Our Oldest Equipment

ARK is first and foremost a ham radio club for the students in Trondheim. For it to be competitive in the many contests we participate in, the radio shack and antennas need to be kept up to date with somewhat “modern” equipment. Whatever is being replaced is often sold to recoup some of the cost of the upgrade, and we don’t have a lot of storage space to have ourselves a little museum.

We still have older radios from the 90’s that occasionally get’s used, an older PA from 1967 which works well on a single band during the Field Day portable contest and whatever random equipment the Germans left in Trondheim during spring 1945. But, how far back does it go? This week we’ll look at the oldest equipment found at ARK’s clubhouse. Not only is it located there, it is used every week and is fully functional.

History

When ARK was founded in 1923, radio had barely any grasp in the country. There were no licensed radio clubs at that point, and in terms of radio broadcasting, all of the programs were transmitted from abroad. There wasn’t even a Norwegian word for broadcasting yet. In 1925 everything changed, with the first broadcaster, first radio license and even a word for broadcasting (“kringkasting”) was getting foothold. There was only one problem: the Norwegian broadcasting was only for the citizens of Oslo.

After a major radio exhibition in the capital during the fall, members of ARK felt Trondheim was just as interested in the new medium and laid plans for it’s very own exhibition in the beginning of 1926. Without being able to acquire a transmitter for the expo, “Trondheims Provisional Broadcaster” was constructed by the club itself to show off the vendor’s new appliances. Even though the exhibition was a success, neither enough funds nor a concession was granted for a permanent broadcasting corporation in Trondheim.

Interest was still there and the club didn’t give up just yet. Before the end of the decade the club would be prepared to give it another go and attained a Philips TA 10/1750 tube (or valve as the British call it). The tube itself is a Low Frequency (LF) tube and is probably among one of several electrical components the club either bought or begged for around this time to expand it’s inventory, and would probably be nothing special for the club except for one thing: it’s still located and used at our clubhouse to this very day.

The Philips tube however would barely or not at all be utilized for it’s original purpose. After trying to gather interests for newer exhibitions in the late 1920’s, often met with little interest from vendors citing fatigue and doubt over the cause, the interest for Trondheim to get it’s own broadcasting company waned. However, in a change of events, it would just take mere months until “Kringkastingsselskapet AS” began relaying it’s broadcasts from Oslo to Trondheim in 1930. Since then, the city has never been without radio; both broadcasting and amateur.

Even though the club never got around to build or contribute permanently to the radio broadcasting in Trondheim, it got to keep the tube that was acquired for the purpose. Later named “Lysholm”, it was big and emitted a cozy orange light if a modest amount of power was supplied to it, perfect for decorating purposes. It wouldn’t take long before the big balloon-looking think was mounted to the wall with a light switch beneath.

Here we are almost a hundred years later it does just the same as when it was first mounted. It would be nice just as a piece of decor, but with the light still transmitting, we can proudly say it’s our oldest (and working) equipment!

Nickname

What even is a “Lysholm”, and how did a low frequency-tube with the original name “Philips TA 10/1750” get a name like that? Loosely translated it means “Bright Inlet”, a rather fitting name for a tube that lights up nicely. While true, it’s also a family name that’s associated much more with student life in Trondheim: Alcohol.

“Jørgen Bernhoft Lysholm” was from a wealthy family of merchants and government officials and began the liquor business of “Lysholm Linie Aquavit” in the early 1800’s. Skip forward a century and a half to the 1960’s, one of his later descendants, “Jørgen Bjarne Lysholm”, would become the CEO at the E.C. Dahls brewery in Trondheim. While they both have confusingly similar names It’s from this latter’s name where “Lysholm”, the tube, got it’s nickname.

While it’s not known exactly which year the tube got it’s nickname, it’s rumoured it got the name during the 1950’s from an enamel sign. Jørgen Bjarne Lysholm was working at E.C. Dahls at the time, before he had risen to the top of the ranks, and ARK was just getting moved into a new club locale at the Student Society after the split from the Amplifier Committee. In 1969 the sign was changed for a newer one in brass, labeled as the perfect crime. It didn’t take long before the student newspaper, “Under Dusken”, wrote about it (although with exaggerated years) and the brewery directors read the scoop. With a playful and serious threat over refusing to deliver beer to the Student Society, the sign was hastily brought back and the enamel one returned as a good gesture. It still hangs below the tube today.

Specifications

Looking through our archives it seems like we no longer have the original flyer at hand. Luckily the project and website TubeData.info has a vast catalog where you can find the one for TA 10/1750 and much more. The website RadioMuseum also hosts a leaflet for the UK market, but unfortunately it’s only reserved for the members of the site. The flyer below is courtesy of Tubedata.info:

Flipping over to page two, we can see the specs. If our German is correct, the tube is suited for up to 17 V input and at 15 A, gives a power of 255 W. To not get blinded by the light, or breaking a proper sweat, the power supplied is severely reduced. It was measured a few years back to be around 5 V, and if the math is correct, it results in a power of roughly 20 W.