heh.
well, I found a site that had a loop calculator (including calculating the length of specific coax for the 75 ohm matching section). I built one for 6m and it worked with only 1 or 2 minor adjustments. I will see if I can dig up that site for you guys.

as for excellent hearing… At 50 years old, I can still hear sounds well into the low 20 Khz range (right ear only). The left ear has a minor partial deafness issue (where I can't hear anything below 200 hz or above 2800 hz. From there a gap exists up to 7 kHz and then from there its gain hearing to around 17 kHz and then it drops into nothing real fast. so far, it hasn't gotten in the way of ham radio. :)

DE n7zzt Eric

On Dec 13, 2015, at 12:01 PM, Howard, W A 9 Y B W wrote:

> For receive only, don't waste your time changing this antenna.  You will not 
> notice any difference.  Kind of like a speaker advertised to have a 
> frequency response from 10 hertz to 30 kilohertz but the human ear cant hear 
> above 20 kilohertz if you have excellent hearing.
> 
> Howard #3
> 
> ----- Original Message ----- 
> From: "Richard B. McDonald" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Sunday, December 13, 2015 8:58 AM
> Subject: Report on 10M Loop Project, and Request for Feedback
> 
> 
>> Hi!
>> 
>> 
>> 
>> I want to report on my 10M full wave loop (FWL) project, and ask for
>> feedback on it.  My aim was a resonant antenna at 28.4 MHz for RX only on 
>> my
>> TS-2000.  I viewed this project as practice for the antenna I *really* 
>> want
>> to make - an 80M FWL for both RX and TX (inspired by Ron).
>> 
>> 
>> 
>> To make my loop, 14 gauge insolated stranded copper wire sits inside 1" 
>> PVC
>> ~12' atop my wooden shack.  It is in the shape of an octagon.  I measured
>> the length of the wire at 1005 / 28.4 = 35.39', which I rounded to 35.5'.
>> There is a 25' run of 75 ohm coax (the kind for TV, which I was told is 
>> fine
>> for RX antenna purposes like this) properly soldered to the ends of the
>> wire.
>> 
>> 
>> 
>> So, my friend from our ham club measured this antenna with his analyzer. 
>> It
>> turned out to be resonant at 25.5 MHz : (  Now, only because I am obsessed
>> with my project and by way of learning, I should like feedback on the
>> following:
>> 
>> 
>> 
>> 1)      I am told that one thing affecting resonance is the "velocity
>> factor" of the wire.  Apparently, the insulation of both a) the wire 
>> itself
>> and b) the PVC affects the velocity factor.  I have no idea what "velocity
>> factor" is, nor how it affects the calculated length of a wire for a FWL 
>> as
>> per the above.
>> 
>> 2)      To bring the resonant frequency up to 28.4 MHz, I *think* I need 
>> to
>> decrease the size of what I have built.  Is that right?  "Decrease" as in
>> shorten rather than "increase" as in lengthen?
>> 
>> 3)      To decrease the size of my loop, I plan to cut 6" (0.5') off each 
>> of
>> the eight sides of the octagons for a total of 4' (including obviously the
>> wire therein).  Check my math (reasoning) on this.  28.4 / 25.5 = 1.11;
>> meaning I am too big by 11%.  0.11 * 35.5 = 3.9; say 4'.
>> 
>> 
>> 
>> Incidentally, even though my loop is a little off, it seems to RX better
>> than my 43' vertical does on 10M.  Some have said that for RX only this
>> resonance differential is insignificant.  In other words, they say that 
>> even
>> if I tune my loop precisely to 28.4 MHz, on 10M it would be imperceptible 
>> as
>> to 25.5 MHz for RX.  What do you think about this?
>> 
>> 
>> 
>> 73,
>> 
>> Richard KK6MRH 
> 
> 
> ---
> This email is free from viruses and malware because avast! Antivirus protection is active.
> http://www.avast.com