In a Nutshell
This 73 years old wireless record player is jaw dropping, it broadcasts (transmits) to all nearby AM radios. You even can play your mp3's through your vintage radio

Introduction:
Starting in January 1939 for the next three years almost all of the bigger American radio manufacturers began to sell wireless record players [RCA VA-20 (1939), Philco RP-1 (1939), GE HM-21 (1940), Zenith S-6622 (1939), Motorola 22A (1940), Wilcox-Gay A-56 (1939), Majestic 3PW (1939), Crosley CR-26 (1942), Stewart Warner 11-2A1 (1940)]. The basics are rather simple (see above block diagram): a multigrid tube (here a 35L6 Pentode, often also a pentagrid converter 6A7 or 6A8) is used to mix a carrier BC frequency and the phono cartridge output signal, to produce an amplitude modulated (AM) high frequency signal (around 580 kHz), which is transmitted through an antenna or an inductive coil to any nearby radio capable of receiving the AM/BC band. The two additional tubes have the only purpose of feeding that tube properly.
These phonographs are so jaw dropping and mind-blowing, that up to this time AM transmitter kits based on the original design are sold (ref.1). Being produced 10 years before 33 rpm was introduced by Columbia and 45's by RCA, these record players are strictly 78 rpm only, in very beautiful bakelite or wooden cabinets and in open air design without cover. Ref.2 contains a detailed description of Philco's RP-1, that I had restored earlier (pict.30), and ref.3 refers to the model offered here (apparently versions with different knob configurations were offered). Originally heavy tonearms and Astatic steel needle cartridges were used, that are not very healthy for 78's. All my vintage record players are equipped with new ceramic flip-flop jukebox cartridges with diamond or sapphire needles (picts.19,20), and have tonearm weight reducing springs installed (pict.15). The cartridges have two sapphire needles for 78rpm and LongPlay, where the latter one can be used for 78rpm too (more noise though) as a spare, or - more importantly - for playing the rare 78 rpm microgroove records, that were produced for a short time around 1948/49, mostly in Canada (14 available on request), and had 3 times the capacity of normal 78's. By providing an extra plug (picts.14,17,27) also devices like cellphones, mp3 players etc. can be connected to the same transmitter to be broadcasted to your AM radio. This is a valid alternative to buying a rare and expensive AM transmitter, in order to play all your music on your preferred vintage tube radio.

Additional information:
ref.1: http://www.amazon.com/AES-Kits-Wireless-Transmitter-DIY/dp/B005XE3GSQ
ref.2: http://www.greenhillsgf.com/IndexOwn_Philco_RP-1.htm
ref.3: http://www.radiomuseum.org/r/sears_roeb_100356.html
ref.4: https://www.youtube.com/watch?v=sokY3IM-MyE

About my Record Player:
The player is in mint condition, with original bottom cover, power cord and plug and no faults in the glossy mottled bakelite cabinet. I recapped the electronics, and replaced the dried-out cartridge with a ceramic flip-flop cartridge, having in addition to the 78 rpm needle a 33/45 rpm needle (pict.s 19,20). Finally I installed a spring at the rear of the tonearm to reduce its weight and the pressure of the cartridge on the record (picts.14,17,27). The record player played for many hours, transmitting to various AM radios, including contemporary wooden tube radios, like a Nordmende Saba C console, or modern transistor radios (click on pict.29 or go to ref.4 to watch a youtube video). When using a transistor, only the ferrite antenna (not a telescope antenna) is needed. It may be worth mentioning, that interest in AM transmitters is increasing, since a. broadcasting on AM is said to terminate soon, and b. connecting devices like CD and mp3 players to vintage radios is getting more and more fashionable. This 73 years old tube transmitter is a valid and well priced alternative to an "SSTRAN" AMT-3000. Please e-mail me (Kris) for any questions, ich spreche Deutsch, je parle Français.

Here are the specifications:

Please have a look at prices and more radios, phonographs and gramophones  here