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Re: Fluke 8125A
Posted: Tue Feb 18, 2025 2:16 pm
by Zenith
Apparently reel to reel has had a comeback in recent years, especially with some prominent artistes and a section of audiophiles.
Are they still made?
Re: Fluke 8125A
Posted: Tue Feb 18, 2025 7:11 pm
by mansaxel
Zenith wrote: ↑Tue Feb 18, 2025 2:16 pm
Apparently reel to reel has had a comeback in recent years, especially with some prominent artistes and a section of audiophiles.
Are they still made?
No, but tape is being made again, I believe. There was a crisis when BASF and Ampex both had quit, IIRC, but there was a resurgence and manufacturing has restarted. Prices are insane. A 762m tape will hold 33 minutes, which is well under 1GiB in 48kHz/24 bit stereo. It costs 70 USD. And you get noise and dropouts and need to align, degauss and clean your machine pretty often.
Re: Fluke 8125A
Posted: Tue Feb 18, 2025 11:45 pm
by Zenith
It's a world I only viewed from the outside. There were domestic tape recorders in the 60s. 5" reels and one speed. There were better ones with 7" reels and several speeds and stereo. There were semi-professional ones Uher, Revox etc. All used 1/4" tape. Then there were huge studio tape recorders which I think were multi-track and used 1" tape. They were used to record things later transferred to vinyl.
Then cassette came along, which was designed for voice recording, but an awful lot of effort went into squeezing a quart into a pint pot and it became a sort of hi-fi format. There were portable Walkman players and recorders. It was convenient for cars and you could buy ready recorded tapes or make your own.
Then there were 1/2" computer tapes, which were in use for a long time. They started to be replaced in the mid 80s by cartridge formats such as DAT.
It's not at clear to me why reel to reel audio has had a comeback, but I suppose its enthusiasts have their reasons.
Re: Fluke 8125A
Posted: Wed Feb 19, 2025 12:14 am
by tggzzz
I still have the Sony TC370 I took to university 50 years ago. it doesn't work anymore, but maybe someone could get it rotating.
I also have many 7" tapes, including one of the first broadcast of Hitchhiker's Guide to the Galaxy.
Re: Fluke 8125A
Posted: Wed Feb 19, 2025 8:55 pm
by 25 CPS
mansaxel wrote: ↑Tue Feb 18, 2025 7:11 pm
Zenith wrote: ↑Tue Feb 18, 2025 2:16 pm
Apparently reel to reel has had a comeback in recent years, especially with some prominent artistes and a section of audiophiles.
Are they still made?
No, but tape is being made again, I believe. There was a crisis when BASF and Ampex both had quit, IIRC, but there was a resurgence and manufacturing has restarted. Prices are insane. A 762m tape will hold 33 minutes, which is well under 1GiB in 48kHz/24 bit stereo. It costs 70 USD. And you get noise and dropouts and need to align, degauss and clean your machine pretty often.
New Revox B77 are being made but they're listed at just under 16,000 Euro dollars.
Edited to add: From what I've seen, they're only making a Revox B77 version of the machine - no Studer PR99 counterpart.
I'm not sure how much or if there was a gap between Quantegy bailing out, RMGI starting up and where the timeline of ATR's tape manufacture lands in all this.
One thing I can say though is audio tape, for that matter even video tape come to think of it, I've never encountered the fire hazard that film handling equipment has with any tape machine I've ever worked on.
Re: Fluke 8125A
Posted: Wed Feb 19, 2025 10:09 pm
by Zenith
25 CPS wrote: ↑Wed Feb 19, 2025 8:55 pm
New Revox B77 are being made but they're listed at just under 16,000 Euro dollars.
Edited to add: From what I've seen, they're only making a Revox B77 version of the machine - no Studer PR99 counterpart.
I'm not sure how much or if there was a gap between Quantegy bailing out, RMGI starting up and where the timeline of ATR's tape manufacture lands in all this.
One thing I can say though is audio tape, for that matter even video tape come to think of it, I've never encountered the fire hazard that film handling equipment has with any tape machine I've ever worked on.
I have a Revox B-something that was given to me years ago. There's also a parts mule. I can't bring myself to chuck it, and I suppose it should go to the end of the fixit queue.
