The Mongrel

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Re: The Mongrel

Postby Harry Dalek » Sat Aug 28, 2021 1:11 pm

Yes Steve its a goner ,i never even got to hook up the heater ! my own fault leaving it out kids are saying they didn't do it but i noticed a scratches on the panel where the paint is now missing so it looks like it was dropped to me ...too late now to cry about it .
I will have a think about it but may go on with a 3Bp1 i will see what i have to do to get one to fit .
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 Mongrel

Postby Steve Anderson » Sat Aug 28, 2021 1:35 pm

If it were the kids, be thankful it didn't implode with potentially shards of glass flying everywhere...and the exposure to the nasty chemicals that often make up phosphors and cathode coatings.

A warning to those maybe new to tubes/valves, wear safety glasses and a face-mask when handling these things (we're all used to those now, no excuses)...especially anything larger than what you'd find in an old radio...CRTs for example...the photo shows something like a 'harmless' little ECC83/12AX7...

If you wear corrective glasses (as Harry and I do, aka, spectacles) make sure the safety glasses are suitable and fit well over them. Also use them when drilling, cutting metal or fibreglass (PCB material). Follow the guidelines of any decent machine-shop. While you're about it, invest in a decent first-aid kit...add stuff for burns too, soldering iron accidents, they happen.

Steve A.

800px-Imploding_vacuum_tube.jpg
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Re: The Mongrel

Postby Harry Dalek » Sat Aug 28, 2021 7:46 pm

Steve Anderson wrote:If it were the kids, be thankful it didn't implode with potentially shards of glass flying everywhere...and the exposure to the nasty chemicals that often make up phosphors and cathode coatings.

A warning to those maybe new to tubes/valves, wear safety glasses and a face-mask when handling these things (we're all used to those now, no excuses)...especially anything larger than what you'd find in an old radio...CRTs for example...the photo shows something like a 'harmless' little ECC83/12AX7...

If you wear corrective glasses (as Harry and I do, aka, spectacles) make sure the safety glasses are suitable and fit well over them. Also use them when drilling, cutting metal or fibreglass (PCB material). Follow the guidelines of any decent machine-shop. While you're about it, invest in a decent first-aid kit...add stuff for burns too, soldering iron accidents, they happen.

Steve A.

The attachment 800px-Imploding_vacuum_tube.jpg is no longer available


Yes what ever happened the CRT got a nasty knock one of the kids more than likely ! having a very sad good look at it
DSCN6585.JPG

DSCN6586.JPG


After the last post i was thinking i don't want this set back to stop me that's even more depressing ! so had a look how a 3BP1 would go in the case its a touch longer than the DG7 ,i also had a mu metal shield for it that fits ,had to once again adjust the case for it being a larger tube and that took most of the afternoon up , least the mounted shield holds the CRT nicely , the front panel will be repainted due to what's happened .
Oh well another reboot ~!
Attachments
DSCN6584.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 Mongrel

Postby Steve Anderson » Sun Aug 29, 2021 12:33 pm

Harry, am I correct in thinking you've done a 3BP1 CRT monitor before? OK, not all valve/tube maybe but worth refreshing ones mind by having a look at it and/or drawings/postings etc..

Steve A.
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Re: The Mongrel

Postby Harry Dalek » Sun Aug 29, 2021 4:15 pm

Steve Anderson wrote:Harry, am I correct in thinking you've done a 3BP1 CRT monitor before? OK, not all valve/tube maybe but worth refreshing ones mind by having a look at it and/or drawings/postings etc..

Steve A.



Oh yes 4th or 5th now if you count the 2 tubes in the Binocular monitor .

I had a think about the way to go forward and since this tube is very familiar to me now i have an idea of its range and need to see how the Transformer works with the power supply circuit i just finished for a test .
I am being very careful since its all exposed for this test also safety switch fused , mind set on the job ..

DSCN6589.JPG


I have taken the transformer out of the case for now for testing on the experimental DC supply circuit ,i have to do this any way to solder wires to it so a good opportunity to test it with the circuit .
Below is your multiplier Steve used on an older monitor showing those results not this one !

oie_akIq1SaXseuT (1).gif
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Below the transformer so grateful you worked out and drew up for me Steve making all this so much easier with out this i would not known enough about the transformers correct windings and i am pretty sure i would of not used it .


Harry's Tube Display 2-Model.gif
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The only thing different to my dc supply to the schematic above is the transformer windings used and positive supply is a voltage doubler and i am just testing hv positive and hv negative on their own for now to see if possible to use both as is on this transformer .

I wanted to see the DC results with using different windings .

Using the Positive HV circuit voltage doubler the 2 10uf caps in4007s top right circuit above
Results
130v 30mA ..........DC result +374 V
200v 30mA...........DC result +581 v

Now trying the HV negative

130v 30mA..........Dc result -370 v
200v 30mA..........Dc result -580 v

Now hook the above AC supply in series 130 + 220 ...Dc result -941V

Next 130v 30mA + 200 30mA + 200 50mA in series DC result - 1500 V

Well using the above windings for the 3bp1's negative supply is enough thinking of hooking it up as below
Attachments
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Last edited by Harry Dalek on Thu Oct 28, 2021 10:42 am, 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 Mongrel

Postby Harry Dalek » Thu Sep 02, 2021 3:38 pm

The problem of mounting the valves in the case has had me head scratching for a while ,but i will go with this idea easy to remove and work on circuits sections ,all the valves fit so on .
I will have to work from behind the board but all the circuits can be removed at once or in the 4 matrix board sections makes it so much easier to work on it than mounting the valve's into metal case and having to work on the circuits with the case upside down i didn't like that idea .

NEXT PHANTASTRON OSCILLATOR
http://www.vk6fh.com/vk6fh/phantastron.htm

I was thinking a good way to finally be able to construct this is to start off with the The phantastron and get the horizontal and vertical time bases going .

Chris longs 72 monitor time bases are pretty much closer to what wanted to go with i was going to try with the 6x9 Tube but its a 10 pin tube not sure i have a socket handy , be easier using the smaller 9 pin 6bX6 .
s-l1600.jpg


As for the rest of the circuits i am not sure i will go with them i don't under stand the 2 deflection amplifiers part and the sync part bit confusing to me sure it works just i don't understand it .
Attachments
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phan007 (1).png
phan005.png
Last edited by Harry Dalek on Fri Sep 24, 2021 7:52 am, 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 Mongrel PHANTASTRON OSCILLATOR

Postby Harry Dalek » Fri Sep 03, 2021 6:09 pm

I finished building the 2 Phantastron time base oscillators to the testing stage just have to ad the the power supply to it ,i think it will be another day or two before i can hook the power up need to double check the wiring and have a bit of time to do this .
Had to get use to wiring valves as neat as i could like it or not a bit of air wiring .
Rather exciting stage now seeing if nothing explodes :wink:
DSCN6601.JPG


Hopefully the ramps will output here

DSCN6606.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 Mongrel

Postby Harry Dalek » Sun Sep 05, 2021 9:18 am

Well a quick hook up this morning has showed the Phantastron circuits work one shown is at 13 hz ,so this is pleasing! so far no problems.

Working with some unmarked Valve spares that seem to be the same devices so gave them a go first and they seem to be correct . Next i will check what frequency range both oscillators can work at .if correct i will move on to the deflection amplifiers for X Y CRT plates .
Attachments
DSCN6610.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 Mongrel

Postby Harry Dalek » Sun Sep 05, 2021 2:18 pm

If this is going standard NBTV i am pretty close to running the time base standard 32 line 12.5 /400 hz here slightly off on both ,may notice i have added a pot and a 102 cap replacing the 2.2uf i had wired in .

The first time base with a 104 timing cap ran the oscillator close to Horizontal and changing the other time base with a 103 cap i can run it 200 to 1khz

i have noticed swapping the valves the slight difference knocks the frequency touch off either .

