen Case S). I used EVA craft foam from Amazon on the inside, with metal shape cutters from AliExpress (they are steel blades folded into rectangles, you choose the closest size, and find a way to push it into the foam (e.g. using a wood sanding block, cut slightly to wedge the steel blade onto it).It contains some of the SMA pieces supplied with the NanoVNA. I added a 50 ohm SMA terminator from Mouser.It also contains a few SMA female sockets on the right side, I cut the legs off them, and soldered resistors or shorted them, to make cheap SMA calibration standards (but the set also contains some slightly more expensive ones which are no longer sold).The attached photo shows how the DIY standards look like on the other side, there's epoxy glue on the back (debatable if that's wise or not, but the intent was to stop the center female contact from coming loose and rotating). There are better ways to make them, mine are not top quality (my uses are non-critical).If you're new to VNA calibration, there's a video here (apologies for the out-of-focus in places, and it is quite colloquial in tone/explanation, zero formulas/calulations etc., it was intended for non-engineers, to quickly convey a few things to some friends/colleagues, but I decided to wrap it into a YouTube video. It was recorded in one take from memory, so it's not the best delivery, but if followed through to the end, it is re-explained with some diagrams too. In the video, a plain through-hole resistor is used for calibration, rather than the SMA cal kit, just to keep things simple. The video uses an R&S VNA, but everything there will work with the NanoVNA too (I didn't have a NanoVNA when the video was created).

author: BillyO
author_rank: Super Contributor
timestamp: August 28, 2025, 02:15:42 am
content: Thanks shabaz,Yeah, I'm familiar with VNA operation. That's why I was interested in the kit. You know, because I'm an incurable gearhead. I may even be suffering from a mild case of TEA. I hear it only gets worse and there is no cure.

author: tooki
author_rank: Super Contributor
timestamp: August 28, 2025, 07:57:34 am
content: Quote from: shabaz on August 28, 2025, 01:13:59 amWell, you could make it cheaply using inexpensive aliexpress or LCSC cable and connectors, which are probably approximately equivalent to the parts rfsupplier is using. If you use parts from Farnell/Mouser/Digikey, you’ll likely end up with a better quality end product, assuming you assemble it skillfully.Quote from: shabaz on August 28, 2025, 01:13:59 amAny difference visible to the naked eye would have to be a grotesquely huge flaw. Remember that the differences between good and bad coaxial connectors (especially smaller ones like SMA) are measured in thousandths of an inch; you can’t tell by eye.Quote from: shabaz on August 28, 2025, 01:13:59 amNot really. From a commercial cable manufacturer I would expect better. The actual crimp on the ferrule should not extend to the end. It should leave a small amount uncrimped (called a bellmouth) so that it doesn’t squeeze a sharp edge into the jacket. A bellmouth improves longevity.Quote from: shabaz on August 28, 2025, 01:13:59 amThe normal crimp shape for these very small pins is a square crimp. An indent crimp is excellent, but rarely seen. Larger pins (like this on BNC) can also use a hex crimp. I dunno why you’d say this looks like a DMC-like crimp, since that is exactly what itdoesn’tlook like. (If one were challenged to make a crimp that looks as different from an archetypal DMC-style 4-indent crimp as possible, it might look like this.)Quote from: shabaz on August 28, 2025, 01:13:59 amEven among western cable manufacturers, the braid tightness on a given type of cable is a huge differentiator between cheap and expensive cables. The tightest I’ve seen is on Huber+Suhner, the loosest on some Italian maker (Tasker or something, I think).

