389
Item nr.
Mini for spare or bedroom; or electronic experiments
| Production | The Netherlands, 1961.
Price was fl 88. |
|---|---|
| Bands | MW (185-580m); IF is 452kHz. |
| Tubes | UCH81, UBF80, UCL82, UY89. |
| Cabinet | Moulded. Size 26x14x14cm. Weight 1.5kg. |
| Power | AC/DC 127/220V, 43W (but now just 16!). |
| Documents | Flyer. |
This B0X19U is similar to the B0X15U, but has a linear dial. Available colors were orange (this one), green, and black. In 1961 this may sound a little early, but orange and green became the hype colors of everything in the seventies. Power consumption is 43W according to specs, and I measured 41 to 43, depending on tuning (AVC reduces current in B1 and B2 on strong signal). These small AC/DC sets are notorious for their high sensitivity: it receives all available stations already on the built in capacitive antenna.
| Obtained | 2/2015 from Kringloopwinkel De Wegwijzer; SN=A70003. |
|---|---|
| Condition |  7; plays perfectly, cabinet has paint spots, chip (photo). |
| Disposed | Sold 6/2020. |
| Sound sample | PLAY SOUND In the second half of August 2015, Radio Nostalgia has its "conversion week". All listeners are advised to throw out their old, obsolete AM sets. They play quizzes every hour where listeners can win DAB+ radio's. |
The model year is 1961, but it has production code 14/63. In its earlier lifetime, the radio witnessed some painting activities in the colors white and grey. Fortunately, the white was the wall paint type, and could be more or less removed. 
Pulling the chassis revealed a big dustpark, probably because of the missing back panel. I dusted out this mess and replaced four capacitors preventively: C11 (g2 decoupler for B1 and B2), C25 (plate of B3), C17 (coupling), and C19 (rattle). All tubes tested OK (in the 80 to 100% range). Then sound was not OK due to a loose contact in the volume pot, but this was quickly repaired. Pin voltages measured OK, so we had a healthy patient here. But noticeably of age. As you can see on the bottom photo, the PCB under the output tube is turning a little black. This indicates some burning of the paper material is taking place, and this can mean the end of the radio in the long term.
Because I have another similar radio, and this one isn't really top state, I used it for a few experiments. In 2017 I modified the radio to play on 39V DC, as demonstration in a lecture about American AA5 sets. These were sometimes modified to play on 32V DC from wind generators, and I demonstrated that a similar modification is possible for European U-sets. This reduced the power consumption to about 8W, but the reception and sound quality suffer considerably.
A next experiment was a modification to series power supply with capacitor. This resulted in a set consuming 16W from the mains, with about the same quality as the original (until you try to play it at max volume). On the left you see the disconnected (now superfluous) series resistor and the red series capacitor under it, and on the right the wave form of the current throught the heater. Observe that when the current is near its negative peak, the voltage on the rectifier is at its positive peak and it will start to draw current.
Playing an ACDC set without a rear panel is not a safe option. Starting from a board piece 25.5x13.8cm I produced a little back board, which fits the radio nicely. Finally I replaced the power chord.
The second set, bottom on photo, is a little bit older (lower sequence number), but looks better than the first one, top on photo, which is dull and has paint spots, and misses the back panel. The first one had a dial coded B A379286, which is marked in meters of wavelength and has the names of 13 (mainly Dutch, Belgium, French, and German) stations. The second radio has a dial marked OV A396954, which is marked in meters and kilocycles, and has no station names. I think the B stands for Benelux and this dial was the standard in Belgium, Netherlands, and Luxembourg. The OV on the other dial could stand for OVerig, or other, or alternatively for OVerzee, or overseas. This dial could be standard for exported units. However, the radio was sold by Electronica De Boer in Zutphen, and I have no indication that the unit actually was purchased with emigration in mind.
