Uploaded September 2024 | Updated September 2026, 1 week ago
UPDATE February 12, 2025:
People, here and in other forums, have commented that this clock does not keep good time. To test this, starting in October 2024, I synchronized this clock, and a TIMEX digital clock that also gets its timing from the AC power line, and one of my "synchronized over the radio from the Atomic Clock" clocks, and my mobile phone, so they were within a couple seconds of each other. Both THIS clock and the TIMEX are nominally based on the AC power line frequency, while the other two clocks are not affected by the AC power frequency. There WERE a couple of power outages of a few hours duration during the test period. As of mid-February, all four clocks still change (for example, rolling over to the next hour) within a couple seconds of each other.
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UPDATE September 30, 2024:
After ONE FULL MONTH since I emailed Heathkit about the missing parts in my kit, I FINALLY received an envelope from Heathkit (from the Ottsville, PA address) with the missing parts. In the meantime, I received no status, shipping confirmation, etc; about this replacement parts order. This is shameful performance, and if my experience in this regard is typical, they will anger many customers. No company should be performing so poorly in customer relations.
******************
In this video, I join the several other folks who have bought and built a Heathkit GC-1006 "Most Reliable Clock" kit and assembled it in a video. But I am doing my usual twist on the subject, going into more depth than most and dealing with issues in my own manner. I also give a quick read through the Heathkit manual and talk about the schematic & circuit theory.
I comment at some length, spaced throughout the video, regarding my personal experience with the "new" Heathkit company, the kit quality, how well the manual approximates the famous old Heathkit manuals, and their customer service (or lack of it). In short, how well does the "new" company provide an approximation of the original "Heathkit experience". I address a potential issue with a 'counterfeit' IC and with a potentially serious design error (see explanation at bottom of this description); both of these issues have been noticed by other builders, and confirmed by me, and both are potentially things that would make this clock LESS reliable.
I also did a bit of a "hack", replacing the original "colon" LEDs with new ones, and also because Heathkit did not supply enough light pipes, or any ribbon cable, I describe how I sourced replacements for those and how well they worked out.
Not trying to be negative, I dish out praise where Heathkit did a good job.
Finally, I have designed a "Quick Guide" card/label which I affixed to the bottom of my clock. This saves having to return to the manual when using the menus and controls, as there are some less-than-intuitive aspects. I have made this available as a PDF download from the following webpage:
serpentwebsite.com/fileshare.htm
Timeline Table of Contents:
00:00 Introduction & unboxing
13:09 What's in the box
16:00 Parts Bags
23:18 "Personal Product Page"
28:43 Circuit board assembly
41:20 Light pipes (issues with)
53:52 Circuit board assembly (continued)
1:10:32 Mechanical assembly
1:39:05 Initial tests
1:43:35 Final assembly
1:48:14 Beauty shot
1:48:23 Demonstration/Setup/Settings
2:18:36 Manual (overview)
2:37:15 Schematic & circuit theory
Explanation of potential design error mentioned above:
Many (most?) digital ICs these days have tiny internal diodes on their pins, as a way to provide some protection against damage from static discharge. Since they conduct with a forward bias voltage of about 0.6V, it is common for manufacturers of such ICs to include in the specifications (datasheet) a "do not exceed" voltage (re: such diode protected pins) of VCC +0.5V and Ground(0V) -0.5V, so that the applied signals won't be high enough to get those tiny diodes forward biased and thus conducting. On many ICs, these diodes are actually implemented with a parasitic transistor, whose collector goes to the opposite supply rail. This means that causing (for example) 1 mA to flow in one of these input protection diodes (transistors) can cause 10-100 mA to flow from VCC to GND (assuming the gain of the parasitic transistor is 10-100). Sometimes this can cause an SCR-like latch-up which results in even more current flowing, causing overheating of the IC, etc.
So, exceeding the "do not exceed" voltage on an IC pin like this (which is happening in this clock design for the conditioned AC signal into one pin of the Atmel ATtiny microcontroller IC), could potentially cause the situation reported by some builders of this kit, namely the IC suddenly fails, and potentially gets quite hot before total failure. It has been suggested that this issue might be fixable by use of a Schottky diode to limit that IC pin's lowest voltage extreme to -0.3V, but I have not tried that personally.