author: shabaz
author_rank: Frequent Contributor
timestamp: August 28, 2025, 12:45:01 pm
content: Quote from: tooki on August 28, 2025, 07:57:34 amFrom that teardown, I've concluded it likely wouldnotbe a significantly better result if one uses similar parts but assembles them at home rather than ordering them.Bear in mind there's a cost to one's time; it would be worthwhile building cables using better materials (which I have done, but as mentioned, there's a significant price hike in doing that - perhaps better reserved for the cases where one does want high performance).There's then the knock-on significant investment too, to do it well with some connectors (and then repeat that investment for the next connector type that you need!). Plus, if you're new to a connector, factor in some spares while you get up-to-speed. And if you're not doing it regularly enough (who is; it's not a core task for a lot of engineers), the reality is that you'd need to add in more spares.QuoteOf course, but I'm _only_ providing photos. That's all you're going to see with photos, I'm not planning on measuring these, and for some use-cases, some attributes such as [an example] loss do not matter, it is either at a level insignificant to those use-cases, or some types of it can be calibrated out) - people could try to measure samples, perhaps for consistency, but I'm not sure anyone is that interested to take the effort to subject $4 cables to more thorough tests; some level of testing will be on-the-job, targeted at the attributes that matter for that job: putting it in perspective, if you're measuring the frequency response of a small audio amp, I'd have no problem using these cables with the signal generator and 'scope, and simply seeing if the result is plausible with the DUT present and removed. If you're measuring an antenna, I'd likely be using a different cable (and different coax type) if it were me.Although a significant physical flaw is all the photos will show; If I hadn't tried to get that photo showing that detail, it would not be a very good effort, and you, or someone else, would have asked me for this obvious photo of the mating end of the view if it were missing.QuoteNo offense, but that's a very sitting-on-armchair-like opinion. In reality, there is only a small amount of strain relief (I think I've already mentioned I'd have preferred better, as a payable extra option on their custom ordering page) so even if there had been a bell-mouth, the cable would still eventually get damaged through wear-and-tear. I would prefer they use better tools, but as mentioned, I think it's acceptable for a cable that you understand will not last forever at the price paid.QuoteI actually didn't say that, nor did I state that I expected a DMC or even DMC-like indent.Does it really matter that the tool mentioned produces indents? I didn't suggest that the rfsupplier tool produced indents. I stated quite clearly that the pin had been crimped to have flat sides, and the photo clearly shows that.I speculated they used some sort of tool that crimped on the sides at a given depth - a shorthand way of stating that, was a 'DMC-like indenter/crimper' tool but that unlike the typical DMC or DMC-like tool, it was designed for flat sides.I wrote "flat sides" and made a point of zooming in to that in the photo too, because people would want to see how that pin had been attached.QuoteAgree, and I have one or two other branded rolls of RG-316 at different price-points elsewhere, I was considering doing a comparison between them, but decided that not everyone is interested in RG-316 anyway, people will have their own preferences, e.g. some may prefer semi-rigid coax for some test setups. The telecoms-application cable was an unfair comparison but still useful to see the very visible difference.

author: David Hess
author_rank: Super Contributor
timestamp: August 28, 2025, 01:08:56 pm
content: Quote from: shabaz on August 28, 2025, 01:13:59 amI would assume that they measure the coaxial cable itself without compensating for the connector length.

