Hello all, I finally wrangled the set back into working order with many adventures and this Pt2 covers that process.
There must be other examples of this RTVH inspired design lurking about that could be brought back to life by patching in a set top box as I have. Alternatively why not have a go at rolling your own?

The set top box takes care of a lot of the front end tech stuff and all you are wrangling is fairly straightforward linear low frequency stuff.

The power transformer is no stopper as you could use a standard 100w radio unit as I did in the first build back in 1967, you only need 6 volts for the valves and 250 to 350 volt HT and a Jaycar transformer for the 6 volt CRT.

All the other components are radio types and we have a couple of suppliers in this site for the electros and poly caps or a trip to Jaycar.
I'll bet many of you have a 3" or 5" CRT lying there doing nothing except looking pretty, why not light it up and see a blurry picture?

Come on guys and gals even a lack of workshop equipment should not be stopper, I started out building and selling guitar amps equipped only with a pistol drill a hacksaw a hammer, a multimeter the lounge room table and lots of enthusiasm. For metal work you could even bolt a couple of radio chassis together to get the required 12 or so valve holes and a couple of transformers for the juice! Bunnings, our members and ebay can supply the rest.

My set is not perfect and needs more sorting to make it better, just a matter of logically identifying the problems and applying fixes.

I'll send a picture of the set and a PDF for Brad to attach to this.

Cheers, Fred.

5 inch TV from a CRO

Hello Fred,
The picture reminds me of that old TV show in the 50s called the Outer Limits. I'm sure you remember the show and even the set looks like its off the the same show, It was a good old show with some strange stories.
pete

Hi Pete, I've been away for a couple of days just catching up.........yes the "outer limits" was that the one that showed the TV set at the beginning and the audio went 'we control the horizontal, we control the vertical' and took over your TV, and your brain, for the rest of the show? Or was that the other sci-fi show...... I forget the name.

Re the TV set "cabinet" , you particularly must just laugh at some of my antics "building" cabinets where I just glue and nail bits of bent Bunnings wood together and spray a thick coat of colour or gloss over it like a dodgy car repair! Shows you how far I can get by just plain ignorance and hitting things with a hammer

Have been following your help and instructions to the guy with the real cabinet problems and reckon you could write a reasonable pamphlet or tutorial on cabinet maintenance and restoration. I'm mighty impressed by the practicality and actually am learning and understanding about woods and finishes just by reading your advice notes.

Cheers, Fred.

Hello Fred,
Yeah thats the show " we are in control of your Television set ! Do not adjust the vertical!

Well , I dont know who is in control now days but there is nothing on!

I read your posts Fred I can tell you are very knowledgeable with electronics.
Im not , but I learn bits here on VR
I do have a love timbers and veneers and a background in furniture restoring.
I might write a post on a finish everybody can do with no tools! and can be done in Gloss or satin or flat. Very easily
In a traditional oil finish.

Im glad I have been a help to you regarding finishes. Veneer is a beautiful thing to work on and its good for the soul. I enjoy in more now than when I started years ago.


Pete

Fred, I LOVE it!

If you ever feel inclined to have a rotary channel change knob, I have the bits to make this happen. We'd need to find a suitable rotary switch with the desired number of positions and poles to encode 4 wires as binary. I have some little boards that can be easily programmed to read the switch and generate the necessary IR signals to get the STB to change channels. It's only a slight change to what this board was designed to do.

Hi Ian now that is a thought! I'll run the ideas past the design team (um.... left brain?)
I like some Brunel way like a rotary switch driving a clicka clicka poking thing at the UP button or some big car radio push button thingy poking away at all 4 of them.
Or even a coding thingy! The remote does work OK with I guess a generic code so that's a goer if all else fails.

When I'm well again (more sudden heart problems) I can get back into the workshop and work on projects, i'm grounded at the moment and will do some coin articles all sit down stuff.for the moment.

Cheers, Fred.

Hang in there Fred.

There's no such thing as a "generic" IR code, they are all different, for obvious reasons when you think about it, although there are about 20 common formats. Each product as a rule has a unique address so a remote for one device does not operate other devices that may be within range. This means there are maybe 50000 different sets of IR codes out there.....
I may have your box in the library, if not, we can just sample the remote. The library and the software to do this is available for free on our website:

http://commbox.com.au/joeytools/

These boards I have are obsolete stock that were used in our earlier DVC network set top boxes. They have an 8 bit uC and some EEPROM memory. They are very flexible, you program them with a simple point-and-click macro language. The software that does this is an old 16 bit Borland C++ application, you need a 32 bit Windows box to run it.

It would take me about half an hour to create the application to read the switch and send the three IR button presses (and not do it again unless the switch is changed of course.) And all this is free to you, I'd just like to see it work!

