Test Equipment Anonymous (TEA) group therapy thread

[SoundTech-LG]

JVC and Pioneer turntable up for farengiing.
(Clearing out surplus stuff ...)

Many moons ago, for want of a good turntable, I went down the HiFi rabbit hole, then the home theater rabbit hole. Many years pass and I have yet to own a turntable. Then TEA happened.

Yeah... mine is here intact, just need to find the time away from TE, and get it hooked up!

https://www.stereophile.com/turntables/284sotastar/index.html

[tggzzz]

found my old log trig tables in the bottom of a box down the basement.

it smells like knowledge. (actual knowledge is musty)

Used 4 fig tables at school, still have 3 fig in the back of a Nuffield Advanceed Science reference book used at school 16-18. I believe there are 7 fig tables, but fortunately never needed to use them.

π² = g = 10.

There were also 8 fig tables. I know this because at school I was one of only two to realise that there were two solutions to a problem on heat expansion. I worked out one and pointed to the existence of the other, but said it was too hard to work out. The exercise came back with a snotty comment saying that there were 8 fig log tables. It was disappointing that I showed such a lack of motivation.

The snotty response to that would have been "no point, given the inputs are specified to 4 sig fig, or whatever"

I vaguely recall reading that the last great table of logs was 20 figures. Someone in Cambridge worked on it from 1927 until 1951? , but by then there were computers coming about. It must have been a tremendous amount of work to work out and validate. Early log tables were plagued with errors.

Probably Godfrey and Siddons. My brain needs a good GC, but that kind of data is in the "permanent generation". I don't mind my brain corrupting eden space, since it is transient and I can regenerate it if required. Losing stuff in "survivor" and "tenured" generations is more irritating and becoming more frequent



There are also excessively long slide rules too, e.g. the 66" https://en.wikipedia.org/wiki/Otis_King and the Fullers cylindrical slide rule with a length of 1000in or 25m https://en.wikipedia.org/wiki/Fuller_calculator !

I've toyed with the idea of writing a program to generate and validate a 20 fig log table. It's a problem that obviously lends itself to parallelism. I fancy that a 6 core, 12 thread AMD CPU clocked at  3.9GHz would have it done and dusted in a couple of seconds. Something of an improvement on over 20 years.

... plus how many years data entry?

[bd139]

Fair point. We’re on the 4th (top) floor so this may be a problem. If it is they will have to fall off  .

The top floor was important for clear sky view (GPS antenna  )

Hmm, also should the unthinkable happen, the worst place to be in the event of fire or other emergency event in the building 

Depends on the "unthinkable", it could be an advantage. Have you seen how slowly zombies and triffids can climb stairs? Slows down baying mobs with pitchforks and torches too, which I think is probably BD's biggest risk.

Serious point: I found your choice of the word "unthinkable" thought provoking. I think that people's reluctance to consider "the unthinkable" is often the thing that turns an emergency into a disaster. Years of dealing with venue safety drummed into me the importance of emergency exits - keeping them working and clear. How many people "think" about how they would get out of their houses in a fire. I regularly catch myself consciously keeping our rear exit route clear of obstructions (i.e. I think about it) and I fear that many people seldom do. Is your back passage full of clutter? (Ooo Matron!)

mnem
they're like the piranhas of the dwagon world. 

I'm sorted:




On TE, some Marconi 2022E progress later today. PCBs round one have arrived:

[med6753]

At least you’re heading in the right direction now  . Repent!

Got rudely awoken by pigeons on top of my chimney this morning. Another thing I won’t have to bloody put up with in a couple of weeks.

Have got inventory appointment next week so I am going to LiDAR the room and plan bench engineering 

Just because you will no longer have a chimney won't deter pigeons, you have a window ledge and maybe even a balcony at the new place, oh and forget that squirrels can climb, so even they will still have the power to haunt you. 

Good luck on the move, you must be looking forward to it now?

Fair point. We’re on the 4th (top) floor so this may be a problem. If it is they will have to fall off  .

