Tagged Questions

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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1answer
64 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 ...
2
votes
3answers
153 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 ...
0
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1answer
52 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 ...
0
votes
1answer
33 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 ...
8
votes
1answer
140 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 ...
2
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0answers
58 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 ...
0
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0answers
16 views

Common failure modes of full-detent SMP connectors?

Full detent SMP connectors are rated to a maximum of 100 mating cycles. What are the typical failure modes of an SMP connector that has experienced too many mating cycles?
-1
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1answer
68 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 ...
1
vote
0answers
43 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 ...
0
votes
1answer
127 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
votes
2answers
100 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.
2
votes
1answer
152 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
votes
1answer
93 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 ...
5
votes
2answers
130 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 ...
1
vote
1answer
129 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
votes
2answers
169 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 ...
0
votes
3answers
411 views

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 ...
3
votes
2answers
97 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 ...
1
vote
2answers
173 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 ...
29
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7answers
2k views

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 ...
6
votes
3answers
180 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 ...
11
votes
1answer
429 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 ...
4
votes
2answers
259 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 ...