Questions tagged [coaxial]

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What do I need to connect an R-SMA male to a standard coaxial male? [closed]

I have a router that has the following type of pigtail connector soldered to the board which I believe is an R-SMA male coaxial cable. I'd like to connect it to a standard male coaxial cable that's ...
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2 votes
1 answer
88 views

How is the center pin supported in air-filled coaxial cables?

In SMA cables, the PTFE dielectric supports the center pin through the length of cable. How is the center pin supported in air-filled cables? E.g., 3.5mm, 2.9mm, K-connector, 1.8mm, V-connector, etc. ...
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2 answers
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Coaxial 75ohm cable parallel to electrical mains 127V AC @ 60Hz

Everywhere we look at, the same recommendation is made: "never run coaxial cable parallel to electrical cables". Well, I get it, but.... I have no other option™. More than that, those cables ...
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2 votes
3 answers
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Effect of small length impedance discontinuity in a transmission line

Consider this arrangement of a radio, a long coax cable, a small length of "random" cable and an antenna. The radio, the coax and the antenna all have the same impedance, but the random ...
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1 answer
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Can telescopic FM/DAB antenna be replaced by Coax?

I tried to search for this prior to asking but with no luck... I have an FM/DAB+ antenna like this: from which a standard 75-Ohm Coax is coming down and I would like to connect it to the radio (...
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-3 votes
2 answers
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Can coaxial TV aerial cables be flat/ribbon? To go under thick rug for TV opposite aerial socket

A round shaped one would cause a ridge in the carpet. I already have setup a flat ethernet cable under the rug for similar scenario whereby device is opposite ethernet socket. Update it's to carry DVB-...
1 vote
1 answer
72 views

What energy/fields if any is generated when radio frequency is passed through a coaxial cable?

I am new here. Just had a question wondering if someone could answer. Let's say I have a generator that can generate RF and send it through a cable (coaxial) if I attached the end of that wire to a ...
8 votes
1 answer
330 views

Why are coaxial cables typically faster/longer than twisted pairs?

I'm having trouble understand why coaxial cables tend to have higher bandwidth compared to twisted pairs. I couldn't find any source explaining why, they just mention the fact. For instance: "In ...
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1 vote
4 answers
334 views

When does one have to take cable capacitance into consideration?

When feeding an RF signal to a coaxial transmission line, when do you have to take into consideration the capacitance of the cable? I am working with a 36 MHz signal. The total cable length is ~3 ft (...
-1 votes
1 answer
108 views

Does Multisim have coaxial cable? What simulation application can I use that has coaxial cable?

I want to use coaxial cable in a simulation. Is it available in Multisim or another simulation program?
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0 answers
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Ampere's Law with dielectric

I am asked to calculate the magnetic-field-strength and magnetic-flux-density for different regions inside a coaxial-cable. I found Ampere's Law for that, but it uses \$\mu_0\$ , and the coaxial-cable ...
1 vote
1 answer
77 views

Coaxial Transceiver - HF Signal & LF Signal on same cable

I have a project which needs a analog video signal & some control data sent on a coaxial cable, I came up with some ideas and I asked about it and some interesting answers were received (Multi &...
1 vote
4 answers
889 views

Attenuation for high frequency when using coaxial cable

Can someone tell me why high frequencies (1 MHz sine signals) are getting attenuated in the below case. I have a function generator with 600 Ω output impedence. I connect this output to a digitiser ...
1 vote
4 answers
307 views

How can I match a transmission line impedance on the source side?

Suppose that I want to transmit a signal by a coaxial cable to a high-impedance load. The signal is a single-ended TTL (3.3V) single square impulse from an FPGA output. The package of the FPGA is LQFP-...
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1 vote
3 answers
97 views

Coaxial Connector Termination

I am studying microwave engineering at university, but I never had a possibility to try to manufacture anything that I have been learned in my courses. So I have decided to try it by myself. I have ...
10 votes
3 answers
2k views

What does "mode-free" mean, in the context of coaxial connectors?

