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Old 6th May 2018, 6:03 pm   #141
Heatercathodeshort
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Have you fitted the adjustable core inside the width coil? As PJL suggests, you now need a decent signal. John.
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Old 6th May 2018, 9:56 pm   #142
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

The problem now, with the signals side of things, is that you are facing way too many unknowns.

You have a TV with unknown faults
You have a home built modulator which is untested
Using a PC to convert to 405 is unlikely to yield the correct signal without a lot of experimentation.
You don't have a 'scope to check the 405 output from the PC to see if it's even close to what it should be.

Don't get me wrong, building your own modulator and using the PC is a great additional part of the project, but unless you can be sure that it's all working perfectly, you can hardly use it to fault find the TV!

All the best
Nick
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Old 7th May 2018, 12:37 pm   #143
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Hi John, yes the core has been fitted inside the coil.

Hi Nick, yes you're right I am very unprepared at the moment! I really should invest in a scope if I'm looking to get this project done and undergo any others in the future, I've had my eye on one for a while actually.

I was under the impression that I could just plug an old digibox into the composite connectors on the modulator and it would convert it into a 405 line RF signal. Is this not the case?

Peter
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Old 7th May 2018, 1:58 pm   #144
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Quote:
I was under the impression that I could just plug an old digibox into the composite connectors on the modulator and it would convert it into a 405 line RF signal. Is this not the case?
You can if it's a STANDARDS converter like the Aurora. A standards converter is a bit more than just a modulator as it provides correct sync pulses for line and field (frame) plus it also interpolates the incoming video from 625 down to 405 (all to do with timing, flyback and other important things). I admit to not fully understanding how standards converters work but I know the basics. Once all the conversion is done, the signal is then passed to the modulator which just converts the signal into RF and something the TV can work from. On it's own, the modulator will not convert a 625 baseband video signal (from a digibox) down to 405....it needs all the other conversion wizardry first.

You can use a PC with a suitable video card (and software of course) for converting to 405 and then connect your modulator to the converted output for the TV.

At the moment I think you have too many 'unknowns'!
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Old 7th May 2018, 2:05 pm   #145
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

No, that's not going to work -- the modulator will still need to be fed with a 405-line signal. The output of a digibox will be 625-line.

You will need to invest in an Aurora standards converter (just search this forum) or else have a computer with a suitable graphics card that can be programmed for random resolutions and timings. Windows now has support for mode lines, which have always been used by the display system of most Unix variants including Linux and BSD since forever to set the video timings. (Different Unix workstations could have monitors with different resolutions and scan rates.) If you have the right graphics card and the right software, you can enter a mode line that will produce a 405-line output. You will then need a small additional circuit (we're talking postage-stamp size piece of breadboard; one transistor and a handful of resistors) to create a composite signal from the separate HSYNC, VSYNC and video lines.

It's all just a forum search away .....
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Old 7th May 2018, 2:11 pm   #146
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

http://www.tech-retro.com/Aurora_Des...Converter.html

Here's the UK supplier:

https://www.crowthornetubes.co.uk/

Lawrence.
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Old 7th May 2018, 2:24 pm   #147
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

I bought mine from Crowthorne tubes via their EBay shop a few years ago. M

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Old 7th May 2018, 2:35 pm   #148
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Yes so did I and a very good investment it was as well!
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Old 7th May 2018, 4:16 pm   #149
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Yes well worth the money. What with built in test card C and switchable to all band I and band III frequencies as well as small size and simple operation I cannot fault it. I have the excellent Domino converter but this has been sidelined since I bought the Aurora converter.

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Old 7th May 2018, 5:31 pm   #150
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Fair enough, I'll order myself an Aurora converter, I'll just have to beg on my knees for some overtime for a while!

Peter
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Old 7th May 2018, 7:01 pm   #151
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

The beauty of the Aurora is that it will just work. In the absence of a video input it will generate a standard test card so once you've set the output channel to match your TV, all you do is power it up (you will need a separate power supply for it...9V at 1 amp will do).
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Old 7th May 2018, 8:09 pm   #152
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Hi, If you can cadge a very old VCR with a 405 recording that may provide a signal source, assuming it has a band 1 modulator

Ed
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Old 7th May 2018, 10:21 pm   #153
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Due to it's tiny size and low price, the Aurora implies that the job of converting 625 to 405 is trivial. It's only due to some amazing modern technology that this is possible.
Back in the late 1960's, it took a double wardrobe sized piece of equipment full of discrete components to do the job. It must have cost thousands and taken a team of people to develop.
25 years ago, when I re-discovered my interest in 405 TV's, an affordable standards converter was the holy grail. Various dedicated people came up with solutions using available technology at the time. Before cheap FPGA chips came along, it was a very hard job indeed!
So we should all worship at the feet of the Aurora and marvel at the amazing piece of kit that we have access to!

Using an old PC wasn't feasible 25 years ago: they just were not fast enough. It is now practical, however, if you have sufficient computer skills.

Peter, getting an Aurora will make getting your TV working correctly much more likely. Once it is working though, it would be good to continue to experiment with the PC conversion method and your home built modulator.

All the best
Nick
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Old 8th May 2018, 8:33 am   #154
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

You will not be disappointed with an Aurora, it is an excellent product.
Just connect it to your aerial socket and you will have test card 'C' and a test tone. Once you have a picture of sorts, the on screen results will allow you to see the faults and address them.

Once the set is working properly, just connect a DVD player or freeview box to the Aurora & enjoy!

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Old 11th May 2018, 1:48 pm   #155
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

I've received the Aurora today in one piece and I've just been reading the quick start guide and there's a few things I've flagged up. Firstly it says I need a 75 Ohm coaxial cable. I have some cable of the good quality brown type but I'm not sure about measuring the impedance. Secondly it says a transformer should be used if the chassis is connected to one of the AC lines, which mine is, any particular transformer?

Peter
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Old 11th May 2018, 5:04 pm   #156
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

The brown coax is fine although you may want to find something a little more flexible in a premade length for everyday testing.
Personally never used a transformer with any of my sets, certainly its fine on any Ekco sets providing you make sure the mains two pin plug is always inserted the correct way around, I tend to mark the plug indicating the live pin, with the same on the chassis.
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Old 11th May 2018, 7:47 pm   #157
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

A live chassis set of course will have (should have) its aerial socket isolated to the outside world, so its worth checking any isolating capacitors are in order and any other insulation is as the manufacturer intended, for example the way the aerial socket is mounted on paxolin away from the chassis. You never know with old stuff whether someone less informed has been messing.

The aurora will generally be isolated (floating) to earth any how but i did once have a batch of wall-warts from CPC which had the 0V secondary connected to the mains earth; they were intended as laptop supplies though it wasn't stated as such.
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Old 11th May 2018, 8:08 pm   #158
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Thanks for the advice thus far I now have a signal on the screen although I can't get it to fill the screen horizontally. The focus control is not doing much and the picture width coil, although working doesn't make much of a difference.

Peter
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Old 11th May 2018, 8:48 pm   #159
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Hi Peter,
The line timebase is running at half the correct frequency, hence two pictures side by side.
Onece you get it running at the right speed the EHT and width will be in the right ball park. The fault will be in the line oscillator.

Cheers
Andy
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Old 11th May 2018, 9:01 pm   #160
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Default Re: First TV Project - Ekco TCG316 - Any Advice Appreciated

Hi again Peter,
I also wanted to encourage you at this stage. This is a great result for a first picture

Cheers
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