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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Why are RF components and cables still so large?

With the advent of ICs in the past decades, circuits have decreased in size exponentially over time. However, it appears RF components and connections, with coax SMA cable, connectors, and components, ...
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43 views

Filter design on coax cable

I need to construct a high pass filter to place on a 75 ohm TV coaxial connection. The filter must be filtering on both the ground side and signal side of the coax cable since I have detected noise on ...
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2answers
98 views

Convert BNC to Ethernet to Coax/HDMI

I need to make a cable run of approximately 150 feet. The source is a security camera box and the destination is a large ~42" television with all the basic hookups. The source box is in a room right ...
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1answer
207 views

Can I solder a RG316 coax directly to a PCB instead of using the intended SMA connectors?

I have a length of RG-316 single shield 50Ω coaxial cable carrying a 5.8 GHz signal that I need to connect to a PCB. While cheap relative to most coaxial connectors, SMA connectors are still quite ...
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47 views

Coax cable + BNC temperature response

I have a couple of cheap prefabricated 1m 50 Ohm cables terminated with male BNC connectors. These connect to a device in an environmental test chamber which is cycling between 5 degC and 60 degC. I ...
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72 views

What is a coaxial balun and what is its construction?

I didn't quiet understand what a coaxial balun is. Is it a regular balun or its wiring is made up of coax? Also, i need to convert 75 ohms unbal to 50ohms bal impedance using "coaxial" balun. How do i ...
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1answer
167 views

Designing a simple ELF-VLF Receiver with Loop Antenna

I'm going to design a simple Receiver and Loop Antenna pair to receive signals repelled from Meteors upon hitting earth aerosphere with the frequencies around 3-30KHz. It's going to be introduced to ...
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1answer
62 views

Ballanced BNC cables?

I'm working in an experiment with high voltages and unfortunately a high voltage AC source is affecting the signal in my BNC coaxial cable (which is going into an oscilloscope or some other measuring ...
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1answer
144 views

Decoding coax signal

There is an old age board (doubt to be a PLC) which outputs keypad and touch panel data through a single BNC connector. I've managed to capture its output signal using oscope which is available in ...
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1answer
65 views

How do I learn to design a 50Ω coaxial interconnection/interface? [closed]

I've designed an electronic load for testing power supplies (circuit and photo in this post: Designing a *linear* MOSFET driver stage). The load can be controlled (programmed) using an arbitrary ...
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2answers
120 views

Cable Connector Identification [closed]

I recently bought Belkin Ultimate Surge Protector for protecting my modem, router and PC. I have a broadband connection from Cable provider (through modem via coaxial cable). Now I wish to connect ...
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2answers
222 views

Is there a simple way to DIY a coaxial male connector?

I have a 12V power supply that has a female coaxial plug like the one on the right in this image: I rigged something up with tinfoil just to see if it would work, but it's not ideal at all. ...
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1answer
366 views

Calculating attenuation of coax cable run

This question is related to my question about long-distance Ethernet. I discovered the Netsys NH-310C, a reasonably-priced device for converting Ethernet to coax for long-distance runs. The ...
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2answers
190 views

Threaded alternative to MMCX connectors which mates to RG-316/U

I'm currently in the process of redesigning the RF section of a communications system for a cube satellite. There are two PCBs in this system: one containing the down/up converters and modem, and ...
0
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1answer
192 views

Explain an oddity with coax internet signal loss

I debated which StackExchange site was best to post this question to. Please feel free to move it if I chose wrong. In my house, coax enters the wall in one bedroom and is terminated 1 foot later at ...
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1answer
102 views

Assembling my own antenna cable - considerations

I need to use a 4 m antenna cable on an application. Due to non-standard cable length and some more unrelated reasons, I am considering to assemble my own cable which I have not done such thing ...
3
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1answer
152 views

40 GHz spectrum analyzer with N-type coax input?

We have an old Rohde & Schwarz FSEK 30 that is advertised as having a range from 20 Hz to 40 GHz, with an N-type input connector. My conundrum is that a type-N connector with air dielectric ...
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3answers
238 views

reflection test on coax cable

I used a silicon coax cable (characteristic impedance 45 ohms) and sent a square wave with frequency 1 Mhz and amplitude 5V through it. The cable was teminated openly with no end resistance. I could ...
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1answer
80 views

How to terminate a coax connection into a receiver for best common-mode rejection?

I am designing a simple HF receiver as a hobby project. The design is similar to the SoftRock Lite II, and the antenna input looks like this: The SoftRock design doesn't really say how the inputs ...
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2answers
521 views

TTL signal: output impedance, overshoot and other characteristics

I have an assignment for my Electronic Measurements and Instrumentation course, specifically me and my group were asked to perform time and voltage measurements using reflectometry on coaxial cables. ...
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1answer
630 views

Jack type for a 12v DC motor

I have an Arduino with a motor shield and I use it to power 4 different DC motors. Motors are connected to the shield through a screw terminal. Since I am in the prototyping step, I am moving them ...
4
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2answers
367 views

Driving 74HC logic with sub-nano second clock reference

My goal: I am trying to phase lock a 74HC-based digital circuit from a clock reference at 10~15MHz pulse repetition rate. The pulse width is around 400 picosecond. The peak voltage is sometimes below ...
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1answer
399 views

Sending Signals over a Coaxial Cable [closed]

Recently I've been trying to understand how multiple signals can travel along a coax cable. Indeed, I have already read "How are multiple signals propagated in a coaxial cable?", but it doesn't seem ...
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4answers
386 views

How should I test a coaxial cable?

