Cool clock. Sleek design. Thanks for showing it to us!
@50sTransistorRadios
4 жыл бұрын
Thanks, I like the sleek look of it too!
@Colin_Ames
4 жыл бұрын
Congratulations on reaching another subscriber milestone. Difficult to know the provenance of this clock. It could have been a kit with a decent case supplied as one of the components. The fact that it has a strange method of setting the time doesn’t surprise me. I worked in technical support for an Italian company between 1978 and 2016, and saw more than one unusual design choice (including the lack of a discharge resistor in a high voltage power supply, which gave me a shock, literally). The fact that the chips are socketed may also indicate a kit, although many of our products from the 70s through the 80s used sockets. The lack of any kind of logo or label is strange. In any case, it’s a nice clock. Thanks for sharing.
@50sTransistorRadios
4 жыл бұрын
Thanks Colin! My suspicion is that it was a kit, partially based on its use of sockets (which I have also seen in higher-end factory made products), but it's just not clear. There are a number of decent ways to de-bounce switches, so going with the clunky potentiometer option seems like a bad call to me, but I'm sure they had their reasons (most likely, cost). However, there's really no excuse for the lack of a discharge resistor, and I almost got shocked too! You sure had quite a long run with that Italian company, they must have been good to work for, some odd designs aside.
@Colin_Ames
4 жыл бұрын
The company I worked for was Marposs. They make electronic gauging systems, and were a decent company to work for. I worked for them from 1978 until 1988 in the UK, then transferred to the US. Interesting job, for sure, although could be stressful at times when installing high-dollar projects in automotive engine and transmission plants.
@50sTransistorRadios
4 жыл бұрын
@@Colin_Ames I can definitely see how working on very expensive and potentially fragile equipment could be stressful, since one wrong move could cost a lot of money (for the company at least). It does sound like interesting work though.
@stefanobozzini6353
4 жыл бұрын
Hi there, you are right. This was a kit produced by Amtron (kit number UK820) in the early 70s. My father built one that I found in my garage months ago, after some chip and capacitor replacement it is now back to life. I have found the original manual with schematics also. If interested I can send it to you....just let me know how. Regards from Italy 🇮🇹 Stefano
@AMStationEngineer
4 жыл бұрын
I remember the first nixies that I'd ever set eyes on, were in a Hobart digital deli/butcher shop scale, pretty much around the same time as this clock was assembled. LED numeric displays came onto the scene (in eastern PA) in mid-1974, and were damn expensive. Unisonic calculators, and LED numeric display watches came into fruition around the early 1975 time frame. Edmund Scientific was the first company that sold them at affordable pricing, then Jameco, then Grabar.
@50sTransistorRadios
4 жыл бұрын
I though I replied to this, but I guess it didn't go through. Nixies and reasonably priced integrated circuits for making clocks only overlapped for a brief period in the early 1970, so clocks like this one are unfortunately quite rare. By 1975 Nixies were thoroughly obsolete (and LEDs were king) and they were getting dumped at low prices by surplus sellers. I wish I could still buy B7971 tubes for the 3-4 dollars they were selling for by the mid 1970s!
@SharkoonBln
4 жыл бұрын
Congrats on the 3,5k subs. Well deserved!
@50sTransistorRadios
4 жыл бұрын
Thanks, I appreciate that!
@bblod4896
4 жыл бұрын
Nice clock. Congratulations on 3,500+
@50sTransistorRadios
4 жыл бұрын
Thanks, I'm pretty happy with how it turned out.
@JIMO415
4 жыл бұрын
Looking good as usual. Amazingly the conditioning in my ESE 112 clock is not nearly as complicated and it is keeping good time! Oddly it creates a 4 volt peak sine wave above zero and that is fed directly to the first 7490 with no squaring. That Graymark clock had a similar 2 transistor shaping circuit to your clock here but it had spike issues and would have benefited from inductors and capacitors like yours here. As you know I just decided to go with a schmidt trigger to fix it.
@50sTransistorRadios
4 жыл бұрын
Thanks Jim! They may have gone a bit overboard on the AC filtering and pulse conditioning, but maybe they were having issues with erratic operation. It's interesting to hear that the pulses can be much less square-wave like and still not cause issues though.
@budandbean1
4 жыл бұрын
Hey congrats on the 3.5K subscribers! That’s very cool, it’s because you produce some pretty fascinating content.
@50sTransistorRadios
4 жыл бұрын
Thanks Buddy, I appreciate that!
@budandbean1
4 жыл бұрын
@50sTransistorRadios My pleasure, you know me... You Rock!
@schitlipz
4 жыл бұрын
If it has sockets for all the ICs then I'm pretty confident it wasn't mass produced. I could be wrong though. [And nice work on solving the frequency problem.]
@bblod4896
4 жыл бұрын
I agree, most likely a kit.
@50sTransistorRadios
4 жыл бұрын
Thanks! My suspicion is that this was a kit too, but I'm just not sure, as the build quality is pretty good.
@misterhat5823
4 жыл бұрын
I agree. Sockets are rare in consumer electronics.
@SharkoonBln
4 жыл бұрын
Given the "quality" of the case, I have another suspicion: The mfgr had an incredibly cheap source for factory rejected 74XX chips and had to just try out / mix&match which ones worked together and which ones did not. In the early 70s wages in italy were quite low, so just having workers to try out which chips worked together seems doable.
@50sTransistorRadios
4 жыл бұрын
@@SharkoonBln I don't think the IC's were rejects, because they all still have the TI logo on them. Fallout parts usually had their markings painted over or scraped off, if they had them to begin with. My guess is that this was a kit, as some of the parts would likely have been cheap-ish by then, like the nixie tubes and drivers (just ~2 years later everyone was trying to get rid of them, because they were obsolete).
@misterhat5823
4 жыл бұрын
Using the high voltage AC input improves the rise time (the slew rate of the higher voltage is greater) and allows for a crude conditioning circuit. In 1972 the price difference between a coupe BJTs vs. a proper comparator was quite a bit.
@50sTransistorRadios
4 жыл бұрын
Good point, and I forgot to mention it in the video, but I checked the output of that conditioning circuit with a scope, and it was a very reasonable square wave.
@misterhat5823
4 жыл бұрын
An LS series chip cannot drive the 7400 series well. To use an LS chip, you'd need to swap them all for LS.
@50sTransistorRadios
4 жыл бұрын
From what I've read online at least, the LS series parts can drive at least a few 74XX parts (I'm seeing varying answers, 5 or 10), but the L series can only drive 1 74XX part. The issue I was having with the 74LS92 chips is that the frequency coming out was too high for some reason, but I didn't try running them unloaded.
@misterhat5823
4 жыл бұрын
@@50sTransistorRadios It was my impression that it was only one or two. But, if it was, say, five, that could still be a problem.
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