author: tooki
author_rank: Super Contributor
timestamp: August 28, 2025, 07:35:12 pm
content: Quote from: shabaz on August 28, 2025, 12:45:01 pmI didn't say "better result" using Ali/LCSC parts. Just that it would be cheap (not cheaper), unlike the one made with quality parts from Mouser etc.Quote from: shabaz on August 28, 2025, 12:45:01 pmPhotos have nothing to do with anything. You said it looks "visually OK", and I was simply pointing out that you cannot judge the quality of a coaxial connector by visual inspection alone. The tolerances are just way, way too small.Quote from: shabaz on August 28, 2025, 12:45:01 pmSo because it will "eventually get damaged through wear and tear", it's OK for them to make mistakes that will further shorten its lifespan?Look man, you gave your opinion on that cable, but you prefaced it with saying you wanted to get a look for how good or bad it is, but then defend its flaws just because it's cheap. Cost shouldn't disallow realistic, honest criticism of the product. (It is totally OK to say "this cheap thing is good enough for X", but not to essentially say "its flaws aren't flaws since it's cheap".)Quote from: shabaz on August 28, 2025, 12:45:01 pmYou said: "The center pin wasn't soldered, they have used a DMC-like indenter/crimper, although it's a flat crimp, so it's some clone crimp tool perhaps."That's like saying something "is a square, but circular." Which means it's not a square at all (because a square's defining characteristic is having 4 equal sides), but rather it is a circle.The tools DMC is famous for are 4-indenter, 8-impression crimps, and so that style of crimp is what one thinks of when something is described as DMC-like. So when you say "DMC-like", but not an indent crimp, then you're saying "DMC-like, but without DMC's most defining characteristic". That's just silly.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 28, 2025, 08:49:47 pm
content: Quote from: tooki on August 28, 2025, 07:35:12 pmAlright, granted you didn't say "better result" but you did say, I quote: "you could make it cheaply using inexpensive aliexpress or LCSC cable and connectors".Istillcannot see the reason why anyone would want to do that, if it's not going to provide significantly better results. For the reasons and costs, see above. It's easy to say "you could make that yourself" when you completely ignore the learning effort, tools cost and your time if you value it. And then repeat with every other connector you use..!QuotePhotos have nothing to do with what? Be clear. And ignore the photos if they are not of interest to you.I specifically saidvisually OKbecause I have not measured pin depth nor obtained any other measurement. I made a _visual_ inspection. Photos have everything to do with a teardown and a visual inspection. This is partially why I limit my effort on this forum. You in particular like to be the "know-it-all". We all know that avisual inspectionis not the same as a suite of measurements and tests, Mr Obvious. Get off your backside and make some measurements on $4 cables if that's what you want. Meanwhile, I will continue to post photos if I want, with no measurements if I want. You can continue to protest over it if makes you feel warm at night.QuoteIt is OK to expect some corners were cut for what's a lower-priced product. You've seen the photos, don't buy them if you don't want to, but you're being disingenuous by suggesting it's that big an issue: I've probably purchased maybe 50 cables from them overall and I've not thrown any out so far, so the impact of that particular corner-cutting isn't as bad as you're making out. If you had asked nicely (which you didn't, so I won't) I would have flexed one end repeatedly for a while to accelerate some wear-and-tear, to see when the coax jacket would show visible damage.QuoteAll I'm seeing is that you're trying to show off with what you think is fascinating esoteric knowledge, when in reality it's about something that is a non-issue, and simply because you don't like my wording.In my very first post, I explicitly stated they had used a tool that produced flat sides and no indents.I didn't say the crimp was DMC-like (I hate repeating myself now a third time). I said the tool they used may have been DMC-like,but produced flat sides, _not_ indents as the DMC tool would.I used DMC-like to refer to a tool that may allow a pin to set to a certain depth, and then apply a force radially toward the pin. I'm sorry (well, not really, since you have no useful point, and are now really wasting time at this part of your discussion) that that doesn't meet your test of "DMC-like", when I'd explicitly described the difference that I observed.Not that it was ambiguous, but if anyone hadanydifficulty understanding from the wording how the pin was attached to the conductor, there was a clear photograph showing it.We know you're a know-it all, but sorry, people _are_ allowed to see other characteristics and use them for describing what a particular tool may be doing.

