Hello again,

Here is one of the formulas i found back around mid 1980's ... i think i have more notes about this i'll have to find though.

time in seconds:
t=2*pi*(C2-C1)*[w*(C1+C2)+1]*s
tape thickness w=100/407125 inches
linear tape speed s=70498/180000 inches per second
C1=start count
C2=end count

Notes:
1. The counts for the deck i was using at the time are the 3 times the counts above, so divide all counter counts by 3 here.
2. The tape thickness and tape speed are curve fit values and may or may not reflect actual values in real life as measured.
3. The time is in seconds so we divide by 3600 to get the time in hours.

For example, the max count for a T120 tape was 5885 on that deck, and so if we ran the entire tape from start to finish then we'd see counts:
c1=0
c2=5885
but the counts in the above formula for that deck would be entered as:
C1=0
C2=5885/3

Alternately this can be entered into the formula of course.

To test this formula, we can look at the entire tape time from counts of 0 to 5885 (t1) and compare that to the sum of the times of counts that takes us from zero to 1/2 of the total count (t2) and from 1/2 of the total count to the full count (t3), and the sum should be the same as the total (all times in hours and tape deck on fastest speed):
t1=t2+t3

It turns out that (times in hours):
t1=1.987039
t2=0.831993
t3=1.155046
so:
t2+t3=1.987039
and so t2+t3=t1
and so this sanity check works out well.

We can also do a sanity check on the length, which is about 712 feet.
I turns out that at the given speed the calculated length is 705 feet, so the total length is off by 7 feet. It is not known what the tolerance of a T120 tape length is however, and i dont remember where i got that length of 712 feet from unfortunately. Perhaps there iis more info about this on the web, and keep in mind it could have been the result of a curve fit not a direct measurement.

The basic premise for the above formula is simply the arc length of an Archimedes spiral. I dont remember if i implemented any approximation such as leaving part of the formula off because after something like 5 turns the formula can be greatly simplified. I might go over this again and see if i can remember what i did back then

 

Getting back to the T.S original post, since Wednesday last, four days ago, 3 people have contacted me via word of mouth (we don't advertise) saying they would like to join the club when I move it to larger premises next year.
I am really pleased that two are professors who work at a nearby establishment, and the third is a teacher from a local school.
They are interested is opening up new directions and training as well as just doing it for fun.
One of the professors has a huge collection of Meccano (similar to the American erector sets) from the 50's and 60's that he is willing to donate.
I learnt so much as a child from having my much loved Meccano, and could not wait for birthdays and Christmas when I would get the kits that added the parts to make it the next level set.
My biggest problem now is my health is not as good as it was, I have a lung problem caused by black mould a few years ago when I lived in a 400 year old farm house. This has left me vulnerable to every cold that passes within ten miles and each one seems to take a long time to clear up.
With that in mind, I really look forward to the extra help.

I would say this to any like minded retirees out there who miss having something positive to do. It is very rewarding to start a small venture like this and see it grow. It keeps the brain (fairly) active and is much better than staying home wondering where your life went.

 

Getting back to the T.S original post, since Wednesday last, four days ago, 3 people have contacted me via word of mouth (we don't advertise) saying they would like to join the club when I move it to larger premises next year.
I am really pleased that two are professors who work at a nearby establishment, and the third is a teacher from a local school.
They are interested is opening up new directions and training as well as just doing it for fun.
One of the professors has a huge collection of Meccano (similar to the American erector sets) from the 50's and 60's that he is willing to donate.
I learnt so much as a child from having my much loved Meccano, and could not wait for birthdays and Christmas when I would get the kits that added the parts to make it the next level set.
My biggest problem now is my health is not as good as it was, I have a lung problem caused by black mould a few years ago when I lived in a 400 year old farm house. This has left me vulnerable to every cold that passes within ten miles and each one seems to take a long time to clear up.
With that in mind, I really look forward to the extra help.

I would say this to any like minded retirees out there who miss having something positive to do. It is very rewarding to start a small venture like this and see it grow. It keeps the brain (fairly) active and is much better than staying home wondering where your life went.

