Introduction to the SCR Preselector-CAT by Nigel Coleman, G7CNF


Working with DDUTIL. Tracking the Preselector by Nigel Coleman, G7CNF


Broadcast band rejection by Nigel Coleman, G7CNF Calibration tables of frequency for tracking reference by Nigel Coleman, G7CNF


"A walk along VLF-LF Bands"

An introduction to the new VLF-LF-MF bands Up-Converter.


"The Big Jump"

"Alexanderson Day" special transmission on 17.2 kHz from SAQ Grimeton radio station in Sweden was received in Granby QC Canada (FN35RK) on 28 June 2015. Distance 5.700 km (3.600mi)
This was the group effort of VE2CRG,the Granby Amateur Radio Club.
The radio station setup included a tuned 1.7m diamond loop, FET balanced preamplifier, Heros Technology VLF-LF Up- Converter model-400, multiband IF receiver tuned on 4.017 MHz and Spectral Analysis software Spectran v2.


Antenna Galvanic Isolator

Effectiveness Demo Video Clip


  Aircraft band RF filter.  


USB Galvanic Digital Isolator for SDR radios

Effectiveness Demo Video Clip