The Binocular

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Re: The Binocular

Postby Harry Dalek » Sun Jun 02, 2019 5:23 pm

The videos were a bit easier than the photos funny enough ,posted a few up here with today's results.



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MVI_0705_x264.mp4
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MVI_0725_x264.mp4
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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 Binocular

Postby Klaas Robers » Mon Jun 03, 2019 6:20 am

I see that you have problems with the line synchronisation of your wave form picture. And that is funny, because your picture (right) is well synchronised. Why do you not use that sync signal?

I see that your picture (right) is focussed well, because now and then I see the individual lines. This is contrary to the wave form, which is unsharp. You should be able to focus the left tube as good as the right one. I hope that you have not just one focus control....

Good luck!
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Re: The Binocular

Postby Andrew Davie » Mon Jun 03, 2019 8:03 am

Loving it! Well done, it's a beautiful thing :)
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Re: The Binocular

Postby Harry Dalek » Mon Jun 03, 2019 7:03 pm

Klaas Robers wrote:I see that you have problems with the line synchronisation of your wave form picture. And that is funny, because your picture (right) is well synchronised. Why do you not use that sync signal?


Oh yes the scopes time base is free running ,it was locked to one line display waveform before when I used the line frequency for monitors deflection ,I made a duplicate circuit where I could control the frequency to show more than one waveform but when I tried to sync it seems to pull the waveform off screen to one side .
So I am still looking into this ,this is the first scope I have ever made happily most of what I had in mind works syncing seems the only problem

. I see that your picture (right) is focussed well, because now and then I see the individual lines. This is contrary to the wave form, which is unsharp. You should be able to focus the left tube as good as the right one. I hope that you have not just one focus control....


Well Klass it was a surprise to me as well that the same crt's would not give the same result ,both crt's 3bp1's are only same in name and almost the same voltage wise but the scope tube seems it needs a touch more voltage or circuit value change to its focus supply circuit .
Both tubes have their own circuits and only share the main HV supplies and heater supply pretty much every thing else to run the crt's are copies of each other .
I think due to their age the tubes would of been hand made and at different factories so slight differences, I am going to swap it for another 3bp1 and try and match it to the monitor crt an easier fix since I have one to match it .


Good luck!


Thanks Klass I will try and fix the syncing problem on the scope later this week and the focus problem ...little bit of you in this monitor as well the sync slice I know is ...so better do you and Steve's circuit justice :wink:
Last edited by Harry Dalek on Mon Jun 03, 2019 7:30 pm, edited 2 times in total.
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 Binocular

Postby Harry Dalek » Mon Jun 03, 2019 7:25 pm

Andrew Davie wrote:Loving it! Well done, it's a beautiful thing :)


Thanks Andrew little did I know the old vcr dvd combo in my shed I was planning on scrapping for spare parts would end up another monitor the case was the last thing I wanted to keep little did I know ...Off cause your help really made me think about what I was going to do for this project and never have been so lucky to make what I wanted as a monitor with out having to worry I don't have that part .
Well I still have more work not over till the lids screwed on ...if any thing the beauty is its all one unit which makes it easier to use and move about .
Still more to come on this one I will work more on it later this week .
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 Binocular

Postby Klaas Robers » Tue Jun 04, 2019 4:40 am

I think Harry, that making a separate focuscontrol and a separate brightness control for both picture tubes is a better solution. Then you can optimise both at the same time.

I like the video signals with the sync pulses negative (down). This is how video signals should look like. Then in the video signal high is white and low is black (dark). Intuitively it is like that.

And for the line width: I think that seeing one line, a sync pulse and the beginning of the next line is enough. That is indeed the situation where you came from.
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Re: The Binocular

Postby Harry Dalek » Tue Jun 04, 2019 5:07 pm

Klaas Robers wrote:I think Harry, that making a separate focus control and a separate brightness control for both picture tubes is a better solution. Then you can optimise both at the same time.


This is what i did Klass i didn't want any problems of one effecting the other so i have 2 of Steves CRT Drive circuits for each CRT .
Voltages shown here are close but mine are a touch higher for the Binocular ...only sharing the main high voltage power supply ...so each is independent of of the other .
kCzgTX1448787622.jpg
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I like the video signals with the sync pulses negative (down). This is how video signals should look like. Then in the video signal high is white and low is black (dark). Intuitively it is like that.


Yes i swapped the deflection pates on the scope tube i am happy too with that .

And for the line width: I think that seeing one line, a sync pulse and the beginning of the next line is enough. That is indeed the situation where you came from.


