[Alexandria Radio Club Reflector] FW: FW: Presentation by Ed Fong to Alexandria Radio Club, Jan 8th 2016

[Don Lewis (KI4D)]

For those who attended  Ed’s presentation last Friday, I am forwarding Ed’s note in case there is interest in making a club buy of Ed’s antenna.  There may also be interest in what he had to say about constructing a 6 meter version.

 

Don Lewis, KI4D 

 

From: edison fong [mailto:edsantennas at gmail.com] 
Sent: Monday, January 11, 2016 11:49 AM
To: Don Lewis (KI4D)
Subject: Re: FW: [Alexandria Radio Club Reflector] Presentation by Ed Fong to Alexandria Radio Club, Jan 8th 2016

 

Don -  your group looks like a great bunch of guys.  I enjoyed do the seminar.  The guys can go and look at my website, but make sure they understand to order through the club to get the discount.  The discount is significant at $25 plus postage (which is cheap when we send everything in a USPS flat rate box).

A simple way to calculate the dimensions for a 6 meter antenna is just to triple the values of the two antenna.  Just consider the RG174 decoupling stub a wire.  Ignore the fact that it is a piece of coax. 



Thanks again for inviting me. 

Ed

 

On Mon, Jan 11, 2016 at 7:08 AM, Don Lewis (KI4D) <ki4d at arrl.net> wrote:

Ed – I am writing this note to thank you again, very much, for visiting with our club and making your presentation last Friday evening.  I have heard nothing but very positive comments about your presentation.  Also, you may not have heard the rounds of applause you received because of the limitations of Skype, but be assured that the club was very appreciative with their applause.  I provided the club with your eBay website address so you may hear from some of our club members.

I would also like to take this opportunity to inquire about a matter I have been interested in and someone asked a question about on Friday, and that is about a 6 meter twin lead J-pole.  Looking at the dimensions for the 2m J-pole I have tried to derive the dimensions for a 6 meter twin lead J-pole.  I plan to install it in a tree or on a fiberglass pole so the length is not important. I am just looking for a good starting point in dimensions before I make final adjustments.  In looking at the your 2 meter antenna, the velocity factor complicates matters a little because the length of the ½ wave section is 37 ¼ inches which turns out to have a factor of .9216 [.9216 * 40.42 in (1/2 wavelength at 146Mhz) = 37.25].  This factor does not seem to work for the stub [(40.42 *  1/2) = 20.21 inches.  20.21 * .9216 = 18.6, not 15 ¼  + 1 1/4 or 16 ½ inches.  Assuming my numbers are right, I was not able to come up with a generic formula that would apply to 6 meters.  Would appreciate any insights or points you might have.

 

Thank you again for your presentation and we will be looking for that old firehouse you spoke of.

 

Don, KI4D