1

I'm using RG-213 coaxial cable for two-way ham radio communication. But due to weather conditions, the metallic shield of my coaxial cable (RG-213) become rusty and carbonated.

If I use copper electrical cable 3/.029 as metallic shield with aforesaid (rusty metallic shield ) Coaxial Cable, what will be the result? Will it be the best solution for my damage metallic shield coaxial cable or not? Can i get the best two way communication with this method?

Kevin Reid AG6YO
  • 24,506
  • 7
  • 51
  • 103
ajmal nawaz
  • 11
  • 1

2 Answers2

2

You cannot repair a coaxial cable by wrapping or replacing the outer conductor (shield) with ordinary wire. The shape of the shield is critical to its functioning (determining the characteristic impedance) and the different impedance created by using differently shaped conductors will lead to reduced performance, and possibly damage your transmitter if it does not have high-SWR protection.

Weather-damaged coaxial cable should be replaced with new coaxial cable. Be sure to apply suitable sealing tape (self-amalgamating tape) to the end connectors after tightening them down if they will be exposed to moisture.

The one thing you can do for damaged cable is to cut off the damaged section and install a connector (a proper coaxial connector, not a splice) to join it to a new length. However, this is not a good idea for outdoor installations since it introduces more places for water to get in.

Kevin Reid AG6YO
  • 24,506
  • 7
  • 51
  • 103
  • That impedance bump has a minuscule effect below 50 Mhz, as it's only a tiny fraction of the wavelength. – Mike Waters Apr 04 '19 at 20:47
  • @MikeWaters I understood the question as asking about replacing a long length of shield with other wire. We don't know what the length is (I removed "bump" from the answer to improve it), and the question isn't about HF specifically either. – Kevin Reid AG6YO Apr 04 '19 at 20:52
  • Yes, he does not specify the frequency of interest (I just asked that), thus my comment. – Mike Waters Apr 04 '19 at 20:54
  • I get that now. But what is "electric strained wire"? :-) – Mike Waters Apr 04 '19 at 21:00
  • Also, "this is not a good idea for outdoor installations since it introduces more places for water to get in" is generally very good advice indeed. We've had years of practice and experience doing just that, and with great success. Others -especially newbies- have not. – Mike Waters Apr 04 '19 at 21:06
  • 1
    i m the user of VHF Band.(140-170MHZ). My Tx co-axial Cable is 150 feet and Rx co-axial cable length is 130 feet. this Tx/Rx is with respect to Repeater Station. I m using Diamond F-22 Antenna for Tx/Rx . – ajmal nawaz Apr 05 '19 at 09:23
  • 1
    Images of damage outer shield of coaxial cable will be posted within 02-03 days. it will clear my question to you and then i think i will be better guided by you. – ajmal nawaz Apr 05 '19 at 09:25
  • 1
    @ajmalnawaz Please edit your question when providing additional information; do not put it only in comments. – Kevin Reid AG6YO Apr 05 '19 at 16:05
1

If part or all of the shield of your coax is corroded, then that entire portion of the coaxial cable must be discarded.

  • The corrosion causes the individual strands of the shield to be isolated from one another, significantly reducing the shielding effect of the braid.

  • It also causes noise to be heard in your receiver.

And as Kevin correctly stated in another answer here:

You cannot repair a coaxial cable by wrapping or replacing the outer conductor (shield) with ordinary wire. The shape of the shield is critical to its functioning (determining the characteristic impedance) and the different impedance created by using differently shaped conductors will lead to reduced performance, and possibly damage your transmitter ...

Mike Waters
  • 7,948
  • 4
  • 18
  • 51