author: tooki
author_rank: Super Contributor
timestamp: August 29, 2025, 10:23:27 am
content: Quote from: shabaz on August 28, 2025, 08:49:47 pmThe statement I originally responded to was this:Quote from: shabaz on August 28, 2025, 01:13:59 amThat made it sound like the main reason for avoiding DIY cables was cost, or the availability of inexpensive parts. So I gave a way to get the cheaper parts if you want. That’s it. I wasn’t saying that you should or shouldn’t, nor did I address any motivations or arguments for or against DIYing it.(And since you already mentioned making your own “better” cables, it seemed fair to assume that tooling and skills were not the limiting factor.)Quote from: shabaz on August 28, 2025, 08:49:47 pmYoubrought up and started discussing photos, not me. I never said anything about them.All I said, and I stand by this, is that a visual inspection is largely meaningless in determining whether a coax connector is good or not. You may know this, but other readers (like the OP, who clearly wants to know what to look for) might not. So I think that this is very important context for people to be aware of.You then replied:Quote from: shabaz on August 28, 2025, 12:45:01 pmBut that’s not true.The original statement I was commenting on wasQuote from: shabaz on August 28, 2025, 01:13:59 amSo you didn’t “only” provide a picture, you said it “seems visually OK”.And it might look visually OK. But the point is that “visually OK” is functionally meaningless, since plenty of bad, noncompliant connectors can look “visually OK”. Worst case, they might actually be bad enough to damage a good connector when mated!99.9999% of us here do not have the specialized tools to actually measure coaxial connectors properly. So what we are left with is to buy good stuff and hope it’s compliant. But a visual inspection won’t catch much — as I said, a connector would have to be grotesquely bad to fail a visual inspection — and I don’t want people to be misled into believing that a visual inspection actually tells you very much at all.That’s it.Quote from: shabaz on August 28, 2025, 08:49:47 pmOne can debate about how bad a mistake it is, or how significant the effect is. (That is, one can debate thedegree.) But there’s a reason the connector manufacturers specify that a bellmouth should be present, and it’s not aesthetics. A professionally-made cable should have one, and IMHO even a low-cost coaxial cable specialist should be crimping properly.Quote from: shabaz on August 28, 2025, 08:49:47 pmYes, my comment was entirely about the wording, not the quality of the crimp itself. You name-dropped DMC for something that couldn’t be less DMC-like if you tried. So either you didn’t understand how a DMC tool works and what makes it special, or it was literally just “look at me, I’ve heard of DMC!” You said it might be a “clone tool”, but a clone of a DMC tool wouldn’t produce that shape of crimp, because a clone tool would work the same as the original. (Otherwise it’s not a clone!)

author: HighVoltage
author_rank: Super Contributor
timestamp: August 29, 2025, 11:01:30 am
content: One of my clients was very happy a few years ago, when he found "low cost and high quality" BNC cables on Amazon in Germany.They were so bad, that some only had a connection when bending them slightly.So, they went all to the trash a few weeks later.It is always good to invest in high quality cables, even as a student.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 29, 2025, 12:27:10 pm
content: Quote from: tooki on August 29, 2025, 10:23:27 amYou really are pointless here then!For a start, my entire comment was literally a teardown about acustom manufactured cable, so people could at least visually see what to approximately expect from that supplier from that one sample.Secondly, maybe engage your brain. I specifically mentioned decent western distributors where connectors will cost tenfold, and yes, I did mention better cables, because what's the point of assembling cables using low-cost parts, when you can buy them ready-made? If you now think there's no point either (you have given no sensible reason) then what's the point of your comment?QuoteWhat a conceited way to state it now. We all "stand by" that a visual inspection isn't the same as turning something on and seeing if it meets your needs or can be adjusted or calibrated out, or performing testing and measuring.You say you're doing it for the OP, a student who who will literally just be able to (and should) make a visual inspection before they plug it into (likely) an oscilloscope or function generator or their circuit, and are very unlikely to make benefit of a high-performance cable (in fact, they may well want to see and discuss loss for instance). From the teardown, it's very clear the cables are constructed about as well as required for that purpose. You wouldn't be using SMA cables for much high performance anyway! And secondly the OP wants BNC, which again isn't high-performance, and a visual inspection again would be sensible.QuoteWell then that tops off your pointless drivel, we've been around it about three times now. I "stand by" that I described things well enough regarding the flattened pin and the indent, and backed them up with a photo of the actual pin, so people could see for themselves. It's not unreasonable to describe any tool that might locate a small pin and then allow radial forces to be applied to retain a wire as DMC-like, especially since the difference was explained! If you don't like it, tough.

author: tooki
author_rank: Super Contributor
timestamp: August 29, 2025, 07:30:36 pm
content: Quote from: shabaz on August 29, 2025, 12:27:10 pmDude, are you making a deliberate effort to be dense?!Youmade it sound as though lack of cheap parts was a primary reason why you didn’t make your own cables (except for when you need really high quality cables). I tried to share a way to get cheap parts, since that’s a solvable problem. That is all I was saying. Nothing more, nothing less.I can’t reach inside your brain to find out what other reasons you had in mind for not wanting to make your own cables!Quote from: shabaz on August 29, 2025, 12:27:10 pmWell no, it isn’t “clear that they are constructed about as well as required for that purpose”, because you cannot determine that visually. You can have cables that look perfect but don’t work at all for any purpose. (Yes, it can be that bad. As in, no continuity at all. Or intermittent contact based on how it’s flexed. All while looking just fine.)Quote from: shabaz on August 29, 2025, 12:27:10 pmSinceallconnector crimp tools (with the exception of the ones for “compression type” coaxial connectors used by cable TV installers) work by applying radial forces to a contact, then your definition of a “DMC-like” tool encompasses practically every crimp tool in existence. So yes, that definition isextremelyunreasonable.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 29, 2025, 09:08:06 pm
content: Quote from: tooki on August 29, 2025, 07:30:36 pmNo I didn't. I never suggested lack of cheap parts being an issue for one moment, and you're not stupid enough to think I didn't know about Chinese low-cost connector availability from AliExpress and so on.I quote:Quote from: shabazQuote from: tookiYou're talking out of your a** again, atbest. From that teardown, it's clear that cable would be fine for typical student purposes with a 'scope and function generator, short of something highly unlikely. At worst, you're completely disingenuous to suggest that such a person should not use such cables. And I've already mentioned I've purchased perhaps 50 cables, and had to throw _zero_ out.And no, I don't get a perverted pleasure at purchasing higher-quality cables when they are unnecessary, as some of the people here might; I certainly don't wish to know about that.Some people are price-sensitive, some won't have the tools, some will value their time more than trying to replicate what can be obtained for $4, and may well accept that they may need to buzz out a cable, may even need to visually inspect it (which they should) and that a failure of one cable in 50 isn't the end of the world. Many failures are not catastrophic and irreversible, especially when doing student work.QuoteCarry on whinging about it. It was clear from the start what the actual pin crimp looked like, in wording and images. You simply were being obnoxious because you wished to. That's nothing new, you like being the "know-it-all", even when you have no point.

author: tooki
author_rank: Super Contributor
timestamp: August 30, 2025, 09:57:47 am
content: Quote from: shabaz on August 29, 2025, 09:08:06 pmYour words:Quote from: shabaz on August 28, 2025, 01:13:59 amThat literally says that it’s because of component costs.Quote from: shabaz on August 29, 2025, 09:08:06 pmI didn’t say that the cable you tore down, nor that others from that supplier,arebad.My point is that a visual inspection alone does not tell you whether a cable is good. Period. You keep insisting that it does, and that is simply not true, and I gave examples of real-world faults that a visual inspection won’t show.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 30, 2025, 02:10:58 pm
content: Quote from: tooki on August 30, 2025, 09:57:47 amDon't pretend that it led you to falsely assume that I was searching for similar quality connectors. It could only have been about the costs of more decent, higher-quality connectors since I mentioned reputable distributors. I did not suggest the problem was obtaining similar quality connectors at a similar China price.Everyone knows you can buy cheap connectors from AliExpress. You didn't have a point. You (in my opinion) deliberately and misleadingly read the desire for low-quality connector sourcing out of thin air. You didn't decide to selectively boldif I make a cablejust a few words prior in the same sentence! Because literally in the sentence before that:Quote from: shabaz on August 28, 2025, 01:13:59 amAnd then let's not forget this:Quote from: shabazAnd, why would you even suggest the option of recreating $4 cables with similar parts? I'm sure you value your time, so quit being obnoxious and implying others might not.Despite you not having any rational reason, you doubled down:QuoteYou decided to share what solution? Everyone knows you can buy low-cost connectors from AliExpess. You had nothing to "share", genius.QuoteWe know this, and indeed the OP might not be aware that it would matter at some point in their career, and that comment actually has a point. Still, that's not how you originally stated it. Considering how obnoxious you were with my wording on something that had zero point regarding the pin crimp description, you yourself could have framed your visual inspection point toward the OP, rather than trying to remind someone who clearly was aware, since they had already mentioned multiple times needing higher-quality cables earlier, such as for VNAs.When you wrote:QuoteYou weren't addressing that point to the OP at all. I didn't need your reminder, and you're not so stupid that you thought I needed it, given what I'd already written about the need for high quality cables. You were either (a) deliberately acting an obnoxious so-and-so, or (b) you’re not very good at constructing sentences yourself, so you’re in no position to whinge about others; so which one was it?