Ran the circuits for some time and every thing seems fine some thing now to work with to feed the future deflection amplifiers i will build next week .

Oh well give it a rest today and study what i will work on after that .
Attachments
DSCN6612.JPG
DSCN6615.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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Harry Dalek
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Re: The Mongrel

Postby Steve Anderson » Sun Sep 05, 2021 3:14 pm

Excellent results Harry! More linear than I expected. No wonder it was called 'Phantaston'. I've not made one myself...

You will see differences between tubes/valves, that's down to amount of use previously, age, production batch and manufacturer. No different to semi's to a large degree. In certain cases even more so, and for semi's throw in temperature too.

Rather than moving on to deflection (which you can be sure will work), I'd tackle syncing/triggering next, it's the next unknown...

Steve A.
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Re: The Mongrel

Postby Harry Dalek » Sun Sep 05, 2021 6:03 pm

Steve Anderson wrote:Excellent results Harry! More linear than I expected. No wonder it was called 'Phantaston'. I've not made one myself...
r

Thanks Steve rather exciting seeing the waveform appear as the Valve's powers up one of those things you don't know you got it right till you hook the power up .

You will see differences between tubes/valves, that's down to amount of use previously, age, production batch and manufacturer. No different to semi's to a large degree. In certain cases even more so, and for semi's throw in temperature too.


Yes not really good to swap valves around after wanted results as they will be a touch off ,i would think to sync these oscillators they need to be running bit under wanted running frequency .

Rather than moving on to deflection (which you can be sure will work), I'd tackle syncing/triggering next, it's the next unknown...

Steve A.


Well my thinking here is if i work on that i pretty much have to work on the front end the amplifier first it would be great to be able to use normal or invent circuit for the video this would come in handy and i want it added , i like your 3 design go's on this ,one below .

6SL7 Inverter 3 (1).gif
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Next amplifier and or syc sep looking at Jean-luc's design looks like i can swap the pentode for one i have handy ,suppressor grid 3 is not mentioned in the circuit few ways to tackle that one ,still haven't made my mind up on this part of the design but jean luc's is a good example to try .

SYNC SEPARATION.JPG
SYNC SEPARATION.JPG (34.11 KiB) Viewed 2116 times


Then to Syncing the Phantaston time bases ,as always one circuit at a time and see what happens ...I rather like Valves apart from all the hardware that go's along with being able to use them they tend to work first go for me any way .
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 Mongrel

Postby Harry Dalek » Sat Sep 11, 2021 9:59 pm

Working on the video normal and invert circuit below one of Steve's but he used a different tube so expected results not perfect part change's may be needed a lower gain tube perhaps first to see .
I can see the plate voltage should be 250v for the 6SL7 the 12AX7 and meter test shows 299 300v so spot on really for maximum any way so i think the problem is here too should be 100 to 250v .
I am using or trying a 12ax7 for the first test well i am finding it is working but results wavy .
I will show a video below.
So am thinking more gain problem in the circuit speculating.

6SL7 Inverter 3 (1) (1).gif
6SL7 Inverter 3 (1) (1).gif (4.48 KiB) Viewed 1971 times


I found this on the gain 12AX7 equivalents
12AX7 equivalents
The 12AX7, 12AT7, and 12AU7 all belong to the same family of nine contact, twin triode tubes. In many cases, these tubes are interchangeable and can easily be swapped. We will take a look at why you might, or might not, want to swap out these different types of tubes.

The 12AX7
The 12AX7 is by far the best-known preamp tube among guitar players. It has a gain output of 100, making it perfect for the preamp stage of an amplifier, allowing it to drive the power section harder, and enabling it to reach high levels of overdrive and distortion. The 12AX7 is used in many audio preamps and in guitar effects pedals, and comes in many different versions and brands. The 5751 is a common military-grade substitute for the 12AX7, with a lower gain output of 70.

