Associazione Italiana Radioascolto www.air-radio.it - info@air-radio.it LEGGI LA RIVISTA RADIORAMA WEB SU: WWW.AIR-RADIO.IT La collaborazione al Blog AIR Radiorama e' aperta a tutti gli appassionati, previa richiesta di iscrizione tra gli Autori. Il CD AIR si riserva il diritto insindacabile di decidere l'ammissione degli Autori e la pubblicazione sul Blog dei relativi articoli inviati.
lunedì 17 gennaio 2022
MARCONI CLUB QSO PARTY DAY
MARCONI CLUB QSO PARTY DAY ed. 2022
La sezione A.R.I di Loano propone per il 2022 la 4° edizione del QSO PARTY DAY con delle novità sostanziali nel regolamento.
La finalità è di far conoscere alle nuove generazioni il nostro club e riunire a livello internazionale tutti coloro che veramente amano e credono nella telegrafia.
Lo scopo della manifestazione è quello di promuovere il MARCONI CLUB A.R.I. LOANO, fondato l'8 maggio 1988 dal compianto Libero Meriggi I1YXN e dal noto DXpeditioners Baldur Drobnica DJ6SI.
Durante la manifestazione, che si svolgerà sabato 22 Gennaio 2022 dalle 07:00 UTC alle 18:00 UTC in CW sulle bande 20m , 40m e 80m , verranno coinvolti tutti gli iscritti allo storico club, che conta ad oggi oltre 870 iscritti da ogni parte del globo e tutti i non iscritti , appassionati di questa stupenda e magnifica arte.....Vi aspettiamo numerosi !
cordiali 73
Tony IK1QBT
Presidente sezione ARI Loano
Presidente sezione ARI Loano
BUONI ASCOLTI
sabato 15 gennaio 2022
Much more on the Mini Whip here with right conclusions
Here there is much more following the previous publication at :
https://air-radiorama.blogspot.com/2022/01/again-someone-who-really-understood-how.html
https://owenduffy.net/antenna/PA0RDT-MiniWhip/
And especially these conclusions :
A) The feed line common mode conductor is a significant part of the antenna system.
B) The lower part of the antenna feed line (which is part of the antenna) provides a large portion of the total current moment.
C) The antenna is very susceptible to noise from sources local to the lower part of the feed line, sources such as house wiring carrying RF polluted current.
D) The PA0RDT certainly works quite differently to the designer's explanation, and the E-field magic just doesn't hold water.
E) As to whether it works well, that seems to be a personal matter for its users!
If you would like to see some practical results and measurements please look here :
http://air-radiorama.blogspot.com/2019/03/anche-bocca-di-magra-le-leggi-delle.html
In Italian , easy translated with Google , but the important are the practical measurements of the C/N till 30 MHz in a real environment respect to other passive solutions ( MAXI WHIP ) .
Claudio Re
venerdì 14 gennaio 2022
Again someone who really understood how a Mini-Whip is acting
From the VLF Group on Groups.io
Re: Practical installation of a PA0RDT mini whip antenna
From: Peter
E
Date: Tue, 11 Jan 2022 22:59:26 PST
Hi Ron,
I have been running one of these antennas for a while now and it seems to work quite well, as I seem to have been one of the few that heard the SAQ transmissions in Australia, and I regularly receive stuff from Germany and the States on 137Khz. I believe there is a bit of a misconception about how these antennas work, in that they should be placed high above ground on an insulated mast. The reality is that the screen on the coax is just as effective an earth as any steel mast, and (I believe) acts as an integral part of the antenna system. I still believe that having the antenna high above the ground improves reception, but whether you have a long antenna on a short mast or a short antenna on a long mast doesn't seem to make much difference.
My antenna uses a 9M long fibreglass squid pole mounted on a 1M high earth stake. A wire taped to the pole acts as the antenna and is connected to a PA0RDT style amp at the bottom of the pole and earthed to the ground stake. The amp is powered by its own solar charged battery to avoid any noise pickup from the mains. A 1:1 isolation transformer drives a 20M length of double shielded coax buried in the lawn, connected to my shack. A LF common mode choke is also used on the feed into the shack and the coax shield is only connected to ground in the shack.
If you have no high trees or objects near the antenna, then this is a big advantage as these objects will "shade" the antenna and reduce reception of VLF signals - I can hear this effect very easily with my handheld VLF receiver, walk near the trees and all the Sferics disappear. You also need to get as far from your house as possible, as it will radiate noise like you wouldn't believe, but you will have to do the best with the space you have.
Just my 2 cents worth...
Cheers,
Peter - VK2AN
giovedì 13 gennaio 2022
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