Re: LF: Wellbrook RX loops

[M0FMT <m0fmt@yahoo.co.uk>]

Hi Graham

 

Don't bring measurement and practical Ham Radio comparisons into this you are fighting "Black Magic" and Voodoo. Its a commercial promotion and specmanship with no real technical data to make an evaluation. Never seen a schematic for one or an explanation why it would be better than a "proper" antenna, an elevated electrode tuned against ground on the frequency of interest.

73 es GL Pete M0FMT IO91UX

From: Graham <g8fzk@g8fzk.fsnet.co.uk>
To: rsgb_lf_group@blacksheep.org
Sent: Friday, 5 July 2013, 19:33
Subject: Fw: LF: Wellbrook RX loops

 

There  is a  good   example  of  Mini-whip   V  40 ft  end fed  vertical  , db levels  are  the  average over  32 mins  , so  that  would  tend  to  give  a  realistic   evaluation  , as opposed to  peak  , which  would  reflect one  major  incident  during  the  time lime

 

Stations  about  25  miles  apart  west<>east

 

G..

 

23:02 136 G3XDV de G4WGT Op32 160 mi -12 dB in Chorley, IO83qo with 0.3w + Inv-L

23:02 136 G3XDV de G0NBD Op32 163 mi -23 dB in Nr Liverpool with 0.3w + Inv-L

 

 

From: DENNIS EASTERLING

Sent: Friday, July 05, 2013 5:26 PM

To: rsgb_lf_group@blacksheep.org

Subject: Re: LF: Wellbrook RX loops

Hi Roger

 

I use a Wellbrook Loop type ALA1530 (MW/HF)  mounted 1m off the ground and a PA0RDT mini-whip mounted about 7m above ground.   Sometimes the loop wins other times the miniwhip.   The miniwhip is omnidirectional and uses the e field, whereas the loop is directional and uses the magnetic field.   The miniwhip is more open to BC breakthough than the loop but more sensitive.   I tend to monitor with the miniwhip, and switch to the loop after homing in on the signal if this helps.   BC breakthough is overcome using a simple series LC circuit tuned to the required band at the RX end of the coax.   The QRM at my QRT can be horrendous, as I am only 100 yards from the OH lines on the East Coast main railway line, surrounded by houses and a block of flats with associated busy roads.   My 'T' transmitting aerial 8m high is useless for RX.   I can fully recommend both miniwhip and Wellbrook Loop, both of which cover from LF to 10m.   For best results, I suppose a tuned loop about 1m square has the edge, but not as convenient. 

 

73 Dennis M0JXM

From: Roger Lapthorn <rogerlapthorn@gmail.com>
To: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>; rsgb_lf_group@yahoogroups.co.uk
Sent: Friday, 5 July 2013, 7:00
Subject: LF: Wellbrook RX loops

Can anyone advise, from actual use,  how well a Wellbrook loop works on 136 and 472kHz RX ? The excellent OIP2 and OIP3 figures and directivity suggest one could be very useful.

73s
Roger G3XBM