Sidebar Sidebar
  • You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

cutting 11 meter antenna down to 2 meter 5/8 wave

medic18d

medic18d

Active Member
Nov 23, 2013
176
32
38
Hello ,

I have an old firestik fiberglass antenna (7 foot) which is composed of a fiberglass rod and simply a copper 14 ga wire wrapped around the fiberglass shaft. I want to use it as a 5/8 wave base antenna . I have spent quite a bit of
money on my 2 meter mobile antenna and i would like to save a few dollars . Money is not tight, i like the thought of using this old antenna vs spending more money. I know there are a few guys on here that are pretty creative and resourceful. any help on this matter would be greatly appreciated.

Does any one have any experience with cutting an antenna like this ?
Do you recommend keeping the copper wrapped around the shaft or unwrap and run it straight?


DOC Cooper
SOC NSW
USN Retired
 

Well; you could do that. But that would just be a waste of a decent 11m antenna - IMO. Because you would have to chop it down to a 1/4 wave length of 2m, which is approximately 19 1/2 inches. You would be better served by just making a 1/4w 2m antenna out of a piece of metal coat hanger or using a 24 - 3/8" threaded rod to accomplish the very same end.

A 1/2w antenna would be twice the length of the 1/4w antenna; but it would require fabricating a loading coil and capacitor to make the impedance 50 ohms. Not saying it couldn't be done; but it would prove to be difficult for anyone seeking instant gratification - IMO . . .
 
  • Like
Reactions: 1 person
Robb said:
Well; you could do that. But that would just be a waste of a decent 11m antenna - IMO. Because you would have to chop it down to a 1/4 wave length of 2m, which is approximately 19 1/2 inches. You would be better served by just making a 1/4w 2m antenna out of a piece of metal coat hanger or using a 24 - 3/8" threaded rod to accomplish the very same end.

A 1/2w antenna would be twice the length of the 1/4w antenna; but it would require fabricating a loading coil and capacitor to make the impedance 50 ohms. Not saying it couldn't be done; but it would prove to be difficult for anyone seeking instant gratification - IMO . . .
Click to expand...

Thank you , ill just buy a 5/8 wave base . i do not want a 1/4 wave for a base.
I do not have a matching system. if i were using it for a mobile i would be ok with a 1/4 wave . thx and 73's
 
Keep in mind that a 1/2 wave or 5/8 wave antenna needs a loading coil and matching system to make it work. Simply cutting an antenna to the proper length is not the only thing you need to do.
 
  • Like
Reactions: 1 person
Yes you can use it ,but you will have to rewind it. You will need to wind a 8 turn coil Approx at the base for matching .And the antenna will require a ground plane.( 4 x 19 "radials)
 
Last edited:
  • Like
Reactions: 1 person
vkrules said:
Yes you can use it ,but you will have to rewind it. You will need to wind a 8 turn coil at the base for matching .And the antenna will require a ground plane.( 4 x 19 "radials)
Click to expand...


Ill atleast try that to see what kind of SWR i can get. Thanks this will give me something to tinker with for a while . If it doesn't work, no worries i do love to experiment. It can be alot of fun and pretty rewarding when it works that is .haha.


DOC COOPER
SOC NSW
USN Retired
 
You can convert a base loaded mobile 1/4 wave CB antenna into a 5/8 wave two meter antenna by simply re-tapping the coil in the base if you can access it. I did that in my early ham days to save a few bucks on 2 meter antennas. I got the idea from the 1987 ARRL Amateur Handbook and found the correct place on the coil by trial and error.
 
Done several, but I'm not familiar with the fire stick ,so I cant give you the exact no of turns. ( the last one I did ended up 8 turns but could be as high as 12)The trick is to end up with an antenna that is about 49 inch ( not that critical)and still have a good swr.A 3/4 wave ( about 58 inch )will have a good swr but the pattern is rubbish. So what we are trying to do is load a electrical 3/4 wave down to a physical 5/8 in length.You see this done with vhf commercial antenna. Start with about 60 " of wire .Hold the coil down with tape and don't cut the wire to start with just fold it over, saves time if you have to do over. Hope this makes sense.
 
RatsoW8 said:
You can convert a base loaded mobile 1/4 wave CB antenna into a 5/8 wave two meter antenna by simply re-tapping the coil in the base if you can access it. I did that in my early ham days to save a few bucks on 2 meter antennas. I got the idea from the 1987 ARRL Amateur Handbook and found the correct place on the coil by trial and error.
Click to expand...

there is no coil just a single wire wrapped around a pole . i wish i could upload a photo.

thanks though
 
IMO - that top-loaded 7 ft Firestick is a decent enough antenna to keep for 11m.

If you really want to build a fine 2m antenna; then try to build a scaled down Sirio Vector 4000. 'Bout as stout as they come. Build it out of aluminum tubing and fabricate the gamma match using RG-8 coax.
That antenna will SMOKE!
 
vkrules said:
Yes you can use it ,but you will have to rewind it. You will need to wind a 8 turn coil Approx at the base for matching .And the antenna will require a ground plane.( 4 x 19 "radials)
Click to expand...

just made a 1/4 wave with copper wire and a cb terminal ill post pics works great
 
  • Like
Reactions: 1 person

dxChat
Help Users
  • No one is chatting at the moment.


      Top Bottom
      Back