FA: Heathkit GC-1000 Most Accurate Clock w/ RS-232
 

Heath GC-1000-H Most Accurate Clock with GCA-1000-1 RS-232 and the
seldom seen GCA-1000-4 Service Manual. The service manual is the only
document Heathkit published with the alignment procedure for the WWV
receiver. Ebay item number 3083413013.