Here is a link to the WBT Product: nextgen™ RCA Connector - WBT-0110 Cu
I don't see how they overcame the fundamental dimensional constraint. I'm not about to buy some to put on the network analyzer to verify their claims. Not even sure what to use for the for the mating connector and nothing in the cal kits would be helpful.
I don't see how they overcame the fundamental dimensional constraint. I'm not about to buy some to put on the network analyzer to verify their claims. Not even sure what to use for the for the mating connector and nothing in the cal kits would be helpful.
I would kill to have some calibration kits! All I have is APC-7, would love an "N", "BNC" and "SMA". Looking at the prices, I simply can't afford one, never mind three! Open, short and 50R sets.
Hi Pavel,
That is some lovely work! Nice and clean, and I doubt you have a problem with RF ingress. Sharp looking stuff. As for the RCA connectors, they aren't locking. Just a friction fit. I can see why you went to BNC connectors.
-Chris
Hi Pavel,
That is some lovely work! Nice and clean, and I doubt you have a problem with RF ingress. Sharp looking stuff. As for the RCA connectors, they aren't locking. Just a friction fit. I can see why you went to BNC connectors.
-Chris
It costs way too much. Simply reducing the shell continuity from a full 360 degree circumfrentially to almost a double stripline is a simple thing to do.
Not sure. But the issue is that normal people see the geometry and say...the capacitance has to go below free space in order to get the impedance up...completely disregarding the inductance..nextgen modified the inductance, but their solution requires a modified female.
The patent lawyers here are really funky when it comes to spending their time getting a patent, they want to make sure there is a good return.
A cheap and fancy solution to a problem that nobody cares about can't be considered a reasonable return. A few hundred or even ten thousand units per year, where the solution costs pennies ain't exactly "return". Sigh..
The theory is sound. Think of a wire pair from a cat5e cable. 100 ohms twisted. spread them the radial distance of an rca, impedance goes up. Put a second conductor opposite the core, impedance drops. A specific number of outer wires spaced equally circumferentially and you eventually get down to 50 ohms. Nextgen did it with wider shield helix (IIRC).
Nextgen does indeed require their female/male combo to work.
Jn
What do you need to measure and with what combo? I have also TEK TDR system. Besides network analyzers to cover audio to microwaves.
Usually, with HP gear and others, you dont need to do a precision Cal with standards for general purpose measurments. Their accuracy is so good without.... you wont miss the <..01dB difference. However you do need to factor out the test setup/layout wiring strays. Do a loop thru and save and subtract from DUT test. Most analyzers will do this for you from thier front panel op.
But it isnt enough to measure the cable with connectors (male and female) only.... you have to have it driven and loaded with real Z of the gear to be used to see the over-all final affect. And connections to connector of the cable with pig-tail leads (shield, for example) is not OK. The braid or shield needs to be connected to the body 360 degrees to maintain Z thru the cable/connector combo.
THx-RNMarsh
Usually, with HP gear and others, you dont need to do a precision Cal with standards for general purpose measurments. Their accuracy is so good without.... you wont miss the <..01dB difference. However you do need to factor out the test setup/layout wiring strays. Do a loop thru and save and subtract from DUT test. Most analyzers will do this for you from thier front panel op.
But it isnt enough to measure the cable with connectors (male and female) only.... you have to have it driven and loaded with real Z of the gear to be used to see the over-all final affect. And connections to connector of the cable with pig-tail leads (shield, for example) is not OK. The braid or shield needs to be connected to the body 360 degrees to maintain Z thru the cable/connector combo.
THx-RNMarsh
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Wow, that's a lot of good work, Damir! I have to admit that I do not prefer unshielded signal wires inside the box, for the reason of measurable pick-up of RFI/HF induced voltages.
Damir, give it a try with a fast scope (>100MHz) at high sensitivity, like 2mV/div, or a HF spectrum analyzer. IME it is impossible not to see the difference when changing from unshielded wires to well shielded coax. cables, like RG-179. Not only outside-box fields are a source of HF pollution, but also power supplies inside the box, or digital circuits of any kind, if used. I have not understood, by now, why audio designers use unshielded, bare wires.
It seems the good RCA is exclusively designed for critical high end digital audio application. Less critical and mundane application such as instrumentation and pro audio has to make do with cheaper connector like BNC.
![sub_wall_body1.1_1000[1].jpg](https://www.diyaudio.com/community/data/attachments/641/641987-49e002d6a2e5cd327cf42e23f9f0509f.jpg "sub_wall_body1.1_1000[1].jpg")
As I said, you can add series inductance but then you don't have a 75R connector, just a 30R-ish connector with a matching network which limits the bandwidth. This may be good enough for some applications - especially those which don't really need 75R connectors at all such as SPDIF.Jakob2 said:
You could add ferromagnetic material to boost the inherent inductance. That could get you a connector which is really 75R at the cost of limiting power handling and possibly adding signal distortion, but then you still have the problem that a transition from 75R of one size to 75R of a different size still gives some reflections.
Are you saying what what they have made is not a 75R RCA, but a connector which when used as a pair provides 75R but will also mate with normal RCA (and then not give 75R)? That eases the problem; it is always easier to solve a problem when you have the freedom to change the problem.Jakob2 said:
No. I was disputing your claim that RCA is 75R, or that some RCA is 75R. As far as I can see, you can have one of the following:anatech said:
1. genuine RCA, not 75R
2. RCA, with impedance matching network such as series inductance - limits bandwidth
3. RCA, with extra ferromagnetic - 75R but limits signal handling and probably bandwidth
4. not RCA, but 75R, yet will mate with RCA
Some people may wish to call 2, 3 or 4 '75R RCA', especially when they hope to take money off you.
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