Graymark Micro-Museum

The Graymark Micro-Museum includes a number of constructed kits that are fully restored and functional; additional constructed kits that are untested; a number of original kits that have not been constructed; and a number of manuals, documents, a poster and a catalog.  Many of the kits were various types of simple radios, but there were many other types of electronic kits.

A brief history of Graymark, the electronics kit company is in the following document.  The company existed from about 1961 to about 2023

Graymark History

This poster of Graymark’s kits is about 3.5 x 2.5 feet.  It dates from the 1970’s and was intended to be displayed where students could see it and browse for a project.

The Graymark poster hanging in the radio shack.

Part of the Graymark Micro-Museum

A 501 Crystal Radio was one of the simpler kits.

The 506 radio has 5 tubes (follows the American 5 tube radio lineup – 50C5 35W4 12AV6 12BE6 & 12BA6).  It covers the standard AM broadcast band and a Shortwave band.  It also has a phono jack input to function as an audio amplifier

The 510 AM radio also uses the 5 tube American radio lineup

The 511 regenerative All Band Radio used 3 tubes and plug-in coils.  By placing the receiver slightly into regeneration, it was possible to receive CW and SSB signals.  However, stability & selectivity were very poor.  Detailed info is here:

The 515 micro-power AM transmitter used 3 tubes.

An unopened 505 AM transmitter kit

An assembled 505 AM Transmitter

A Graymark 512 8-transistor portable radio kit that was never assembled.

The Graymark 525 table top radio came with a wooden cabinet.  It used a standard 5-tube American radio lineup like the 510.

The 509 audio amplifier had a bright red chassis.

The 502 is a 12 VDC power supply using a transformer, full wave rectifier and capacitor filter.

The 523 strobe light had psychedelic lettering.

The 802 was a 2-transistor radio similar to the earlier 508.

216 VOM

218 Digital Multimeter

Project Ideas Booklet – It contains about 10 simple projects

Graymark Catalog from 1974  –  This contains many of the Graymark kits up to that time, but also a number of discrete components and kits from other companies

Manuals for some of the kits.

601 robot kit

603A robot kit

606A robot kit

Komponent kits