Hi,

What club is that? Sounds interesting.

 

Hello,

@MrAl , @recklessrog has a small club near his hometown in England.
He already wrote about the club in this post:
https://forum.allaboutcircuits.com/...edge-within-the-uk.148138/page-3#post-1326771
I already donated some materials to the club.

Bertus

 

Hello,

@MrAl , @recklessrog has a small club near his hometown in England.
He already wrote about the club in this post:
https://forum.allaboutcircuits.com/...edge-within-the-uk.148138/page-3#post-1326771
I already donated some materials to the club.

Bertus

Thanks Bertus, I know that this forum goes a long way to promoting interest and help in electronics, but to many, there is nothing quite like "hands on experience" so a combination of both keeps the hobby thriving.

 

When I first became interested in electronics back in the mid/late 1970s, there were half a dozen or so monthly hobby electronics magazines on sale at newsagents. They ranged from accommodating complete beginners to some quite advanced circuit designs.

I used to buy a selection after thumbing through their content and even subscribed to my favourite for over 10 years – one of my circuit designs was published within the reader’s circuits section. I used to look over each of the published circuits to gain a basic understanding of how they worked and even built a few of the projects.

Until recently, the only hobby magazine available within a well-known UK high street newsagents was Elektor – but that is no longer stocked by the outlet. So now there are no hobby electronics magazines available to the general public at newsagents in the UK.
And this despite a proliferation of magazines covering some very obscure topics.

For the most part, I suspect the reason for no longer stocking the magazine is the low demand. A magazine covering say farm tractors might interest a few people, but for most people in the UK, an electronics magazine might as well be written in a foreign language – having virtually zero readership.

I’d be interested to know what the situation re the availability of hobby electronics magazines in other countries around the world is – and whether the situation is as dire as that in the UK.

 

Hi,

What club is that? Sounds interesting.

Hi MrAl, The way the club started was almost by accident. As I said in the original post mentioned by Bertus, I had run my own business for many years, and although it was primarily an electronics service centre for consumer electronics + commercial equipment, we often had customers coming in for components not stocked by our local Maplins parts store.
Being a radio "ham" I often used to rag chew on 40M and 2m with fairly local other hams and would offer a discounted repair/tune up service to local hams who belonged to our now long defunct amateur radio club. This strangely had started out as a C.B club, but we helped more than a few to take the exam and get into proper amateur radio.
When I retired and sold off the business, I kept a shed load of "useful" bits and pieces just in case they might come in handy one day.
Within a year, I found I was spending a lot of time just trying to fill my time. I hated being inactive and could not drum up the enthusiasm to make any projects, often starting something and not finishing it.
At this time, a friend had a brain operation that left him unable to control his thinking and get any mental peace. His brain waves were always in the Beta range, around 13-20 or more cycles per sec. and were never into the more relaxed Alpha-8-12 c/s, Theta-5-7 c/s, and the most desired for him Delta-1-4 c/s which is sound asleep. Although strong medication put him to sleep, the side effects were most undesirable.
I went to see his surgeon who put me onto some work done with mind sync. This is achived with slowly pulsing lights accompanied with sounds at specific frequencies modulated at the same rate as the light pulses. You may scoff, but the OMMMMM is the best frequency to use.
I spent three months working day and night researching and building prototypes until I had a one that worked for him. Within a week, the effects were amazing, Just 15 mins use every night and he was able to get deep recuperative sleep, 6 months on from that, he barely ever needed it.
The upshot for me was my interest in electronics as a hobby was rekindled but now "what next"?
It was then that I went along with a neighbour to a computer club in a nearby town and met a couple of members who were more interested in electronics than computers, we kept in touch and soon the idea of a more local to us club seemed a distinct possibility. We were lucky to be offered a venue and the vicar asked if he could bring a group of disabled people to see my amateur radio in operation. We set up on a wet Sunday afternoon, and to their great enjoyment, we made a good number of contacts that day.
One thing led to another, and from an initial once per month meeting, we now have up to two per week depending on venue availability. We soon ran out of projects and parts, but thanks to the generosity of Eric Gibbs and Bertus, + a bit of scrounging from local companies, we have an ever increasing stock of all sorts of useful bits and pieces. With reference to the information library that Bertus hosts, we won't run out of projects in my lifetime.
As a note of caution, because we have young and vulnerable members, we do not publicise our activities, and ask for references for all members to ensure safety in this day and age.
From a personal point of view, it is extremely rewarding, even if sometimes my body doesn't quite want to do what my mind asks it too, but hey, that's what getting old does to you I guess.

 

When I retired, I sold my business but had accrued a large stock of new old stock components that the new owner did not want. These, along with many useful things things donated by this forums members, have provided the club members with nearly everything they need to enjoy what they and I think is a very rewarding hobby.

I am in the same situation, faced with 'disposing' of many still useful and originally 'Pricey' items, too bad you are so far away as I don't seem to find anything like it here that can make use of it.
How far south are you there, incidentally?
Max.

 

Hello,

@MrAl , @recklessrog has a small club near his hometown in England.
He already wrote about the club in this post:
https://forum.allaboutcircuits.com/...edge-within-the-uk.148138/page-3#post-1326771
I already donated some materials to the club.

Bertus

Hi,

Oh that's very cool. I got together with someone a few years back and we thought about starting a club, but then realized that the people interested were too far and few around this area. There's a ham club somewhere around here but for me it is still some 40 miles away which makes making meetings rather difficult.

 

Hi MrAl, The way the club started was almost by accident. As I said in the original post mentioned by Bertus, I had run my own business for many years, and although it was primarily an electronics service centre for consumer electronics + commercial equipment, we often had customers coming in for components not stocked by our local Maplins parts store.
Being a radio "ham" I often used to rag chew on 40M and 2m with fairly local other hams and would offer a discounted repair/tune up service to local hams who belonged to our now long defunct amateur radio club. This strangely had started out as a C.B club, but we helped more than a few to take the exam and get into proper amateur radio.
When I retired and sold off the business, I kept a shed load of "useful" bits and pieces just in case they might come in handy one day.
Within a year, I found I was spending a lot of time just trying to fill my time. I hated being inactive and could not drum up the enthusiasm to make any projects, often starting something and not finishing it.
At this time, a friend had a brain operation that left him unable to control his thinking and get any mental peace. His brain waves were always in the Beta range, around 13-20 or more cycles per sec. and were never into the more relaxed Alpha-8-12 c/s, Theta-5-7 c/s, and the most desired for him Delta-1-4 c/s which is sound asleep. Although strong medication put him to sleep, the side effects were most undesirable.
I went to see his surgeon who put me onto some work done with mind sync. This is achived with slowly pulsing lights accompanied with sounds at specific frequencies modulated at the same rate as the light pulses. You may scoff, but the OMMMMM is the best frequency to use.
I spent three months working day and night researching and building prototypes until I had a one that worked for him. Within a week, the effects were amazing, Just 15 mins use every night and he was able to get deep recuperative sleep, 6 months on from that, he barely ever needed it.
The upshot for me was my interest in electronics as a hobby was rekindled but now "what next"?
It was then that I went along with a neighbour to a computer club in a nearby town and met a couple of members who were more interested in electronics than computers, we kept in touch and soon the idea of a more local to us club seemed a distinct possibility. We were lucky to be offered a venue and the vicar asked if he could bring a group of disabled people to see my amateur radio in operation. We set up on a wet Sunday afternoon, and to their great enjoyment, we made a good number of contacts that day.
One thing led to another, and from an initial once per month meeting, we now have up to two per week depending on venue availability. We soon ran out of projects and parts, but thanks to the generosity of Eric Gibbs and Bertus, + a bit of scrounging from local companies, we have an ever increasing stock of all sorts of useful bits and pieces. With reference to the information library that Bertus hosts, we won't run out of projects in my lifetime.
As a note of caution, because we have young and vulnerable members, we do not publicise our activities, and ask for references for all members to ensure safety in this day and age.
From a personal point of view, it is extremely rewarding, even if sometimes my body doesn't quite want to do what my mind asks it too, but hey, that's what getting old does to you I guess.

