40A/B Transmitter


The 40A/B was Collins’ first desktop phone transmitter. Based on the 30W, it added a 9C Amplifier-Modulator and antenna tuner unit. Plug-in coils for 160, 80, 40, and 20 meters were available, with the coils for one band being standard. The unit was priced at $235.00 including either a 34″ table rack, or standard 60″ floor rack. It first appeared in the Collins QST ad for October 1932. The 40A was cw only.

The 40B ran 30 watts and covered the frequency range of 1,715 to 14,300 kHz.

An external input amplifier, the 90C, provided the necessary gain to drive the transmitter with a condenser or double-button carbon microphone ($32.00). It used two type 56 tubes resistance-coupled and had a flat frequency response from 80 to 8,000 cycles. Power for the 90C was obtained from the same batteries as used for the receiver or condenser microphone.

A model 5A Broadcast qualilty Condenser Microphone was also offered. It used a pair of 864 tubes and came with 20 foot shielded cable and steel battery cabinet.

The 5A was priced at $125.00 and the 90C amplifier at $32.00.