The Thylacine higher line rate monitor

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Re: The Thylacine higher line rate monitor

Postby Steve Anderson » Wed Feb 07, 2018 1:21 pm

I used wire-wrapping quite a lot in the 80s, it's fast and creates boards of high density. The downside is the wire is quite expensive and so is the powered cut/strip/wrap tool. Just the bit alone was almost 200 pounds, and that was in the 80s!

Wire-wrapping is considered more reliable than soldering and the AGC (Apollo Guidance Computer) was built with it. Instead of just one soldered joint wire-wrapping creates around 40 cold-welds , one on each corner of the square peg/pin, 4 per wrap-turn with a 10-turn wrap.

You don't see it much these days as creating PCBs is so quick, easy and cheap...well, for those who can use Eagle and the like...not me yet.

Steve A.
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Re: The Thylacine higher line rate monitor

Postby Harry Dalek » Wed Feb 07, 2018 5:58 pm

Steve Anderson wrote:I used wire-wrapping quite a lot in the 80s, it's fast and creates boards of high density. The downside is the wire is quite expensive and so is the powered cut/strip/wrap tool. Just the bit alone was almost 200 pounds, and that was in the 80s!

Wire-wrapping is considered more reliable than soldering and the AGC (Apollo Guidance Computer) was built with it. Instead of just one soldered joint wire-wrapping creates around 40 cold-welds , one on each corner of the square peg/pin, 4 per wrap-turn with a 10-turn wrap.

You don't see it much these days as creating PCBs is so quick, easy and cheap...well, for those who can use Eagle and the like...not me yet.

Steve A.


How does it go with age as in the wire tarnishing ? i think the wire that is wrapped around its connector would stay clean speculating ...
There is something nice and very Versatile doing the wire to component connections does cut out a lot of designing making your own board may not look as professional ..also keeps your mind busy as to what is the most logical placement of the next wire so you don't block a path for the next connection step .

ON this project i got the second half of the DAC sawtooth circuit going thanks to my son william's camera work got to show the switching of the line frequencies ..
I only had a 5 pole switch handy for the line frequency one side of it does 5 positions with another side 5 positions not used at the moment i can add a switch i'll add the rest ,so one of the old cassette panel switches will come in handy here .
Really i will be mainly looking at 64 and 128 line but i will see later what it can to on maximum settings if every thing works out .

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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: The Thylacine higher line rate monitor

Postby Robonz » Wed Feb 07, 2018 6:09 pm

Great looking scope Harry. It looks really clean.

Just a little feedback on wire wrap. The connections actually get better with age. It something to do with the silver coating on the wire leaching into the pin or something like that. My chemistry expert friend explained it to me many years ago. The wire and wire wrap tools are pretty cheap these days on ebay and online etc. Old school TV's I worked on actually had wire wrap in their volume production e.g. Sanyo TV's' had a lot of wire wrap. Anyway, it is just another way to do stuff. Something that I prefer. Its not much easier than your method. It is just more reliable and easier to manage changes when you realise you stuck the wire on the wrong pin.

Cheers
Keith
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Re: The Thylacine higher line rate monitor

Postby Harry Dalek » Thu Feb 08, 2018 2:40 pm

Robonz wrote:Great looking scope Harry. It looks really clean.

Just a little feedback on wire wrap. The connections actually get better with age. It something to do with the silver coating on the wire leaching into the pin or something like that. My chemistry expert friend explained it to me many years ago. The wire and wire wrap tools are pretty cheap these days on ebay and online etc. Old school TV's I worked on actually had wire wrap in their volume production e.g. Sanyo TV's' had a lot of wire wrap. Anyway, it is just another way to do stuff. Something that I prefer. Its not much easier than your method. It is just more reliable and easier to manage changes when you realise you stuck the wire on the wrong pin.