I've seen a number of coaxial connectors claimed to be rated for "mode-free operation up to (whatever) GHz"--but after much searching, I can't seem to find any definition of "mode-free&...
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1 answer
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What to do when studying "travelling wave" in a coaxial cable?

Propagation of travelling waves on cables may sometimes be difficult to apply and understand. There is a method called in french "abaque de Bewley" or "diagramme de Bergeron" (in ...
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0 answers
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Coaxial Cable Wiring on PCB (WiFi-Card)

*This post is just serving it's purpose as a discussion in case somone chance upon the same situation as me I'm really really new to this, so please bear with me. I got this PCIE wifi card from China, ...
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1 answer
72 views

Multi "Master "Coaxial Driver Design

I have an application which requires sending PAL video signal & UART infomation over a 50R coaxial cable without disrupting the PAL protocol while doing it, the total length of the cable is around ...
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1 answer
88 views

Why my television provider doesn't measure the coaxial cable length?

I recently put cable TV in my room (we already had cable TV before, but not in my room). The technician from my TV provider, through a split, ran a coaxial cable up to the TV in my room. When he did ...
1 vote
1 answer
85 views

Why do some SMA connectors have a rectangular center pins?

I came across an edge mount SMA connector where the soldering portion of the center pin is rectangular rather than round like normal. My initial assumption is a stronger solder joint. Any other ideas? ...
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1 answer
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Connect antenna to FM circuit

I designed a Colpitts oscillator with a single transistor amplifier stage. I now have to connect the antenna to the circuit through a coaxial cable. Do I have to redesign the output impedance of the ...
1 vote
1 answer
202 views

How to select a coaxial cable for 5kV DC and 0.1 mA

I need to select a coaxial cable that is safe to use with a DC voltage of up to 5kV DC and very low current - less than 0.1 mA. This cable will be used to supply power to a microchannel-plate (MCP) ...
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Name of a single-conductor coax test cable

Alright, bit of a silly question but I can't seem to get Digikey or Mouser to show me what I want. I'm wanting to replicate Fig. 7 of this INA116 datasheet almost exactly. Before I go and buy this ...
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2 votes
1 answer
89 views

Is an (n+1/4) wavelength transmission line impedance transformer comparable to a 1/4 wavelength line of the same composition?

I use coaxial transmission line transformers for simple power splitting and combining networks. This is for connecting multiple resonant antennas in array configurations. It's a standard technique ...
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3 answers
2k views

Derivation of resistance of coaxial cable

As given here, the derivation of Resistance for Coaxial Cables Consider a coaxial cable of length \$L\$, consisting of a cylindrical conductor of radius a surrounded by a cylindrical conducting shell ...
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1 answer
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The coaxial cable is claimed to show the highest common inductance (M) relative to any other cable configuration?

The coaxial cable is claimed to show the highest common inductance (M) relative to any other cable configuration [Henry W. Ott, (1988), Noise Reduction Techniques in Electronic Systems, 2 Ed., AT&...
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3 votes
1 answer
176 views

Can someone explain me these waveforms?

During this experiment, I connected a 10m coaxial cable to pulse generator and at the load end I connected capacitor and inductor one by one, I got these waveforms. Can someone explain me the the ...
0 votes
1 answer
181 views

Very old dual coaxial TV outlet, how to fix it to connect to a modern TV? [closed]

i've recently moved into an older updated apartment building and want to connect to the TV outlet but have a connection that i've never seen before. Can someone point me in the right direction of how ...
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1 vote
2 answers
230 views

Coaxial cable in IT Earthing System

We are developing a shipboard system which needs to be connected in a IT network (Unearthed neutral). In order to comply with this scheme we need to avoid negative-grounded, as all the metal ...
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1 vote
1 answer
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Coaxial cable test with VNA to estimate Wave Velocity and Attenuation