The firmware in a Joey works in a similar way to that in the Hills nurse-call system in use where I work. Ian's right about the number of codes out there for remote controls. Samsung is one of few brands where the remote from their first set will work on their latest one, bar any extra features. Most brands stupidly change their codes every few model lifecycles and because of this I need to keep around ten different sets of codes on the nurse-call system so that when a television is replaced I can upload the correct ones to the bedhead panel in the patient's room. There's no less than four sets of codes just for the Hisense brand.

We had Joeys at the school I last worked at and I can't say I was too disappointed when lightning struck one of the patch cabinets and cooked half of them. End of an era in about a second. By that stage the school was getting ready to remove all the televisions from the classrooms as video projectors interfaced with electronic whiteboards were being rolled out.

One of the tricky things is getting these systems to issue several codes in succession, to make the television change its A/V source, for example.

Yes Brad I doubt there'd be many schools that don't have some of our stuff in them, we've been doing it for over 50 years.

When we first sampled IR remotes it was with a CP/M machine. Before the IBM PC and DOS.

Basically the trick with IR macros is to test it first with the device's native remote. You can implement pauses and, in some of our environments, conditional statements and more sophisticated stuff.

It's possible your nurse call system is using some of our stuff to control the TVs. We made a lot of Hospital TV interfaces a few years back.

Yes you are right about the major brands tending to be backward-compatible and the lesser-known brands changing all over the place. The thing we have noticed with Chinese-sourced brands is they don't register their manufacturer address and frequently just set it to zero. So you can get a TV and a DVD player for example responding to each others remotes in unpredictable ways.

The thing we have noticed with Chinese-sourced brands is they don't register their manufacturer address and frequently just set it to zero

Probably copied from who knows who?

Back in the CRT days it was a bit easier. Nurse call vendors such as Inteltec/4C and Sedco would simply hard wire their bedhead panels to the contacts on the pushbuttons on the front of the set via an RJ45 connector mounted on the back of the set. CH up, CH down, VOL up, VOL down, PWR, COMMON and mono sound took up the eight available connections. The upside was simplicity. The downside was that if the telly flamed out during the warranty period, the nurse call vendor took the hit for it because they had to open the sets to modify them. Because of this they don't like opening the tellies anymore though that provides the customer with an advantage too - I can buy the tellies from the Good Guys at half the price that the nurse call vendor sells them for and it's the same set.

It'd be great if all the manufacturers treated remote codes like trailer connections on cars. There's been a few different types of plug/socket arrangements over the years but if you buy a new car and a new trailer now, both will come with the flat seven pin version and this will apply if the car is a Hyundai Excel or a Mercedes S Class. Each telly manufacturer does have some buttons on their remotes that are unique to the features offered on that set but they could easily standardise the basics - Channel, Volume, Power and Source. Source is important because private hospitals offer Foxtel channels as well. Whilst the FTA channels are just taken off-air these days, rather than going via modulators on the MATV system, the Foxtel black boxes still tend to occupy analogue channels created by a rack of modulators. Upgrading to digital is easy enough but certainly not cheap. Prices for a large hospital are in the order of tens of thousands, rather than thousands, making the business case hard to justify.

GTC
The thing we have noticed with Chinese-sourced brands is they don't register their manufacturer address and frequently just set it to zero

Probably copied from who knows who?

Hahaha,, Completely Agree!!
Pete

There have been a few attempts to standardise device interconnections and/or control over the years. Some that come to mind:

SCART
PJ-Link
CEC

I guess in a way we built a business out of the lack of success of these efforts....

The widely used and copied NEC protocol was introduced precisely to avoid this kind of problem. Setting the manufacturer address to zero is just plain lazy, or perhaps they are being pig-headed because it's Japanese.

It's quite easy as a manufacturer to obtain a unique manufacturer address. There are 65 thousand odd available. And 65 thousand odd possible unique commands for each manufacturer address depending on how you use the error checking function.

IR control sounds simple and in many ways it is but it is in fact a very large subject...........!

Actually we have drifted from the subject in hand!

I looked at sourcing a suitable rotary switch and found they are very expensive. Cheapest and easiest solution was a 1cm square binary encoder switch. This would work but it's hardly the "Clunk! Clunk!" type of thing you want.

Idea!!

I do have a sad-looking Philips NT3001 tuner that came with a parts set that I'll never use. We could wire the RF side biscuits to encode 4 bit binary and even leave the valves in (heaters only) for effect. So it just becomes a clunky rotary switch.

I think this would fit..........

Thanks for all the thoughts, mulling a problem around is never a waste of effort you never know where that can take you.

I'll be back in hospital today, my heart will not settle down and run correctly so may need a good zap or a pacer to force the issue.

Ian, I nearly put the PCB assembly into an enclosure with a couple of valves poking out the top for fun!

Once I get over this heart thing i'll try some of the mechanical ideas.

Fred