Emud Record 176
This is nice little 1958 Bakelite unit with several bands including FM AM Broadcast and SW. It also has a phono input. This unit receives well on all bands. An external antenna improves reception considerably on the AM bands. A dipole needs to be attached to receive reliable FM signals. There are six tubes in this unit. But only a filament transformer.
I must caution any owner of this unit that one side of the line cord (mains) is connected to the metal chassis within. If the line cord is plugged in the so the chassis is connected to "Hot" instead of "Neutral" then serious currents could flow. I have installed a UL rated safety capacitor for the RF bypass positions (from hot to chassis). But this is no guarantee of protection.
It is my understanding from the gentlemen at Radio Museum.org that this is acceptable engineering for this period radio. Further comments on Radio Museum.org state that an "Isolated" turntable or phono should be used. See the conversation here. The schematic posted on the web site does not represent what I observed in the chassis. The Rekord 176 (note the spelling) schematic has the circuit ground connected to the chassis through a 5nF cap. The actual radio, Record 176, has rivets on the chassis with numerous component wires soldered to them. An ohm meter proved a closed circuit from the power plug to the chassis. I would recommend that an isolation transformer be used on this radio. Especially if you should have intensions to connect a turntable or other input.
Restoration particulars include all paper caps replaced, one cathode resistor was burned. That lead me to a intermittently (flick it with you finger and the short would go away for a while) shorted ECL82. I replaced the burned 1w, 320 ohm resistor with a two 1w resistors in parallel for 2 watts of dissipation. When I looked up the max cathode current in the RCA tube manual I calculated about 0.85 watts. I did not like the power margin. All other tubes tested strong on the Heathkit emissions tester. All of the other resistors tested good. Usually I replace resistors like capacitors. However, I have found the foreign German radios use a coated resistor of apparently higher quality. They stay stable and in tolerance.
Cosmetically a new dial cord was needed, the plastic dial scale took some TLC to clean and preserve, and the dial indicator got a shot of Clorox Clean up along with the dial scale background. The Bakelite case was cleaned with Clorox Cleanup and numerous Q-tip swabs. Stray strands of the speaker grill were pushed back into the weave with a dentil pick and/or clipped off and a few spots cleaned. The knobs and buttons took a soak in Clorox Cleanup and were scrubbed with a tooth brush. Round felts were used under the knobs. I hate that scraping feeling when a knob contact something hard. The bakelite case, buttons and dial scale got a healthy dose of Magnolia's Glazit.
The only thing left to do is add a polarize plug so the chassis is connected to the neutral side of the line.
Enjoy the pictures below.
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