Tesla Model 308U "Talisman" Radio (1956)

           

           

The Tesla model 308U "Talisman" radio is a gorgeous example of Streamline design and much sought after by world collectors. Manufactured in Czechoslovakia in the mid-1950s, its sleek, modernistic lines rival anything produced by Western countries during the 1930s and 1940s.

The cabinet has a teardrop or bullet shape. Compare it to other streamlined radios in my collection. From left to right, you can see the Talisman, FADA 1000 Bullet, Farnsworth GT0-51, Belmont 6D-111, Airline 74BR, and Truetone D2017.

              

Description

I purchased this radio from Boskoop, Netherlands in 2005. It was in excellent original condition, needing only routine electronic service.

Here is the 308U seen from the front. Notice the distinctive red color.

Yes, this is a Bakelite cabinet. Although Bakelite is most often seen in dark brown, or less often, black, it could be manufactured in a dark red or maroon color as seen here. Most 308U Talismans are found in the more common colors, making the red cabinet most desirable, almost unique in the world of vintage radios.

This is a three-band radio, covering the longwave, standard broadcast, and shortwave bands. The dial scale is marked in meters: 16.5-51.5m, 187-572m, and 1000-2000m.

The next images are taken from the owner's manual. From left to the right, the knobs are: power/volume, tuning, and bandswitch. The logo page shows that this model was made from 1953-1958.

  

In the back view you can see that this is a four-tube radio, with connections for an external antenna as well as a ground wire. Typical of many European radios, it can be powered by either 220-volt or 120-volt current, selected by a switch plug in the lower right corner.

Unlike similar American radios of the era, the back does not include a built-in loop antenna for standard broadcast band reception. You must connect an external antenna to receive anything at all, which is typical for a multi-band radio like this.

Here is the chassis removed from the cabinet.

If you look closely, you can see the radio's manufacturing date stamped on the tuning capacitor frame: February 8, 1956. All of the tubes are Tesla originals. The leftmost one still has its paper label, with a red stamped manufacturing date and (on the other side) the city name Zagreb written in ink.

This radio uses four tubes, in a design popularized by Philips radios of the era. The tubes are European types UCH21, UCH21, UBL1, and UY1N.

The next photo shows the chassis from the front. Like some German radios that I own, this Talisman has a "bonnet" cloth cover over the speaker, which keeps out dust. The round bonnet fits snugly around the speaker body and is secured with a string around the back. This is in addition to the speaker grille cloth, which is all that typical American radios provide to keep dust out the speaker cone.

The dial is made of glass, reverse-painted in two colors. Above the dial are dual pilot lamps. Here's a closeup of the dial in a dim room.

This radio was manufactured for domestic Czechoslovakian use. The manual states that export models lack city names (since those would be different in other parts of the world).

Restoration

Here is a view underneath the chassis. No real surprises here. The black cylinders are capacitors; the tan ones are resistors.

Below are the Tesla 308U schematic diagram and wiring diagram:

  

Once an American reader gets used to a few different conventions, a European schematic is not hard to puzzle out. Two different power resistors are employed when you change from 220 to 120 volts. Otherwise, it is not dissimilar from American "All American Five" radios of the time.

This is an AC/DC type chassis, in which the tube filaments are connected in series with the AC power line. Together with the power resistors and the pilot lamps, their voltages add up to the line voltage. This eliminates the need for an expensive power transformer, but also dictates greater care when powering up the chassis on the workbench, to avoid a shock.

This radio has better build quality than my Soviet Irkutsk Rekord-53. The construction is similar to German radios of the time, and the components are of decent quality. In addition to the cloth speaker bonnet, it includes other welcome details, such as the machined brass inset for the screw that secures the chassis from behind, and knob setscrews that go all the way through machined holes in the knob shafts.

Preliminary testing revealed that the rectifier tube had an open filament. I ordered a replacement, along with needed capacitors, from Jan Philipp Wuesten at Ask Jan First Elektronik in Germany. Jan also emailed me the service data at no charge. After replacing the old rectifier tube and capacitors, the radio works beautifully on all bands.

Tesla made a few different 1950s radios using the Talisman name. If you do an Internet search, you can learn more about them. I consider this radio the most attractive of the Talisman family.

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