The Reslo RL-1 (Ribbon Lavalier 1) is a pretty unknown microphone. It is a ribbon type lavalier microphone, with a cardioid pick up pattern.
Lavalier mics are seldom seen these days, wireless transmitters with clip-on microphones have taken over their task. In the sixties, and seventies, lavalier mics were all the rage, they freed their users from microphone stands and large microphones that might hide them from sight, they offered freedom of movement.
Lavalier mics were used on tv, for news-readers, in panel-shows and for interviews, as well as on stage, for speakers and fora, and last, but not least, in churches. No wonder Reslo decided to jump the bandwagon, so they came up with their own variant, which, of course was in their case, a ribbon transducer in a small housing, to be worn around the neck.
As far as I know, RCA was the only other company that ever made a ribbon lavalier mic; the type 30A, from 1939.
Although RL-1 was not the cheapest Reslo ribbon, it was very basic; the ribbon element was the same as in the Reslo PR (Pencil Ribbon) according to Stewart Tavener, who is an expert on the subject of ribbon microphones.
The bottom of the RL-1 has two holes, probably for airflow.
The casing is very smooth, to avoid contact sounds and rubbing against clothes. The low frequencies were diminished, to counter chest tones. It was available in two versions, RL1 /L 30-50 ohms, RL1/M 300 or 600 ohms.
Storage pouch of the RL-1
The neck cord, was not adjustable; just a piece of black nylon, that could be loosened or fastened to quick release loops, at both sides of the RL-1.
The die cast casing had a grey polychromatic coating (Hammer finish paint) and an aluminium mesh.
Its dimensions were 40 mm high, 52 mm wide (63 mm including quick release loops), and 30 mm deep. It was light-weight; just 144 grams. The RL-1 was only manufactured for a short time, in 1964-65, after that it was replaced by the Reslo dynamic MMD .
These days this vintage model is truly outdated, but it is a nice relic of earlier communication.