I was going to have a switch to flip between one line and the free running so either is no problem .

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Last edited by Harry Dalek on Thu Jun 06, 2019 5:13 pm, edited 1 time in total.
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 Binocular

Postby Harry Dalek » Thu Jun 06, 2019 3:33 pm

Today i fixed the scope focus problem and have either fixed one line or free running time base for the scope .
Below is a test on 64 line video


Below i found some 64 line videos work same subject , i knocked the line control as i was filming so went off angle a bit funny enough on both .

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MVI_0739_x264.mp4
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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 Binocular

Postby Steve Anderson » Thu Jun 06, 2019 3:39 pm

The poor focus on the 'waveform' CRT does need addressing. That circuit was created around a 'nominal' tube, but with age, maybe use and other things this CRT is not quite nominal.

The simplest thing to try is to swap the two CRTs and see what happens. Also check the resistors and pot that form the focus circuit are actually correct. Older parts, especially pre-70s, are notorious for going high in value, particularly resistors, simply with age. Capacitors, especially those wax-covered paper variety are not worth salvaging.

Try the tube-swap first - let us know the result.

Steve A.

Actually, having played the videos rather than looking at them still, the focus on the waveform CRT isn't that bad. If the focus control is at one end of the track a small adjustment to either of the two resistors each side of the focus pot may be required. i.e. try changing the 470k to 560k or 390k. Or the 220K, try 180k or 270k.

There is the possibility of the CRT going 'soft'. Over the years a small amount of air has leaked in - and it only needs a small amount to cause de-focusing. Let's hope that is not the case. If the 'getter' has a hint of white then that's probably the cause. The getter is the (usually) silver coloured metallic gunk sprayed into all tubes just prior to final sealing. In most CRTs it's usually near the base on the inside of the glass. If it's starting to look a bit white then that's a sign of air getting in. This applies to all tubes/valves, not just CRTs. The photo shows a tube with what a getter should look like.
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Re: The Binocular

Postby Steve Anderson » Thu Jun 06, 2019 4:49 pm

Here's a small picture of a normal getter (right) and one where the tube/valve has gone 'soft' (left) - air has got inside.

'Soft' means it's not a 'hard' vacuum.

The main function of the getter is to mop up those few remaining molecules of air once the tube is sealed - there is no such thing as a perfect vacuum pump.

Refuse to buy any tubes/valves where the getter is showing signs of turning from a nice silvery finish to white.

Steve A.
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Re: The Binocular

Postby Harry Dalek » Thu Jun 06, 2019 5:55 pm

Steve Anderson wrote:The poor focus on the 'waveform' CRT does need addressing. That circuit was created around a 'nominal' tube, but with age, maybe use and other things this CRT is not quite nominal.


Must of posted around the same time as i just finished fixing the problem i swapped the CRT and it was very similar problem to the one i replaced so went on to checking its circuit .

IMG_0736.JPG


The simplest thing to try is to swap the two CRTs and see what happens.


Yes that's done now and ended up not being it so i was dead wrong there but as you thought worth a try .

Also check the resistors and pot that form the focus circuit are actually correct. Older parts, especially pre-70s, are notorious for going high in value, particularly resistors, simply with age. Capacitors, especially those wax-covered paper variety are not worth salvaging.


And you picked it it was an old resistor in the focus circuit so they do go bad it went right in to focus and brighter replacing .
I wish i could buy every thing new as i know that's better but i have to use whats handy funds are not unlimited so a lot of scrapped parts apart from the main stuff and safety first very much so on the power supply .

Try the tube-swap first - let us know the result.

Steve A.


All good here Steve not to bad now ...i am moving onto seeing why some video's play others don't having the scope handy onit i can see the video levels are lot lower on the ones playing up and i will post up some tests ...may be its fixable .

It played a 64 line video well which was interesting ....have to see if i still have some 48 line the devil monitor played those well .

i am also looking into switching for vert horz ramps to the deflection amplifiers for dual horizontal vertical scan .

Actually, having played the videos rather than looking at them still, the focus on the waveform CRT isn't that bad. If the focus control is at one end of the track a small adjustment to either of the two resistors each side of the focus pot may be required. i.e. try changing the 470k to 560k or 390k. Or the 220K, try 180k or 270k.


Thanks for that advice Steve its fine now but i can come back here for any future problems and keep this on mind ,i like to know how things work than just copying and reason i keep making the monitors for me is to learn and advice on different parts of the monitor is believe me kept on mind .