Around 1970 I heard of a video tape recorder put on the market, but the tape speeds were so high it was dangerous, and so was rapidly withdrawn. By then helical scan may have been a thing and I think the BBC were using video tape.
In the early days cine film was based on cellulose nitrate. There are various forms of cellulose nitrate, with differing amounts of nitration. This must have been the little brother of gun cotton, used as a propellant in artillery, but when compressed it will go off with a bang when set off with a detonator. It's normally used as a booster for something like gelignite. The film stock degraded with time and temperature, and burned easily - not fantastic when you have a very powerful bulb near and things can go wrong and it bunches up.
They they moved to cellulose acetate - Safety Film. Still something of a safety hazard, but it tends to shrivel up when hot, and it's more stable with time. You can still buy 35mm film now. Dunno what they use these days in still cameras or at the pictures.
Back in the day, 50's, 60's, audio tape must have been a very hi tech product.
Re: Fluke 8125A
Posted: Wed Feb 19, 2025 10:16 pm
by tggzzz
Zenith wrote: ↑Wed Feb 19, 2025 10:09 pm
Around 1970 I heard of a video tape recorder put on the market, but the tape speeds were so high it was dangerous, and so was rapidly withdrawn.
Faster than 1000cps paper tape flying horizontally across the room into a large hopper?
Think "paper cut" with a chainsaw
Re: Fluke 8125A
Posted: Wed Feb 19, 2025 10:45 pm
by Zenith
I had a boss who'd worked for Lyons (ice cream, tea and grim corner cafes) in the early 60s. Strangely they were very switched on to technology. They created LEO (Lyons Electronic Office) which was a very powerful computer for the time. They had forms which could be filled in with a special pen and fed directly into the system.
They also had a page printer - at the time line printers were crude and expensive. This thing worked on a Xerox principle, new at the time, where toner was heated and baked onto paper. So they had paper rushing past a 2kW heater at a rate of knots. Sometimes the paper would jam and the operators would step in and stop it. One weekend the ends didn't quite meet. The paper jammed, built up into a huge pile, caught fire and the printer and the building it was in were destroyed. Lyons abandoned the idea.
The boss never mentioned paper cuts, but I suppose it would have been a possibility the ops were well aware of.
Re: Fluke 8125A
Posted: Thu Feb 20, 2025 1:02 am
by tggzzz
Zenith wrote: ↑Wed Feb 19, 2025 10:45 pm
I had a boss who'd worked for Lyons (ice cream, tea and grim corner cafes) in the early 60s. Strangely they were very switched on to technology. They created LEO (Lyons Electronic Office) which was a very powerful computer for the time. They had forms which could be filled in with a special pen and fed directly into the system.
Something IBM never seems to mention: LEO I was the first computer used for commercial business applications.
https://www.sciencemuseum.org.uk/object ... s-computer
They also had a page printer - at the time line printers were crude and expensive. This thing worked on a Xerox principle, new at the time, where toner was heated and baked onto paper. So they had paper rushing past a 2kW heater at a rate of knots. Sometimes the paper would jam and the operators would step in and stop it. One weekend the ends didn't quite meet. The paper jammed, built up into a huge pile, caught fire and the printer and the building it was in were destroyed. Lyons abandoned the idea.
Haven't heard that one before.
Plenty of lovely stories about playing tunes loudly on lineprinters, or waking up the operators (or worse) by printing the sequence of characters which caused all the hammers to fire at the same time.
Somewhere I've got a 1975 compendium of cartoons about (mainframe) computers and fun things to do with them. Ought to dig it out.
The boss never mentioned paper cuts, but I suppose it would have been a possibility the ops were well aware of.
It was one of those "bleedin' obvious" things. If someone couldn't recognise and avoid the possibilities inherent in a 2m*1m bucket with paper tape flying horizontally into it, then the species was improved. Much like water spraying onto rock above a 200ft chasm at Gullfoss; is a railing
really necessary?
Re: Fluke 8125A
Posted: Sat Feb 22, 2025 1:54 am
by vk6zgo
Zenith wrote: ↑Wed Feb 19, 2025 10:09 pm
25 CPS wrote: ↑Wed Feb 19, 2025 8:55 pm
New Revox B77 are being made but they're listed at just under 16,000 Euro dollars.
