If I replace it with a 1/2 wave, granted the SWR is the same as the 1/4 wave, will it give me a little more reach, lets say 3 miles instead of the 2.5 I get with the quarter wave?

Sorry if this is a stupid question, thanks for your answer...

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If I replace it with a 1/2 wave, granted the SWR is the same as the 1/4 wave, will it give me a little more reach, lets say 3 miles instead of the 2.5 I get with the quarter wave?

Sorry if this is a stupid question, thanks for your answer...

prcguy

If I replace it with a 1/2 wave, granted the SWR is the same as the 1/4 wave, will it give me a little more reach, lets say 3 miles instead of the 2.5 I get with the quarter wave?

Sorry if this is a stupid question, thanks for your answer...

What will make a HUGE difference is getting the antenna outside, and above the roof line of your house. Any antenna inside the house is going to perform poorly.

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......but goodness know how they would work at VHF.

Stick to the quarter wave ground plane and get it outside - it'll do the job.

An ideal 1/2 dipole antenna will have a 2.14dB increase of radiated power compared to a 1/4 GP. That is a bit more than a 50% increase.

To make a real dipole, that is a balanced antenna, properly connect to the coax, that is unbalanced, you must use a balun. Otherwise the dipole will work as a bad 1/4 with a lousy ground pin that is worse than your current 1/4 GP. The balun should be a 1:1 type for 50 or 75 ohm. The missmatch loss between 50 and 75 ohm is something like 0.2dB and the balun itself will probably also give a loss of 0.1-0.2dB but you will still have your needed 40% increase in power.

/Ubbe

prcguy

An ideal 1/2 dipole antenna will have a 2.14dB increase of radiated power compared to a 1/4 GP. That is a bit more than a 50% increase.

To make a real dipole, that is a balanced antenna, properly connect to the coax, that is unbalanced, you must use a balun. Otherwise the dipole will work as a bad 1/4 with a lousy ground pin that is worse than your current 1/4 GP. The balun should be a 1:1 type for 50 or 75 ohm. The missmatch loss between 50 and 75 ohm is something like 0.2dB and the balun itself will probably also give a loss of 0.1-0.2dB but you will still have your needed 40% increase in power.

/Ubbe

"A ¼ wavelength Ground Plane (or Mono-pole) is half of a dipole. Its major currents flow in the mono-pole radiator, and virtually none in the counterpoise. Its angle of radiation is very high, whereas, the (vertical) dipole has a radiation pattern near the horizon. Consequently, and practically speaking, the Ground Plane has half the gain of the half-wavelength dipole."

/Ubbe

You're right in that a 1/4 wave has half the gain of a halfwave. The 1/4 wave has 1.21 dbi gain and the halfwave has 2.14. Half of human observers can't even sense a change in a signal of 1 db, therefore the best bang for the buck is to get an antenna outside and in the clear, with low loss cable so that antenna height gain isn't nulified by feedline loss.

"A ¼ wavelength Ground Plane (or

Mono-pole) is half of a dipole. Its major currents flow in the mono-pole radiator, and virtually none in the counterpoise. Its angle of radiation is very high, whereas, the (vertical) dipole has a radiation pattern near the horizon. Consequently, and practically speaking, the Ground Plane has half the gain of the half-wavelength dipole."

/Ubbe

Pay particular attention to prcguy and ZL2MC in this thread.

Yes, a 1\2 wave ground plane will have 2 db gain over a 1\4 wave gp

and a 5\8 wave will have 3 db gain over a 1\4 wave gp

DBI is a non existent reference which is meaningless when comparing gain over a ground plane

and a 5\8 wave will have 3 db gain over a 1\4 wave gp

DBI is a non existent reference which is meaningless when comparing gain over a ground plane

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prcguy

Yes, a 1\2 wave ground plane will have 2 db gain over a 1\4 wave gp

and a 5\8 wave will have 3 db gain over a 1\4 wave gp

DBI is a non existent reference which is meaningless when comparing gain over a ground plane

Actually a reference to dbi is quite valid, establishing a reference point from which all antenna gains are derived. A 1/4 wave antenna exibits about 1.2 dbi gain, while a halfwave exibits 2.14 dbi, or an increase of .94 db.

and a 5\8 wave will have 3 db gain over a 1\4 wave gp

DBI is a non existent reference which is meaningless when comparing gain over a ground plane

An increase of 0.94dB over a theoretical 1/4 wave? Phooey - you'll never hear the difference.

Martin, I can certainly respect your opinion, because it's true for many folks. Those in pursuit of every fraction of a db advantage might disagree. You may not pursue the weakest of signals but some do. In some applications, in land mobile radio, 1/2 wave antennas have been historically preferred where no ground plane was available. I personally prefer the 5/8th wave most often.

An increase of 0.94dB over a theoretical 1/4 wave? Phooey - you'll never hear the difference.

prcguy

An increase of 0.94dB over a theoretical 1/4 wave? Phooey - you'll never hear the difference.

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