Antenna Material

[HHD1]

WARNING!

Super Noob Question!

What is the best material to construct your own antenna with?  I was thinking about the metal part.  My mind says Copper.  What are your thoughts and experiences?

[WSFL951]

32 minutes ago, HHD1 said:

WARNING!

Super Noob Question!

What is the best material to construct your own antenna with?  I was thinking about the metal part.  My mind says Copper.  What are your thoughts and experiences?

Copper is always the best material; it works well for HF but is not as effective for UHF and VHF.

[SteveShannon]

25 minutes ago, HHD1 said:

WARNING!

Super Noob Question!

What is the best material to construct your own antenna with?  I was thinking about the metal part.  My mind says Copper.  What are your thoughts and experiences?

Copper is excellent from a conductivity perspective, but it’s soft enough that a long length of it can stretch from its own weight.  One nice thing about copper is that even if it oxidizes at the connections it still has good conductivity.  
Aluminum is another excellent material from a conductivity perspective, but aluminum oxide is an insulator, which must be dealt with.

For a wire antenna, copper clad steel is one of the very best. At UHF current flows on the surface, rather than throughput the material, so copper clad steel wire sacrifices nothing and resists stretching.

But constructing an antenna is about more than just the material.  A lot depends on what kind of antenna you want to build and just as much depends on the frequency needed.  If you want a really good vertical antenna for a single UHF band like GMRS, you can easily build one using copper pipe or aluminum tubing.  The lengths are short so mechanical stresses are almost nil. 

[WSFL951]

5 minutes ago, HHD1 said:

What is a good average length for GMRS using copper pipe?

https://www.tothewoods.net/Comms-Inside-Baofeng-Rubber-Ducky-Antenna.php

Baofeng Rubber Ducky Antenna

[WRYZ926]

It really depends on what type of antenna you want to build as far as length goes. You typically want 1 foot for a 1/2 wave antenna for GMRS. A 1/2 wave is better than using a 1/4 wave. 1/4 wave antennas definitely need a good ground plane while 1/2 wave antennas do not need a ground plane.

You will definitely need a NanaVNA or antenna analyzer if you plan on building your own antennas. Always start a little long so that you can cut/trim to get the SWR correct. Like wood working, it is always easier to cut material off than it is to add material.

One of the guys in my local club has built j pole antennas for GMRS, 70cm, 6m, and even 11m/CB. He used aluminum tubing for the 6m and 11m/CB antennas. He had some old 75 ohm solid core coax that he used to make the 70cm and GMRS j pole antennas.

Some solid wire around 6 gauge will also work well for a 1/2 wave vertical GMRS antenna. You can always put the wire in some PVC pipe to protect it.

[WSEZ864]

I made a 2 meter ground plane from doubled up solid #12 wire. Worked well, but bent easily, even doubled and soldered for the entire lengths. Birds kept bending the radials down. I'm using it indoors for an SDR receiver and it does fine for broadcast FM and up.

@HHD1: A VHF/UHF ground plane is extremely easy to make using an SO239 bulkhead connector and pieces of copper wire. I think mine cost me about $8 to put together.

https://mgs4u.com/product/so-239-uhf-female-4-hole-panel-mount-solder-connector-for-0-405-inch-od-coax-7511-uhf/

https://w6af.com/wp-content/uploads/2012/02/quarter-wave-ground-plane-antenna-building-instructions.pdf

 

I was gifted a homebrew 2 meter J-Pole made of 3/4" &  1/2" copper pipe and it worked fine for what it was and was quite durable. The coax connection points eventually corroded and SWR went pretty high. Instead of repair, I just replaced it with a commercial aluminum ground plane, which seems to work better anyway.

[Borage257]

Aside from copper wire, I’ve used tape measures and rings from a trashed baby gate. If you use scrap, metal keep in mind, if it is coated in a white or light colored paint, your calculated measurements will be about 10%-15% bigger than what you need. This is because white paint has titanium dioxide in it. Titanium dioxide attenuates RF signal.

Edited Thursday at 10:03 PM by Borage257

[HHD1]

I'm talking about the part that picks up on the RF.    What metal works best?  Aluminum...? Copper...?  What do you think?

[Socalgmrs]

I got a marine buddy that build a great antenna from a coat hanger and it’s hanging in his attic.  Does about 60 miles from a 40w base unit.  I personally don’t have the time to mess with such things.  

[HHD1]

4 minutes ago, Socalgmrs said:

I got a marine buddy that build a great antenna from a coat hanger and it’s hanging in his attic.  Does about 60 miles from a 40w base unit.  I personally don’t have the time to mess with such things.  

That's interesting. 

I don't have time to experiment either.  But I feel like some knowledge while in a pinch, would be handy.  Life can change hard and fast.

Thanks for the reply.  Apparently, I have reached some kind of limit to reacting to posts.  It won't let me leave a like on your post.

[HHD1]

7 minutes ago, SteveShannon said:

If you want a really good vertical antenna for a single UHF band like GMRS, you can easily build one using copper pipe or aluminum tubing.  The lengths are short so mechanical stresses are almost nil. 

What is a good average length for GMRS using copper pipe?

[SteveShannon]

37 minutes ago, HHD1 said:

I'm talking about the part that picks up on the RF.    What metal works best?  Aluminum...? Copper...?  What do you think?

Either material works well at picking up RF.  Of far more importance is matching the design of the antenna to the need.

[HHD1]

1 hour ago, WSFL951 said:

https://www.tothewoods.net/Comms-Inside-Baofeng-Rubber-Ducky-Antenna.php

Baofeng Rubber Ducky Antenna

Very interesting

[WSFL951]

57 minutes ago, HHD1 said:

Very interesting

$20 Baofeng's antenna looks like.

is Made of copper wire?