LOL fairly easy do I think🙂
Alligator clips do mount very badly between a signal generator and a scope or DUT 🙂
Alligator clips do mount very badly between a signal generator and a scope or DUT 🙂
Again, I use a mix of BNC to BNC cables for the shielded connections between instruments but its all audio frequency stuff. For the HF and UHF I will use the appropriate cable (50 or 75 Ohm) with appropriate connectors. Usually generic will work unless you need precision RF measurements. If you do not have a VNA its most likely you aren't making precision RF measurements where the cable is critical.
I still recommend Mogami or Canare cables 2 Ft CANARE LV-61S 75 OHM PRECISION BNC WORD CLOCK INTERCONNECT CABLE | eBay as the best for your applications. And get real scope probes for scope measurements e.g. Amazon.com: RioRand(TM) Probe for RioRand ARM DSO 203 201 Nano digital Oscilloscope: Electronics
I still recommend Mogami or Canare cables 2 Ft CANARE LV-61S 75 OHM PRECISION BNC WORD CLOCK INTERCONNECT CABLE | eBay as the best for your applications. And get real scope probes for scope measurements e.g. Amazon.com: RioRand(TM) Probe for RioRand ARM DSO 203 201 Nano digital Oscilloscope: Electronics
Yes I did look at that and I think I did ask you about it being a 75 Ohm. Is it usable? Everything else in my system is 50 Ohm.
The probes looks great. My problem is now mostly sending signals to the DUT and if your suggested coax is ok at 75 Ohm. 🙂
The probes looks great. My problem is now mostly sending signals to the DUT and if your suggested coax is ok at 75 Ohm. 🙂
Again I may just have understood 10% of it all but to was it very interesting! So 50 Ohm is in fact a compromise? Alternative should one use two different cables?
A 75 Ohm is perfect for TV and so on because they would in fact get a less perfect signal by using 50 Ohm?
Thanks a lot🙂
A 75 Ohm is perfect for TV and so on because they would in fact get a less perfect signal by using 50 Ohm?
Thanks a lot🙂
Not quiet, LMR cable is just a Times Microwave naming convention for their product line, however the LMR100A and LMR195 appear to be replacements for RG58 cable, not that I can recall anyone using LMR as test cables as it's mostly used for radio communication installations.
Anything above LMR240 will be getting large in diameter, LMR240 is 6.1mm in diameter and LMR400 is 10.29mm and the largest is LMR1700 at a whopping 42.42mm !
Well it depends and I'll try to explain in simple terms, 50 Ohm and 75 Ohm coaxial cables are traditionally used as RF transmission lines, that is connecting RF devices like a Television or a radio transmitter to an antenna. Lets use this as an example, take the antenna connector on the back of your TV it is connected to the internal tuner electronics and which has an impedance of 75 Ohms and it connects to the TV antenna which also has an impedance of 75 Ohms so to maximise the transfer of signal from the antenna to the tv the coaxial cable also needs to be 75 Ohms, the same applies to antennas and RF devices which use 50 Ohm impedances.
The same above terminology will also apply to testing RF devices using RF signal generators. When it comes to testing general electronic circuits the test equipment will normally have a high input impedance to avoid loading the circuit. The impedance of the coaxial cable when used in this manner won't have much influence as the source impedance (the electronics your measuring) and the test equipment will have vastly different impedances.
Hopefully I have explained this so you can make sense of it all .🙂
Yes I think you have made it super clear! So you chose high impedance to make the test unit "invisible" but use the common impedance, all the way to let the signal go trough without "feeling" any change, a sort of open smooth tube for water?
Your explanation about LMR was also very clear🙂 I understand it as the RG standard is the one I shall use, that other types have there usage but I would know it if I had to use them. LOL and it sounds like LMR1700 is fare from the flexibility and diameter I am looking for! 🙂
What I hope to get is some sort of coaxial that feels more like standard 115V-230V cable. Instead of TV cheap antenna solid core wire.
Your explanation about LMR was also very clear🙂 I understand it as the RG standard is the one I shall use, that other types have there usage but I would know it if I had to use them. LOL and it sounds like LMR1700 is fare from the flexibility and diameter I am looking for! 🙂
What I hope to get is some sort of coaxial that feels more like standard 115V-230V cable. Instead of TV cheap antenna solid core wire.
Yes, the cable is important when connecting devices and test equipment of the same impedance (Mostly in RF applications).
You'll find that most technicians will have many types of RG58 type test cables with all manner of connectors and adaptors.
Do a search in Mouser, Digikey, RScomponents, element14 or your local electronics distributor for test leads.
You'll find that most technicians will have many types of RG58 type test cables with all manner of connectors and adaptors.
Do a search in Mouser, Digikey, RScomponents, element14 or your local electronics distributor for test leads.
What is wondering me is that RG-58 coaxial cables can be different, isn't a standard each cable have to adhere to, to be allowed to put RG-58 on?
I have tried to search several sites, including those you writes, but none do tell about there flexibility. I would love to get some coaxial cables that is about as flexible as standard power cables or even more flexible. It would also be nice if the cables is thin.
The sites I have found, call everything flexible, I have seen RG-142 under ultra flexible!! And they are about as flexible as a coat hanger🙂
I have tried to search several sites, including those you writes, but none do tell about there flexibility. I would love to get some coaxial cables that is about as flexible as standard power cables or even more flexible. It would also be nice if the cables is thin.
