Two Way Radio Antennas

Two radio antennas A and B radiate in phase. Antenna B is a distance of 110 m to the right of antenna A. Consider point Q along the extension of the line connecting the antennas, a horizontal distance of 50.0 m to the right of antenna B. The frequency, and hence the wavelength, of the emitted waves can be varied

Part A
What is the longest wavelength for which there will be destructive interference at point Q?

What is the longest wavelength for which there will be constructive interference at point Q?

Sorry this all I had time to get.not ans.
λ = 300,000,000/f
Destructive interference occurs when 1/(nλ)^2 = 1/(λ(m + 1/2)^2, or 1/(n)^2 = 1/(m + 1/2)^2

2008-11-19 01:25:01 by Sidhucer

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The two antennas radiate in phase at a frequency of 5.6 MHz. All radio measurements are made far from the antennas. The smallest angle, reckoned north of east from the antennas, at which destructive interference of the two radio waves occurs, is closest to:

a) 13 degrees
b) 9.7 degrees
c) 19 degrees
d) 6.4 degrees
e) 16 degrees

λ = 300,000,000/5,600,000 = 3000/56 m
λ/2 = 1500/56
200/λ = 56/15 cycles
Now the question becomes, "measured North of East from where?".
Destructive interference occurs when 1/(nλ)^2 = 1/(λ(m + 1/2)^2, or 1/(n)^2 = 1/(m + 1/2)^2

2007-04-02 02:19:32 by The one and only

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The two antennas radiate in phase at a frequency of 3.6 MHz. All radio measurements are made far from the antennas. The smallest angle, reckoned east of north from the antennas, at which constructive interference of two radio waves occurs, is closest to:

a) 50 degrees
b) 40 degrees
c) 45 degrees
d) 55 degrees
e) 35 degrees

this is Young interference problem with radio waves

if you consult your textbook you will find

dsin(theta)=k(lamda) for constructive interference
here k=1 because it is said that it is the first max (smallest angle) lamda is the wavelenght of the radiation, and d=130m,

lamda=c/f where c=speed of light in meters, and f=frequency in hertz

so

sin (theta)= lamda/d

here lamda= 83 meters
then sin (theta)=83/130 then theta=40 degrees

2007-04-02 02:13:05 by The one and only

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Can someone tell me about CB antennas? i have two fiberglass antennas, one is 4' the other is 3' and i'd like to use the both of them on my truck.

Do i just get two lengths of coax and use a Y adapter to join them in the middle to the radio or is there more to it?

I have them mounted to either side od the hood in the front.

also, is it much better to solder the conections or can i just use solderless?

thanks!
rhsaunders... just cirious as i do not know, but how can this be true when every big-rig truck i see has two antennas?

the set-up you are referring to is called "Twin Truckers" and yes you can.

setting up two identical antennas on either side of the vehicle will give you a more omnidirectional range. you'll want to mount them as close to the center of the vehicle as possible. ideally mount one at the front center bumper of the truck and one at the back center bumper... but it'll look funny.

keep your connections tight and it'll work just fine.

2007-03-14 09:35:24 by RagingEmpire

LRRA uses FMCW signal to find out the aircraft altitude above the terrain ,for transmission and reception it uses 2 different antennas.

one to receive, one to transmit.

2007-01-18 08:04:51 by meelindpaande