There is the possibility of the CRT going 'soft'. Over the years a small amount of air has leaked in - and it only needs a small amount to cause de-focusing. Let's hope that is not the case. If the 'getter' has a hint of white then that's probably the cause. The getter is the (usually) silver coloured metallic gunk sprayed into all tubes just prior to final sealing. In most CRTs it's usually near the base on the inside of the glass. If it's starting to look a bit white then that's a sign of air getting in. This applies to all tubes/valves, not just CRTs. The photo shows a tube with what a getter should look like.


The CRTs look good here look new infact so none of those problems well not as yet .


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DSCN9699.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 Binocular

Postby Steve Anderson » Thu Jun 06, 2019 7:28 pm

Yep, that generally looks better. Even with brand-new resistors I check the resistance before I fit them. Often the colour code can be 'off'. What should be a red looks more like a brown for example. With 'reclaimed' resistors I would always check them, it only takes a few seconds and can save you hours later trying to find what is causing you a problem.

There are many places in a circuit where a resistor could be twice or half it's supposed value, e.g. pull-up resistors in logic circuits. But in an analogue circuit like this they should be near the intended value...what is near? Say 10% or better still 5%. Many resistors used in domestic gear were 20% up until the end of the tube/valve era...and that's when they were new!

When measuring resistances (or anything else) remember that your meter has an accuracy specification too. Most modern yet inexpensive DVMs aren't too bad in that respect, but often the resistance ranges are those with the greatest error. Keep that in mind. Just because it's digital doesn't mean it's accurate.

I have seen others using DVMs where the lo-battery symbol is showing, "It's still working, so I'll use it until the display dies." The problem there is that the DVM chip generates a reference voltage - all measurements use this to calculate what it should display. If the reference is 'off' because of a low battery the result will be too. If you live right next door to a 711 - no problem, otherwise always keep spare batteries.

Steve A,
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Re: The Binocular

Postby Harry Dalek » Fri Jun 07, 2019 7:07 pm

Steve Anderson wrote:Yep, that generally looks better. Even with brand-new resistors I check the resistance before I fit them. Often the colour code can be 'off'. What should be a red looks more like a brown for example. With 'reclaimed' resistors I would always check them, it only takes a few seconds and can save you hours later trying to find what is causing you a problem.


Yes as I found out a few times ,if lights dim constructing in the evening can cause mistakes ,here I needed some higher watts resistors bit harder to get these days at the local electronics shop.

There are many places in a circuit where a resistor could be twice or half it's supposed value, e.g. pull-up resistors in logic circuits. But in an analogue circuit like this they should be near the intended value...what is near? Say 10% or better still 5%. Many resistors used in domestic gear were 20% up until the end of the tube/valve era...and that's when they were new!


Well I found some of the old resistors were double or just plan random values the colour band code on them were worthless.

When measuring resistances (or anything else) remember that your meter has an accuracy specification too. Most modern yet inexpensive DVMs aren't too bad in that respect, but often the resistance ranges are those with the greatest error. Keep that in mind. Just because it's digital doesn't mean it's accurate.


Well I have two which I double check with if I think something is up .....here was some thing new of a problem good to learn from a mistake not a bad one just a little annoying.

i have seen others using DVMs where the lo-battery symbol is showing, "It's still working, so I'll use it until the display dies." The problem there is that the DVM chip generates a reference voltage - all measurements use this to calculate what it should display. If the reference is 'off' because of a low battery the result will be too. If you live right next door to a 711 - no problem, otherwise always keep spare batteries.

Steve A,


Most are 9 volts I use and I just got rechargeable ones so it's always handy to have one charged ready in case of the dreaded low battery ......mine play up on voltage readings in they go low .


Today I neatened the wiring and put in a switch to switch between vertical and horizontal scanning to the deflection amplifiers,it will be tested tomorrow and I will post up then.
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 Binocular

Postby Harry Dalek » Sat Jun 08, 2019 7:14 pm

Not much more to do i am pretty happy with the results for what i had planned below the panel controls

addtext_com_MDM0NjE1NDcyMTM.jpg


I Tried and built in dual vertical horizontal scan i need to place panel controls to do this correctly not great for aspect ratio but for now this horizontal adjustment this will do ...give me an excuse to make a monitor just for horizontal scan in the future .

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Last edited by Harry Dalek on Sat Jun 08, 2019 7:40 pm, edited 1 time in total.
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 Binocular

Postby Harry Dalek » Sat Jun 08, 2019 7:36 pm

A few videos of today's try soon the lid is going on and my mind will wonder on to some thing else :roll:






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MVI_0059_x264.mp4
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MVI_0001_x264.mp4
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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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