Dr Bruce Taylor HB9ANY describes a ground-breaking shortwave transistor receiver.
Dr Bruce Taylor HB9ANY bgtaylor@ieee.org
Although the Heath Company started producing electronic kits in 1947, and the US manufacturer had sold a crystal controlled three-valve CW transmitter as early as 1952, it was from 1956 that the Heathkit brand name became well known in the world of amateur radio, with the launch of the popular DX-100 transmitter. This was followed in 1959 with the first of the Native Indian Tribes series, the Apache transmitter and Mohawk receiver. All these rigs were vacuum tube designs, for transistors with high performance at HF were expensive at that time. (The retail price of a humble OC45 in mid 1959 was 35/-, about £43 in today’s money).
But in March 1960, three years before Eddystone launched the transistorised EC10, and four before National introduced the transistor version of the HRO, the fully solid-state Heathkit GC-1 Mohican receiver kit was produced using ten transistors, four diodes and a Zener voltage stabiliser. This was followed in 1962 by the more successful GC-1A version, with improved audio quality and better HF stability. These attractively styled sets were some of the earliest of what became the extensive series of successful Heathkit Green Machines.
Although it was possible to import US Heathkits to the UK, they often had 115V power supplies and were subject to high customs duty and purchase tax. Hence Daystrom Ltd (a subsidiary of the Daystrom Group that owned the Heath Company at the time) decided to produce a British version of the Mohican that used largely UK components, including Mullard transistors instead of 2N series types. It was designated the GC-1U, Fig. 1.
In its heyday, Daystrom Ltd employed almost 200 people and occupied part of a large facility near Gloucester, Fig. 2. It also had Heathkit Centres in London and Birmingham and a mobile showroom that displayed kits at amateur radio events across the country. US advertisements claimed that an experienced amateur could assemble the GC-1A from the kit in around 30 hours. The GC-1U required less work because the RF front-end was preassembled and Daystrom also offered ready-built sets for a cost supplement. During the golden Heathkit years, some Daystrom employees (and at least one teenage son) earned a bonus doing ‘out working’, assembling kits in their homes in the evenings to keep up with demand.
The GC-1U kit was launched in the UK in August 1961 at a price of £38.75. (About £920 in today’s money). It remained in production until 1969, when the price of the kit was £37.88 while the ready-built mode
