My new scope

[Steve Anderson]

Here's a fairly common example of the use of hybrid circuits used in the 60s for scopes. In this case it's being used a decade into the 21st Century. This is the deflection amplifiers for the 3" CRT monitor currently under construction here as mentioned in Karens' 625-NBTV thread.

The tubes are two ECC91s (6J6s) twin triodes, perfect to develop the 125v p/p (or thereabouts) for the CRT deflection plates. The semis are simple current sources feeding the cathodes of each differential pair.

The circuit and photo are attached, the empty area to the right is now occupied by the two ramp generators required...sadly sand-state.

The items in red are simply not set in stone yet and may change in the final version.

Steve A.

[Harry Dalek]

Hi Steve

Shocked all your nbtv monitors are no goers ! i have seen what you have posted they looked very well made boy we have no hope then!

Using tubes and transistors together is something i have never done ,i must have the mind set to use one or the other .

When i started off in electronics i used to make a fair few tube projects i don't also recall ever seeing or reading using both together ! looking some old 60's magazines tonight its again either one or the other mmmm

It looks good Steve ! you will have that new monitor up and running soon by the looks of it

BTW THE SCOPE i have been looking in old magazines there's many full page adds for those scopes in my Electronic Australias have not found my model but the 63 one is close 301 number so i'd say mines a 64 model
i see they use the year in the model number .

[Steve Anderson]

...Shocked all your nbtv monitors are no goers !

Not quite sure what you meant here, but if it's what I think it might be, no, they all worked. It's just their longevity is but a few days.

Put it this way, if the one under construction now is completed in the next day or so, it's doubtful it would live long enough to see this years convention.

However, as I mentioned, I'm gonna try and change my ways with this one...

Steve A.

[Harry Dalek]

I mean that your construction is better than what i seen any one do in making an electronic NBTV monitor ..if they have gone faulty what hope do we underlings have
Btw did you ever finish the brute ? you got pretty far on that one ..i saw you had done a tiny crt monitor had a great display .
Good luck on this one not that it wouldn't work but it lasts!
i will be watching for sure and thanks for posting the deflection schematic ,if i ever track down my valve collection (which box it was in when i moved house ) i will copy it .

[Steve Anderson]

..if they have gone faulty what hope do we underlings have
Btw did you ever finish the brute ? you got pretty far on that one ..i saw you had done a tiny crt monitor had a great display.

Harry, I don't think you quite grasped what I said elsewhere here, the displays worked fine, they didn't go faulty, well except the odd dry-joint and the like, otherwise they were in fine fettle until their demise...

....So I've had to build yet another! Since this forum started I perhaps have built five, I'm not sure, but once they get operational, documented, photographed and maybe published here or in the newsletter...they're doomed! No mercy.

If they see one hour of operational life I would be surprised. Their innards are plundered for parts, circuit boards consigned to the trash...and they don't even carry Donor Cards.

That is, I put them to death, they don't die of their own accord...I build them, play with them for maybe half-an-hour, then that's it. I'm bored, "NEXT!"

As for "The Brute", it never got finished, Again I got bored. When I returned from an overseas trip I realized that the thing was far too big to be of any practical use. The photo below I took in December last year, already the tubes and the CRTs had been stolen, two years of dust gathered, and I had to evict a family of Gekkos before tearing it apart. I saved the transformers and the tube sockets, that's about all.

Sad really.

Steve A.

[AncientBrit]

Look on the positive side Steve, your circuits are text book examples.

I'm always impressed by the presentation and design.

And a lot of them get archived by me for reference purposes.

Regards,

Graham

[Harry Dalek]

Hi Steve

I understand now ! you need to make one to keep .make this one a keeper !

Yes its hard not to reuse parts for other projects .... Yes lucky your not a Doctor you'd be in jail doing some one in !



RIP Brute looked such a nice build ,,,but i think the same these days need some thing not to big ...i need stuff to move around at times .

This sort of makes it more interesting to see what you come up with this time///

Would you make your new monitor a multi system 32 60 ?