Questions tagged [coax]

Coaxial cable, or coax, is a type of cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield.

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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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Connect antenna to circuit

I have an antenna with an N-type connection that I am trying to connect to a circuit. I have soldered wires to a connector: I have attempted to connect the wires to the circuit: However, I am not ...
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Coax cable 130 dB vs 135 dB, which one is better?

I need to buy some coax cable for TV via satellite. I see they are marked in dB: 135, 130, 120 down to 95. Then there are multiple layers (up to 5) and shielding copper (cu) vs aluminum (alu.) Is my ...
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Two devices sharing the same coaxial cable, what frequency channel should I chose? [closed]

The 2-stories house is equipped with a coaxial cable that has wall plugs in 1st and 2nd floors (it's also connected to the antenna on the roof). Our IAP installed a modem for Internet (Arris CM820C) ...
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RF pickup noise through coaxial cables and connectors [closed]

We use RF antenna to transmit RF power in the near field regime. The typical wavelength is ~ 10 MHz whereas the antenna itself is only a few cm long(3 loops of a copper wire). We see that for a power ...
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What causes common mode currents in a coaxial cable?

I have been messing around with a signal generator, an RF current probe and an open ended coax cable. From about 50 MHz onwards, I can measure a significant common mode current if I attach some wires (...
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How to switch off the CATV signal on a splitter port

I'm trying to create some automation of switching off the CATV signal on a splitter port. Using a regular 5V Arduino relay module I've tried to interrupt the wire from the center of the coaxial cable ...
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What is this metal box with BNC connectors for?

I found this box with a schematic drawn on it. What is it for?
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Differential signals in micro-coax

I have seen many applications where micro-coax is used for differential signals. For example display panels with LVDS or eDP, and a I-PEX VS type connector. The I-PEX connector even names USB4, HDMI ...
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Coaxial Cable with signal applied to shield and center conductor grounded

The standard way to drive a signal through a coaxial cable is to have the shield grounded, and a single-ended signal applied to the center conductor. (Throughout, I will assume that \$R_{term}\$ and \...
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Why don't oscilloscope probes use twisted pairs?

I was reading online about how Ethernet cables use twisted pairs instead of coaxial cables because it's better in some way. Some websites say that twisted pairs cost less, can carry higher frequencies,...
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Why are Coax-to-Ethernet converters causing the entire network to stop working?

I have installed nine of these Coax-to-Ethernet passive converters, which allow me to use existing coax cables to transmit Ethernet traffic from IP cameras. This was necessary due to the inability to ...
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Can alligator clips be soldered to PCB pads?

I have a coaxial Teflon wire that is carry some high voltage signal. I do not want to solder it directly to the PCB pad as there can be issue of short circuit as there are components placed nearby the ...
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How to quantify Td and Z0 for a given length of RG-58 coax cable in LTspice?

I want to simulate a current source (on the left in below) is connected to a scope input via a meter long RG-58 coax cable. But, I cannot figure out what should Td and Z0 be. I only found the coax ...
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Instrumentation for high frequency pulse

to be updated... I have an optical pulsed laser source (has no manual.) Its monitor output has on its certificate for at 3MHz frequency stated as 0.5 ns pulse duration (ON time.) The output supposed ...
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What does a 50 ohm coax "look like" when neither the source nor the load are matched to it, and the center conductor and shield are used for signals?

Say I have a π-network filter for which the inductor is on a separate board. For convenience, I use a 50 ohm coax (4" long, frequency is 13.56 MHz) to connect to the inductor, using the center ...
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Replace a short length of triaxial cable with a PCB transmission line

I am working on a project that benefits from a short (~1") length of triaxial cable. At first I was skeptical that the cable would have any effect given its short length, but the performance is ...
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Is there a wired block wifi signal amplifier?

I already have a directional wi-fi 2.4 antenna with a gain of about 25 dbi. I also have an adapter, however, the power of the receiver/transmitter is not enough. My apartment is on the 9th floor, ...
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Modeling bidirectional communication across a coax?

I was reading about the history of cable internet and I'm interested in a simple model of full-duplex communications across a single coaxial cable. My first attempt is simply a transmission line with ...
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How do terminate the coax shield of AC coupled LVDS signal? (isolated grounds)

I have an LVDS clock signal that goes to several PCB cards. Frequency: 100Hz --> 20MHz I am going to use a fan out IC to supply each card with it's own buffered CLK signal; I am not going do a '...
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Can I use Ethernet UTP instead of COAX for satellite TV

I'm planning on having a satellite TV subscription installed on my home, when the satellite dish is installed they will need to run a coax cable from the satellite dish all the way to the decoder ...
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Connecting 50ohm coax with regular wires on slipring

I'm building a device where I need to interface coax cable (50ohm RG174) to a slipring. The slipring has several channels, breaking out into regular (silver-plated copper) cables. I assume I can ...
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2 votes
1 answer
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Passive Ethernet-over-coax converters... how do they work?

I just bought a pair of these passive ethernet-over-coax converters. I was very skeptical, but they actually work! I just can't figure out how... they do not require external power, coax only has ...
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Best way to connect coax along a microstrip

I have an open-ended (stripped, if needed) coaxial cable that I would like to use to insert a signal into a microstrip. The circuit (operating at ca. 18 GHz) however, is made in a way where I can't ...
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Antenna Attenuation, Gain and RSSI calculation

I am using a RAK7258 LoRa gateway operating at EU-868MHz. I am looking to have the gateway and the antenna on each side of a wall (gateway inside, antenna outside) and receive some packets from some ...
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3 answers
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Why is a coaxial cable unbalanced?

