Questions tagged [link-budget]
The link-budget tag has no usage guidance.
10 questions
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Can an HT be harmed by transmitting near it with another HT?
Title sums the question up fairly well. I was recently testing two HTs and it was not until after keying a repeater with one that I thought about the fact that the other was sitting (turned on) only ...
- 21
4
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1
answer
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A first homebrew design: Band, antenna, and ground wave propagation
I'm working on a very simple homebrew transceiver and request review of our selected band, antenna, and power.
Background: A child got very interested in ham radio, as an incentive for to earn his ...
- 301
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2
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Link budget with transmitter duty cycle (satellite earth station to a 5G terrestrial receiver)
I want to calculate link budget in a communications link where transmitter is a small satellite earth station and victim is a 5G base station. The question that I have is whether we can account for ...
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5
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1
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Why does my received power rise so much when I connect an antenna?
I am in early stages of making a narrow-band radio receiver (block diagram below). To give you an idea, I am using a simple CP-FSK based modulation scheme, and have achieved 5dB SNR with a Tx signal ...
- 153
2
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2
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173
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Is the noisy spectrum from 20MHz to 330 MHz normal?
I have recently been testing some VHF/UHF antennas for reception in my Lab, and have noted something I could not explain. Following are the spectrum plots captured on our R&S FSV spectrum analyzer,...
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2
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1
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275
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Link budget validation for a UHF satellite ground station
I built a UHF satellite ground station. It has a yagi with G=16.1dBi and an LNA with G=20.1dB. It’s a 430 - 450 LNA with NF=0.68. The RF cable, rg174/u has I think close to a 1dB/m, which would mean ...
2
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1
answer
93
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Link Budget - Are there any restrictions in the formula?
Depending on the parameters used in the link budget formula it seems that one may come up with a received power (dBm) larger than the transmitter output power (dBm).
For example:
Frequency: 50 MHz
...
- 55
0
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1
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393
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Passive antenna system as a Wi-Fi repeater [duplicate]
I want to extend WiFi signal using a passive repeater between two isolated boxes (have to make both box wireless).
Transmitter antenna from box A is placed in the gap between box A and B.
In the same ...
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0
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306
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Uplink-limited vs. Downlink-limited
What is the definition of these terms? Would a system with signal to noise ratios of uplink 100dBHz and downlink 80dBHz be downlink-limited?
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4
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1
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Is there a technical reason to sell an LNA without advertising its gain?
I recently bought a couple SPF5189 low-noise amplifier boards via an online marketplace. One thing that struck me is that while nearly all the listings highlighted the LNA as having a noise figure of ...
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