Edited to add: From what I've seen, they're only making a Revox B77 version of the machine - no Studer PR99 counterpart.
I'm not sure how much or if there was a gap between Quantegy bailing out, RMGI starting up and where the timeline of ATR's tape manufacture lands in all this.
One thing I can say though is audio tape, for that matter even video tape come to think of it, I've never encountered the fire hazard that film handling equipment has with any tape machine I've ever worked on.
I have a Revox B-something that was given to me years ago. There's also a parts mule. I can't bring myself to chuck it, and I suppose it should go to the end of the fixit queue.
Around 1970 I heard of a video tape recorder put on the market, but the tape speeds were so high it was dangerous, and so was rapidly withdrawn. By then helical scan may have been a thing and I think the BBC were using video tape.
In the early days cine film was based on cellulose nitrate. There are various forms of cellulose nitrate, with differing amounts of nitration. This must have been the little brother of gun cotton, used as a propellant in artillery, but when compressed it will go off with a bang when set off with a detonator. It's normally used as a booster for something like gelignite. The film stock degraded with time and temperature, and burned easily - not fantastic when you have a very powerful bulb near and things can go wrong and it bunches up.
They they moved to cellulose acetate - Safety Film. Still something of a safety hazard, but it tends to shrivel up when hot, and it's more stable with time. You can still buy 35mm film now. Dunno what they use these days in still cameras or at the pictures.
Back in the day, 50's, 60's, audio tape must have been a very hi tech product.
Smoking in cinemas has been banned in Australia for as long as I can remember. I think that must date back to cellulose nitrate film.
I was bemused to see smokers puffing away contentedly when I first went to a film in the UK.
In Oz, the addicts would all rush off to the lobby to light up at Interval.
Re: Fluke 8125A
Posted: Sat Feb 22, 2025 1:42 pm
by Zenith
I can't remember people smoking in cinemas in the UK after the late 70s. I can certainly remember seeing the light from the projector showing up on the swirling smoke earlier.
Looking it up, I found Rank Leisure was the first major chain to provide smoke-free cinemas in 1987. I thought it was earlier.
Re: Fluke 8125A
Posted: Sat Feb 22, 2025 8:05 pm
by tggzzz
Zenith wrote: ↑Sat Feb 22, 2025 1:42 pm
I can't remember people smoking in cinemas in the UK after the late 70s. I can certainly remember seeing the light from the projector showing up on the swirling smoke earlier.
Looking it up, I found Rank Leisure was the first major chain to provide smoke-free cinemas in 1987. I thought it was earlier.
Pubs were more irritating than cinemas; too many conversations along the lines of "Let's go to a pub. X has nice beer. Yes, but it will be too stinky at this time"
Re: Fluke 8125A
Posted: Sun Feb 23, 2025 6:22 pm
by AVGresponding
Re: Fluke 8125A
Posted: Sun Feb 23, 2025 6:49 pm
by tggzzz
Typical yootoob:takes forever to say something. How long did he spend twittering about capacitor leakage measurements?
Nonetheless: he indicated the big resistors were heaters for when it was cold. Possible, but surprising, and I'd like to see where the temperature sensor and switch are located.
Re: Fluke 8125A
Posted: Mon Feb 24, 2025 6:14 am
by AVGresponding
In other words, you want me to tear mine back down and figure it out, in order to make a less wordy and more concise analysis.
I did point out in the comments for his video that the ladder transistors seem to have been swapped out on his, from ge to si, and I wonder if that is (more) gorilla evidence and a possible cause of his ring counter instability
Re: Fluke 8125A
Posted: Mon Feb 24, 2025 8:44 am
by tggzzz
AVGresponding wrote: ↑Mon Feb 24, 2025 6:14 am
In other words, you want me to tear mine back down and figure it out, in order to make a less wordy and more concise analysis.
It isn't up to the audience. The "content creators" should do that, to show they respect their audience.
I did point out in the comments for his video that the ladder transistors seem to have been swapped out on his, from ge to si, and I wonder if that is (more) gorilla evidence and a possible cause of his ring counter instability
I didn't bother to read the comments; most comments on most yootoob videos are unenlightening at best.