Let's consider a coaxial cable which supplies a dipole antenna. My reference for all my statements is here. My reference says: Note that the current along a transmission line should be of equal ...
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Coax or STP input to the Deserializer

I have this MAX9278 deserializer. I am planning to give Shielded Twisted Pair (STP) input to the IN+ and IN- pins of the deserializer instead of COAX input. Can someone help me to let me know what ...
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How to identify a coax connector vs twisted pair connector

I need to have a connector that will bring in COAX input to my PCB. I have this Rosenberger HSD Connector Catalog. On page 33, "99S12D-40MA5-y" - is this connector a twisted pair connector ...
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12 DC Power 3.5A to TV via Antenna Cable [closed]

I am looking for a single connection to a TV which is powered by 12Vdc 3.5A Max, I would like to power the TV via the coaxial cable and also use the coax cable as an antenna input. I am looking for ...
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Problems with small signals through BNC connectors?

I have a 120kHz signal from a transducer with peak to peak values of typically 40mV being carried over coax cable and connected at both ends via BNC connectors. Most of the time this seems to work, ...
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How does one properly strip coaxial cable to nonstandard strip lengths?

For my job, I need to put SHV connectors on a couple lengths of RG-59. I have the cable, the connector, and the crimping tool, but I've hit a snag: I don't have the slightest idea how to properly ...
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Power loss due to mismatch impedance connector in coaxial line

Not being an electronics professional but face the following problem I hope you can help me. I would like to estimate the losses due to an impedance mismatch of connector used in wall-crossing of a ...
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Effect of coax mismatch

I have some accelerometer vibration sensors that pass into a cabinet. They use BNC type bulkheads. Several of the bulkheads got damaged. The original bulkheads are 50 ohm and the coax cables on either ...
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Female F connector diameter

I am having trouble finding the exact spec for the female F connector- what I need exactly is to know what is the connector diameter and the thread width. I found some info on Wikipedia, but its not ...
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Does using a push only plug for and F connector in a coaxial cable decreases the signal or adds noise?

I'm intending to find a replacement cable for my cablemodem unit. The existing cable that the phone company installed is a screw in terminal on both ends of the coaxial cable with one end connected to ...
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1 vote
1 answer
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Protecting LEDs driven by pulse generator via coax cable

I am a student in physics, and I have a project where I need to pulse LEDs with short pulse widths. I have a SRS DG645 pulse generator and using these LEDs. I have an RG58 coax cable with a BNC ...
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signal types and wire types

I am trying to understand the selection criterion for choosing between a signal types and wire type out of the following: Signal types: Gnd reference uni-polar signal Gnd reference bi-polar signal ...
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Digital Communication \$T_x\$ and \$R_x\$ for Dish - Coaxial Cable - TV Setup

I have a question in mind regarding transmitters and receivers. Let's say we have a dish then a coaxial cable connecting our dish to the TV. Can we consider the Dish as a transmitter \$T_x\$ and the ...
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Op-amp input signal problem, mismatched

My signal generator drives a 50 ohm coaxial cable, terminated with a 50 ohm to ground at the input of a voltage amplifier. However, when I look at my input signal over frequency, it doesn't behave as ...
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Can a differential probe and regular coax wire be connected safely to only one channel of scope using a tee connector?

I would like to ask if I can connect a differential probe and a coax wire through a tee connector to 1 channel of an oscilloscope, in order to take different DC measurements. The connection topology ...
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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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2 votes
2 answers
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My simulated coax cut off frequency is way far off the calculated value

I used the lumped model to model a coax cable as a low pass filter in MATLAB. I also included ESR which is supposed to resemble the dielectric losses. I derived my transfer function from the circuit ...
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3 votes
1 answer
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"To ground" or "not to ground" a coax to prevent RF ingress?

I have a communications system that connects a self-powered sensor circuit to a wall-powered processing/analyzing circuit by coax cable The coax reaches out about 60m, and it is matched/terminated at ...
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Measuring Current in Coax Cable Using Clamp on Current Probe

I once again find myself needing to measure the RF current in a coaxial cable. The signal in question is a high power (100W-1kW range) signal which is a stepped waveform with a 5MHz fundemental with ...
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1 vote
1 answer
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Coax Cable Wave Impedance, Capacitive Load

I am studying the behaviour of cables over frequency, especially what a source sees, and have 2 Questions, as I did some simulations in LtSpice. As a model for the cable I used the "Lossy ...
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DC Coaxial Power Connector Rated for 20A

I have a 12V 20A power adapter seen here (https://www.ledwholesalers.com/v2/index.php?route=product/product&path=40_117&product_id=999). I would like to connect to this power supply, but my ...
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2 votes
5 answers
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Coax cable - capacitive load

I still have an understanding problem with impedance matched coaxial cable and its behaviour. We do impedance matching to prevent reflections. How does my signal source see the whole cable? At a ...
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Troubleshooting NOAA double cross antenna

I've been trying to recive NOAA automatic picture transmission (APT) pictures for a year now. I never got a picture with V-dipole, so I decided to build a double cross antenna. I used 75 ohm coax ...
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1 vote
2 answers
218 views

Jacket diameter of coaxial cable : how to read those documentations?

Before anything: I am not an electrical engineer: I don't know very much coaxial cables (just the very basics). I need to do some orders of magnitude calculation of heat transport of typical coaxial ...
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Coaxial cable terminology : how to read?

I need to understand the nomenclature used for coaxial cable. For example: UT-085-SS-SS, or UT-085-SS, or UT-085-NbTi As far as I understood, the number 085 here is the total diameter of the cable ...
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