For your consideration is this gorgeous 1926 A. Grebe MU-1 Synchrophase 5-tube, 4-01A’s and a 112, battery radio, Serial XRSA. For a collector, the Grebe MU-1 is one of the most desirable of all the early 1920′s battery radios. It is considered one of the best working TRF-Neutrodyne circuits and is housed in a handsome solid mahogany cabinet with a mottled mahogany bakelite front panel accented with s. Tunning bright brass diamond hooded dial covers. This MU-1 works with the pair of vintage earphones, which will accompany the radio, and will require a range of different d. Voltages as shown in the hook-up chart mounted on the bottom of the cabinet(next to last photo). An ARBE III was used to provide all the required voltages…. Which is not included. This radio has two tuned RF stages and a tuned detector stage. The original grid-leak resistor was open so a modern resistor was shunted across it. The three stages can be tuned separately or ganged together by locking the thumb nut on the left and on the far right dial. All three stages are tuned simultaneously using the center “Master Dial”. All three stages are connected with a ball-chain drive. You can see the chain connection in my photos. The instruction sheet lists calibrated dial readings corresponding to wavelengths for the low and high ranges. The high range covers from about 175 m (1,700 khz) to about 315.6 m (950 khz). The low range covers from about 263 m (1,140 khz) to about 526 m (570 khz). The radio has the “high-low range switch” coupled to the center “Master Dial”. To place the radio in the “high range” you move the “Master Dial” past 100 as far as it will go. This action moves a lever inside that changes taps on the three “Binocular” coils. To place the receiver in the low range, you move the “Master Dial” below zero as far as it will go and this action moves the lever in the opposite direction. The three tuned circuits use the Grebe trademarked “Binocular Coils”. The design of these coils allow the RF stages to have significant gain without oscillating. The tube sockets all have spring-mounted tops to reduce sensitivity of the tubes to microphonic vibrations. This modification also mitigated another annoyance and that was customers complained that slamming the top lid would shake the tubes and the filaments would break. Another modification was the addition of a middle dial lamp, a new #40 was installed, and on the rear of the chassis another bulb acts as a fuse. You can see both in photo #9. The original Grebe MU-1′s didn’t have an earphone plug, so this was a modification by a technician in the past. This radio should also work with a period speaker connected as shown on the bottom hook-up sheet, however, none was available at this time. The 6-position “Colortone” dial on the center left controls tone and the volume control located on the right controls the filament voltage. (I noticed that the circular brass dial plates are opposite after I took the photos and will swap the tone and volume plates so that they are correct). The is some minor dings on the top lid of the cabinet, but nothing to detract from the beauty of the radio. This is a early battery radio and you’ll need a source of the required voltages, a long outside wire antenna, ground and some experience with operating TRF radios…. If you would like one of the best looking 20′s battery radios, then don’t pass this one by. You may not find one this nice… Especially one the works! I have taken a lot of pictures so that you can see how really nice this Grebe MU-1 is. Thank you for looking. Because this radio is big, approximate dimensions are: 22 1/2″ long, 9 1/2″ tall and 13 1/2 deep. The radio itself weight approximately 25 lbs. The item “GORGEOUS ANTIQUE VINTAGE 1926 GREBE SYNCHROPHASE MU1 BATTERY RADIO WORKS WithPHONE” is in sale since Sunday, October 25, 2015. This item is in the category “Collectibles\Radio, Phonograph, TV, Phone\Radios\Tube Radios\Pre-1930″. The seller is “autoprints” and is located in Manchester, New Hampshire. This item can be shipped to United States.
