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CTV [Sticky] 1974 20" Ferguson 3C03; Thorn 4000 ; Super Rare

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crustytv
(@crustytv)
Illustrious Member Admin
Topic starter
 
Posted by: @irob2345

Your board brings back memories!

It ain't pretty but it will work.

Hopefully it will only prove to be a temporary measure, until I can fathom how to produce a decent PCB via my newly acquired CNC. It's getting more tricky on the last remaining hook-ups, having to raise the wires slight above now.

20211218 125352
 
Posted : 18/12/2021 10:11 am
Red_to_Black, Nuvistor, Till Eulenspiegel and 9 people reacted
PYE625
(@pye625)
Illustrious Member
 

I think that is a brilliant effort and it deserves to work.

The good thing is that it is not especially high frequency, thus prototype layout should not matter too much.

 
Posted : 18/12/2021 6:53 pm
crustytv
(@crustytv)
Illustrious Member Admin
Topic starter
 

Sorry for the lack of progress updates, I'm still working on the CNC trace pattern, but I knew that was going to be a steep learning curve and a long process. John finally had success with the etching, and produced a good board, this was due to be with me before Christmas. Unfortunately, and I'm sure John won't mind me saying, he etched it the wrong way around. So looks like I'm still forging ahead for now with my Franken-Hardwired-Vertical board. I'm on the home stretch, with only about 10-paths left to install, then the output pair.

20211222 105150
20211222 110246
20211222 154626
20211222 154638
 
Posted : 22/12/2021 10:57 am
Red_to_Black, Nuvistor, Red_to_Black and 3 people reacted
Cathovisor
(@cathovisor)
Illustrious Member
 
Posted by: @crustytv

Unfortunately, and I'm sure John won't mind me saying, he etched it the wrong way around.

Ah, let he who has not etched a doppelganger cast the first stone...!

 
Posted : 22/12/2021 11:28 am
Red_to_Black, freya, Doz and 9 people reacted
Jayceebee
(@jayceebee)
Noble Member
 
Posted by: @cathovisor
Posted by: @crustytv

Unfortunately, and I'm sure John won't mind me saying, he etched it the wrong way around.

Ah, let he who has not etched a doppelganger cast the first stone...!

And it was very nearly perfect😭😭. Anyway I now have produced one not quite as good but will be perfectly usable and with an added touch I think you will like. I will get it to you as soon as I can as unfortunately I am run off my feet at work ATM. You may hear a clink in your letterbox at some ungodly hour😀

 
Posted : 22/12/2021 4:03 pm
crustytv
(@crustytv)
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Topic starter
 
Posted by: @jayceebee

You may hear a clink in your letterbox at some ungodly hour

Aww..... Surely the chimney. 😉 

 

“Twas the night before Christmas, when all through the house
Not a creature was stirring, not even a mouse.
The stockings were hung by the chimney with care,
In hopes that St Jayceebee soon would be there.”

 
Posted : 22/12/2021 4:26 pm
freya, freya and freya reacted
Jayceebee
(@jayceebee)
Noble Member
 

Ho ho ho! 🎅 

 
Posted : 23/12/2021 7:53 am
crustytv
(@crustytv)
Illustrious Member Admin
Topic starter
 

I've finally finished wiring up my Franken-Vertical-Deflection replica. I did check, and double check as I went, but still found the odd mistake. Now the long, laborious task of checking it all again.

fin1
fin4
fin5

What I also plan to do is build John's board up over Christmas, assuming it arrives, that is. I have all the components required, and can share the coil/2-in plug between the two boards. I will also add the official Thorn thick films, to John's board, and then set about installing. Having the two gives me the best of both worlds, should mine turn out to be an unmitigated disaster.

After all that, I will sort out the problems on the HMV line timebase, i.e., missing Thick film, and disconnected EHT regulator transistor. Power up of one of them will then ensue.

 
Posted : 23/12/2021 12:21 pm
Red_to_Black, Lloyd, Till Eulenspiegel and 15 people reacted
Cathovisor
(@cathovisor)
Illustrious Member
 

Can't wait...!

 
Posted : 23/12/2021 1:19 pm
crustytv
(@crustytv)
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Topic starter
 
Posted by: @crustytv

“Twas the night before Christmas, when all through the house
Not a creature was stirring, not even a mouse.
The stockings were hung by the chimney with care,
In hopes that St Jayceebee soon would be there.”

The delivery of all etch attempts were dropped off by John, many thanks John. The surprise on the final etch was a silk screen, it looks very good in the vertical frame, nice work John.

The final etch as John mentioned has some faults, no trace continuity on a few, and a bridge. The open tracks were easily fixed with my PCB repair kit and the bridge cut away.

The first board etch had not taken too well, but I had an idea for that, and it's now another usable board, with full continuity on all traces. A perfectly usable board now, even if It's not pretty, it's nowhere near as ugly as my hard-wired jobby.

All the boards I now have, including franken-board.

etcdmod
etch4

The First board etch that did not take well, amazingly the very fine traces had continuity, but most others did not. This was fixed with wire and tinning the copper. It  now reminds me of some early PCBs I've seen in old BW TV's.

etch1
etch1a

Next, The Ooops Board 😉 

Shame it was the wrong way around as it was with doubt the best etch.

etch2

Now the etch with the silk screen, the faults indicated, and rectified. This will be populating over the Christmas hols.

etch3a4
etch3a6
etch3a5
etch3a2
etch3a3
etch5

I may even have a CNC version soon, fingers crossed.

 

 
Posted : 24/12/2021 10:39 pm
malcscott, colourmaster, Red_to_Black and 15 people reacted
crustytv
(@crustytv)
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Topic starter
 

4K Vertical Deflection PCB replication.

With just a few hours left of 2021. Well, it's all but done, all I'm waiting for is a .68R 5W resistor to arrive. I do have a .68R 7W cement, but I'm not happy with how it looks. So I ordered an axial one identical to the original, but it's not arrived yet.

I abandoned the hard-wired effort I had been working on, there seemed little point in continuing with it after John delivered me his etched boards. Over the holiday, I've slowly populated it with components, and fitted original NOS thorn parts where possible, even down to the Thick-Films TF401, TF402 & TF403.

My heart-felt thanks to Jim for providing the all important original Thorn mounting frame/heat-sink, coil & 2-pin plug, without these the task would have been extremely difficult. Also, to John for spending the time when he was extremely busy at work, etching multiple boards. Finally, a big thank you, to Mr anonymous who must have been following the thread on the forum, and contacted me via my website, to sell me a whole raft of thick films.

20211231 211705
20211231 214644
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20211231 214747

As the main vertical board has now been supplied and a spare, I see no point in trying to replicate it on the CNC. My efforts with that device will now be switched to manufacturing Thick films. These being the Achilles heel of the 4K are more than likely going to fail, being able to replicate with more reliable modern components is going to be essential.

Again, in this endeavour John has come up trumps for me, producing everything for TF402 in Kicad. This was chosen as it was the simplest for John to tackle. This evening, I received the Kicad project files, which includes all the gerber files and drill files. Now I have to get this into the CNC and produce the Gcode necessary for production.

This is going to be a fairly mammoth task in its own right, as the 4k has 22 of the blighters. I'm not sure how many will actually need fabrication, certainly TF401, TF402 and TF303 appear to be troublesome, there may be others.

proj1
proj2
proj3
proj4
4ktfs
 
Posted : 31/12/2021 10:23 pm
Red_to_Black, WayneD, Lloyd and 9 people reacted
Jayceebee
(@jayceebee)
Noble Member
 

My pleasure, doing this has spurred me on to get into the real nuts and bolts of Kicad. It's not quite a year ago since I took the first steps and it's been a steep learning curve, It was to design a new PSU PCB and send it to one of the fab house such as PCBway. It was for one of my A823s. One of PSU boards is very heat damaged and I wanted to add slow start so I could get rid of the thyristor input varistor, also to add a series regulator for the LT rather than the massive zener. I still think I've only scratched the surface so far and not yet mastered how to make correct footprints for the original circular Pressac connectors.

BTW the components are on the same side as your matrix board TFs, C1 and R8 may need some judicious bending so as not to interfere with ones on the main PCB 

I'll tackle TF401 next, if you could let me know the pitch of the capacitors please.

 
Posted : 01/01/2022 2:44 pm
crustytv
(@crustytv)
Illustrious Member Admin
Topic starter
 
Posted by: @jayceebee

I'll tackle TF401 next, if you could let me know the pitch of the capacitors please.

C1 5mm
C2 10mm
C3 10mm
C4 5mm

 
Posted : 01/01/2022 4:55 pm
Doz
 Doz
(@doz)
Noble Member
 
Posted by: @crustytv

4K Vertical Deflection PCB replication.

With just a few hours left of 2021. Well, it's all but done, all I'm waiting for is a .68R 5W resistor to arrive. I do have a .68R 7W cement, but I'm not happy with how it looks. So I ordered an axial one identical to the original, but it's not arrived yet.

I abandoned the hard-wired effort I had been working on, there seemed little point in continuing with it after John delivered me his etched boards. Over the holiday, I've slowly populated it with components, and fitted original NOS thorn parts where possible, even down to the Thick-Films TF401, TF402 & TF403.

My heart-felt thanks to Jim for providing the all important original Thorn mounting frame/heat-sink, coil & 2-pin plug, without these the task would have been extremely difficult. Also, to John for spending the time when he was extremely busy at work, etching multiple boards. Finally, a big thank you, to Mr anonymous who must have been following the thread on the forum, and contacted me via my website, to sell me a whole raft of thick films.

20211231 211705
20211231 214644
20211231 214709
20211231 214726
20211231 214747

As the main vertical board has now been supplied and a spare, I see no point in trying to replicate it on the CNC. My efforts with that device will now be switched to manufacturing Thick films. These being the Achilles heel of the 4K are more than likely going to fail, being able to replicate with more reliable modern components is going to be essential.

Again, in this endeavour John has come up trumps for me, producing everything for TF402 in Kicad. This was chosen as it was the simplest for John to tackle. This evening, I received the Kicad project files, which includes all the gerber files and drill files. Now I have to get this into the CNC and produce the Gcode necessary for production.

This is going to be a fairly mammoth task in its own right, as the 4k has 22 of the blighters. I'm not sure how many will actually need fabrication, certainly TF401, TF402 and TF303 appear to be troublesome, there may be others.

proj1
proj2
proj3
proj4
4ktfs

In a side note: Kicad 5 users ... once you've upgraded to Kicad 6 (and sorted out the library cock-ups which the current installer seems to inflict) there's no going back to 5. It took me nearly 2 days to get a working kicad 6. I'd wait if I were you until it's a little more proven.

 
Posted : 03/01/2022 3:40 pm
Red_to_Black, crustytv, Red_to_Black and 3 people reacted
crustytv
(@crustytv)
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Topic starter
 

After waiting almost 3-weeks, Royal Fail yet again lose another order of mine, funny how Amazon consistently deliver next day, every day and have never lost an order. Am I angry with RM? Absolutely I am. 😡 

Anyway, the order they lost were some really nice OHMite .68R 5W resistors, these were to finish off the last part needed for the missing 4K vertical deflection replication. As these went AWOL, at the weekend I ordered some .68R 5W axial Cement ones. Not as pretty looking, but needs must, I awaited RM to lose these, hiding behind Covid as an excuse for their incompetence. Shock horror, they just arrived!

Duly installed, this now completes the Thorn 4000 Vertical Deflection replication. Phew!

vert1
vert2
vert3
vert4

Had I used larger caps for C408/C409, I think at first glance you might be hard-pressed to spot the difference. Next, in between manufacturing on the CNC, I'll replace the Orange electrolytics on the original.

 
Posted : 12/01/2022 12:57 pm
Nuvistor, Mikey66, Red_to_Black and 18 people reacted
Jayceebee
(@jayceebee)
Noble Member
 

Looks great, can't wait to see it perform.

 
Posted : 12/01/2022 9:43 pm
RichardFromMarple
(@richardfrommarple)
Reputable Member
 

Good work so far, I hope the effort is worth it.

 
Posted : 13/01/2022 10:10 pm
crustytv
(@crustytv)
Illustrious Member Admin
Topic starter
 

A little update; related to the replication of the vertical deflection module.

John @jayceebee is far too humble to post about this, however his recent efforts deserve to be showcased. We're all probably aware that John has been developing his KiCad skills, and will admit he is a 'Jedi Junior', though well on the path to being a 'Jedi Master'.

As some of you who have followed the Thorn 4K journeys, will know, Thorn released many modifications to the 4000 series, ultimately leading to the 4002. One of these many modifications, was to dispense with the 'Thick film' modules, TF401 & TF402, on the vertical deflection board.

Later versions of the vertical deflection had an addition 17 holes drilled on the PCB. My only original board does not have these holes, being an early version. The etched version john provided for the missing replicated that. However, Jim @jcdaze does have one of these new vertical deflection boards. Although the additional holes are present, they are not used as TF401/TF402 are present.

What are these new holes for? As I stated above, this was to accommodate a modification. Thorn, as a replacement for TF401 & TF402, produced a daughter board for the Vertical Deflection module. This daughter board was known as the PCA440.

As I've mentioned on numerous occasions, Thorn 4000 series in the UK as far as we knew were extinct. That was until Jim declared he had a 3C05 and now myself obtaining these two (HMV-2627/Fergy-3C03) 4k's. I think it's reasonably safe to say, neither of us have the PCA440.

Finally, I'm getting to the point, honest!

Unbeknown to me, John had been beavering away in the background and has replicated the PCA440. A fantastic effort and many thanks to John for his hard work. Initially, the plan is to get my two 4K's repaired to working order. I will then have one set (3C03) as a bog-standard 4K. The flagship model, the HMV 2627, will have the PCA440. John is also working on a replacement for his etched vertical board, and will be providing a replacement for that via his KiCad route, this will have the holes for the PCA440.

pca440
pca440cct
 
Posted : 16/07/2022 9:08 am
Red_to_Black, malcscott, WayneD and 12 people reacted
crustytv
(@crustytv)
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Topic starter
 

The replica vertical deflection is now installed in the 3C03, this photo clearly illustrates how the 4K chassis was reduced in size to squeeze into the 20" cabinet. The HMV chassis (right) is wider with more spacing each side of the vertical deflection. Also, the Hoz timebase and signals boards as a result are closer to the neck/CRT PCB. I wonder how this performs in these cramped conditions.

4kchas
 
Posted : 10/08/2022 5:06 pm
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