The 12AT7
The 12AT7 is another very well-known tube among guitar players. It has a much lower gain output at 60, but what you lose in gain you get back with more headroom, higher fidelity, and an increased current output. Because of their high fidelity, they are also used in many tube microphone preamps, compressors, recording equipment, and organs. Due to the higher current, you sometimes see them driving effects such as tube-driven spring reverb in many guitar amps. Like the 12AX7, the 12AT7 has many different variations of this model created with certain specifications in mind, such as low noise or a more “rugged” sound. The 5965 is a common version of the 12AT7 that has a lower output gain of 47.

The 12AU7
The 12AU7 has the lowest gain of these three, with an amplification factor of 20. This is used much less as a preamp tube and more often as a driver for spring reverb. The 12AU7 is also used quite often in the “phase inverter” position of the amplifier, because of the high fidelity and great headroom that it provides. The 12AU7 is featured in many hi-fi audio systems and recording equipment; the current from the tube is enough to drive a pair of headphones or a guitar speaker. Because of this, it is used in many different headphone amps, several small one-tube guitar amplifiers, and in many home hobby projects. Similarly to the 12AT7, the 12AU7 is also heavily used in all stages of organs, and has many different kinds of variations.

As you look at each tube, you might notice that as the amount of gain decreases, the amount of current increases. As the gain decreases, the amount of headroom increases, and fidelity is improved. Noise is also reduced with lower gain tubes.

You can usually swap out 12AX7 tubes with 12AT7 tubes if you want a cleaner guitar tone with more headroom, and don’t mind a drop in volume. This might be helpful for a jazz guitar player, and could also be helpful for using keyboards, vocals, and any other instrument with a lot of high frequencies that you don’t want distorted. The 12AU7 makes a less ideal swap for the 12AX7, because other factors such as bias come into play, and the mismatch can cause the tube to sound unpredictable and very quiet. You may need to look into your guitar wiring to get the proper resistance load necessary to use a 12AU7 in place of a 12AX7.


Took a video of the invert connection of the switch increasing the video signal to the circuit ..

DSCN6617.JPG

DSCN6619.JPG

So need to fix this to move on ,i will do some ore tests tomorrow ,i have built also the video amplifier and sync separator but have not tested them yet ran out of time today .
Found this circuit similar to Steve's might be an easy fix
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DSCN6618_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 Mongrel

Postby Harry Dalek » Sun Sep 12, 2021 10:55 am

Increasing the triode's plate resistor resistance has improved results i am happy with this i will adjust circuit and move on.
Attachments
6SL7 Inverter 3 (1) (1).gif
6SL7 Inverter 3 (1) (1).gif (4.48 KiB) Viewed 1955 times
DSCN6628.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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Harry Dalek
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Re: The Mongrel

Postby Harry Dalek » Sun Sep 12, 2021 2:09 pm

I spent a bit of time before i started constructing this choosing the circuits so i have now Tested Steve's video inverter this works and Jean-luc's design of the video amplifier and sync separator tested so to syncing the line Phantastron ramp oscillator .

I have already shown the now 12AX7 inverter which its the front end of the coming monitor ,the next circuit is Jean-luc's video amplifier but with half a 12Ax7 and a EF80 or 6BX6 i have noticed the 6bx6 is a smaller vacuum tube but the larger has the same marking number The EF80 is closer to what i am using .
addtext_com_MjI0NDQxMzgwNzI.jpg


Next i have also used Jean-luc's sync separator with again valve change another EF80

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Sync separator line output
DSCN6632.JPG


Results look like hooking the line sync separator output to the Phantastron line ramp oscillator its syncing i think ! the line frequency is off a touch on the scope meter but stable the signal is bit large for the scope might be effecting the frequency display ? any case need to double check results when i have time.
DSCN6639.JPG


Next i need to check the framing side and move on to the deflection amplifiers .
Attachments
DSCN6636.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 Mongrel Pentodes connected as Triodes

Postby Harry Dalek » Tue Sep 14, 2021 11:20 pm

bit off topic but something i was wondering about and seems so.
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ETF06TS.pdf
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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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Harry Dalek
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