Hi,

It's really cool that you have such a club. We dont have enough people in my area for such a thing (central NJ, USA) so it would not work out for me. Even the local chess clubs all closed up long ago.
How often do you meet?
Even once a month would be cool, once a week cooler

 

I am in the same situation, faced with 'disposing' of many still useful and originally 'Pricey' items, too bad you are so far away as I don't seem to find anything like it here that can make use of it.
How far south are you there, incidentally?
Max.

Hi max, without being too specific we are halfway between London and Southampton.
Why don't you offer the parts to members of this forum for the cost of postage? At least they will be put to good use.
One thing that I always keep in mind is that old technology does not mean useless. I can't really work with surface mounted components nowadays, so all my experimenting is with through hole and leaded components.

 

Hi,

It's really cool that you have such a club. We dont have enough people in my area for such a thing (central NJ, USA) so it would not work out for me. Even the local chess clubs all closed up long ago.
How often do you meet?
Even once a month would be cool, once a week cooler

Hi, take a look at my reply post #87

 

Hi max, without being too specific we are halfway between London and Southampton.
.

Gotcha, I grew up in Oxfordshire,.
Most of the stuff I have was geared towards motion control and CNC etc.
Max.

 

Gotcha, I grew up in Oxfordshire,.
Most of the stuff I have was geared towards motion control and CNC etc.
Max.

Probably still very useful stuff, yes it's a pity you are so far away.

 

When I first became interested in electronics back in the mid/late 1970s, there were half a dozen or so monthly hobby electronics magazines on sale at newsagents. They ranged from accommodating complete beginners to some quite advanced circuit designs.

I used to buy a selection after thumbing through their content and even subscribed to my favourite for over 10 years – one of my circuit designs was published within the reader’s circuits section. I used to look over each of the published circuits to gain a basic understanding of how they worked and even built a few of the projects.

Until recently, the only hobby magazine available within a well-known UK high street newsagents was Elektor – but that is no longer stocked by the outlet. So now there are no hobby electronics magazines available to the general public at newsagents in the UK.
And this despite a proliferation of magazines covering some very obscure topics.

For the most part, I suspect the reason for no longer stocking the magazine is the low demand. A magazine covering say farm tractors might interest a few people, but for most people in the UK, an electronics magazine might as well be written in a foreign language – having virtually zero readership.

I’d be interested to know what the situation re the availability of hobby electronics magazines in other countries around the world is – and whether the situation is as dire as that in the UK.

Many here have highlighted the demise of the paper hobbyist prints. The only thing in life that I have come close to calling a hobby is photography. Perhaps that is because I have actually subscribed to one for about a year.

One thing that I have learned over the years is that I could never really get into anything from ground up. In other words the only reason why I get into anything is just out of curiosity and need. If my dishwasher breaks I become a mechanic if that doesn’t fix the problem I become an electrician or a plumber . . .

As a result, I know a little bit of everything – master of none . For me the best learning environment are FORUMS and online videos, because if I am interested in something it’s for the most part requires troubleshooting or reverse engineering. Many years of fixing stuff and reverse engineering stuff give me a solid basic foundation.

Most magazines focus on simple basic design, and that just does not get me exited to get into it. However, when the heating furnace stop working in the middle of winter I have no option but to become an “electrician” fast.

If it’s any consolation, I guess what I am trying to say is that with the creation of new type of information media (internet) new type of “practical hobbyist” like myself are coming out. I am not a mechanic but I can take a car apart and put it back together, I am not a programmer but I can write code in a handful of languages, I am not a plumber but I can fix most of plumbing issues, am not a photographer but I okay with SLR in manual mode.

I have a lot of tools as a result of my quest and need for knowledge. I have lots of voltmeters and ampmeter. My last investment into DC/AC understanding required me to get an oscilloscope, so after some research (again forums and online videos) and luck I picked up an old but reliable Tektronix 475.

My quest today is to understand the little parts and how they all come together in harmony to create a elegant solution to a problem.