The top floor was important for clear sky view (GPS antenna  )

Hmm, also should the unthinkable happen, the worst place to be in the event of fire or other emergency event in the building 

Depends on the "unthinkable", it could be an advantage. Have you seen how slowly zombies and triffids can climb stairs? Slows down baying mobs with pitchforks and torches too, which I think is probably BD's biggest risk.

Serious point: I found your choice of the word "unthinkable" thought provoking. I think that people's reluctance to consider "the unthinkable" is often the thing that turns an emergency into a disaster. Years of dealing with venue safety drummed into me the importance of emergency exits - keeping them working and clear. How many people "think" about how they would get out of their houses in a fire. I regularly catch myself consciously keeping our rear exit route clear of obstructions (i.e. I think about it) and I fear that many people seldom do. Is your back passage full of clutter? (Ooo Matron!)

I've thought about it. I have 2 alternate exits if the doorway is blocked. Easy one is right over bench 2 out the window to 1st floor roof which has easy access to the ground. Harder exit is out the window between bench 1 and the audio rack to the first floor roof then over the roof peak to the rear.     

[gnif]

Guys, stop posting crap that is completely unrelated to Electronics!

[Cerebus]

3-4 digits at best. Not logs of number <1.

(Anybody remember what $$\bar{1}.3010$$ meant when using 4-fig log tables?)

Yes, even better I can tell that $$10^{\bar{1}.3010} = ~0.2$$ from inspection.

Somewhat sad that we remember that!

Naaa, just proves that we're still compos mentis and reliable witnesses to past events and, come the zombie apocalypse with no electricity or batteries, those of us who can still use slide rules and log/trig tables will be kings amongst men, well kings amongst engineers anyway.

[Zoli]

...
On TE, some Marconi 2022E progress later today. PCBs round one have arrived:

Only 3 JLCPCB projects? I was expected something in the middle two digits... 

[bd139]

...
On TE, some Marconi 2022E progress later today. PCBs round one have arrived:

Only 3 JLCPCB projects? I was expected something in the middle two digits... 

There’s three more sets or boards on the way for projects 

[Zoli]

...
Naaa, just proves that we're still compos mentis and reliable witnesses to past events and, come the zombie apocalypse with no electricity or batteries, those of us who can still use slide rules and log/trig tables will be kings amongst men, well kings amongst engineers anyway.

I think in case of ANY apocalypse we should start preparing our personal version of "A Canticle for Leibowitz". Instead of chasing the latest&greatest, write down your basics, and bind them on plastic.

[Zoli]

...
On TE, some Marconi 2022E progress later today. PCBs round one have arrived:

...

Only 3 JLCPCB projects? I was expected something in the middle two digits... 

There’s three more sets or boards on the way for projects 

And that will place you in the mid-two-digits? 

[Specmaster]

<snip>

what?  a kit built sinclair scientific?

if it were anyone else you would be dead to me.

but since you are usually a voice of reason around here........ you get a pass.

Well thanks for sparing me  What can I say, I was young and full of cum back then and the Sinclair was the only scientific calculator within my price bracket. When that calculator was launched in 1974 it sold as a kit for £49.95 and in today's money that equates to £579 

https://en.wikipedia.org/wiki/Sinclair_Scientific#Assembly_kit

No, you've misread the pricing:

In January 1975, the kit was available for US$49.95, half the price at the time of introduction a year earlier,[13] and in December 1975 it was available for GB£9.95, less than a quarter of the introductory price.

So that's $49.95USD (£21.90GBP at Jan '74 exchange rates, about £165 in today's money) and then £9.95 by the end of the same year (about £75 in today's money).

Oh No I didn't.. the following is an exert from the other link I also posted. Wikipedia has a typo $ in place of a £.

"Conclusions
The Sinclair Scientific came out in 1974 and was the first single-chip scientific calculator (if you ignore the display driver chips). It was stylishly compact, just 3/4 inch thick. It originally sold for the price of $119.95 or £49.95 and by the end of the year was available as a kit for the amazingly low price of £9.95.

