My First HomeBrew Antenna!

[Zard0z]

Ok I had fun making this Dipole antenna! Thanks to all here for the info. I plan on putting this on my
pole outside. It works great indoors almost as good as the Omni X at some freqs! Wow what fun this was.
All that is left is to get a bracket and get some cable. I will post a outside mounted pic when I can afford.

This cost more than one made in china but that was not the point.

So what do you all think... not too ugly

 

[kb2vxa]

Nice looking job but why is one leg so much longer than the other?

 

[mdulrich]

Nice looking job but why is one leg so much longer than the other?

http://www.radioreference.com/forum...3-off-center-fed-vhf-uhf-vertical-dipole.html

Mike

 

[specman]

Congrats on your antenna; I like your use of the conduit joint at your feedpoint there. I've been meaning to try one of these antennas to compare with my other stuff.

 

[n4yek]

Nice and neat, good job!!

 

[KC4RAF]

Good looking job Z.

Let us know how well it works. As you said, the price may be up and over store bought, but the thrill of building it yourself and getting great results is what it's about. Now you next project should be an 11 element yagi for the 800!

 

[AlmostHandy]

Very nice job, dude! Homebrew antennas are really fun to make.

Definitely let us know how it works!

 

[Zard0z]

Now you next project should be an 11 element yagi for the 800!

hahahahaha. very funny! Way beyond my pay scale! (for now)

Very nice job, dude! Homebrew antennas are really fun to make.

Definitely let us know how it works!

Thanks! I must admit that it turned out better than I thought. But it was a progression of sorts and
I did not share all of my pics!

Congrats on your antenna; I like your use of the conduit joint at your feedpoint there. I've been meaning to try one of these antennas to compare with my other stuff.

Yeah it was the only way I could figure to get a indoor balun to be a outdoor one! Guess I could have made one or bought one that way.
I wanted to weather proof all of the componets and this is what I came up with!


I still have to seal the Balun area and use a rubber boot on the connector. I will use silicone to seal the gaps around the Balun and I have the boot already.
I won't do this step until I get my mounting bracket and drill the holes in the conduit. More pics as I finish it up!

BTW seems to work very well around the house! Kinda big for my desktop!

Thanks Guys

 

[Zard0z]

Got it!

Well I finnaly figured out how to mount my antenna to a standard 1 1/2 inch mast!

I will attached pics. I drilled the holes in the plastic connector box one size too small and the machine
screws I used threaded in nicley! Plus I put bolts on the inside for good measure.
Now all I have to do is to weather seal the exit hole with the balun in it and weather
proof the connectors. I have buryfelx cable to use once I get the other ten foot mast piece
placed on the side of my house. I will post final pics and preformance data when I finish up.

For now the long wire will be place on the top just to see how that works, then I will mount it
in reverse just to see if there is any difference.

 

[W6KRU]

Your metal mast is going to interfere with the antenna, IMO.

 

[specman]

Your metal mast is going to interfere with the antenna, IMO.

Agreed. Although I admire the ingenuity of using commonly found parts for this, the mast is going to act in a negative parasitic manner in this case. The antenna needs to sit out a lot further from the mast; likely around a 1/4 wavelength or so of the lower portion of freqs this being used for.

 

[a84b1]

biulding an antenna?

would love to try to build my own antenna. i only know that it needs a BNC conector to my scanner and that it can go outside but not too high like 8 to 10 feet total.. i need some some to help with a material and easy instructions ?? anyone care to help??

 

[AlmostHandy]

Yeah Zardoz, Get a piece of schedule 80 PVC conduit for the very top section of the mast. It only needs to be as long as the lower section of your dipole extends, so about 4 feet or so above the top of the metal mast. Your antenna doesn't look like it weighs a ton, and the wind shear will be minimal with it's low profile. I'm betting 1 1/2" sch80 PVC will work fine.

 

[AlmostHandy]

would love to try to build my own antenna. i only know that it needs a BNC conector to my scanner and that it can go outside but not too high like 8 to 10 feet total.. i need some some to help with a material and easy instructions ?? anyone care to help??

Hey a84b1! Building your own antenna is great fun!

It's actually pretty simple too. Zardoz here made an offset dipole. I've constructed a couple of vertical ground planes, and there are a couple of folks here who have put together their own homemade Yagis!

Check out the wiki section about scanner antennas. That's where I started. If you have any specific questions, just do a quick search in the antenna forum and see if anyone else has had the same question. If not, just ask us, we're here to help!


EDIT: Here's a link that takes you right to the homebrew scanner antenna section of the wiki. Check it out!!

 

[Zard0z]

rodger that!

Yeah Zardoz, Get a piece of schedule 80 PVC conduit for the very top section of the mast. It only needs to be as long as the lower section of your dipole extends, so about 4 feet or so above the top of the metal mast. Your antenna doesn't look like it weighs a ton, and the wind shear will be minimal with it's low profile. I'm betting 1 1/2" sch80 PVC will work fine.

Ok great thanks guys! remember I am going to invert the top/bottom so the 18 inch wire will be pointing
down and the 48 up. The only thing is how to connect the PVC pipe/pole to the metal one. I will think
on this one..... Maybe try a 3 foot PVC piece first and the go as long as I can. Also I can move out
the antenna with a larger piece of metal but this might not be nessasary if the PVC works good!

Still I want to keep it as lightweight as I can. Thanks again for your good input everyone. I will get the
PVC and see what kind of monster I can come up with.

 

[Zard0z]

Polled!

Ok here is a couple of pics showing the mount design as of now! Thanks to everyones input.

So what do you all think? I am only concerned with the mating point of the metal pole and the
PVC pole. It will have to be tapped down to fit(this is good) but I don't know if my PVC cement
is going to be up for the job of weather weight and metal?

Will PVC cement work on mating to metal? It will fit real tight when I tap it down. In the pics
it is not tapped down all the way and holds the assembly better than I thought. If PVC cement
is not the answer what would be a better solution?

If anyone sees a problem please let me know. I still have to put connectors on my cable and
then she goes on the house!!!!!

PS I will be able to thread the coax thru the inside of the PVC and out the elbow joint! and then
down the metal pole......(end caps on pvc to keep water out) ...kewl huh!

 

[AlmostHandy]

That looks great!

I wouldn't count on PVC glue holding to metal at all. It's designed to sort of melt the two plastic mating pieces together, effectively making a chemical weld. I would fit the two pieces together, and drill a hole completely through both walls of both pieces, and run a bolt with a couple of large washers. You won't need to torque it down very tight to get a good connection, and one of those urethane lined lock nuts can help if you don't want to use a threadlock compound.


Nice work!!

 

[digitalanalog]

It's a nice looking antenna, hope it works out well for you.
Great job.
Jim

 

[Zard0z]

That looks great!

I wouldn't count on PVC glue holding to metal at all. It's designed to sort of melt the two plastic mating pieces together, effectively making a chemical weld. I would fit the two pieces together, and drill a hole completely through both walls of both pieces, and run a bolt with a couple of large washers. You won't need to torque it down very tight to get a good connection, and one of those urethane lined lock nuts can help if you don't want to use a threadlock compound.


Nice work!!

Thanks, Great Idea on the bolt. I will drill and attach that way with washers!!

Looks like I will have room for a nice yagi underneath too!!

 

[KD8CPI]

I like that design. I made mine using the copper. It was comparible to the RS-170 except it was deaf on 800. I also like your idea on the coax down the tubes.

Pat yourself on the back, that is a great looking homebrew.