Narrow-Bandwidth Television Association

Yes, generally that's true. However you have to take into account our weather here. We're now coming to the end of our 'wet season', the humidity here has not been below 90% for six months except for the odd day, often it's 97% or more with the dew point and temperature separated by less than one degree. Stainless steel corrodes here, though slowly, but corrode it does. Add in the effects of temperature, rarely below 30C, and they all conspire to produce ideal conditions for corrosion.

I also have a reed switch on my bicycle for logging speed/distance etc., never a problem at similar voltages/currents. The version I used is filled with Nitrogen which presumably helps. But I thought all were filled with some gas or another, nitrogen, carbon dioxide, etc., or perhaps even a vacuum.

Steve A.

Steve, there are two kinds of stainless steel. One corrodes, the other (more expensive) does not corrode. My neighbour worked as a commercial man at a company that sells metal sheet, tubes, profiles and so on. He knows everything about metals and he told me about the two kinds of stainless steel. The bad one starts to corrode if you get it into contact with Clorine, the better one doesn't. It depends on the amount of chromium and nickel in the alloy.

About the tempertures and humidity, I know, I have been several times in Singapore to give classes. Mean temperature = 30 degrees, if it is 28 degrees it is feeled as cold, if it is 32 deg. it is hot. And the humidity is about 90%. I experienced the afternoon rains there, so severe, that I could not see the other side of the street.

Klaas Robers wrote:Mean temperature = 30 degrees, if it is 28 degrees it is feeled as cold....

Same here mostly. If it cools off to say 25C I start shivering and have to put warmer clothes on. The last time I was in the UK/Europe was 2017. It was about 17C and people were laughing that I was wearing a big wooly sweater...while they were just in T-shirts...it's what you get used to. Having been in S.E. Asia since 1989 I've adapted...

Here's an unused battery holder that's been sat on a shelf for 2-3 years (hence the dust), that's corrosion simply from the atmosphere...though I suspect that's cheap spring steel, not stainless...

Steve A.

I'm still occasionally working on this useless exercise, I'll start on the hardware build early next week, it's quite simple. I've been mainly concentrating on the coding which determines how fast this will process numbers, especially as they get large...

...I guess I should really be working on something more useful, now let me see...

Steve A.

As a postscript, for quite some time I've been looking into doing some reasonably useful (I hope) YouTube videos. all based on what I have done and will do on this forum. I'll need to get a reasonable video camera, though many use their phones, audio isn't a problem, then there's piecing it all together (editing). That's quite a challenge...updates as and when as it might help or inspire others to do the same...

Well, I've decided to put this Collatz Conjecture 'thing' to bed, as novel as it may be, along with others, it's all been done before...and I'm most unlikely to be the one who finds any resolution to it...but if anyone else wants to have a go...

So I've decided to resume work on a more useful NBTV/SSTV project I started not that long ago.

However, to some degree there are constraints imposed by the current chip-shortage situation, but I guess there are work-arounds for those.

Steve A.

Update...Over a few beers with a friend (I do have a few) I mentioned this conjecture. He became deeply fascinated with it and almost insisted that I go ahead and build this 'thing'. Of course it could be done on a PC which would be vastly faster, but it does tie up the PC which has to be continuously on and supported by a UPS for the odd power 'blip'.

I was tempted to say, "Why don't you build it?" But electronic design/construction isn't in his skill set. So, somewhat reluctantly, I agreed do it. It is actually quite simple if you look at the circuit diagram posted previously. Writing the code probably is the biggest challenge...but not that big a challenge really...

According to Wikipedia this conjecture has been taken to a starting number of 2^68 as of 2020, probably somewhat more now. Even so, that's 'just' 8.5 bytes. Now, knowing that there's no number below that which eventually zooms off to infinity or gets stuck in a loop greater than the starting number, do we start there or being thorough start at 1? I'm tempted to start at one for completeness. It will be interesting to see how long this little micro takes to get to 2^68...if ever it does...

2^68 is 2.95E20 in decimal Excel speak, or 295,147,905,179,352,825,855 in plain decimal.

Steve A.

Here's an example applying the rules with a starting number of only 27. It reaches 9,232 before ending up in the apparently inevitable loop of 4,2,1,4,2,1...

Steve A.

Ah! I see no-one is really paying attention. I said previously, "2^68 is 2.95E20 in decimal Excel speak, or 295,147,905,179,352,825,855 in plain decimal.", but any integer power of two is always going to have an even number as a result...

The previous should read."2^68 is 2.95E20 in decimal Excel speak, or 295,147,905,179,352,825,856 in plain decimal."

The more I dwell on this the more trivial, hopeless and useless it all becomes. No different to calculating pi to the nth digit I guess...

Oh well, I'll plod on anyway....you can tell I've got nothing much else to do! I realise I still have a number of 'open-ended' NBTV/SSTV projects that I really should get on with - someone give me a push, shove or a dig in the ribs...

Steve A.

Steve Anderson wrote:Oh well, I'll plod on anyway....you can tell I've got nothing much else to do! I realise I still have a number of 'open-ended' NBTV/SSTV projects that I really should get on with - someone give me a push, shove or a dig in the ribs...

Steve A.

SHOVE

Thanks for the SHOVE Albert...also this link provides a sound reason why not to pursue this 'thing'...

https://www.youtube.com/watch?v=094y1Z2wpJg

Steve A.

...though a potential bonus may be honing my programming skills in dealing with immense numbers...as someone with an interest in Astronomy, you may understand...though that's a pretty weak justification...

I don't know how old you are, Steve, but I'm nearly 89.
As we age we all know that time left for us is shrinking down to zero.
Hence, I always consider if using up time on any project, whether
it is worth it or not before I commence it ?

Was it worth my spending a few minutes writing this !
Mmm, I think it was.

...66 years young Albert. (Feb. 1956). Mostly we all assess whether something is worth doing or not subconsciously, sometimes it requires some 'front-of-mind' activity. This is an example.

We all do things that could be viewed as useless, pointless, trivial and with no immediate or long-term return on the time expended (and maybe cash too).

The only resultant from this exercise I see is myself learning to handle very large numbers in software. It has all been done before by others, true, but not by me. So I view it as an educational exercise for myself, possibly others too, plus being a novelty there's an entertainment element in there somewhere...I know - I need my bumps felt...(see link)...

The hardware/construction element is the quick and easy part, I doubt I'll learn much from that. The challenge is the coding. Challenges of this nature exercise the grey matter, and hopefully expand one's repertoire in this discipline.

Steve A.

https://en.wikipedia.org/wiki/Phrenology

OK, I've come to my senses (again), and yet again I've decided to abandon this 'thing'. I really cannot see how this conjecture is ever going to zoom off to infinity or get stuck in a loop other than the final one of 4,2,1,4,2,1 and so on... Now all I have to do is convince my friend of my reasoning...I'm not going to go into my reasoning here, few are probably interested anyway....

So, as far as I'm concerned this is a closed subject. Others may want to have a go, good luck!

Now, I should (must) get onto something relevant to NBTV/SSTV or simply TV in general...of the 'open threads' I have at the moment, any suggestions as to which one I should tackle first?

Those I can recall right here and now are:-

1). A still picture storage for NBTV, akin to Ralph Taggart's 'Rom Scanner', but brought up to date with much more storage, easy 'recording' and not using EPROMS. A 'Flash Scanner'...
2). Based on the above, a 'Movie-Stor', movies at 12.5 FPS with mono sound. (Which would probably incorporate the below).
3). A NBTV recording system down to DC (or at least nearly so), with mono sound.
4). All of the above? Other ideas welcome too.

Steve A.

Steve Anderson wrote:OK, I've come to my senses (again), and yet again I've decided to abandon this 'thing'. I really cannot see how this conjecture is ever going to zoom off to infinity or get stuck in a loop other than the final one of 4,2,1,4,2,1 and so on... Now all I have to do is convince my friend of my reasoning...I'm not going to go into my reasoning here, few are probably interested anyway....

So, as far as I'm concerned this is a closed subject. Others may want to have a go, good luck!

Now, I should (must) get onto something relevant to NBTV/SSTV or simply TV in general...of the 'open threads' I have at the moment, any suggestions as to which one I should tackle first?

Those I can recall right here and now are:-

1). A still picture storage for NBTV, akin to Ralph Taggart's 'Rom Scanner', but brought up to date with much more storage, easy 'recording' and not using EPROMS. A 'Flash Scanner'...
2). Based on the above, a 'Movie-Stor', movies at 12.5 FPS with mono sound. (Which would probably incorporate the below).
3). A NBTV recording system down to DC (or at least nearly so), with mono sound.
4). All of the above? Other ideas welcome too.

Steve A.

Has to be something we don't have i think something that would get the interest up ....sure standard NBTV but if it could also output 70 line or so above a bit hell that would be some thing we cant do out putting from a pc or cd player without major loss in bandwidth ,so a test card image to that would be interesting to me .

Thanks for that Harry, feedback is always good to have.

Now, I'm not going anywhere near audio CDs or DVDs as they're about as reliable as the British summer and their 44.1kHz sampling rate is a pain, though the 48kHz audio sampling rate of DVDs is OK. I don't have a CD/DVD drive anyway, nor have I any reason to get one.

I have one or two other ideas in addition to those above, any other suggestions chaps?

Steve A.