I'm doing a lab course concerning microwave measurements, during which I'm supposed to test an open, short and 50 Ohms terminated coaxial cable. The cable is connected to a VNA at the S_11 port and ...
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1 answer
293 views

How does the shield of a coaxial cable work?

let's consider a coaxial cable with only two conductors (the core and the external metallic shield), and let's consider the case in which it propagates TEM mode at a certain frequency: My question is:...
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1 vote
1 answer
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disagreement between theoretical calculation and measurement of upper cutoff frequency of a circuit based on RG58 coaxial cable

For a 100 meters RG58 coaxial cable, according to the datasheet, the capacitance of the cable is 10 nF and the inductance is of 25 µH approximately. A sinusoidal voltage is applied at the input of the ...
1 vote
2 answers
125 views

Why/How alternating currents through coaxial cable do not interfere with each other?

I know that cable TV use coaxial cable with alternating current frequencies varying from 5 MHz to 750 MHz. Why/How a alternating current of, for example, 5 MHz , 10 MHz, 20 MHz, 100 MHz, 300 MHz, 500 ...
1 vote
0 answers
105 views

Making my own coaxial hardline

I need about 50mm of coax hardline. I don't have any at home, but I do have a lathe, some copper, and some teflon stock. Can I make my own coax hardline on the lathe? According to my calculations, ...
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1 vote
2 answers
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Coaxial connector pins on dielectric

I have a single-side ifa antenna design to which I wish to solder a coaxial feed. Now, I only have this female SMA connector with 5 pins on the otherside that I wish to solder to my PCB. This may ...
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1 vote
0 answers
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What would you call a cable which combines both a coaxial transmission line and regular conductors?

I'm looking for a cable that can carry both dual supply (+5V and -5V at <100mA) DC power and a relatively high bandwidth analog signal. The intended application is powering the amplifier of an ...
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0 votes
1 answer
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Ultra Miniature Coaxial connector what does 50ohm stand for

In my current project I designed a PCB board for the ESP8266EX chip. Instead of making an onboard antenna, like in the datasheet described, I have placed this connecter. The goal is to be able to ...
15 votes
5 answers
3k views

How are unbalanced coaxial cables used for broadcasting TV signals without any problems?

As far as I know, in telephony STP or twisted pair cables are used. This creates balanced line impedances which is useful to mitigate for common mode related interference. So using balanced cables in ...
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6 votes
4 answers
212 views

Can two 802.11n devices communicate via a coaxial cable?

Coaxial cables with RP-SMA connectors are often used as extensions for external antennas / with software defined radios. What would happen if I were to connect two access points (wifi chips, via ...
1 vote
0 answers
146 views

Permittivity measurement using open-ended coaxial probe

I am trying to understand how the complex permittivity of liquids can be measured using an open-ended coaxial probe. For this kind of measurement, we put a open-ended coaxial line into the liquid ...
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1 vote
3 answers
321 views

LC Filter Design with coaxial input and output

I was trying to design a Chebychev high pass filter of 400MHz corner bandwidth, 0.2db ripple and 5 poles. I am confused with the proposed design in this filter design calculator. This calculator asks ...
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2 answers
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Rogowski coil current rating

Is there any relationship between sensitivity of rogowski coil and voltage rating of coaxial cable with it. For example if I just have the sensitivity of the coil and spec of coaxial cable, is there a ...
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1 vote
2 answers
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why is it bad if a coax cable (used for antenna cable) has multiple paths to ground?

I have an Internet modem/router device connected to a 20 foot LMR400 coaxial cable which uses N-to-N type connectors to connect to a 10 foot LMR400 cable, which is then connected into an ...
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7 votes
1 answer
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Why did CATV standarize in 75 ohms and everyone else in 50?

All of the CATV industry runs on 75 ohm systems, while most of the rest of the radio world uses 50 ohms. Why was this standard chosen? I was wondering this because good quality RG6 cable can be ...
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