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Old March 25th 18, 03:15 PM posted to rec.radio.amateur.antenna
Ian Jackson[_4_] Ian Jackson[_4_] is offline
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First recorded activity by RadioBanter: May 2017
Posts: 32
Default Antennas That Don't Need Grounding For An Apt.

In message , Catweazel
writes
On 25/03/2018 04:09, wrote:
I am taking my ham test in two weeks and I just found out you have to
ground your equipment. I live in a apt without copper, water pipes. I
have heard a dipole antenna would work. Any comments.

so would a loop antenna; no ground required.


I have a feeling that you might not be quite ready for your test -
unless the level required is (say) only for you to know where the on-off
switch is, and which socket is for the antenna and which is for the
microphone.

But to answer your post, it rather depends on what purpose the 'ground'
connection serves. If it's only for safety, it may serve no function for
carrying RF currents.

If the ground IS for RF purposes, maybe it helps if you think of feeding
RF into an antenna as being a bit like when you're sitting in a rowing
boat on a lake - but without any oars.

Assuming you don't resort to paddling with your hands (!), there are two
obvious ways you can make your boat (the RF) move:
1. Push against something that can't move (for example, the shore). In
this case, the shore doesn't move, and all the movement goes into your
boat.
2. Push against something that CAN move (for example, another, similar,
rowing boat). In this case BOTH boats will move - but half of the
movement goes into your boat, and half goes into the other boat.

[I'll leave it to you to work out which (rather crude) analogy applies
to an antenna that needs a ground, and which one doesn't.]

Of course, with some antennas the 'ground' might not be a physical
connection to ground (earth). The 'ground' (which doesn't radiate) might
be part of the antenna system that simply makes the 'hot' side of the
antenna (which does radiate) think that it DOES have a ground.

But as I said, before your test, you might need to do some very basic
study on some of various types of antenna, and how they work.
--
Ian