My home built Dipole

[ausscan]

Thought I'd share what my last project was, a home made Dipole.



It is made from 2m of 20mm aluminum tube, a 20mm conduit a "t" piece, 3 chair end caps, a couple of screws, a few pop rivets, a couple of terminals and coax to suit. All up cost me less than AU$40, and it outperforms any antenna I've had before.

This is it mounted to my hockey stick on the side of my house.



I know its a bit wonky, when I drilled the holes for the bracket I used my cordless and it wasnt on a straight surface.

For info on how to build see here

[ridgescan]

Hmm.76 reads and not one reply...typical RR fashion-that's a cool one-what freqs are you monitoring with it? VHF high?

[kb0nly]

I got busy otherwise i would have replied sooner! Looked at it but now that i got time to comment...

Nice job!

I see you put some wraps of the coax on the boom for a choke also, good job! What frequency is it for? Considering its length i'm guessing its not VHF.

[n4yek]

Originally Posted by kb0nly

What frequency is it for? Considering its length i'm guessing its not VHF.

He cut it for 421 MHz according to the link below his picture in post #48 of that forum.

[digitalanalog]

Nicely done, thanks for sharing

[Zard0z]

Nice work! I always like to see the home made stuff! I just made a offest Dipole myself.

I was amazed like you how well the do work!! Plus I had a blast so far building it. Mine
cost more cause i needed supplies but my next one will cost less

Let us know if you can get a wide range of freq's than what it was built for! I would be
interested in any performace data that you come up with.

[ausscan]

I built it primarily for 421-422 mhz as that is what the Ambo's and Metro Fire use around here, but it performs just as well at 163 & past 500mhz too. I use it on my 396 and it can pick up 800mhz systems from about 45km's away without fail

[kb2vxa]

I'm not surprised, it's a half wave on 400 and a full wave on 800. It's a BS impedance on 500 but what the heck, it works. Now MY questions are what is a "hockey stick" antenna and is the dipole mounted to an active antenna element or is that the support for what is above it? It may sound silly but what prompted me to ask is in my neighborhood there is a scanner antenna mounted ON a CB antenna without a mast, the mounting sleeve is held by a single wall bracket. Yeah, he's using one antenna to support another... CBsexy (whacker) style.

[alfapapamike]

Nice job ausscan, it looks pro!

I proof-of-concept built a dipole out of two old shelving support tubes, zip tied to a paintbrush handle. Just goes to show that with sound mathematics and measuring you can build a decent antenna with just about anything. Pulls in stuff way better than anything I've used too.

[ausscan]

The "hockey stick" is the fascia that mounts on the eaves, and what the antennas are actually mounted on. The 4.5db whip was going to be for a local UHF CB but the base appears to be grounding out, and I'm not planning on fixing it until I move.

[kb2vxa]

I see, sort of. (;->) The mast and antennas silhouetted against the clouds really stand out but are too dark to see much detail which is why I asked so thanks for clarifying. Now I REALLY should have thought of this before, DUH. Here we are again, after cropping and a little gamma correction the detail comes out even if the picture looks a little grainy.

[ausscan]

Just an update, I built another one just to see how much it would really cost me.
1m Aluminum pole - $8
"T" peice - $3
U Bolt/clamp - $6
Had lying around the rest, so for the best part of $20 I have myself a brand spanking new antenna. Here are the pics:



And this is how it ended up in the sky: