Gerard's EAK Super 64/50 GWP

161
Item nr.

EAK Super 64/50 GWP Mini Radio

Small Bakelite mini with six bands.

**Data for EAK Super 64/50 GWP**
Production	Germany, 1952.
Bands	LW (152-300 kHz), MW (520-1700 kHz), 49m, 41m, 31m, 25m (see below).
Tubes	UCH11, UBF11, UEL51 (selenium rectifier).
Cabinet	Bakelite. Size 28x21x12 cm. Weight 3.5 kg.
Power	ACDC 220V.

The Design

EAK means Elektro-Apparate-Fabrik, Köppelsdorf. Otto reports that the last digits of EAK models are the model year, so the radio was designed in 1950. The letters in German type numbers often indicate power, where G means Gleichstrom (DC) and W means Wechselstrom (AC). Indeed this radio is an ACDC type. The P probably means Pressstoff, for Bakelite; other sets with wood case have an H (for Holz) there. I have a schema for the 64/50 GWS (with UCL11 output; S probably stands for Super) but my radio is GWP and has UEL51, a later tube. The letter T in the type, if present, stands for Trocken or dry rectifier.

The radio is equiped with a symbolic dial. For the SW bands the dial gives no frequencies nor stations, but only a ruler from 0 to 100. Except on radios of the twenties and special measuring equipment I had never seen such a setup before. The tubes are special "German" eight and ten pin types, not very commonly found here in The Netherlands. The output tube is the 10 pin UEL51. Rectification is by a big selenium diode, but I bypassed this with a modern silicon type. for safety. The chassis is cast metal and the entire build-up is very cramped so that it is hard to work on it, especially on the AF amplifier.

Frequency Measurements

One often finds receiving frequencies listed for radios, also for the sets in Gerard's Radio Corner. These data are sometimes taken from documentation, but more often they are simply the leftmost and rightmost figures found on the dial. As the EAK lists no frequencies for the shortwave bands, and nobody has full service documentation, its receiving frequencies are a mystery. I measured the actual receiving frequencies for my EAK using the LM13 frequency meter. A rough test with the dipmeter was faster, but the dipmeter is not accurate enough.

Band 0 33 67 100 Length
25m 11895
25.22m 11921
25.16m 11997
25.01m 12103
24.79m 218 kHz
31m 9583
31.31m 9614
31.20m 9708
30.90m 9856
30.44m 273 kHz
41m 7162
41.89m 7196
41.69m 7307
41.06m 7492
40.04m 330 kHz
49m 5910
50.76m 6046
49.62m 6102
49.16m 6360
47.17m 450 kHz
I measured the frequency of each of the four SW bands at points 0, 33, 67, and 100 of the scale, and computed the length of the band. Of course my radio may receive different frequencies from those intended by the manufacturer, and your set may be different from both again. The accuracy of my measurements is better than 10kHz. Some observations that jump to mind:
(1) Tuning is really very smooth due to bandspread. Even the longest band (450 kHz) is less than half as long as the Medium Wave band.
(2) The frequency is far from linear: stations are more cramped on the high end of the scale than on the low end. This hapens in most radios and I can remark that due to the bandspread tuning is actually quite easy on all SW bands.
(3) The bands of lower frequency are longer (have more kHz in the last column) than the higher frequency bands. This is the other way around in most radios, and I assume this is caused by the inductive tuning used in the EAK.

Band	0	33	67	100	Length
25m	11895 25.22m	11921 25.16m	11997 25.01m	12103 24.79m	218 kHz
31m	9583 31.31m	9614 31.20m	9708 30.90m	9856 30.44m	273 kHz
41m	7162 41.89m	7196 41.69m	7307 41.06m	7492 40.04m	330 kHz
49m	5910 50.76m	6046 49.62m	6102 49.16m	6360 47.17m	450 kHz

Obtained	9/2000 from Paul van Berlo.
Condition	6.
Disposed	Sold 10/2004.

This Object

The radio worked very poorly initially: only one station could be heard. I gave it a medium electrical overhaul, replacing the leaking capacitors and bypassing the rectifier by a diode. Now it works satisfactorily. The external state was more of a problem. The picture on the left shows the radio when I got it, the right picture shows a similar radio I saw at a flee market.

I used Commandant Cleaner for the bakelite and freshened up the white lines with Tipp-Ex. The broken dial was the most problematic, but fortunately Otto supplied me with a sharp scan of the dial. I digitally removed dust and printed it on a transparancy.

The radio looks a lot better now, and sounds a lot better too, but because of the design I consider it to be among my most unsafe radios and never play it when I'm not in the room. In June 2002 it stopped playing and blew a fuse in my power supply.

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