Page 1 of 2 12 LastLast
Results 1 to 20 of 23

Thread: Ideas on 2M Vertical

  1. #1

    Default Ideas on 2M Vertical

    I ran across this 2M vertical antenna and am thinking about making one with some changes:

    http://kv5r.com/ham-radio/simple-2-meter-antenna

    I am thinking of using 1" aluminum tubing with a separator machined from either Nylon or Delrin. I would run the coax up through the lower tube then out through a hole in the separator and then attached to the elements with SS screws with the shield attached to the lower aluminum tube.

    Reckon this would work OK?

    Thanks,

    Justin B.
    KI5GKD

  2. #2
    Super Moderator 5B4AJB's Avatar
    Join Date
    Mar 2008
    Location
    Meneou, Cyprus
    Posts
    2,219

    Default

    A dipole for 2m won't give you much gain, you'll probably lose whatever signal you do get down the coax on the way to the radio.
    It might be worth a try as an experiment, but don't expect much DX with it...

    Have a look at this if you want to build a semi-decent antenna for 2m, take your time building it and it will perform well.
    However, I don't recommend mounting it outside, they are rather flimsy. On the other hand, its just wire & wood. The most expensive component is the variable capacitor trimmer...

  3. #3

    Default

    Dem - Thanks for the reply. Not really looking for any DX work right now but just wanting to stick up a simple external vertical antenna to talk through local repeaters. I just got my General this week and the last time I was on the air was in the early 70s with a Novice license, 40 meters, and CW so all this 2 meter phone stuff is new to me!

  4. #4

    Default

    I'm going to give it a whirl and see what happens. Ordered some 1" Al tubing from McMaster today so should be able to start on it by weekend. I'll let you know how it works.

  5. #5

    Default

    I see my last reply hasn't been approved but I'll post this anyway. My aluminum tubing should be here tomorrow and if I have time I'll start putting the antenna together and post pics

  6. #6

    Default

    probably okay, no worse than a cheapo mobile once adjusted, maybe you should look on youtube for the pvc cubical quad for 2 meters, thats what I'mm looking to use for my portable.

  7. #7
    Super Moderator 5B4AJB's Avatar
    Join Date
    Mar 2008
    Location
    Meneou, Cyprus
    Posts
    2,219

    Default

    It might be worth going for a mobile whip, you can reuse it on the car then...

  8. #8

    Default

    UPS was running really late today so maybe I'll play with it tomorrow.

    I have an MFJ-1402 on my truck so this will probably be up at our cabin. Our cabin is at 962 feet and I will be putting it on top of a tree that has been topped off at about 20'.

  9. #9

    Join Date
    Oct 2009
    Location
    Oulu, Finland
    Posts
    614

    Default

    Quote Originally Posted by Justin B View Post
    I have to confess, that I don't see the point of such an aerial - at least where I live (Finland), the metallic tape and plastic tubing would cost more than aluminium tubing. Also, Al tubing is just as easy to work with and to make the feed point, you can either use the method shown in the link or drill a small hole and use a screw for a more permanent/reliable fix. The centre joint piece can be short length of plastic tube or wood.

    I do "get" some of these "cheap 'n' cheerful" aerials, such as using copper tape on a backing of paper or card to make a "roll-up" Slim-JIM or a light-weight portable quad antenna, but this for one, I would say to use aluminium tubing.

  10. #10

    Join Date
    Oct 2009
    Location
    Oulu, Finland
    Posts
    614

    Default

    Quote Originally Posted by 5B4AJB View Post
    A dipole for 2m won't give you much gain, you'll probably lose whatever signal you do get down the coax on the way to the radio.
    It might be worth a try as an experiment, but don't expect much DX with it...

    Have a look at this if you want to build a semi-decent antenna for 2m, take your time building it and it will perform well.
    However, I don't recommend mounting it outside, they are rather flimsy. On the other hand, its just wire & wood. The most expensive component is the variable capacitor trimmer...
    If you take a little bit more time and effort, it shouldn't be flimsy and should last quite a while outside I have an old ARRL Antenna handbook, from 1968 and many of the complex aerials, such as quads and the like, are made using wood - they are even for HF, so are much bigger than the linked one.

