800 MHz CANTENNA

[bharvey2]

I think you will have much better luck with a corner reflector or a pair of Yagi's stacked and phased properly. Nothing magic about a can antenna and it has no special directional properties beyond what a small Yagi can do.

I'll second the corner reflector. They're fairly easy to make. My quick and dirty corner reflector didn't do as well as my commercially built Yagi but it did a pretty could job of picking up the local public service network and fighting off simulcast distortion.

 

[RFI-EMI-GUY]

I'll second the corner reflector. They're fairly easy to make. My quick and dirty corner reflector didn't do as well as my commercially built Yagi but it did a pretty could job of picking up the local public service network and fighting off simulcast distortion.

Foil backed insulation panels, aluminum duct tape and a loop dipole!

 

[bharvey2]

Foil backed insulation panels, aluminum duct tape and a loop dipole!

I used a few pieces of aluminum sheetmetal I had laying around and may a tiny little dipole out of some #12 solid copper wire. Wouldn't a folded dipole make the impedance too high?

 

[RFI-EMI-GUY]

I used a few pieces of aluminum sheetmetal I had laying around and may a tiny little dipole out of some #12 solid copper wire. Wouldn't a folded dipole make the impedance too high?

yeah you might need a matching transformer made of coax.

 

[bharvey2]

yeah you might need a matching transformer made of coax.

Okay. I don't do much with folded dipoles but I recall their impedance was 3-4 times that of a standard dipole. Proponents of loops bring up the fact that they're less noisy that a standard dipole. Do you know if that's the case with a folded dipole?

 

[radioman2001]

Any chance of using galvanized AC ducting, can be had in any length or diameter, and I think 8in might work.

 

[RFI-EMI-GUY]

Okay. I don't do much with folded dipoles but I recall their impedance was 3-4 times that of a standard dipole. Proponents of loops bring up the fact that they're less noisy that a standard dipole. Do you know if that's the case with a folded dipole?

For RX only, I a 75 to 300 ohm TV balun would work.

 

[RFI-EMI-GUY]

Any chance of using galvanized AC ducting, can be had in any length or diameter, and I think 8in might work.

You will need a bit more than 9 inch diameter. You could go to a sheetmetal shop and ask them to roll a custom diameter and perhaps even in thin aluminum. But you will need an end cap. If you go that route, make the end cap adjustable to tune the antenna. Now you are approaching the $30 range for this project!

A while back there was a company offering distributed antenna systems for commercial buildings. There idea was to utilize existing ductwork and push cellular and wifi through the ducts, I don't know whatever came of them. It would seem the market would be quite small.

 

[radioman2001]

I hope not, that could be a nightmare to keep all that RF from interferening with itself. Everytime you open or close a duct you will change the system. It's bad enough with our 60+ amplifiers all over our building and tracks in keeping them balanced especially on simplex.