Cheers
Keith


Thanks Keith i suppose you have to use a type of wire same as the connector ? not just copper as that does tarnish with time ,i know its not good mixing metals on causes it to deteriorate quicker .
Here's a magazine with some tips on the subject boy looking at the work be a pain to debug a big project like that .
https://archive.org/stream/radio_electr ... 3/mode/2up
Off topic i just the other day had the insides of a very far gone 60s tv it was a fire hazard the EHT unit area with large pentode and EHT valve diode all the wiring was black cooked from years over heating no wonder it was all enclosed in a metal case like an oven ...all the transformers were covered in tar i am sure the transformer's would of been better not to have been dipped in tar ..i don't think any one bothered to check if these things were safe or not back then .
Back on this project again i have hooked the sawtooth up to the deflection amplifiers this looks ok am getting a little noise more visible on the blank raster on the lower line rates .
Here checking 128 line 12.5 hz ..
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: The Thylacine higher line rate monitor

Postby Andrew Davie » Thu Feb 08, 2018 8:28 pm

I have a gorgeous 1975 computer - still working last I tried it about 10 years ago - which is totally wire-wrapped. A Datanumerics DL-8A. I think it's the only one left in the world. Serial #29 - something like that. Front panel toggle switches and LEDs.
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Re: The Thylacine higher line rate monitor

Postby Harry Dalek » Thu Feb 08, 2018 9:00 pm

Andrew Davie wrote:I have a gorgeous 1975 computer - still working last I tried it about 10 years ago - which is totally wire-wrapped. A Datanumerics DL-8A. I think it's the only one left in the world. Serial #29 - something like that. Front panel toggle switches and LEDs.


I had a google Andrew as i was curious to see this beast ? it looks to be an analog computer ?
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: The Thylacine higher line rate monitor

Postby Andrew Davie » Thu Feb 08, 2018 9:08 pm

Harry Dalek wrote:
Andrew Davie wrote:I have a gorgeous 1975 computer - still working last I tried it about 10 years ago - which is totally wire-wrapped. A Datanumerics DL-8A. I think it's the only one left in the world. Serial #29 - something like that. Front panel toggle switches and LEDs.


I had a google Andrew as i was curious to see this beast ? it looks to be an analog computer ?



That's the one. No, it's not an analog machine - it has an 8080 inside, and 8-bit registers, 16-bit addresses, as shown on the front panel.
You flip the switches to set the 8-bit value, flip the switches to set the 16-bit address, and then hit "deposit"... and it writes a single byte. It auto-steps the address so you only need to flip the 8-bit value to the new value and hit deposit again. When you've entered your program, flip the address switches to the start address, and hit "RUN". Pretty awesome :)
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Re: The Thylacine higher line rate monitor

Postby Harry Dalek » Fri Feb 09, 2018 5:59 pm

Andrew Davie wrote:That's the one. No, it's not an analog machine - it has an 8080 inside, and 8-bit registers, 16-bit addresses, as shown on the front panel.
You flip the switches to set the 8-bit value, flip the switches to set the 16-bit address, and then hit "deposit"... and it writes a single byte. It auto-steps the address so you only need to flip the 8-bit value to the new value and hit deposit again. When you've entered your program, flip the address switches to the start address, and hit "RUN". Pretty awesome :)


OH i see i was wondering how you worked the thing ..no key board no monitor ,the results are in binary via those leds Yes ? what was its main use i am thinking its crunching numbers like a calculator but they had those in 75 just as i recall that was the first electronic thing i had at high school .

