Smiley Antenna tuned to 160Mhz?

[Tier4GEVO]

Smiley Antenna offers a factory tuned 160 MHZ rail antenna, and is about 9-10 inches long. Although the antenna is tuned to 160MHZ (rail band), is the short 9-10 inch length going to negatively impact its performance, compared to a Diamond SRH77CA dual band 2M antenna (16 inches)?

[hoborich]

The short length would negatively effect it's performance, even if it is cut for 160 mhz, simply because the shorter length presents less capture area to the transmitted signal. A short antenna or rubber duckie uses a coil to achieve the desired length for a specific frequency, but it lacks the capture area of a true 1/4 wave antenna. A true 1/4 wave 160 mhz antenna would be somewhere around 17 1/2 inches, just off the top of my head. It can be calculated accurately, but it is a lot more than 9 or 10 inches.

Here is a link to a calculator: http://www.csgnetwork.com/antennageneri ... ncalc.html
Required Data Entry
Frequency
160
Mhz
Half Wavelength 2.925 Feet
Half Wavelength 35.099999999999994 Inches
Quarter Wavelength 1.462 Feet
Quarter Wavelength 17.549999999999997 Inches
Calculate Clear Values

[Tier4GEVO]

The short length would negatively effect it's performance, even if it is cut for 160 mhz, simply because the shorter length presents less capture area to the transmitted signal. A short antenna or rubber duckie uses a coil to achieve the desired length for a specific frequency, but it lacks the capture area of a true 1/4 wave antenna. A true 1/4 wave 160 mhz antenna would be somewhere around 17 1/2 inches, just off the top of my head. It can be calculated accurately, but it is a lot more than 9 or 10 inches.

Here is a link to a calculator: http://www.csgnetwork.com/antennageneri ... ncalc.html
Required Data Entry
Frequency
160
Mhz
Half Wavelength 2.925 Feet
Half Wavelength 35.099999999999994 Inches
Quarter Wavelength 1.462 Feet
Quarter Wavelength 17.549999999999997 Inches
Calculate Clear Values

Thank you Rich. I have seen varying sisters give 17.5 to 18.4 inch measurements. Smiley also makes a Telescopic 160 MHz that can go from 10 inches to 48, so I could label the 17.5 for 1/4 wave performance, and fully extended gives 5/8 wave.