 

As a note of caution, because we have young and vulnerable members, we do not publicise our activities, and ask for references for all members to ensure safety in this day and age.
From a personal point of view, it is extremely rewarding, even if sometimes my body doesn't quite want to do what my mind asks it too, but hey, that's what getting old does to you I guess.

I need to say WOW! too. I had very few friends, especially when they all started to take advantage of my talents and even benefitting by it.
I never learnt the Kiss your ass principle.

I wasn't about to complete portions of a large project just to get brownie points when there were unknowns ahead, no designs and lead times. Furthermore, it would all be on me anyway because I was the last person to finish before commissioning could begin. I refused to get hammered at both ends. It was the worst project ever. I found doors put on backwards early and I get in trouble for being in the construction zone.
I could have been because most of the time I would have been out of the way. Then the bozos were going to move a piece of equipment"as is" when it required upgrades to work. I had to do all design and wiring while I was doing another job. No schematics to work from. Just notes.
The contractor did his designs first. The contractor REFUSED to do it alone without my help. I actually had the training in project management (GHANT charts) etc. I tool a stroll by myself one day and noticed stuff like air handler valves cemented into a wall rendering it inoperative.
It was then and only then, did my boss agree to a walk-thru with another person. 8 years later, my stuff is either still working or all ripped out.
Basically, I ordered a "pile of stuff" and hoped that was what I needed.

Since I was the last person, I needed sometime to further implement some safety stuff without the toxic gasses turned on. I didn't get that. It was to integrate a system that would not allow 2 out of 3 valves to be open at the same time which would allow toxic gas into the room. There was a manual valve that needed to be closed at certain times and it would have made pressure bypass unnecessary. This is another way to leak into the room through an open load lock door.

The first time around, the hydrogen detectors were sitting in a box. The explosion involved Hydrogen. Guess what got installed?
The system shut down, but not through an anticipated method. The ventilation sensor popped. 1500 psi of hydrogen vented into an enclosure through a line rated for vacuum. An analysis of the accident created many changes. I missed the accident. My system worked.

 

I need to say WOW! too. I had very few friends, especially when they all started to take advantage of my talents and even benefitting by it.
I never learnt the Kiss your ass principle.

I wasn't about to complete portions of a large project just to get brownie points when there were unknowns ahead, no designs and lead times. Furthermore, it would all be on me anyway because I was the last person to finish before commissioning could begin. I refused to get hammered at both ends. It was the worst project ever. I found doors put on backwards early and I get in trouble for being in the construction zone.
I could have been because most of the time I would have been out of the way. Then the bozos were going to move a piece of equipment"as is" when it required upgrades to work. I had to do all design and wiring while I was doing another job. No schematics to work from. Just notes.
The contractor did his designs first. The contractor REFUSED to do it alone without my help. I actually had the training in project management (GHANT charts) etc. I tool a stroll by myself one day and noticed stuff like air handler valves cemented into a wall rendering it inoperative.
It was then and only then, did my boss agree to a walk-thru with another person. 8 years later, my stuff is either still working or all ripped out.
Basically, I ordered a "pile of stuff" and hoped that was what I needed.

Since I was the last person, I needed sometime to further implement some safety stuff without the toxic gasses turned on. I didn't get that. It was to integrate a system that would not allow 2 out of 3 valves to be open at the same time which would allow toxic gas into the room. There was a manual valve that needed to be closed at certain times and it would have made pressure bypass unnecessary. This is another way to leak into the room through an open load lock door.

The first time around, the hydrogen detectors were sitting in a box. The explosion involved Hydrogen. Guess what got installed?
The system shut down, but not through an anticipated method. The ventilation sensor popped. 1500 psi of hydrogen vented into an enclosure through a line rated for vacuum. An analysis of the accident created many changes. I missed the accident. My system worked.

Was this meant to be a reply to a different thread?!?!

 

Was this meant to be a reply to a different thread?!?!

I was wondering the same thing.
I know that threads do wander on this site, and while some tales are interesting they are not really related, at least not to an outsider. Probably it is time, once again, to remember that most of the folks here are not mind readers, especially at a distance.. My mind-reading skills are terribly poor, by any standard. But my text reading skills are great!!