Monthly Archives: May 2020

Radio Mercur, 1960

1960MayEIIf you look carefully at this picture, from the May 1960 issue of Electronics Illustrated, you’ll see at the top of the mast a Yagi antenna for 89.55 MHz. The ship is the Cheeta, and flies the Panamanian flag.

The ship is in international waters off the Danish coast, and is serving as the transmitter site for Radio Mercur, a pirate radio station. From studios in Copenhagen, programs were recorded in Danish, Swedish, and English, and brought to the ship anchored in international waters.

According to the magazine, the sale of FM receivers boomed in the ship’s listening area of about 50 miles, with an ERP of about 1500 watts. The Danish government had been unable to silence the station, but this changed a few years later with legislation forbidding anyone in Denmark from cooperating with the broadcasts.



1920’s Answer to the Zoom Worship Service

1920ElecExp1With most of the world locked down due to the threat of COVID-19, places of worship have been scrambling to deliver the Word of God to the faithful at home. But long before Zoom and YouTube were a thing, churches have relied upon technology to connect with members, as shown by this illustration from a hundred years ago this month, in the May 1920 issue of Electrical Experimenter.

Zion English Baptist Church, Penycae - geograph.org.uk - 729952.jpg

Zion English Baptist Church, Pen-y-cae, Wales, the likely origin of the 1920 transmissions.  Wikipedia photo.

Shown here is miner Sam Pritchard of Penycas, Ruabon, Wales. In 1919, he was injured by the fall of a rock. Undaunted, he was able to hear the service at the Baptist Church thanks to a telephone rigged by three of his friends.

A button microphone and batteries were strategically placed near the pulpit, with wires run to Mr. Pritchard’s bedside some distance away. A telephone receiver was strapped to his head, through which he was able to take part in the service. The magazine noted that the apparatus required was not expensive, and that such a setup could prove valuable in the northern or western United States where deep snows often cover the country.

Of course, over the years, churches have moved on to radio, then audio recordings, then television, and then the internet to deliver their message to those shut in at home. Incidentally, the OneTubeRadio Laboratories are currently hard at work preparing a 100 mW AM transmitter which will operate, with a 9 foot antenna, to broadcast church services within a parking lot. The internet works well for those who are at home, but everyone signal is slightly out of synch with everyone esle. At such time as it becomes possible to congregate a bit more closely, in parked cars, radio will allow everyone be able to listen simultaneously (or as simultaneously as the speed of light allows).  We have verified that the transmitter is up to the task, and today, we received the parts necessary to provide a high-fidelity audio feed.  We’ll post updates as the project is completed.



1945 Three Tube Shortwave Receiver

1945MayPM11945MayPM2This three-tube shortwave set from the May 1945 issue of Popular Mechanics was designed around wartime parts shortages, and the magazine touted that it could be assembled entirely out of odds and ends of salvaged materials. The gentleman at left is shown scavenging parts from a discarded radio. Despite the low tube count, the set would pull in shortwave stations from around the world and fill the room with loudspeaker volume. It featured a 6C8-G as regenerative detector, 6K6-GT audio amplifier, and 6X5-GT rectifier. Plug-in coils allowed a tuning range of 160-19 meters. The magazine advised that the set was designed specifically for the short waves, and that the builder was advised not to try and alter it to tune the standard broadcst band.

The filaments were powered from a 6 volt transformer, and the B+ came straight from the AC line, with the familiar “hot chassis” design, and the familiar caution not to hook the chassis directly to ground.

1945MayPM3



Friendly Cheer Magazine, 1940

1940MayPSConventional wisdom is that, prior to the Internet, it was impossible for individuals to reach a wide audience. Fortunately, nobody bothered to share this conventional wisdom with Charles Edward Caswell of Concord, N.H. , who wrote, edited, printed, and distributed his own magazine, Friendly Cheer.

This article appeared in Popular Science, May 1940, which noted that copies of the magazine went to every state and 14 foreign countries.

We haven’t been able to figure out what happened to Friendly Cheer magazine, and the domain name friendlycheer.com is still available. So if anyone wants to pick up where Caswell, left off, there’s your opportunity. And if anyone has a copy of the magazine, we would love to see it.