almost as big a practical joker as I am
I must confess, I don't know Elso, other than reading a few of his many posts and contributions to other forums. I have never contacted him for ideas, information, or schematics. Perhaps he was joking with his accusation of plagiarism? I don't know. Regardless, thank you Elso for posting your schematic (it is the first time I have seen this one). With it you prove my point. We are both standing on the shoulders of giants.
Here are a few of the schematics I researched when beginning my design (and it wasn't for a HagClock, but rather a VCXO for HAGDAC).
Clearly, anyone can see the originations of our respective circuits. From 30 years ago! I would be suprised Elso, if you are trying to take credit and ownership for any such novelty.
The HagClock design was not hatched in a matter of days, either. It took a lot of research and experimentation on my part to get to where I wanted. I built over a dozen variations, some shown below.
Eventually, I came up with the unusual buffer configuration. It reduces the effects of loading and reverse transfer of comparator input switching glitches. Combined with the inductively coupled output, I was able to obtain the purest sinewave possible.
Ok, so what do our circuits have in common? A sine wave oscillator neither of us invented, and an output comparator to square up edges. The schematic of a Kwak Clock I had seen used a very similar Maxim comparator (and TL431 based regulators). So what?
Are there better comparators than the LT1016? Perhaps. And I looked at a number of them. But my requirements (half-kit DIY) prevented me from selecting a surface mount part, which precluded use of just about everything newer than the LT1016. It also had to be a part available from Digi-Key. As such, my choices were severely limited. So I went with the best possible solution for the application. Besides, I had used this part before and was familiar with it. Any comment claiming "obsolete" is disengenuous, as these parts are still manufactured by LT.
Elso, you also opine that the supply regulators are not suitable, but refuse to back up your claim. I admit, you have a valid point here in that clock circuits must often start up very fast. The low noise filters on the reference voltages do add some significant startup delay. I minimized this achieving less than 100ms. And as stated in the assembly manual, if it proves problematic, the solution is to replace these capacitors with lower values. I wanted to preserve as much performance with the stock design, sacrificing only when necessary.
In short, any claims of plagiarism or copyright infringement are clearly baseless and paranoid.
jh