Did he indicate any reason for swapping the transistors? That might point to root cause failures elsewhere.
I saw a little of the scope trace for the ring counter. With a multichannel DSO it ought to be possible to work out the source of the problem, by just leaving it running and capturing the eye diagrams using infinite persistence.
Re: Fluke 8125A
Posted: Mon Feb 24, 2025 5:41 pm
by AVGresponding
tggzzz wrote: ↑Mon Feb 24, 2025 8:44 am
Did he indicate any reason for swapping the transistors? That might point to root cause failures elsewhere.
I saw a little of the scope trace for the ring counter. With a multichannel DSO it ought to be possible to work out the source of the problem, by just leaving it running and capturing the eye diagrams using infinite persistence.
I doubt he noticed. In fairness, I only did because the nice TO-5 cans have been replaced with grubby little plastic TO-92's.
Re: Fluke 8125A
Posted: Sat Mar 01, 2025 8:54 am
by AVGresponding
tggzzz wrote: ↑Sun Feb 23, 2025 6:49 pm
Typical yootoob:takes forever to say something. How long did he spend twittering about capacitor leakage measurements?
Nonetheless: he indicated the big resistors were heaters for when it was cold. Possible, but surprising, and I'd like to see where the temperature sensor and switch are located.
Erik was kind enough to email me some jpegs of the schematics from a paper manual he scored. I will convert them to pdf and upload to BAMA et al at some point.
In the meantime, I'll attach the ones of the heaters and the thermostatic control here
IMG_4685.jpg
IMG_4686.jpg
Re: Fluke 8125A
Posted: Sat Mar 01, 2025 10:42 am
by tggzzz
It is possible to do a 9:1 kb reduction on those files, down to ~40kB. I'd post the full result of the first image here, but I can't upload a pdf for some reason. The image below is a section that is just small enough to fit within this forum's 2k*2k limit, and is sufficient to show the quality.
The closed loops in some characters are present in the photo you supplied. The second photo isn't worth showing for those reasons.
I'm happy to convert more photos, if beneficial. I'd prefer slightly better source quality, though!
Re: Fluke 8125A
Posted: Sat Mar 01, 2025 11:40 am
by AVGresponding
I uploaded the raw jpegs, no idea if the forum compresses them at all. Erik isn't set up for scanning, I'd guess he used his phone or a digital camera
EDIT: The forum definitely compresses the images, down from around 1.6MB to 240kB
Re: Fluke 8125A
Posted: Sat Mar 01, 2025 11:59 am
by AVGresponding
Re: Fluke 8125A
Posted: Sat Mar 01, 2025 2:10 pm
by tggzzz
Those have been heavily compressed, to 0.75MB/image, and to have artefacts surrounding the lines. They appear to have been taken with an "iPhone X", so I would expect better.
I can automatically improve the text and schematics, but the images don't improve.
Is there any way of getting the original images to me, e.g. dropbox or email?
Re: Fluke 8125A
Posted: Tue Mar 04, 2025 6:22 pm
by AVGresponding
tggzzz wrote: ↑Sat Mar 01, 2025 2:10 pm
Those have been heavily compressed, to 0.75MB/image, and to have artefacts surrounding the lines. They appear to have been taken with an "iPhone X", so I would expect better.
I can automatically improve the text and schematics, but the images don't improve.
Is there any way of getting the original images to me, e.g. dropbox or email?
Gaaaah... I didn't realise servimg compressed the images as well. PM me your preferred email
Re: Fluke 8125A
Posted: Thu Mar 06, 2025 3:06 am
by 25 CPS
tggzzz wrote: ↑Sun Feb 23, 2025 6:49 pm
Typical yootoob:takes forever to say something. How long did he spend twittering about capacitor leakage measurements?
Nonetheless: he indicated the big resistors were heaters for when it was cold. Possible, but surprising, and I'd like to see where the temperature sensor and switch are located.
You know, I was totally expecting a Mr. Carlson's Lab video based on that description before I clicked on the link. The excess length leaky capacitor discussions are so tedious I skip ahead in videos until they're over now. Same with anything "the sponsor of today's video is ____" with a lengthy advertisement.
