11
votes
Accepted
Difference between antennas for Wi-Fi vs. ham repeaters
In order to use the same antenna design at different frequencies, "all you need to do" is scale all elements of the antenna proportionally to the difference in wavelength. For example, if you take a ...
8
votes
Accepted
What does an antenna range really mean?
With so many variables (antenna height, terrain, power, receiver sensitivity, frequency band, modulation mode, line loss, interference, time of day, other obstacles, (just to name a few)) such "...
6
votes
Can I communicate 40 miles away with a base setup
With 2 meter FM and common 50 W base or mobile transmitter power and plain vertical quarter wave antenna, range over flat ground to a similar station is roughly twenty-five miles, or forty km (limited ...
6
votes
How far does a watt equal in range in the FM band?
This is a link budget question. Transmit power is just one factor: others are terrain, antennas, frequency, quality, noise, and so on.
If we restrict the variables to typical values for FM commercial ...
6
votes
Accepted
Yagi vs Parabolic Dish for 2.4GHz Campus Wifi from 1,800ft away?
You can make a first order approximation by using typical WiFi ranges in combination with two free space path loss calculations.
802.11b/g has a typical indoor range of 150 feet. By calculating the ...
6
votes
Yagi vs Parabolic Dish for 2.4GHz Campus Wifi from 1,800ft away?
Depends on the particular Yagi or dish. Look for a published gain. Beware of low-quality manufacturers that publish erroneous data. Higher gain will correlate with higher probability of working. Point-...
6
votes
Radio Range vs. Frequency
This is an interesting question and while we may not be able to get to an exact answer, we can certainly explore the issues to consider.
First we start by calculating a primitive link budget. The ...
5
votes
Accepted
Can I estimate range of a low power transmission based on power (in mW)?
When a transmitter and receiver antenna are in line of sight with one another, we can calculate the effective loss of the path based on the distance between the transmitter and receiver antenna, the ...
5
votes
Increasing communication range by boosting output and input power
Is it possible to do without the power amplifier at TX ... by using a
high gain antenna for RX?
It is. You need another 27 dB (37-10) of antenna gain in addition to whatever you included in your ...
5
votes
What's the realistic SSB reception range for 25W on 20m and 40m?
Depends on ionospheric propagation conditions (sun spots, solar flux index, time-of-day, direction, and etc.).
People have completed QSOs at well over a thousand miles with a few milliwatts in CW. A ...
5
votes
What's the realistic SSB reception range for 25W on 20m and 40m?
All things are possible (if a bit harder). The CQ WW SSB contest has a QRP category (maximum of 5 watts of power), and the top scorers in that category in 2020 worked more than 100 countries in 48 ...
5
votes
Accepted
How to predict radio range of a product?
They use range specs to market VHF/UHF handhelds to people who don't understand radio, but those specs are essentially useless. Half a watt will easily go hundreds of km if there's nothing in the way, ...
4
votes
Can I communicate 40 miles away with a base setup
For VHF or UHF, your range is mostly going to be limited by terrain, like Zeiss Ikon writes. On flat terrain the radio horizon can be estimated by a simple formula, but that's not of much use if the ...
4
votes
Distance of Received Signals
The earlier iterations of the Chinese radios had their issues. This has gotten notably better in the last year or two but people largely dismiss minor issues since they are so inexpensive. So it could ...
3
votes
Could I expect 12 mile range with the GXT1000VP4 radios?
These radios will operate largely on a line of sight basis with a slight boost from refraction. This is known as the radio line of sight. It is given as:
$$D\approx1.41\sqrt{H} \tag 1$$
where D is ...
3
votes
Accepted
Could I expect 12 mile range with the GXT1000VP4 radios?
In Suburban Pennsylvania how much range could I expect from these
wallow talkies?
Well, this if very hard to answer, other than "it depends".
If you have an absolute clear day, high pressure, no ...
3
votes
Accepted
RF Coverage range doesn't improve inspite of increased Tx power
Transmit range involves a number of factors.
Propagation
At 100 MHz your signal range will be largely limited by line of site (LOS) although you may experience some fringing and reflections. This ...
3
votes
Distance of Received Signals
The manufacturing processes used for this brand of radio aren't very consistent. So, it wouldn't surprise me at all if one worked better than the other. You might also notice differences in how well ...
3
votes
Accepted
Amateur Radio Long Distance Data Communication
The most accessible way to get digital communication at that speed is WiFi. You could use unmodified consumer equipment, or getting a ham license would allow you to use frequencies not usually ...
3
votes
Increasing communication range by boosting output and input power
Amplification at the receiver is not equivalent to amplifying at the transmitter. This is because at the receiver, the signal is mixed with signal and noise. An amplifier can not distinguish between ...
3
votes
What's the realistic SSB reception range for 25W on 20m and 40m?
Can one reasonably make SSB contacts with 25W?
Yes you can, I have.
In fact I have transatlantic QSO's with 10 W.
Already mentioned prior: the lower the power the more the challenge, and more it ...
2
votes
Can I communicate 40 miles away with a base setup
At 40 miles (65 km), assuming that terrain doesn't get in the way, you have a choice between HF and VHF/UHF. For HF the radios are expensive, maybe \$600 for a good used one, and a simple wire ...
2
votes
Cobra hand held 50wxst aftermarket antenna
If you are going to buy an antenna designed for use with that handheld, then it should work fine. Otherwise, you need to make sure that you get an antenna designed for the frequencies used by the ...
2
votes
Accepted
Understand Radio Pattern of a WIFI antenna
The numbers arranged vertically are decibels. They tell you the relative radiant intensity in each direction. For example if in one particular direction you read 0 on that scale, and in another ...
2
votes
Amateur Radio Long Distance Data Communication
In a word, No. For 1Mb/s you'd need a line-of-sight connection, so over a 180-mile path, you would need multiple hops. The alternative would be satellite communications but the ham satellites have ...
2
votes
Accepted
How far does a watt equal in range in the FM band?
This depends in your intended communication. Are you trying to hit a fixed receiver, in which case you can aim an antenna to that receiver? or are you trying to communicate with a handheld or other ...
2
votes
What is the power increase required to double the range of RADAR?
I feel the answers here have gotten too complex. The simple answer to OP's question is for his radio transmission example there is only 1-way propagation hence the inverse square law. For radar ...
2
votes
What is a link budget, and how do I make one?
Let me take the later question out of the title.
how do I make one?
By using a tool, such as
Radio Mobile Online
Help is here, you don't need a free account to read it
This is a free tool, and ...
2
votes
Amateur Radio Long Distance Data Communication
What you are looking for does not 100% exist yet.
However there is something close to it:
AREDN , Amateur Radio Emergency Data Network
https://www.arednmesh.org/
It is mesh networking using Wifi ...
2
votes
LoRa Radio RFM96/98 SX1276/8 configuration settings for Longest Range
If your interest is simply to increase range, the metrics to watch on the tool are the "Link Budget" and the "Receiver Sensitivity" (lower right screen). These two numbers will change in concert. You ...
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