[time-nuts] Re: WWVB Loopstick Antenna Project

[glen english LIST]

The referred article by Richard Q. Marris is a good one but liekly mass 
overkill for this application.

Seek a rod that is good at the 125kHz RFID frequency. Type material 78 
comes to mind,  but almost any Manganese Zinc Ferrite is going to work.

Although they'll probably be fairly small . All the higher frequency 
rods will be fine on losses but have low perm and need lots of turns. 
Something with an initial permeability of at least 2000 will be suitable.

greater Length/Diameter will increase mu-rod. 6" x 3/8" sounds good.

You might not need that much rod, I dont know what the field strengths 
are (does anyone know) but something like this might be suitable  :

https://www.fair-rite.com/product/antennarfid-rods-3078990901/

a ferrite rod is not necessary if you have space... if this is a fixed 
application,  many turns around a foot square will be just as 
effective.  No need for a ferrite rod.

Suggest electrostatic shield and balanced  feed for the wire , coreless 
loop.

For a small ferrite  rod, put the rod length wise in a deep aluminium 
channel section.

It's certainly easier to build a ES shielded small rod than a loop.

-glen



On 11/09/2022 12:38 pm, Lux, Jim via time-nuts wrote:
> On 9/10/22 7:59 AM, D. Resor via time-nuts wrote:
>> I exploring the parts needed to construct this particular VLF Loop Stick
>> Antenna by Richard Q. Marris G2BZQ.
>>
>> I have uploaded the article to my DropBox Account here:
>>
>> https://www.dropbox.com/s/niv64xqmghu76z3/1_1201157_4_Ultima_loopstick_VLF_a 
>>
>> ntenna.pdf?dl=0
>>
>> The project explains you should use 9.5mm (3/8") Diameter X 15cm (6") 
>> Length
>> Ferrite rods.
>>
>> The closest I have been able to find are 10mm (0.393") Diameter X 160mm
>> (6.299) Length.
>>
>> Will it make much of a difference?
>>
>> Thank You
>>
>> Don Resor
>
>
> Not much difference.. the diameter 0.375 vs 0.393 isn't much. Length 
> doesn't much matter, as long as the windings fit.
>
> A bigger issue might be the permeability of the rod.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe send an email to time-nuts-leave at lists.febo.com

-- 
Glen English
RF Communications and Electronics Engineer

CORTEX RF

Pacific Media Technologies Pty Ltd trading as Cortex RF

ABN 40 075 532 008

PO Box 5231 Lyneham ACT 2602, Australia.
au mobile : +61 (0)418 975077