ON the project i have added a Small transformer to handle the panel 2 globe meter lighting and CRT heater ,might also get away with it driving the 5 volt EHT unit also .
i still have to hook up the monitors power supply to the video circuits .
i will also solder and wire up all the old panel pots and switches so i can mount that panel back on i may replace a audio socket or 2 with extra pots which would be more useful .
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: The Thylacine higher line rate monitor

Postby Harry Dalek » Sun Feb 11, 2018 7:16 pm

I worked on the panel Meters circuit today and wiring up the the pots and switches so i can connect them up when i get to that ,problem was i could not do that later as the panel they are on has to be mounted when mounted i could not solder, my solution was solder those before hand to a circuit board which i could get at later .
Had to reposition the little crt heater transformer again due to the board ,
The meters circuit has been tested and works well ,the ic more than likely should be worked off a dual supply but works as is so not to bothered .
http://www.circuitlib.com/index.php/sch ... pathway-28
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needle_vu_sch.jpg
Circuit used for panel meters
needle_vu_sch.jpg (53.08 KiB) Viewed 1785 times
IMG_0773.JPG
constructed panel meter circuit bottom of board ...boards also used for part of the dual 12 volt power supply and the CRT video modulation circuit
IMG_0772.JPG
Bottom of the switch pot panel
IMG_0774.JPG
Now the top of the panel circuit board far bottom all the switch connections
IMG_0778.JPG
IMG_0777.JPG
bottom of panel now 2 extra pots for the sawtooth size controls
IMG_0781.JPG
Panel as is as from today still need to add the line and frame frequency switches ...
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: The Thylacine higher line rate monitor

Postby Steve Anderson » Wed Feb 14, 2018 12:51 pm

Only one thing I might point out - the polarity of C3 & C6 are incorrect in the circuit diagram. If the input is an audio signal (NBTV or similar) it should be centred around 0V/ground. Pins 3 & 5 of the chip are biased to +6V by the combination of R1/R2 & R5/R6, therefore the input caps are the wrong way around.

The single-supply arrangement as shown is fine.

Steve A.

Postscript...As those caps are quite small in value (1uF), use a film/poly component instead. Actually, the combination of 1uF and the two 100k resistors has a -3db point at 3.2Hz, so for audio they could be reduced to something like 0.22uF/220nF.
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Re: The Thylacine higher line rate monitor

Postby Robonz » Wed Feb 14, 2018 5:19 pm

Great point Steve, Actually non polarised caps would be more ideal.
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Re: The Thylacine higher line rate monitor

Postby Steve Anderson » Wed Feb 14, 2018 5:33 pm

Thanks. In fact because the op-amp inputs are J-FETs the resistors could be raised to 330k each and drop the caps to 100nF/0.1uF. -3db point becomes around 10Hz.

Steve A.
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Re: The Thylacine higher line rate monitor

Postby Harry Dalek » Wed Feb 14, 2018 6:18 pm

Thanks Keith and Steve on the meters circuit, i will have a look at doing the slight changes mentioned .
I am really just using them as they are there and does give an indication on whats happening in the right and left audio channels so will come in handy .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: The Thylacine higher line rate monitor

Postby Harry Dalek » Fri Feb 16, 2018 1:56 pm

Nothing overly exciting yet just some more wiring let those interested know how its going ,i always work a little bit on it when i have time ,i will power it up again over the next few days .
Changes are the large front panel pot controls are now the frame and line rate switching and contrast brightness and volume for a little amplifier to come pot controls are under the CRT ,the yellow and green pot controls are the sawtooth size controls which is really needed for something like this .
I searched for all the panel LEDS and connected the wiring up to those to be used ,and some of the pots are still to be wired in to replace the on board trimmers all those wires hanging over the front are those ,now i will have to one by one hook those up.
The back of the case has some sockets i will out put at least the sawtooth to check on scope .
Attachments
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IMG_0788.JPG
IMG_0786.JPG
IMG_0789.JPG
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: The Thylacine higher line rate monitor

Postby Harry Dalek » Wed Feb 21, 2018 6:20 am

I had a bit of trouble with the power supply i was getting some distortion via the DAC board i was at first thinking it was my wiring bundles but it looks like it was its power supply so i am working on that at the moment .
I have fired it up here for a look so getting there .
BTW bottom photo is a model up from my cassette deck as i forgot to take a photo of the case before i started scrapping
Attachments
IMG_0805.JPG
IMG_0804.JPG
IMG_0810.JPG
6839056-1494__03630.1510751938.jpg
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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