Amateur radio 2 meter J pole build from house wire.
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- Опубликовано: 6 сен 2024
- I've had a few requests for the 2 Meter version of the GMRS J pole, so here you go.
J pole calculator:
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Ed Fong J antenna website for twin lead J poles:
edsantennas.we...
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I have made this from 450 ohm ladder line, it was called a sloppy J, I put this in a pvc tube and used that as my first 2 meter antenna for at least my first year, now I use the same antenna as fieldday antenna. 73 pd5rv
Just built this, I set my goal for 146.000, center of the 2m band. I got 1.02 :1 SWR according to my Nano VNA. At 144 I got 1.4:1, at 148 I got 1.6:1. Look below for demensions.
I am American but got tired of converting metric to inches so I just went to Lowe's and bought a tape measure that measures standard and metric.
My exact measurements were: long leg 145.7 cm , short leg 47.6 cm, feed point 4.9 cm, the gap between short and long leg was 2cm.
Pro tip mentioned by someone else was, to straighten your wire before you start, put one end in a vice the other in a drill and hit it, it twists it and makes it incredibly straight.
If you twist it enough it will also work harden the copper too. It will be more rigid. This can be good and bad.
Nice instructional video. Best PVC J Antenna I've seen in a while. Straight forward, to the point, no fluff, and repeatable. Great job.
They are fantastic for the purpose. Handheld at home antenna. 10W is about all you can use. No more!
How would one make one of these so that you can use it with a 25 to 50 watt mobile radio?
Please explain why you think this can only handle 10 watts. To be honest, that sounds untrue. I would imagine hundreds of watts would be more accurate.
Thanks for the videos on the grms and 2 meter j pole. It’s nice to be self sufficient 73
I use 10ga. And 12ga. Just have to shave a bit in length as diameter increases, the length shortens. Copper pipe jpole is 2" shorter than speaker or house wire.
Great Information, Thanks Brother.
Great video, I'm going out to buy PVC now.
I'm planning on building one this weekend. Thanks for the video. Question; wont the small hook at the top affect the performance?
What feed line did you use on this? I'm thinking of giving it a try myself 🙂
I used some leftover RG8x I had laying around, but any good coax will suffice.
I made the gmrs j pole you did a video on, except I used bare ground wire. My swr on a vna shows 1.4:1 at 462.500 but at repeater input frequency it jumps to 2.5:1. What I see on the vna is a decent start but it ramps up fast in the graph through the gmrs band. Kinda like this one when you first tested it. Curios where I should trim? I took a very small cut on the short side without much change, maybe I need to trim the long side down to get the swr lower on the higher portion of the band? That part is confusing to me, lol. I'm a rookie at all this.
There's three adjustments you are able to make. Long leg length, short leg length, and feedpoint. By carefully notating SWR changes as you alter settings, you should be able to figure out what is going on.
@ricksshop I'm going to mess with the feed point this weekend, I have not tried that yet.
I messed with tuning and got my swr down to 1.1 at 462.575 and 1.6 at 467.675. Ended up trimming it and the long leg made the most difference. Thanks for the reply and the videos!
Did he really just say that his Tape Measure was only in inches?
The PVC pipe doesn't effect the effectiveness of the antenna at all eh? (Or atleast significantly)?
Gonna' make one of these BUT also have a long Cushcraft where the fiberglass "snapped" and was thinking about using a PVC pipe "brace" to sleeve over it. (maybe a foot to 18 inches toward the bottom). It's too good an antenna to just throw away (also, a new one like it is VERY expensive).
THANKS for he video!
Will 12 gauge wire work? That’s what I have on hand.
I used 12 gauge, it worked great
OH, BTW, how many watts will this handle?. I want to use it with atleast 80 watts...Thanks
does it matter if I use 12AWG wire?
It will work, lengths may be slightly shorter.
@@ricksshop yeah last night I just wound up making it anyway and you’re right the length were a little bit shorter. I’m getting a 1.5 SWR pretty much but I think I can make it better.
@@ricksshop I’m actually getting a 1.2 to a 1.5 right now but I think I may try moving the feed point, but I don’t know if I should move it up or down
A t-coupler could have made this easier for you.