Thanks a lot, I do not know if I'd need above 500 MHz because what I shall measure is below 500 MHZ but I have read something about i.e. 2.4 GHz, casting "shadows" on signals if the cable do let i.e. 2.4 GHz trough?
About length do I expect between 2 and 5 feet , but running near lots of EMI and RF due to "Hong Low" transformers, cheap gear and so on, being on or near my bench.
About length do I expect between 2 and 5 feet , but running near lots of EMI and RF due to "Hong Low" transformers, cheap gear and so on, being on or near my bench.
All high quality RF cable will provide good shielding, 2.4Ghz wifi signals are low level.
500mm to 1500mm test cables are fine.
500mm to 1500mm test cables are fine.
Okay great, I have tried to use word like pliable and flexible but I do not find anything useful about coax's bend ability. The only I can find is marketing BS, i.e. that RG-142 is super bendable or a 1 inch coax with solid core, they call ultra-flex!! 🙂
I have taken a look at the RG-316, RG-58 but nothing obout how they bend.
I have taken a look at the RG-316, RG-58 but nothing obout how they bend.
There are challenges in making 500MHz coax cables, stranded central conductors and flexibility add to those challenges.
Here is a Belden Blog about making an even higher frequency coax cable.
A New Coax Cable Design (Part 1)
Here is a Belden Blog about making an even higher frequency coax cable.
A New Coax Cable Design (Part 1)
Yes it's not easy, but to my luck, do I not have to build it my self🙂
I have maybe found a usable cable: 3D-FB
Do anyone of you know of them or similar?
I have maybe found a usable cable: 3D-FB
Do anyone of you know of them or similar?
if you are looking at HF and UHF signals the cable the connections and the terminations all play into what you will see. A coax, 50 or 75 Ohm plugged into a 1Meg scope with clip leads at the other end won't tell you anything useful about 250 MHz signals. The connections and cable will all resonate in various ways to give you a really distorted picture. this is where scope probe design becomes very important and not trivial.
The coax is useful at HF (really over 10 MHz) going from a 50 or 75 Ohm source to a terminated load. At low frequencies its a different story and the coax can be quite useful.
The coax is useful at HF (really over 10 MHz) going from a 50 or 75 Ohm source to a terminated load. At low frequencies its a different story and the coax can be quite useful.
Okay thanks! 🙂
I am planning on using the cable as connection to DUT and that kind, only to max 500Mhz
What cable would you recommend if I need to send a i.e. 10Hz-5MHz signal from my signal generator?
I am planning on using the cable as connection to DUT and that kind, only to max 500Mhz
What cable would you recommend if I need to send a i.e. 10Hz-5MHz signal from my signal generator?
Pretty much any cable with decent connectors and flexibility would work. I still like the Japanese cables and connectors for fit, finish and feel. For a network analyzer its a different and really expensive story but would make no difference ion your application. look at Mogami and Canare BNC terminated coaxes.
3D-FB is not that flexible, it has a solid centre conductor and is double shielded.
You can always use the search facility from Mouser, Digikey, element14 and farnell and similar to give you an idea of what sorts of cables are available.
There are no such challenges, RG58 has been around for decades and is good for 3ghz as are most coaxial cables used for RF.
The belden blog is more about distributing high speed video signals around a building and it's based around the same technical challenges to distributing ethernet signals around a building.
Hello,
Do you have 50 Ohm input oscilloscope?
Passive probe cable is much specialized and normal coaxial cable is not suitable for 1MOhom input.
>3. Measures against reflected waves with high-loss coaxial cable
(Written in Japanese)
http://www.mogami.com/notes/probe-cable/probe-cable.html
(Google translated)
Google Translate
If you do not have 50 Ohm scope, you have to use feed through terminator to convert 50 Ohm input..
Do you have 50 Ohm input oscilloscope?
Passive probe cable is much specialized and normal coaxial cable is not suitable for 1MOhom input.
>3. Measures against reflected waves with high-loss coaxial cable
(Written in Japanese)
http://www.mogami.com/notes/probe-cable/probe-cable.html
(Google translated)
Google Translate
If you do not have 50 Ohm scope, you have to use feed through terminator to convert 50 Ohm input..
Thank you both, I did not get any notification on replies so did first get one now.
the RG-58 should be, as I understand it, a number with as many different types as the number itself. Everything from a $1 75 Ohm TV cable, over 13 Ohm plastic toys to the genuine 50 Ohm high quallity cable. I have read that the RG-58 is the most used one for general usage and therefore do all sort of fakes get called RG-58. I do not know if it's true, but I would have a hard time to spot the real among the fake.
Thanks for the link and the translation link🙂
I have always regret not learning Japanese, one of the most beautiful languages in the world, with a honorable culture!! But when you is self thought, does it not amount to much, only my main language, two secondary languages and a couple of I can understand and read language. 🙂
the RG-58 should be, as I understand it, a number with as many different types as the number itself. Everything from a $1 75 Ohm TV cable, over 13 Ohm plastic toys to the genuine 50 Ohm high quallity cable. I have read that the RG-58 is the most used one for general usage and therefore do all sort of fakes get called RG-58. I do not know if it's true, but I would have a hard time to spot the real among the fake.
Thanks for the link and the translation link🙂
I have always regret not learning Japanese, one of the most beautiful languages in the world, with a honorable culture!! But when you is self thought, does it not amount to much, only my main language, two secondary languages and a couple of I can understand and read language. 🙂
I have now read the translated site and I have to admit I may not have understand half of it and with the danger of you all thinking I am a lost cause, I'll try to explain in noob-language what I think I have got out of it. Please understand that the following is grossly over simplified and properly formulated in gibberish.
A coaxial cable do make capacitance between the inner core and the outer shield, the inner wire has some resistance, the 50 Ohm specification is not the resistance in the inner wire but calculated by some sort of combination of the capacitance and the inner wire resistance. A non terminated inner wire's length can "amplify" a certain wavelength if that particular wavelength devised into the cable length. That's why termination is very important. Is that a F- or shot by dawn? 🙂
A coaxial cable do make capacitance between the inner core and the outer shield, the inner wire has some resistance, the 50 Ohm specification is not the resistance in the inner wire but calculated by some sort of combination of the capacitance and the inner wire resistance. A non terminated inner wire's length can "amplify" a certain wavelength if that particular wavelength devised into the cable length. That's why termination is very important. Is that a F- or shot by dawn? 🙂
Termination is very important in high frequency.
You will encounter stepped response, ringing, etc with incorrect termination.
You will encounter stepped response, ringing, etc with incorrect termination.
You want Belden 8241F RG59/U Type Flexible. It has 7 strands in the center conductor instead of one solid one. Note that you cannot use a press-and-crimp connector with this cable because the 7 strands collapse instead of pressing into the center hole. Must use solder or screw-on connectors.
Normal coaxial cable is low resistance in DC.
Then you have to terminate to reduce recflection.
Probe cable is much specialized to oscilloscope measurement.
It uses resistive materiatl for center core to reduce reflection side effects.
Feedthrough terminator is 50 Ohm female BNC and 50 Ohm terminaor resister and output to male BNC connector.
Then you have to terminate to reduce recflection.
Probe cable is much specialized to oscilloscope measurement.
It uses resistive materiatl for center core to reduce reflection side effects.
Feedthrough terminator is 50 Ohm female BNC and 50 Ohm terminaor resister and output to male BNC connector.
Maybe I should, with the new knowledge, rephrase my question so it may fit better.
What types of test cables do you use between your test equipments?
What about from test equipment and DUT?
What types of test cables do you use between your test equipments?
What about from test equipment and DUT?
Untill now have I looked trough every LMR number I could find on the internet, where flexibility is specified, and the following cables should be flexible:
LMR 100A
LMR 195
LMR 200
LMR 240
LMR 300
LMR 400
LMR 500
LMR 600
LMR 900
LMR 1200
LMR 1700
Is the LMR and RG just two number systems of the same cables or?
LMR 100A
LMR 195
LMR 200
LMR 240
LMR 300
LMR 400
LMR 500
LMR 600
LMR 900
LMR 1200
LMR 1700
Is the LMR and RG just two number systems of the same cables or?
