I just did some calculations from the ARRL Antenna Handbook. I came up with a 6-turn helical with a diameter of 25.826" and a length of 121.65". My first thought was "whoa, dude, like OMG!" (I'm a high school teacher, ok?) I rechecked my calculations and came up with same, plus an impedance of 150 ohms.
Years ago I used a Fritzel Helical for 2m when I was DA1BB and VP2EHF (during Hurricane Luis in 1994 it ended up someplace out in the Anagada Straights between Anguilla and Sombrero Island).
What say, you all? Advice, comments welcomed
73 Dave, N4CVX
Sent from my iPad
Yes, a 2m helical is huge. We have one for 250 MHz almost half the wavelength, as 2m and it is about as big as one wants to handle. Bob, WB4APR
-----Original Message----- From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Dave Mann Sent: Sunday, February 05, 2017 10:06 AM To: amsat-bb@amsat.org Subject: [amsat-bb] Helical Antenna for 2-meters
I just did some calculations from the ARRL Antenna Handbook. I came up with a 6-turn helical with a diameter of 25.826" and a length of 121.65". My first thought was "whoa, dude, like OMG!" (I'm a high school teacher, ok?) I rechecked my calculations and came up with same, plus an impedance of 150 ohms.
Years ago I used a Fritzel Helical for 2m when I was DA1BB and VP2EHF (during Hurricane Luis in 1994 it ended up someplace out in the Anagada Straights between Anguilla and Sombrero Island).
What say, you all? Advice, comments welcomed
73 Dave, N4CVX
Sent from my iPad _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Thanks to all! I researched more and found a design on a VK's website. I'll be digging into that real soon now.
73 Dave N4CVX
Sent from my iPad
On Feb 5, 2017, at 09:06, Dave Mann cwo4mann@comcast.net wrote:
I just did some calculations from the ARRL Antenna Handbook. I came up with a 6-turn helical with a diameter of 25.826" and a length of 121.65". My first thought was "whoa, dude, like OMG!" (I'm a high school teacher, ok?) I rechecked my calculations and came up with same, plus an impedance of 150 ohms.
Years ago I used a Fritzel Helical for 2m when I was DA1BB and VP2EHF (during Hurricane Luis in 1994 it ended up someplace out in the Anagada Straights between Anguilla and Sombrero Island).
What say, you all? Advice, comments welcomed
73 Dave, N4CVX
Sent from my iPad
participants (2)
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Dave Mann -
Robert Bruninga