  11. #11

    Default

    I agree that it likely wouldn't be durable and that's what prompted me to go the tubing route. The center insulator will be Delrin and adjustable so the spacing between top and bottom can be varied.

  12. #12

    Join Date
    Nov 2017
    Location
    With my wife
    Posts
    175

    Default

    I'm just glad to see someone is actually experimenting with antennas!

  13. #13

    Default

    OK, had some spare time this afternoon and I have finished the antenna! But, it's dark so I'll have to wait and test it tomorrow...

    I changed up from the first post and used the dimensions from this example:

    https://kv5r.com/ham-radio/2-meter-sleeve-dipole/

    I first made the center insulator. I cut a 6" piece of 1.25" Delrin and machined the ends to fit the ID of the tubing.






    I then cross-drilled into the insulator at an angle so the coax could be threaded through it.






    It was then time to est fit everything.






  14. #14

    Default Part 2 of build

    I then attached the lower element, soldered a lug to the coax shield, and connected it to the element with a stainless steel sheet metal screw.




    I had decided I wanted to be able to change the gap between the two elements and see if that changed the SWR so I slotted the top element.




    I then had to slot the insulator for clearance for the screw that would attach the coax to the top element.




    I then drilled a through hole and secured the top element with a stainless screw, washers, and nut to allow adjustment.




    Finally a lug was soldered to the coax center conductor and attached to the top element with a sheet metal screw.




    Finally a finished antenna!!


  15. #15

    Default

    Tested the antenna today, until wife.gov got tired of holding it and decided tweaking was in order. As initially assembled SWR was 1:3! I loosened the aduster screw and pulled the top element out about 1/2" and it got a little worse. I will disassemble and work over the separator insulator to allow the elements to be closer and try again when I get time. This will likely be the last update on this thread as having each and every post moderated, even after being registered for 12 days, is starting to get really old.
    Last edited by Justin B; Wed 25th Sep 2019 at 03:49.

  16. #16

    Default

    Well, it looks like I'm out of quarantine so thank you mods! I plan on getting a chunk of white PVC pipe next time I'm by HD so wife.mil doesn't have to hold it as she wasn't amused by being a tower. That might also have affected the SWR so we'll see.

  17. #17

    Default

    Quote Originally Posted by Justin B View Post
    Well, it looks like I'm out of quarantine so thank you mods! I plan on getting a chunk of white PVC pipe next time I'm by HD so wife.mil doesn't have to hold it as she wasn't amused by being a tower. That might also have affected the SWR so we'll see.
    Looks great! Thank you for posting the pictures.

  18. #18

    Default

    I had a little spare time today so I played around with this a bit. I mounted it on a 10' piece of 1 1/2" white sch 40 PVC with the coax running down through the pipe. I didn't do any element tuning but played around with different frequencies and found that at 146.92 I had achieved a 1:1.7 SWR and playing around further showed a pretty narrow range around that before SWR started climbing rapidly. I guess it is not a real high bandwidth antenna maybe using larger tubing would improve that characteristic. I'll do some more playing next week.

  19. #19

    Join Date
    Nov 2017
    Location
    With my wife
    Posts
    175

    Default

    Just having the machine shop makes antenna putzing so much more fun. That tubing looks pretty big as it is right now, not sure if you will gain anything that direction.

    Perhaps try making a 1/4 wave ground plane out of 1/2" tube stock for the upright and radials and see how the bandwidth compares.

    Man, I wish I had a milling machine and lathe.....

  20. #20

    Default

    If you lived a little closer I'd make you a great deal on an extra lathe! It took me years to convince wife.gov that I needed a lathe and now that I am a retired machinist she saw my wisdom. Every time I make something she needs/likes/uses I don't forget to subtly remind here...

    I might try the ground plane when I get caught up with other projects but that will be a ways down the road.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •