The Mongrel

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The Mongrel

Postby Harry Dalek » Sun Aug 08, 2021 8:59 pm

I have been thinking about the idea for some time having a few ic transistor CRT Monitors under my belt the all valve semiconductor free job is something i have never tried and don't try it never happens ! and got to learn some thing new or old in this case !
Yep not even in the power supply no cheating :wink:
Have to case the idea up choose the CRT from my stocks ,valves and such i have laying around from 40 years of collecting so always have some thing cut costs down pretty much just need solder and i have that as well
The circuits i will pretty much use most from Jean-luc's design from a few years back apart from power supply and modulation ,have to look at the time bases as they use Thyratrons might not have those so will work that out and depending on what CRT i use.
http://www.taswegian.com/NBTV/forum/viewtopic.php?t=971
So still putting the idea together in my head but starting today was listing the Valves i have about 60 i couldn't see any marking letters numbers but a lot could just be a duplicate of valve of others i have ....the ones i could make out and those were just as many and have some others just laying around as well i will have to dig them out .
only need a few for monitor so i am sure some thing here will work in the various circuits.
Some of the old Valves were hard to read even using the blowing on mist on trick list below
GAL5 Pentode
6AV8
6v4 Full-Wave Vacuum Rectifier
6Av6 duplex triode diode
6BQ7A
BE8F..or B
6BX6 have 3 with markings
6AL5 have 2
6AQ5 Beam Power Tube Power/Output pentode
6BE6 type: Pentagrid-Converter (Heptode) Pentagrid (new) Controlling (mu
5y3GT have 2 Full-Wave Vacuum Rectifier
6GM5 pentode
6SN7 GTA dual triode
6GG7 or 66G7
6AU4 Damper, booster, flyback diode
6FL2 low power beam tetrode
6AU6 have 2 pentode
6X4 have 3 Full-Wave Vacuum Rectifier
6CB6 have 2 Pentode beam power RF/IF-Stage.
6CM5 have 2 pentode audio
KT66 tetrode
CRC-6G6-G power amplifier pentode
6V6 GT/Gbeam-power tetrode
6AR7-GTDuo Diode, medium cut-off RF Pentode
64Q5
12BY7 pentode but the construction is as a beam tetrode.
5AS4 Full-Wave Vacuum Rectifier
6BU8 also on valve 6HS8 Double Pentode
6BM8 Audio Dual Package, Triode
BCF80 Foreign
3B4 Instantaneous heating beam power amplifier intended for use as oscillator or frequency multiplier in VHF battery-operated transmitting sets. Up to 100MHz full rating pentode
6AU2
KT66 beam tetrode tube
6DQ6A television line output pentode
6u8 Triode-Pentode
6BA6 pentode
6cB6
6SN7 GTA dual triode
6BL8 Triode-Pentode audio
? 6A6
6ES 2 or 3
12AT7 twin triode Audio
8CB6A
6U4GB
1S?
8KU8
5U4GB Full-Wave Vacuum Rectifier
6?K6
1s5 Diode-Pentode Audio Frequency
6BL8 medium-mu triode
6N3 dual triode audio
N78
6N8 Double Diode-Pentode
6BY7 RF pentode
6Bx6 RF pentode
1s2 Half-Wave Vacuum Rectifier
6D76 have 2
6CM5/EL36 Pentode Power/Output
6HG5-6AQ5 Beam Power Tube Power/Output pentode
6M5 Pentode Power/Output
6AL8 pentode triode RF
6GW6 Beam Power Tube pentode
6DX8 Triode-Pentode
6BL8 Triode-Pentode,
6N8 Double Diode-Pentode,
12AU7A Double Triode Universal
LXB2?
1B3GT Half-Wave Vacuum Rectifier
6VC6-87
6BX6 RF pentode
5U4G-B rectifier 100watts
6BM8 High Performance Audio Dual Package, Triode and Pentode
6BQ8 Double Triode RF
?6W8
BE8F have 2
6N3 dual triode audio to RF
6BV7 Double Diode-Pentode Power/Output
6X4 indirectly heated full wave rectifier
3B4 RF pentode
6BL8 have 2 TRIODE + PENTODE Audio
12AX7 dual-triode audio
68Y6
Attachments
IMG_0881.JPG
IMG_0881.JPG (125.71 KiB) Viewed 2372 times
Last edited by Harry Dalek on Sun Aug 15, 2021 7:04 pm, edited 9 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 semiconductor free NBTV monitor

Postby Harry Dalek » Mon Aug 09, 2021 10:48 am

Studying the circuits below can the Thyratron's be replaced by normal valves in this circuit ?
The 6k7 seems fine to replace but i am not sure about the gas filled triode's
Attachments
VERTICAL TIME BASE.JPG
HORISONTAL TIME BASE.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 semiconductor free NBTV monitor

Postby Harry Dalek » Mon Aug 09, 2021 12:50 pm

Also found today
6x9 3 of those Triode-Pentode rf
6es8 Twin Triode
6au6 pentode rf
6es8 Double Triode RF
6bx7 Medium-mu twin triode; vertical deflection amplifier.
6v4 2 of those Full-Wave Vacuum Rectifier
6y9 2 of those Double Pentode
6au6 pentode rf
6cw5 2 of those
ecc88 VHF double triode
6al5 Double Diode Detector
6cq8 Triode-Tetrode

and a few others no markings
Last edited by Harry Dalek on Wed Aug 11, 2021 9:21 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 semiconductor free NBTV monitor

Postby Steve Anderson » Mon Aug 09, 2021 2:29 pm

Harry Dalek wrote:Studying the circuits below can the Thyratron's be replaced by normal valves in this circuit ?

Sorry, no. They do need to be gas-filled Thyratrons. I do have a book somewhere devoted solely to valve/tube timebases, not only Thyratrons, but normal (hard) tubes as well. If not too big I'll post it up later...

Steve A.

Later...Hmm, too large, nearly 40MB. I'll think on it...a quick review and really it's quite theoretical, no actual 'build this' examples...I'll keep looking...
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Re: The semiconductor free NBTV monitor

Postby Harry Dalek » Mon Aug 09, 2021 3:03 pm

Steve Anderson wrote:[
Sorry, no. They do need to be gas-filled Thyratrons. I do have a book somewhere devoted solely to valve/tube timebases, not only Thyratrons, but normal (hard) tubes as well. If not too big I'll post it up later...

Steve A.

Later...Hmm, too large, nearly 40MB. I'll think on it...


Finding out the Triodes are Thyratrons makes its a touch harder than just copying and i don't think i have any shocking for me .

There's always plan B or C or D :wink:

Thanks for trying to upload the book ,i am about to look in the old Newsletters just see what's been done before ,at the moment its research what i have handy what i can substitute how it can be built safely.
So just gathering ideas below is a 525 line to scope schematic ,i don't like the no transformer idea but the time base could adapted looking at that part ..see whats in the news letters .
Attachments
tvscope11.gif
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 semiconductor free NBTV monitor

Postby Steve Anderson » Mon Aug 09, 2021 5:13 pm

Harry Dalek wrote:...! don't like the no transformer idea but the time base could adapted looking at that part...

What's called a 'hot chassis' in the UK, though a very old term. I suggest no-one follows anything vaguely similar, it's simply unlawful these days due to safety concerns, DON'T DO IT!

Parts of the circuit could be adapted though it is designed for oscilloscope use. The B+ voltage was probably quite low being half-wave rectified from 110/120V, around 150V maybe...it's not an unreasonable starting point though...the 12AT7=ECC81. From the value of the 1K/0.5W dropper/filter resistor the HT current is under 22mA. So only a small transformer that can also support the heaters is required. This would require a change of the 12AU6 to a 6AU6, though there are ways to get around this quite easily...

Steve A.
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Re: The semiconductor free NBTV monitor

Postby Harry Dalek » Mon Aug 09, 2021 5:37 pm

Steve Anderson wrote:
Harry Dalek wrote:...! don't like the no transformer idea but the time base could adapted looking at that part...

What's called a 'hot chassis' in the UK, though a very old term. I suggest no-one follows anything vaguely similar, it's simply unlawful these days due to safety concerns, DON'T DO IT!

Parts of the circuit could be adapted though it is designed for oscilloscope use. The B+ voltage was probably quite low being half-wave rectified from 110/120V, around 150V maybe...it's not an unreasonable starting point though...the 12AT7=ECC81.

Steve A.


I can see its a way of doing away with a Transformer but i am sure a few tv repair men never made it home working on Televisions with this idea .

I found this idea the first is Sawtooth time bases for NBTV pentodes but not mentioned the type !
Screen 00000.jpg
Screen 00000.jpg (43.05 KiB) Viewed 2340 times


I suppose the ramp could just go to one deflection plate ,i liked your idea of the deflection amplifier but i want it all Valve this time is it possible to replace the 2n2222 with Triodes ?
32 Line 'Club Standard' 3.gif
32 Line 'Club Standard' 3.gif (12.05 KiB) Viewed 2340 times


Chris long has a Flying spot monitor can't see the valve types for he's deflection side once again not mentioned

So a little bit here to look into ,Still also thinking about the CRT to use i think ii have a DG7-32 one might be nice to use it here as some thing different .
Attachments
Screen 00001.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 semiconductor free NBTV monitor

Postby Steve Anderson » Mon Aug 09, 2021 6:13 pm

I have no idea what is being done in the first cct., an error I think...mainly around V5 and its heater...so dump that...

My own version, the transistors could be simply replaced with resistors, though to a somewhat higher negative voltage, not as linear, but probably good enough, say around -150V. The 1k's (Rxxx) would become 68k or 82k (1W) as a guess. Your power supply is becoming more complex...sure you want to continue? Especially if you don't want to use semiconductors in that too...

As for the last circuit...it's such a mess I'm not going to bother with it...guys, learn how to draw, it's not that hard! Even at a quick glance there are errors...

Steve A.

The DG7-32 is a comparatively modern low-voltage CRT, if you're really serious in continuing with this, that's probably the CRT I'd select.

Of more concern to me would be the sync ccts, the video to the grid/cathode (these are going to be the biggest headaches) and the general size/weight/bulk and hidden expenses of this...but knowing you Harry, you'll manage it...it's something I wouldn't leap at, but good luck...though given the supplies and resources available in the late 50s, I might be tempted...but not today...there unfortunately isn't such a thing as a PNP valve/tube...
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Re: The semiconductor free NBTV monitor

Postby Harry Dalek » Mon Aug 09, 2021 7:22 pm

Steve Anderson wrote:I have no idea what is being done in the first cct., an error I think...mainly around V5 and its heater...so dump that...


I think that was another NBTV Scope not very detailed your eyes here are better than mine seeing faults in the schematic listen i will .

My own version, the transistors could be simply replaced with resistors, though to a somewhat higher negative voltage, not as linear, but probably good enough, say around -150V. The 1k's (Rxxx) would become 68k or 82k (1W) as a guess. Your power supply is becoming more complex...sure you want to continue? Especially if you don't want to use semiconductors in that too...


OK that sounds good for a start for the deflection amplifier side .
I know that one was a work in progress but hell i will build it ,the power supply i sort of enjoy tinkering with as i used to be so bad at it so a few voltages needed is ok just a problem to work out i am ok with the above suggestion .

As for the last circuit...it's such a mess I'm not going to bother with it...guys, learn how to draw, it's not that hard!

Steve A.


It was a very old one pre PC days circuit drawing days , i suppose people just did draw schematic's to their style their way not to standard procedures .

The DG7-32 is a comparatively modern low-voltage CRT, if you're really serious in continuing with this, that's probably the CRT I'd select.

Of more concern to me would be the sync ccts, the video to the grid/cathode and the general size/weight/bulk and hidden expenses of this...but knowing you Harry, you'll manage it...it's something I wouldn't leap at, but good luck...


If it wasn't for the fact i have just about all this laying around i for sure would have second thoughts .
i do not intend to spend any thing apart from use what i have CRT transformers sockets switches caps resistors so on all handy .
The last monitor would of made a nice valve monitor due to its size but that was more see if i could get that CRT working it has a life of its own when it did .
All the problems mentioned you sort of have to tackle one at a time i have no idea how it will look at the end as far as all the circuits together but your deflection amplifier is a start sounds good to me looks familiar as well .
The sawtooth timebase is still some thing to feed it perhaps i should have a look at some scope valve time bases over the years ,well the Beast i just used passive modulation on th control grid with a little transformer very simple .
Yep the DG7 sounds good to me nice short tube lower voltage .
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 semiconductor free NBTV monitor

Postby Steve Anderson » Mon Aug 09, 2021 7:44 pm

Right, now, assuming you've decided to go with the DG7-32 the next hurdle is a suitable power transformer, something from an old radio as a start, 250-0-250V and a 6.3V winding. You'll need to add more to this in the PSU, but the HV bit is the most important. Current, if it's plundered from an old valve/tube radio, more than enough. alternatively as I have done in the past, use two transformers back-to-back. Look at old radiograms, old tape recorders[1}, record players, even jukeboxes[2}, anything with tubes/valves in it. Old TVs, though unless of historical value, rip 'em apart...

[1] Though plundering them I find a bit (more than a bit) upsetting...I have a 'thing' about tape recorders...
[2] Though probably worth a lot more if properly restored.

Really, anything from the late 50's until the demise of tubes/valves is of no real value, or even historical value, though there are exceptions...

Steve A.

Go for the things that are hard and/or expensive to get today, tubes/valves, their bases/sockets, transformers, both power and audio output. Hi-voltage non-electrolytic capacitors. Otherwise, with few exceptions the rest can be junked...
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Re: The semiconductor free NBTV monitor

Postby Harry Dalek » Mon Aug 09, 2021 8:54 pm

Steve Anderson wrote:Right, now, assuming you've decided to go with the DG7-32 the next hurdle is a suitable power transformer, something from an old radio as a start, 250-0-250V and a 6.3V winding. You'll need to add more to this in the PSU, but the HV bit is the most important. Current, if it's plundered from an old valve/tube radio, more than enough. alternatively as I have done in the past, use two transformers back-to-back. Look at old radiograms, old tape recorders[1}, record players, even jukeboxes[2}, anything with tubes/valves in it. Old TVs, though unless of historical value, rip 'em apart...


Well Yes the DG7 new old stock from the look of it thanks to Andrew once again so be good to make use of it now ,any case its been on my to do list .

Well the Ac supply knowing me will come from from an old case broken Radio no great loss . and do have a AC bench supply for testing handy .
[1] Though plundering them I find a bit (more than a bit) upsetting...I have a 'thing' about tape recorders...
[2] Though probably worth a lot more if properly restored.


I have 2 or 3 of those as well i will leave those be ; ) I have yet to really test them out another to do one day .

Really, anything from the late 50's until the demise of tubes/valves is of no real value, though there are exceptions...

Steve A.
[/quote]

Radios and such i like in the wooden cases metal never really liked bakelite rather make a monitor out of them if they are not perfect .

I think as always it would be good to case the CRT the rest sort of follows this again i will see what is laying around , a longer case seems to have always worked for the magnetic field problem ,i will look into this tomorrow ,i have i think a Mu metal shield just see if it fits the neck of the DG7.
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 semiconductor free NBTV monitor

Postby Steve Anderson » Mon Aug 09, 2021 9:31 pm

Harry Dalek wrote:..I think I have a Mu metal shield just see if it fits the neck of the DG7.

I get around that problem by separating the required transformers into a box placed some distance away from the CRTs, then having an umbilical to the display itself. Not that elegant, but when you can't get the stuff (Mu-metal) there's not much of an alternative. The transformer box on the floor, the display itself a metre or more away on a two metre multicore cable, or individuals to get what you need...it solves a problem...when needs must...

Plus if you're clever the same 'transformer box' can be used for more than one display device...plug and play...

Steve A.
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Re: The semiconductor free NBTV monitor

Postby Harry Dalek » Mon Aug 09, 2021 11:32 pm

Steve Anderson wrote:
Harry Dalek wrote:..I think I have a Mu metal shield just see if it fits the neck of the DG7.

I get around that problem by separating the required transformers into a box placed some distance away from the CRTs, then having an umbilical to the display itself. Not that elegant, but when you can't get the stuff (Mu-metal) there's not much of an alternative. The transformer box on the floor, the display itself a metre or more away on a two metre multicore cable, or individuals to get what you need...it solves a problem...when needs must...

Plus if you're clever the same 'transformer box' can be used for more than one display device...plug and play...

Steve A.


Yes i have that idea already Steve plug multi pin HV socket in for a monitor and Banana sockets for testing stuff bench HV AC power supply from the 3Bp1 Anderson days and Deep image SSTV and the devil monitor which all use the same Ac supply .
I don't think i will use a compact case i have some thing the right size looking today so the Transformer is placed to one corner which has worked the last 2 or 3 times tried .
Its really only a problem for compact casing the L type case the long one like this I______I similar to your Bute build and my Beast size wise should work again .
I also enjoy the room to work with cases like this and will be needed for Valve monitor circuits
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 semiconductor free NBTV monitor

Postby Steve Anderson » Tue Aug 10, 2021 2:00 pm

I forgot to mention...toroidal transformers, an almost non-existent external magnetic field, better regulation and generally smaller per watt. But you're most unlikely to find them in domestic gear so it would mean purchasing new...unfortunately they're a bit more expensive than the standard E-I lamination versions...

Steve A.

One advantage though, you can add an additional winding over the existing ones, say 6.3V for valve/tube heaters...once you've measured the turns-per-volt. Though you can only take that so far...

toroidal-transformer-500x500.jpg
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Re: The semiconductor free NBTV monitor

Postby Harry Dalek » Tue Aug 10, 2021 2:31 pm

Bit productive today got the DG 7 out of its box and the mu metal shield fits it like a glove .

DSCN6495.JPG

DSCN6493.JPG


Next i also looked into the case i can play around here room wise depending if i mount the Valves the old way or try it on a circuit board either way they are not the easiest things neatest things to wire up ,but i was not expecting the case to be so valve friendly in the traditional way drill a hole for the socket way and have room under to wire it up might be telling me go with the flow !
DSCN6508.JPG


Next it was find the HV transformer cleaned it up and put a bit of vanish on it again might last another 70 or so years ,all i know it worked before i removed it from the radio .
DSCN6512.JPG


So that's where i am at at the moment next step is mount the CRT and transformer and a bit of catch 22 i sort of have to mount the valve sockets but i need to know what i am using in the circuits i suppose a case of do the power supply and every time i have to drill a hole for a new circuit valve take them out and put them back .
Oh well does not have to be done in a day so plenty of time to think at it
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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