Shortwave listening atop Sant Pere Màrtir in Barcelona

Monday, July 17, 2023

Sant Pere Màrtir summit, Barcelona, Spain. © 2023 London Shortwave
I was very lucky to be able to spend one week in Barcelona at the end of June, which also happened to be my first holiday abroad since Singapore in 2019. Apart from immersing myself in Gaudi's architectural wonders and spending countless hours walking around the Gothic quarter of the city, I was also able to explore some of the surrounding hills. My longtime Twitter friend David EA3IEK suggested that I should try Sant Pere Màrtir for shortwave listening, so I made my way there on Saturday July 1st and reached the top around 16:38 local time. 

Radio listening and spectrum capture QTH on 01/07/2023

The hill summit hosts a communications tower that was originally a television signal repeater, from which the first transmission was made in 1959.
© 2023 London Shortwave
The view of Barcelona is quite simply stunning from this location: 

I set-up my 2x6m dipole antenna together with my AirSpy powered portable spectrum capture set-up right by the surveillance tower. The antenna was facing north-north-west. 

Antenna span and orientation marked in red

It was a relaxing evening of listening to shortwave while admiring the mountainous landscape surrounding the city. 

This particular listening spot also presented an interesting technical challenge. The Torre de Collserola television and radio tower, located at one of the adjacent hilltops, transmits multiple high power VHF and UHF signals. As David EA3IEK pointed out to me during my trip, whenever it is in the line of sight, many portable radios are overloaded with noise and FM breakthrough signals

Torre de Collserola television and radio tower, as seen from Sant Pere Màrtir. © 2023 London Shortwave

My trusty Belka-DX handheld receiver definitely suffered from this problem. In the video below, you can see me tuning across the 31 meter band, starting with the Voice of Korea on 9425 kHz. You can hear the blown out and distorted sounds of what is likely to be an FM transmission persisting across multiple frequencies, including an empty channel on 9580 kHz. 


However, as you can see in the clip above, there are no such artefacts in the spectrum recording I made at the same time and in the same location using my default GPD MicroPC / AirSpy Mini / SpyVerter 2 SDR combination, despite the dipole antenna being many times larger than Belka's own whip! These AirSpy products appear to be immune to breakthrough FM signals and general overloading – a very fortunate outcome given the effort involved in hiking up to the top of this hill!

Torre de Collserola and Sant Pere Màrtir, as seen from Tibidabo. © 2023 London Shortwave

I was able to enjoy listening to Belka-DX a bit more on the 25 meter band, with the BBC World Service coming in nicely from Kranji, Singapore on 12025 kHz.

There was a nice but weathered site information panel about Sant Pere Màrtir, which covered the latter's early history and its use as an optical telegraphy relay hub.

Sant Pere Màrtir site information panel. © 2023 London Shortwave

All in all, it was an excellent day trip combining hiking and DXing – one that I'm eager to repeat. Below is a recording of Sri Lanka Broadcasting Company's broadcast that I extracted from the spectrum capture I made at this location.

The recording was made outdoors in Sant Pere Martir, Barcelona, Spain on July 1, 2023, at 1628 UTC using a GPD MicroPC, AirSpy Mini, SpyVerter 2, Wellbrook UMB130 balun and a 2x6m dipole.