Unfortunately, as calculator prices collapsed, so did Sinclair Radionics' profits, and the company was broken up in 1979 after heavy losses. Clive Sinclair's new company Sinclair Research went on to sell the highly-popular ZX 80 and ZX Spectrum home computers. Clive Sinclair was knighted for his accomplishments in 1983, becoming Sir Clive Sinclair. "

http://files.righto.com/calculator/sinclair_scientific_simulator.html

http://www.vintagecalculators.com/html/sinclair_scientific.html

"US$" in place of "GB£" is rather more than a "typo". Those sources differ, and who knows who copied whom when it came to recording the price.

I had one, also built from a kit, and bought the year they came out. I highly doubt the £50 UK price simply because I know that my father wouldn't have sprung for that, not in a month of Sundays. I still remember him having a fit when the bill from the opticians for a new pair of glasses came in at £60 two years later. No way was he going to voluntarily shell out £50  for something non essential. My father was a stereotypical "thrifty" Northener.  I'll see if I can find an old Practical Electronics with an ad for it online - that's almost certainly how I came to get him to buy it for me - and get an accurate price for it from primary sources.

Scratch that, check reference 13 in the Wikipedia article, a US Popular Mechanics advert (Jan 75) with a $49.95USD price on it. So it was dollars, not pounds, and reference 14 is an ad from New Scientist at the end of the year (Dec 75) with the £9.95GBP price clearly shown. So, not typos but verifiable from primary sources. The page at http://files.righto.com/calculator/sinclair_scientific_simulator.html that you've quoted to support the £49.95 price is either wrong, or is referring to the built calculator's retail price not the kit.

Moreover, I can believe my father springing the £9.95 for a Christmas present, just. 

Dear me, are you needing some glasses? It was launched in 1974 @£49.95 (UK) and $139.95 (US) and as a kit @$99.95, ie. 71% of the assembled price. Lets assume that the UK differential is the same, that would make it around £35.36 at launch.

I quote this paragraph from the History section of Wiki article.
The Sinclair Scientific first appeared in a case derived from that of the Sinclair Cambridge, but it was not part of the same range.[5] The initial retail price was GB£49.95 in the UK (equivalent to £478 in 2016), and in the US for US$99.95 as a kit or US$139.95 fully assembled.[6] By July 1976, however, it was possible to purchase one for GB£7[5] (equivalent to £46 in 2016).
The price you quoted was @ Jan 1975, after prices of calculators tumbled, probably as a result of Sinclair's entry into that market arena.

This theory seems to be highly likely as this extract from the Wikipedia article tends to both highlight the tumbling prices and the relationship between the prices you quoted by citing the US Popular Mechanics advert (Jan 75) [red highlight] and the actual launch price which I quoted. It also goes on to further demonstrate the price collapsing even further by December 75 to just £9.95, {green highlight} less than 25% of its introductory price, back in 74 which is precisely what I quoted, all the evidence is right there in the Wiki article.

Extract from the Wiki article.
"Assembly kit

The assembly kit consisted of eight groups of components, plus a carry case.[13] The build time was advertised as being around three hours, and required a soldering iron and a pair of cutters.[13][14] In January 1975, the kit was available for US$49.95, half the price at the time of introduction a year earlier,[13] and in December 1975 it was available for GB£9.95, less than a quarter of the introductory price.[14] "

I was quoting launch prices, yours was a year later, not the same thing at all.

[Cerebus]

<snip>

what?  a kit built sinclair scientific?

if it were anyone else you would be dead to me.

but since you are usually a voice of reason around here........ you get a pass.

Well thanks for sparing me  What can I say, I was young and full of cum back then and the Sinclair was the only scientific calculator within my price bracket. When that calculator was launched in 1974 it sold as a kit for £49.95 and in today's money that equates to £579 

https://en.wikipedia.org/wiki/Sinclair_Scientific#Assembly_kit

No, you've misread the pricing:

In January 1975, the kit was available for US$49.95, half the price at the time of introduction a year earlier,[13] and in December 1975 it was available for GB£9.95, less than a quarter of the introductory price.

So that's $49.95USD (£21.90GBP at Jan '74 exchange rates, about £165 in today's money) and then £9.95 by the end of the same year (about £75 in today's money).

Oh No I didn't.. the following is an exert from the other link I also posted. Wikipedia has a typo $ in place of a £.

