[Milsurplus] VLF & ELF Antennas

[Antonio A. S. Magalhaes]

Hello Mike! 

The best antenna that you could use at LF and VLF is a loop. 

Make the area of the loop, and the number of turns as big as you can. 

The screening of the conductor turns avoids the penetration of the
E-field component. Thus, the S/N ratio is improved. This can be done by
using the inner condutor of a coax for signal picking, and leaving the
outer conductor for the shielding. 

Do not forgive: 

1- To leave a gap on the shield as to avoid a closed turn; 

2- This type of antenna is directive; the plan of the loop must point to
the transmitter. 

Best regards,

---

 Dr. António A. S. Magalhães
asmagal at fc.up.pt 
Investigador Auxiliar (aposentado)
Observatório Astronómico do Prof. Manuel de Barros FACULDADE DE CIÊNCIAS
DA UNIVERSIDADE DO PORTO
Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
www.fc.up.pt [1] 

A 2019-09-11 01:21, mike christie via Milsurplus escreveu:

>> 

> Hello to the Group 
> 
> I've been playing around on the VLF & ELF bands using my RAK-7 and found a number of NDB'S. The furthest I've received was about 65 miles away on my 80 Meter inverted V antenna.  I've exchange Emails with some of you and gained a lot of good information.  I wanted to improve my antenna system for those bands.  So I wanted to see what you all were using for antennas.  I've experimented with a couple antennas those being an  Efield probe antenna which turn out to be very noisy and the MiniWhip antenna. The MiniWhip didn't work at all, I think it was faulty from the beginning as it wouldn't receive the lower AM broadcast stations at night. So that went back and I got my money back.  I ask the seller to check it out and let me if it was indeed faulty.  
> 
> I did some research on this and found that you don't have to have high gain antenna, the biggest factor is to keep the noise factor low.  Glad to hear from anybody good or bad on antennas for these bands. 
> 
> Thanks 
> 
> Mike 
> 
> W1ZFB 
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Links:
------
[1] http://www.fc.up.pt
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