FMDX EQUIPMENTS

FMDX as a pastime is relatively new to me. Actually, I began to DX the FM band more “seriously” during the Summer of 2016, since acquiring the SDRPlay (see this site dedicated page). In the past, I could experience occasional FMDX on the car radio for example but this was nothing compared to SDR technology where a portion of the band can be recorded for later review. Moreover, many capable SDRs can be found nowadays at a very reasonable price. Be careful however concerning the choice of a computer because recording a 10 MHz chunk takes a good amount of computing power and this has to be considered seriously in the planning of a SDR acquisition.

FM propagation compared to MW can be quite unpredictable, with the exception maybe of Tropospheric Ducting (Wikipedia) whose events are closely tied with certain weather conditions. During good “Tropo” conditions, signals can travel up to 800Km. But the most thrilling events come without contest from E-Skip (Wikipedia) propagation where signals can be heard thousands of kilometres away. The good news is that we already know that E-Skip is likely to happen in North America for instance, roughly from June up to August. The bad news now is that it can happen at any hour so unless you’re a retired person, there’s a great deal of luck in being at the right place at the right time when such conditions occurs.

As for my own experience, if I’m not taking in account scarce E-Skip events from the past years on my car radio,  I’ve been witness of my first big opening on June 13 2017, live while sitting at my listening post and with my SDR running. This lasted for nearly one hour. That was a truly exciting moment. Now that you’re aware of which receiver I’m using, let me describe you the antenna system I use for FM broadcast. Many years ago, I bought myself (if I recall correctly) a Canadian made Delhi 10 elements antenna for FM (above pictures). It’s a double folded dipole type. My intention at the time was nothing more than to improve the reception of Montreal’s stations. Now, getting more extensively into this hobby, it is back on duty again.

Regarding the matching transformer, I wanted something that has good performance and obviously, I couldn’t trust those cheap commercial models. Therefore, I turned (again) to my friend Jürgen Bartels, who’s himself a very active FM-TV-FT8 DXer for advice about a quality match. He kindly provided me a solution using a BN- 43-2402 binocular core. Each windings has two turns of enamelled wire. Choose a gauge as large as it could fit the core for a lower loss.

A view of my antenna sitting on our house rooftop tower @ 12m / 40ft looking towards Eastern US

Page edited in July 2020

A portion of the FM band on a regular July morning, there centered at 95.3 on a 10 MHz bandwidth spectrum from SDRUno, the native software of SDRPlay