TINY homemade UHF ant. WORKS

Useful information regarding antennas for SDR products.
bubblegumpi
Posts: 49
Joined: Fri Oct 14, 2016 11:41 pm

TINY homemade UHF ant. WORKS

Postby bubblegumpi » Wed Nov 02, 2016 12:47 pm

This antenna works really well, even does an excellent job down to the FM broadcast and picks up the "problem AM station" down in the SW frequencies.

Its made from three pieces of solid copper wire at 45' angles to the center aligator clip and solder and soldering braid. Does this preserve the 50' that the white cable ties into it with? Picks up alot of stuff in the GHz range, I want to mount it on the roof and see what it does. I didn't think it was going to really work, was too easy.
Attachments
smalantjpg.jpg
smalantjpg.jpg (124.21 KiB) Viewed 2986 times

Reason: No reason

g1hbe
Posts: 228
Joined: Sat Jan 17, 2015 3:28 pm
Location: Cheshire

Re: TINY homemade UHF ant. WORKS

Postby g1hbe » Wed Nov 02, 2016 1:16 pm

That's about the right length for ~450 MHz, but those little stubs aren't going to have much effect either way. I see you have nothing attached to the braid of the coax, so the antenna will not be working at its best. You need to make another two 6-inch lengths of wire and solder them onto the braid just underneath the antenna part. Even just one length would do. This will improve the match into the coax and you should get even better performance.

Reason: No reason
Andy

bubblegumpi
Posts: 49
Joined: Fri Oct 14, 2016 11:41 pm

Re: TINY homemade UHF ant. WORKS

Postby bubblegumpi » Sat Nov 05, 2016 2:55 pm

Does it matter how close the 6" pieces are from the top? Thats aluminum braid so soldering is out. I tried this on my VHF antenna I showed in another post. Adding the bottom horizontal elements are more for impedance match then reception? Makes sense...

Reason: No reason

g1hbe
Posts: 228
Joined: Sat Jan 17, 2015 3:28 pm
Location: Cheshire

Re: TINY homemade UHF ant. WORKS

Postby g1hbe » Sun Nov 06, 2016 9:18 am

Connect them to the braid somehow and either let them dangle down (this will make the antenna more like a dipole) or make them stick out horizontally (this will make a ground-plane antenna). Those little V pieces sticking out aren't doing anything, they could be removed.

Reason: No reason
Andy


Return to “SDR Antennas”

Who is online

Users browsing this forum: No registered users and 1 guest