Re: LF: Wellbrook RX loops

[DENNIS EASTERLING <dennis.easterling@btinternet.com>]

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