"Conclusions
The Sinclair Scientific came out in 1974 and was the first single-chip scientific calculator (if you ignore the display driver chips). It was stylishly compact, just 3/4 inch thick. It originally sold for the price of $119.95 or £49.95 and by the end of the year was available as a kit for the amazingly low price of £9.95.

Unfortunately, as calculator prices collapsed, so did Sinclair Radionics' profits, and the company was broken up in 1979 after heavy losses. Clive Sinclair's new company Sinclair Research went on to sell the highly-popular ZX 80 and ZX Spectrum home computers. Clive Sinclair was knighted for his accomplishments in 1983, becoming Sir Clive Sinclair. "

http://files.righto.com/calculator/sinclair_scientific_simulator.html

http://www.vintagecalculators.com/html/sinclair_scientific.html

"US$" in place of "GB£" is rather more than a "typo". Those sources differ, and who knows who copied whom when it came to recording the price.

I had one, also built from a kit, and bought the year they came out. I highly doubt the £50 UK price simply because I know that my father wouldn't have sprung for that, not in a month of Sundays. I still remember him having a fit when the bill from the opticians for a new pair of glasses came in at £60 two years later. No way was he going to voluntarily shell out £50  for something non essential. My father was a stereotypical "thrifty" Northener.  I'll see if I can find an old Practical Electronics with an ad for it online - that's almost certainly how I came to get him to buy it for me - and get an accurate price for it from primary sources.

Scratch that, check reference 13 in the Wikipedia article, a US Popular Mechanics advert (Jan 75) with a $49.95USD price on it. So it was dollars, not pounds, and reference 14 is an ad from New Scientist at the end of the year (Dec 75) with the £9.95GBP price clearly shown. So, not typos but verifiable from primary sources. The page at http://files.righto.com/calculator/sinclair_scientific_simulator.html that you've quoted to support the £49.95 price is either wrong, or is referring to the built calculator's retail price not the kit.

Moreover, I can believe my father springing the £9.95 for a Christmas present, just. 

Dear me, are you needing some glasses? It was launched in 1974 @£49.95 (UK) and $139.95 (US) and as a kit @$99.95, ie. 71% of the assembled price. Lets assume that the UK differential is the same, that would make it around £35.36 at launch.

I quote this paragraph from the History section of Wiki article.
The Sinclair Scientific first appeared in a case derived from that of the Sinclair Cambridge, but it was not part of the same range.[5] The initial retail price was GB£49.95 in the UK (equivalent to £478 in 2016), and in the US for US$99.95 as a kit or US$139.95 fully assembled.[6] By July 1976, however, it was possible to purchase one for GB£7[5] (equivalent to £46 in 2016).
The price you quoted was @ Jan 1975, after prices of calculators tumbled, probably as a result of Sinclair's entry into that market arena.

This theory seems to be highly likely as this extract from the Wikipedia article tends to both highlight the tumbling prices and the relationship between the prices you quoted by citing the US Popular Mechanics advert (Jan 75) [red highlight] and the actual launch price which I quoted. It also goes on to further demonstrate the price collapsing even further by December 75 to just £9.95, {green highlight} less than 25% of its introductory price, back in 74 which is precisely what I quoted, all the evidence is right there in the Wiki article.

Extract from the Wiki article.
"Assembly kit

The assembly kit consisted of eight groups of components, plus a carry case.[13] The build time was advertised as being around three hours, and required a soldering iron and a pair of cutters.[13][14] In January 1975, the kit was available for US$49.95, half the price at the time of introduction a year earlier,[13] and in December 1975 it was available for GB£9.95, less than a quarter of the introductory price.[14] "

I was quoting launch prices, yours was a year later, not the same thing at all.

Go back and re-read. You talked about the kit being £49.95 (or £579 in modern money), and now you're estimating it at £35.36. That felt wrong to me, precisely becuase I had one, and ours was not a rich spendy household. So I looked at the wikipedia article which quoted $49.95 for the kit and pointed that out. You then said that was a typo, primary sources prove it wasn't. Frankly I don't want to get into a pissing contest about who can read better, especially if it involves digging into a dissection of the wikipedia history page and large shouty and/or multicoloured text, life's too short for that. I'm out...