The sites I have found, call everything flexible, I have seen RG-142 under ultra flexible!! And they are about as flexible as a coat hanger🙂
There's no standard for RG58 type cable per se as there are many variants, some have double shielding, different dielectrics, solid centre conductor, stranded centre conductor.
Most RF type cables don't need to be flexible as they are used in fixed installations, however if a cable is designated to be used as a test cable then you can assume that it will be flexible.
Most RF type cables don't need to be flexible as they are used in fixed installations, however if a cable is designated to be used as a test cable then you can assume that it will be flexible.
Is it like that with every cable? RG-172, RG-6 and so on?
Okay great, can I just search for "bnc coaxial test cable"?
Okay great, can I just search for "bnc coaxial test cable"?
Yes, unfortunately. There are dozens upon dozens of coaxial cables with all different types of characteristics and connector types.
Yep, do a search like that, it will keep you busy for hours. 🙂
Yep, do a search like that, it will keep you busy for hours. 🙂
LOL hours and hours🙂
But about coaxial cables, hwo do you then know what you get?
Lets say you need more of your RG-400 cable but you can't buy it from the same place anymore?
And why give them names if you would be better of saying I need double shielded, multi strand core.....
But about coaxial cables, hwo do you then know what you get?
Lets say you need more of your RG-400 cable but you can't buy it from the same place anymore?
And why give them names if you would be better of saying I need double shielded, multi strand core.....
Most coaxial cables are used for RF applications, so you'll determine how long the cable run will be, what frequency, how much signal loss can be tolerated, how much power is being transmitted, bending radius, fixed installation, mobile installation and it goes on and on. 😱
Alot of the naming conventions are historical, from Wikipedia Coaxial_cable:
"A series of standard types of coaxial cable were specified for military uses, in the form "RG-#" or "RG-#/U". They date from World War II and were listed in MIL-HDBK-216 published in 1962. These designations are now obsolete. The RG designation stands for Radio Guide; the U designation stands for Universal. The current military standard is MIL-SPEC MIL-C-17. MIL-C-17 numbers, such as "M17/75-RG214", are given for military cables and manufacturer's catalog numbers for civilian applications. However, the RG-series designations were so common for generations that they are still used, although critical users should be aware that since the handbook is withdrawn there is no standard to guarantee the electrical and physical characteristics of a cable described as "RG-# type". The RG designators are mostly used to identify compatible connectors that fit the inner conductor, dielectric, and jacket dimensions of the old RG-series cables. "
There are just too many variations to use a descriptor for a coaxial cable, for example if you wanted a double shielded cable there would be dozens of variations.
Coaxial cables don't really go out of production, if a cable was no longer available you can always find a substitute.
Alot of the naming conventions are historical, from Wikipedia Coaxial_cable:
"A series of standard types of coaxial cable were specified for military uses, in the form "RG-#" or "RG-#/U". They date from World War II and were listed in MIL-HDBK-216 published in 1962. These designations are now obsolete. The RG designation stands for Radio Guide; the U designation stands for Universal. The current military standard is MIL-SPEC MIL-C-17. MIL-C-17 numbers, such as "M17/75-RG214", are given for military cables and manufacturer's catalog numbers for civilian applications. However, the RG-series designations were so common for generations that they are still used, although critical users should be aware that since the handbook is withdrawn there is no standard to guarantee the electrical and physical characteristics of a cable described as "RG-# type". The RG designators are mostly used to identify compatible connectors that fit the inner conductor, dielectric, and jacket dimensions of the old RG-series cables. "
There are just too many variations to use a descriptor for a coaxial cable, for example if you wanted a double shielded cable there would be dozens of variations.
Coaxial cables don't really go out of production, if a cable was no longer available you can always find a substitute.
Thanks, but I did thought that if you ordered RG-58, you did know how it was build, it's RF-specifications and so on. But to me does it sounds like you can order RG-172 and RG-58 from two different places and get exactly the same cable, because that's what the two different places chose to the cable you ordered.
Well that's quiet possible if you order cable from one of the trusted manufacturers, however it always pays to check the datasheets so you can compare if there any differences more so if you order cable from unknown sources.
Ok great, yes it's best to buy from one you know you can trust.
But instead of me hoping that I maybe find a flexible coax, I'd hoped that someone on this forum, did have some and could say: "get the RG-8765xxy from cable-junk, that's where I got them from" 🙂
But instead of me hoping that I maybe find a flexible coax, I'd hoped that someone on this forum, did have some and could say: "get the RG-8765xxy from cable-junk, that's where I got them from" 🙂
You could try RG-223, double shield, high spec version of RG-58. It has silver plated copper conductors and solid core conductor, still quite flexible.
Or try RG-400, similar to RG-223 but with multi strand inner conductor (more flexible) but a PTFE outer sheath which can be harder to work with when terminating.
Or try RG-400, similar to RG-223 but with multi strand inner conductor (more flexible) but a PTFE outer sheath which can be harder to work with when terminating.
I'll take a look, but I do own RG-400 multi stranded coaxial cable, but the version I have is very stiff, I think it have a minimum bend radios of 8 inch. I would like something like a power cable, it will only be used to <500MHz but if it can shield even higher HZ, will it be fine.
