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Can I substitute a vertical antenna for a dipole? (Also, how do I protect it from lightning?) Answered

I have a project that requires a 87 foot long dipole antenna. Would it be possible to use a 44 foot long quarter-wave vertical antenna in place of it, to save space?
And is there any DIY way to protect the antenna from lightning? How well do they work compared to store-bought lightning arrests?


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blkhawk
blkhawk

11 years ago

You could attache an uninsulated copper ground wire to the antenna and connect the  to a copper ground rod hammered to the ground. To be honest with you lightning carries so many thousands of volts that it is almost impossible to protect our homes from lightning.

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Re-design
Re-design

Answer 11 years ago

I you connect the antenna to a ground you're defeating the purpose of the antenna.

A lightning ground has a small air gap to bridge to go to ground.

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blkhawk
blkhawk

Answer 11 years ago

I have seen many antennas grounded and they work perfectly fine. Grounding your antenna will protect your equipment from a build up of static electricity. Remember that electricity travels 'trough the path of least resistance". A lightning hit will cause catastrophic effects on any structure. Therefore, it is futile to try to reduce thousands of volts with an arrestor. Even surge protectors will not protect your electronic equipment from a lightning surge.
The only time you don't want a grounded antenna is with a crystal radio.

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Re-design
Re-design

Answer 11 years ago

You ground the pole.  You ground the radio. you don't ground the active element except thru an arrestor or a grounding block.  That actually grounds the outside line of the coax but during a strike acts as a short to ground.

Except on a GROUND antenna which uses the actual ground as the element.

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blkhawk
blkhawk

Answer 11 years ago

If you make an internet search you will find that grounding an antenna is highly recommended. Although it will not protect your equipment, your house, your antenna, or any other structure from lightning strike. Lightning strikes are catastrophic and will cause great damage to anything attached to the antenna.

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NachoMahma
NachoMahma

Answer 11 years ago

.  The antenna itself is NOT directly grounded. The spark gap that Re-design speaks of is one of the more common setups.
.  As you say, electricity takes the path of least resistance and if the antenna were grounded, all the signal would go to Earth (no transmission or reception).

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blkhawk
blkhawk

Answer 11 years ago

I stand corrected!

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Re-design
Re-design

Answer 11 years ago

Thru a grounding block or arrestor.

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NachoMahma
NachoMahma

11 years ago

.  The ARRL is the place to go for technical info on all thing radio.
.  It should be very easy to do, but you will lose some efficiency/range and you may need to add impedance matching circuitry.
.
.  ARRL also has some very good info on DIY lightning protection.