Again with the help of Artur from Maresme DX I received a very nice email and a scan of a QSL letter from Radio Surco, broadcasting from Tomelloso, Spain, on 91.4 FM. I posted a recording of my reception on YouTube. Radio Surco has two transmitter sites: 2 kW on 91.4 MHz, and 1.2 kW on 99.2 MHz:

Radio Surco transmitter locations

Dear Peter,

Thank you for contacting us and receiving news from the Netherlands. This year, at least, we have received three messages like yours, from different locations. We assume that due to the location of our broadcast tower and the very flat area where we are, the waves work their magic and allow us to reach distant places.

We are a radio station with two broadcasting centers, but according to your instructions, it is Tomelloso’s that you heard. Radio Surco Tomelloso was born in 1986 and is an independent commercial station. Its cover, being a flat land, covers “La Mancha”, an area of the Autonomous Community of Castilla La Mancha to which four of its provinces belong. Tomelloso is in CiudadReal, specifically.

The emitting center is located at this point
https://maps.app.goo.gl/EZCdtXyXT9uYUA6N7

Location of the Radio station Surco TOMELLOSO
https://maps.app.goo.gl/AMhjJvCLcrBaeRet8

The Radio Surco Tomelloso station is located about 12 kilometers as the crow flies or cross-country

I attach the certificate you are requesting, although we do not have an official model. Thank you for being on the other side and greetings from Spain.

Montserrat Castellanos Cañones
Directora

QSL Radio Surco Tomelloso 91.4 MHz
QSL letter from Radio Surco, Tomelloso, Spain, 91.4 MHz