1939 Masterpiece VI (6)

The 1939 Masterpiece VI (39MPVI) does not include a specific cabinet. It is only the receiver chassis, amp chassis, and 18-inch McMurdo Silver Super Giant speaker.

 

During 1938, a newly-revised Masterpiece was designed by McMurdo Silver - truly the last of this line. They were manufactured by Hallicrafters. As of late-2016, only 4 of these radios have come to light. Based on the Hallicrafters serial numbers of these 4 receivers, two were manufactured in the August 1938 timeframe, just before the production run of the Hallicrafters DD-1, and two were manufactured in the early-October 1938 timeframe, exactly at the same time McMurdo Silver closed its doors forever. It is estimated from the known serial numbers that just 50-60 of the 39MPVIs were produced, total. The only advertisement found for this radio ran in the Nov. & Dec., 1938 editions of Radio News, after McMurdo Silver had already ceased operation. The earliest description of this radio found was in 2010 on AntiqueRadios.com, however it was not recognized as a distinct model until 2014.

 

Outwardly the 39MPVI looks very similar to the 1938 Masterpiece VI (MPVI), but there are several physical differences and numerous design changes. Physically, the chassis cover of the 39MPVI has rounded corners and sits on top of the chassis, compared to the covers of the Masterpiece V (MPV) and MPVI, which were square-cornered and slid down over the edges of chassis. Once the cover is removed, the chassis reveals a different tube layout with one tube missing, immediately to the left (from the front) of the tuning capacitor and just behind the dial. The 3 Intermediate Frequency (IF) transformers (not 4 as in the MPVI) have trimmers on top like the 15-17, and the other 3 transformers on the IF/Audio side of the chassis have holes with rubber grommets but no trimmers.

 

The tube lineup employs all-glass G-style tubes, but has significant modifications from the MPVI. It turns out to be an interesting combination of the now-familiar RF section from the MPV and MPVI, mated to an upgraded version of the IF section of the 15-17 and a rearranged Audio (AF) section unique to itself. The Fidelity control is greatly simplified from the MPVI, using the design of the 15-17, but enhanced to provide the 4 bandwidth options of the MPVI, instead of 3 on the 15-17. Gone are the 6B8s used as the MPVI's RF- and IF-AVC tubes, replaced by individual 6K7/6H6 combinations like the MPV's AVC circuit, except separated for RF and IF as in the MPVI. The double tubes used are dual-triode 6F8s in the AF section. One 6F8 implements the Detector & BFO, and the other implements the Expander circuit. The reduced tube count from 21 to 20 comes from having only 2 IF amps instead of 3 in the MPVI.

 

The 1939 Masterpiece VI amplifier chassis has a power supply with 2 x 5Z3 tubes and power amplifier with 2 x 6L6 tubes. Like the late MPVIs, power supply choke L1 is mounted outboard on the speaker pedestal, and a 7-wire harness runs between the amp and the speaker.

 

Like the MPVI, the 39MPVI has five bands, double-preselection, volume expander, 4-bandwidth Fidelity control, separate bass and treble controls, two-speed tuning knob, cathode-ray tuning indicator and great art deco styling. The "1939 Masterpiece VI" name comes from the ad in Radio News. All four radios found have "Masterpiece VI" embossed in the escutcheon like the 1937/38 MPVI. The 5 bands cover the same frequency ranges as the Masterpiece VI.