UPDATE February 12, 2025:
People, here and in other forums, have commented that this clock does not keep good time. To test this, starting in October 2024, I synchronized this clock, and a TIMEX digital clock that also gets its timing from the AC power line, and one of my "synchronized over the radio from the Atomic Clock" clocks, and my mobile phone, so they were within a couple seconds of each other. Both THIS clock and the TIMEX are nominally based on the AC power line frequency, while the other two clocks are not affected by the AC power frequency. There WERE a couple of power outages of a few hours duration during the test period. As of mid-February, all four clocks still change (for example, rolling over to the next hour) within a couple seconds of each other.
******************
UPDATE September 30, 2024:
After ONE FULL MONTH since I emailed Heathkit about the missing parts in my kit, I FINALLY received an envelope from Heathkit (from the Ottsville, PA address) with the missing parts. In the meantime, I received no status, shipping confirmation, etc; about this replacement parts order. This is shameful performance, and if my experience in this regard is typical, they will anger many customers. No company should be performing so poorly in customer relations.
******************
In this video, I join the several other folks who have bought and built a Heathkit GC-1006 "Most Reliable Clock" kit and assembled it in a video. But I am doing my usual twist on the subject, going into more depth than most and dealing with issues in my own manner. I also give a quick read through the Heathkit manual and talk about the schematic & circuit theory.
I comment at some length, spaced throughout the video, regarding my personal experience with the "new" Heathkit company, the kit quality, how well the manual approximates the famous old Heathkit manuals, and their customer service (or lack of it). In short, how well does the "new" company provide an approximation of the original "Heathkit experience". I address a potential issue with a 'counterfeit' IC and with a potentially serious design error (see explanation at bottom of this description); both of these issues have been noticed by other builders, and confirmed by me, and both are potentially things that would make this clock LESS reliable.
I also did a bit of a "hack", replacing the original "colon" LEDs with new ones, and also because Heathkit did not supply enough light pipes, or any ribbon cable, I describe how I sourced replacements for those and how well they worked out.
Not trying to be negative, I dish out praise where Heathkit did a good job.
Finally, I have designed a "Quick Guide" card/label which I affixed to the bottom of my clock. This saves having to return to the manual when using the menus and controls, as there are some less-than-intuitive aspects. I have made this available as a PDF download from the following webpage:
serpentwebsite.com/fileshare.htm
Timeline Table of Contents:
00:00 Introduction & unboxing
13:09 What's in the box
16:00 Parts Bags
23:18 "Personal Product Page"
28:43 Circuit board assembly
41:20 Light pipes (issues with)
53:52 Circuit board assembly (continued)
1:10:32 Mechanical assembly
1:39:05 Initial tests
1:43:35 Final assembly
1:48:14 Beauty shot
1:48:23 Demonstration/Setup/Settings
2:18:36 Manual (overview)
2:37:15 Schematic & circuit theory
Explanation of potential design error mentioned above:
Many (most?) digital ICs these days have tiny internal diodes on their pins, as a way to provide some protection against damage from static discharge. Since they conduct with a forward bias voltage of about 0.6V, it is common for manufacturers of such ICs to include in the specifications (datasheet) a "do not exceed" voltage (re: such diode protected pins) of VCC +0.5V and Ground(0V) -0.5V, so that the applied signals won't be high enough to get those tiny diodes forward biased and thus conducting. On many ICs, these diodes are actually implemented with a parasitic transistor, whose collector goes to the opposite supply rail. This means that causing (for example) 1 mA to flow in one of these input protection diodes (transistors) can cause 10-100 mA to flow from VCC to GND (assuming the gain of the parasitic transistor is 10-100). Sometimes this can cause an SCR-like latch-up which results in even more current flowing, causing overheating of the IC, etc.
So, exceeding the "do not exceed" voltage on an IC pin like this (which is happening in this clock design for the conditioned AC signal into one pin of the Atmel ATtiny microcontroller IC), could potentially cause the situation reported by some builders of this kit, namely the IC suddenly fails, and potentially gets quite hot before total failure. It has been suggested that this issue might be fixable by use of a Schottky diode to limit that IC pin's lowest voltage extreme to -0.3V, but I have not tried that personally.