author: tooki
author_rank: Super Contributor
timestamp: August 30, 2025, 05:34:21 pm
content: It’s neither a nor b: An explanation or elaboration of a point in a public forum can be for any reader, not just the person being replied to.

author: TimFox
author_rank: Super Contributor
timestamp: August 30, 2025, 05:50:17 pm
content: Going back to the original question:Amphenol BNC connectors have been suggested as a quality part for making ones own cables, and I agree wholeheartedly.Note that Amphenol makes two different versions for their BNC line, both of which are high quality."RFX" is a lower-price series, suitable for < 1 GHz use, e.g.https://s3-us-west-2.amazonaws.com/catsy.582/c031-326-rfx.pdfThe "regular ones", e.g.https://www.amphenolrf.com/031-326.htmlare rated up to 4 GHz, but are more expensive.See a discussion athttps://forum.digikey.com/t/part-comparison-amphenol-rf-vs-rfx/71The RFX series uses Delrin instead of Teflon for the insulation: Delrin has good electrical properties, but its moisture absorption is "Low" vs. "None" for Teflon.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 30, 2025, 05:55:29 pm
content: Quote from: tooki on August 30, 2025, 05:34:21 pmBull! You called me out earlier for my trivial tool vs pin crimp description that did not affect understanding_whatsoever_, and yetyoucannot be precise inyourwording - the word "Remember" was directed at me, not the OP, nor some random reader who you magically guess was taught and has forgotten and needs to remember. Or, you're incompetent at constructing sentences yourself, and yet you now refuse to acknowledge that when such criticism is returned back at you.Of course, going by the entirety of your comments, and your general attitude, it's clearly a mix of both - you are a condescending know-it-all, and not so great at sentence construction yourself.

author: tooki
author_rank: Super Contributor
timestamp: August 30, 2025, 09:45:18 pm
content: Quote from: shabaz on August 30, 2025, 05:55:29 pmYour asinine, deliberately obtuse interpretations are your problem, not mine.As for attitude: you reap what you sow, and you’ve been planting nothing but hostility. My original comments were worded very neutrally, and YOU chose to take the discussion in this direction. I kept trying to steer it back towards the subject matter, and you keep pushing it back to getting personal. You made that bed, you get to lay in it.

author: shabaz
author_rank: Frequent Contributor
timestamp: August 30, 2025, 11:29:21 pm
content: Quote from: tooki on August 30, 2025, 09:45:18 pmNow you're just typing random cr*p! That actually only seems to suggest you're telling me you're being hostile because you think I am.If it's to even remotely suggest you think that I specifically picked on you because I felt like being hostile to you that day, then your ego is only kidding one person.Youwere the one that pointlessly picked on wording, and doubled down on it repeatedly! And couldn't accept criticism back when it was suggested you yourself had problems with sentence construction.Quote from: tookiComplete and utter bull. Your words are now effectively meaningless;youcompletely steered off the quality of the crimp, and the subject matter - and eventually admitted yourself:Quote from: tooki

author: tooki
author_rank: Super Contributor
timestamp: August 31, 2025, 05:27:31 pm
content: Quote from: shabaz on August 30, 2025, 11:29:21 pmWell because you very obviouslyarebeing hostile.