Electronics > Beginners
FM antenna
MarkF:
Your whiskers and spacing may be too short.
The previous design was for HD Over-the-Air TV. I think the FM band is a little lower.
And his last picture looks like he has a 300 to 75 ohm balun.
HDTV design source is https://m4antenna.eastmasonvilleweather.com/index.html
The FM band is just below analog VHF TV channel 7.
fixit7:
Is there anyway to test my balun?
ocw:
The main problem is using a UHF TV antenna to receive the FM broadcast frequencies. The elements should be close to 5 feet (1.5M) from tip to tip. The vertical spacing should be about the same distance for a short vertically spaced antenna, over twice the width for normal full wavelength spacing.
MarkF:
--- Quote from: fixit7 on May 27, 2019, 09:21:22 pm ---Is there anyway to test my balun?
--- End quote ---
I doubt that it is bad.
I believe they are just a transformer inside.
For a sanity check, you can check continuity between the input terminals and between the output terminals.
richnormand:
1)
As I said in my reply #11 the antenna length is about 150cm (152.4cm is 5 feet). Close for FM 88 to 108MHz.
2)
Baluns rarely go bad. In particular if used inside. Simple DC conductivity test will tell. You have an ohm meter? If not a battery with an LED will do.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version