Heathkit Most Accurate Clock II
Model GCW-1001

This little machine is another mainstay of my shack. This was the last clock of it's type produced by Heathkit before discontinuing the line. Mine was acquired used ( as usual ) from a want put out on alt.horology ( and no, that's not the study of anything dirty, look it up! ) newsgroup. It was in mint condition in the box with manual and all accessories. The guy I got it from said he couldn't pick up WWV inside where he lived. It works fine here on an indoor dipole WWV comes in most of the day unless conditions are real bad.

Here is a brief description of the clock taken from the manual:

The Heathkit Most Accurate Clock II, Model GCW-1001, is a unique timepiece capable of setting itself to the highly accurate time signals broadcast by the National Institute of Standards and Technology. Not only will it set itself automatically, but it will continually adjust itself for best accuracy during good signal conditions, and also maintains high accuracy during poor signal conditions.

The standard features of the Most Accurate Clock II include:

There were a few optional accessories available for the clock.

GCW-1001-1 Remote Clock. This clock can be plugged in anywhere in the house and will display correct time automatically by the signals it receives from the GCW-1001 Master Clock with the GCA-1001-1 Powerline Interface installed.

Note: The Master Clock can use either of the next two accessories, but not both at the same time.

GCA-1001-1, Powerline Interface Accessory. It easily installs in your Master Clock and sends time information to any number of GCW-1001-1 Remote Clocks plugged into AC outlets throughout the building. However, the Clocks do have to be on the same leg ( or phase ) of the AC line.

GCA-1001-2, RS-232 Interface Accessory. It also easily installs in your Master Clock and allows a computer or terminal to access time and clock status. This accessory includes PC utility software.

GCA-1001-3, 10 MHz Dipole Antenna. It is a high-quality antenna designed to provide an optimum signal for your Master Clock.

Heathkit recommend that you use only an alkaline type 9V battery for the backup feature. The following manufacturer types are mentioned:

I've had very good luck with a half-wave dipole stretched around the perimeter of the ceiling of my shack. My clock has the Powerline interface installed and I've located 3 of the remote clocks. I've not decided whether to keep all of the Remotes yet. If you can't plug them into the same phase you have the Master on, the will still work as a stand alone unit. In this case however you will need to manually set them.

Update: I sold the remote clocks. I use this clock primarily in my ham shack which is detached from my home. Also I power the master unit from a surge protector power strip and the Data will not travel to the remotes if the master is plugged into a surge proctector type power strip. So I decided to let someone else that could use them buy them.

If you own one of these units or a previous Model I'd like to hear from you. If I can find the information I'll put another page up on the previous models. Send comments or suggestions.


Heath Company
P.O. Box 1288
Benton Harbor, MI 49023-1288

Main 1-800-253-0570
Repair 616-925-3273
Parts 616-925-5899
Technical 616-925-4914

This page designed by : Ricky Lee Ponder Copyright 1999 All rights reserved.