Re: Loop antenna amplifier with 30cm loop

David Cutter

Hi Stan


It's good to see the USA getting it's feet wet at last, though 40 years down the line according to that document.  I agree we should use mm instead of cm but, it's not a big deal.  I don't see anything wrong with specifying the loop size in metres, eg 1m - you'll have to explain that one to me, but I'm not about to get into an argument about it !!  Even though we've been metric for a long time, we still see and hear folk using the imperial system and most of us to the sums in our heads, whichever way it goes. 


73 David G3UNA


From: [] On Behalf Of Stan Vause
Sent: 06 October 2019 00:13
Subject: Re: [CrossCountryWireless] Loop antenna amplifier with 30cm loop




How do Chris


I have been following your fine work and most-helpful correspondence for some time and have noticed your adherence (most of the time except, for length measurements) to using correct SI metric nomenclature.  It is a rare trait even among those who call themselves 'professionals',  such folk who should be setting an example to the hoi polloi.   Sadly, ham newsletter editors pay scant heed to conformity with the  international standards, thus bad habits, and the ambiguity resulting therefrom, simply continue getting worse.   

The attachment provides full SI metric nomenclature specifications, despite coming out of America!


The best illustration of my allegation comes from your own hand,  with my annotations in brackets to show what is meant:



On 06/10/19 8:35 AM, Chris Moulding wrote:

Following a request to test the Loop antenna amplifier with a small 30cm (sic) diameter loop I ran a test today.

I made a 30cm (sic) loop out of RG58/u cable connecting the outer braid to two M6 solder tags to connect to the prototype amplifier box.

In comparison to the 1m (sic) diameter coax loop or the 1m (sic) per side wire delta loop the RF levels were 10 dB (nice) down.

Performance was OK to 198 kHz (nice) and dropped off below that but I could easily hear the 60 kHz (nice) time signal.

The null was as deep as that shown on the bicycle loop test video but it was much broader and easier to find handheld. It would be very easy to null an interfering signal or noise out especially if it had to be used indoors.

It would be limited by amplifier noise on the higher HF bands if used at a quiet rural location but would be perfectly useful inside a house or other RF noisy environment.



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