[Cerebus]

Somebody's having a laugh...

[Cerebus]

Have we had this one? Datron 1065.

Ebay listing https://www.ebay.co.uk/itm/255668981352 "For parts or not working"



Doesn't look too rough. Might be a useful parts mule or a repair challenge for someone who's up for it.

[Specmaster]

<snip>

Go back and re-read. You talked about the kit being £49.95 (or £579 in modern money), and now you're estimating it at £35.36. That felt wrong to me, precisely becuase I had one, and ours was not a rich spendy household. So I looked at the wikipedia article which quoted $49.95 for the kit and pointed that out. You then said that was a typo, primary sources prove it wasn't. Frankly I don't want to get into a pissing contest about who can read better, especially if it involves digging into a dissection of the wikipedia history page and large shouty and/or multicoloured text, life's too short for that. I'm out...

I was quoting 1974 launch prices, yours is 1975 price. The article does not state if the £49.95 price was kit or built, I did say kit and for that I'm sorry for not stating that was NOT 100% certain.

Either, you were almost a complete year out in pricing and as we all know, a year in electronics is a long time.

[themadhippy]

dissection of the wikipedia history page

Why not take a look at the original adverts,plenty of 1974 mags online to chose from,for those in the uk corner https://worldradiohistory.com/Everyday_Electronics.htm

[Specmaster]

Meanwhile, in a Facebook vintage electronics group, these photos were posted today of this person's collection of meters and test gear, impressive or what?

[capt bullshot]

Meanwhile, in a Facebook vintage electronics group, these photos were posted today of this person's collection of meters and test gear, impressive or what?

One can build quite an amount of smiling face steampunk lighting devices out of these 

SCNR   duck, run and hiding from the mob now

[med6753]

Progress. Checked the HV and it was -2150V. Way too high. Per manual -2000V +/-5V. Adjusted to spec. Noticed immediately that the vertical gain which was low increased to spec when HV was properly adjusted. Interesting. 

Sweep speed now set to spec. DC balance adjusted. Both channel attenuator switch decks are much better but are still noisy and intermittent at times. I write that up to cheap switches that are somewhat worn. Live with it or junk it. This scope isn't going to get much use anyway.

Left to do is compensation. Tomorrow's activity.

   

[Calambres]

I've got a couple of Metrix 460 multimeters as seen on Specmaster's second and third photos. Old bakelite beauties...

[bd139]

New Marconi oscillators populated. Testing after I’ve run an errand

[Cubdriver]

Progress. Checked the HV and it was -2150V. Way too high. Per manual -2000V +/-5V. Adjusted to spec. Noticed immediately that the vertical gain which was low increased to spec when HV was properly adjusted. Interesting. 

Makes sense - the higher accelerating voltage makes the beam less inclined to deflect - the faster moving electrons go through the deflection plates in less time so either don't feel their influence as long or simply have less time to move off axis during their shorter transit time - not exactly sure of the mechanism.

-Pat

[Zucca]

Nice shot too!

I am missing you here:
https://www.eevblog.com/forum/chat/best-lens-for-macro-electronic-components/

[Specmaster]

dissection of the wikipedia history page

Why not take a look at the original adverts,plenty of 1974 mags online to chose from,for those in the uk corner https://worldradiohistory.com/Everyday_Electronics.htm

Thanks for posting the link to this wonderful archive, it would seem that possibly myself and cerebus have incorrect data as far as the UK is concerned 

In Jan 1974 copy of Everyday Electronics, there is a multipage advert for the Sinclair Cambridge 4 banger calculator £32.95 built and £24.95 in kit form and over the next few months this price a lot until Nov 74 when the first Scientific advert appears for £32.95 built and £19.95 as a kit and by this time, the price for the Cambridge is just £21.55 built and £14.95 in kit form.

So this time we were both incorrect so we can both stop the sabre-rattling. It would appear that the calculator wars were taking no prisoners at the time.

[Specmaster]

New Marconi oscillators populated. Testing after I’ve run an errand

Looking really neat.