# Questions tagged [gain]

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### Calculating a real antenna gain from electric field strength?

Could someone please tell me if it is possible to measure the antenna gain simply by placing a field strength meter at a selected distance to my antenna, knowing the power applied to the antenna. ...
• 23
1 vote
351 views

### How to calculate passive repeater gain?

An active club in my area moved its repeater to a new location behind a big hill, and we can't join the regular social nets anymore. I'm not holding my breath that anyone in the gated HOA at the top ...
• 7,411
1 vote
3k views

### UV-5R High Gain Antenna Performance

My Baofeng UV-5R came with a shorter 6.5” antenna and a “high gain” 15.3” RH-771 antenna. In your experience, how much of a difference in range does the use of the longer antenna achieve?
• 229
208 views

### Half wave dipole with parasitic element, (Gain calculation)

good morning all, I have difficulties to find the correct formula that allows me to calculate the gain of half wave dipole in parallel with another parasitic half wave dipole. I'm trying to calculate ...
• 45
402 views

### Stacked Yagi Gain calculation

I had a quick look at a practice exam for the license in my country and had a question on stacked Yagi antenna. I have been looking around but the only thing I can find is the mention of an additional ...
• 209
244 views

### Gain of Yagi turnstile?

I am currently working on a system to communicate with amateur CubeSats. I have decided to use the turnstile crossed-dipole style yagi because it is relatively easy to construct and uses circular ...
• 23
3k views

### Give vertical antenna directional gain?

So here is a strange thought. If a vertical electrically speaking is a half dipole with the other half as a ground plane to balance out. Perhaps there are ways to make equivalent director and ...
• 135
4k views

### How does lowering the RF Gain help with SNR?

Let's say for sake of example we are in the 40m band. I've read articles and posts about riding the RF gain (or even just simply lowering it). And I can see how it is useful in overload situations. ...
• 781
1k views

### How to derive antenna gain from radiation pattern

I need to calculate the antenna gain in both dimensions: azimuth and elevation. The datasheet of the antennas I am using has two different radiation patterns, one for the elevation and one for the ...
2k views

### Gain difference between half-wave and infinitesimal dipole?

In discussion around another Q&A here, Glenn W9IQ commented: The directive gain difference between a half wavelength dipole and an infinitesimal dipole is only 0.39 dB I'm curious where this ...
• 7,411
3k views

### USRP Safe Gain Values

I am working with USRP N210 and USRP B200 radios with GNURadio. I have connected the TX/RX port of one radio to the RX2 port of the other with an RF cable as a simulated radio link. In GNURadio, I ...
• 33
1k views

### Gain in long wire antennas

DARA (you know, Hamvention) TNG is looking for projects. Thursday, I will be proposing building and characterizing a vertically-polarized 1 wavelength on a side reentrant rhombic. Since in doing the ...
404 views

### Why is gain used?

It always confused me why 100 watts out of your transmitter could radiate 200 watts coming from a high-gain antenna. Why is the term gain used instead of directionality?
• 7,620