I'm a ham radio operator, but haven't been very active on HF bands for a while. I have an inverted-V antenna and a long run (approximately 25m) of coax that runs from my upstairs "shack" down the ...
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1answer
139 views

Two different length antennas can cause problems?

I am using two 443 MHz transceivers (FY-605 transceiver) with both having different antenna lengths. One antenna is around 12cm long and the other antenna is around 17cm long. Will this cause ...
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1answer
114 views

Help understanding onboard power supply measurement test connections

I recently came across this circuit for measuring the output of a TPS54620 switching regulator (12V->3.3V). I'm not a power engineer, so I'd like some help understanding the parts in red boxes ...
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1answer
2k views

Effects of impedance matching between 50 and 75 Ohm coaxial cables for 10 Mbit/s, Manchester-coded signals (20 MHz)

TL,DR: This is quite a bunch of text because I have included plenty of background info. However, there will finally be a good, and precise question: Should I use an impedance matching network when ...
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1answer
113 views

Why does it take less force to mate a full-detent SMPM connector than to demate?

As seen in the table at the bottom of the page the mating force of a full-detent SMPM connector is less than its demating force. This is the opposite of every other type of SMP/SMPM connector listed ...
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1answer
469 views

How boost a DVB-C signal [closed]

I receive a DVB-C signal from my broadcast TV provider, and I use coaxial cables and some splitters to connect my three televisions to the coaxial wall-socket. Unfortunately I have problems to ...
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0answers
106 views

Push-on coaxial connector with RF leakage performance comparable to threaded-coax connector?

In examining the performance characteristics of the push-on SMP connector I've noticed that the RF leakage is at best -80dB @ 3 GHz and then continues to degrade as the frequency increases to -65 dB ...
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1answer
767 views

Live wire touching ground, sends power back through TV cable [closed]

This bizarre show happened twice at my house. The first time it happened I only realized something was at fault when I was having to call the cable company every two weeks to fix the cable internet. ...
2
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2answers
341 views

Capacitance and Inductance properties of coaxial transmission lines

I'm interested to understand what affect the capacitance (between cable core and shielding) and the inductance have on a signal transmitting down a coaxial cable.
4
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1answer
595 views

Closed circuit Wifi over coax?

If you connect an access point to (PCIe/USB) Wifi card over coax (i.e. no antennas) will it work? If it would work, what would the maximum cable length be? (This is just a thought experiment. I ...
2
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1answer
132 views

Connecting two RF devices

I plan to build two RF modules. One is an analog down converter with a balanced output IF of ~50 MHz The second in a fast ADC @ 100 MSPS with balanced input. I want to have them separated for ...
7
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2answers
237 views

Industry standard measure for coaxial cable stiffness?

Is there an industry standard measure for coaxial cable stiffness? By stiffness I mean the spring force experienced when bending or deforming the cable. In my search for a highly flexible lab test ...
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1answer
414 views

GPS USB device with external coax antenna? [closed]

I've been looking around for a bit searching for a USB connected GPS reciever which i can hook up to my laptop. However, the building i'm sitting at is not ideal for recieving GPS signals but i do ...
3
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2answers
403 views

Why does coaxial cable cause this effect?

This is a follow-up question related to my non-contact voltage detection circuit (here). I wanted to be able to detect voltage in a wire a few feet away from the Arduino, so I added a length of RG174 ...
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3answers
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BNC splitter which separates ground and signal?

I'm a student doing research in a physics lab and we often have the need for a certain type of BNC cable splitter. This splitter has a BNC jack which accepts a single coaxial cable as input. It has ...
4
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2answers
135 views

Coax Impedance Explanation

I have been trying for a while to understand Coaxial Cable impedances for ham radio etc. use. I only know what it is not though. Coaxial Cable does not measure the rated impedance from one end to ...
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2answers
771 views

Re-broadcasting a wideband satellite television signal over a short distance?

Normally a coax cable connects a satellite dish to the receiver. I'm in a situation where I can't easily install a coax cable, but a wireless signal ought to be possible because it's only 10 meters ...
32
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7answers
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Why were coax cables used for networking?

Often, if older standards become obsolete, it's because they are superseded by newer technologies. In the past networking was done using coax, instead of the twisted pair used today. Why did they use ...
7
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3answers
398 views

Are the currents that travel on the outside of coax really “common mode”?

Consider a ladder-line transmission line. Given any currents on the two conductors, we can describe those currents as the current on each conductor individually, or: currents that flow one way on ...
13
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1answer
645 views

Is it possible to reject noise traveling on the outside of a coaxial transmission line?

Say I have some ordinary coax between a receiver and an antenna. That coax will have three currents in it: the desired signal an exactly equal an opposite current on the inside of the shield ...
6
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2answers
575 views

How good is coaxial cable?

My question relates to the accumulated AC voltage that will appear on the screen of a length of coax: If the cable is properly terminated at one end and fed with data (or any signal) at the other ...