405 to 625 Line

[Radio Tech]

Please can anyone tell me if there is such a converter to go from the signal that the auroa produces normally used to go straight into the coax socket of a 405 line TV to 625 line. Or is there a circuit diagram available to build a low power transmitter that will produce both sound and vision for 625 television by feeding in a 405 line sound and vision signal?

Best wishes

Ken

[Nicklyons2]

I'm baffled to know why? If you have an Aurora you presumably started with a 625 line signal and used the Aurora to convert it to 405. If you need a 625 line signal at UHF to feed into a relatively modern TV set surely all you need is a UHF modulator with composite video and audio in. Amongst others Maplin will be able to provide this.

[Dave Moll]

I would have thought that there was little point to converting the ouput of an Aurora from 405-line standard to 625-line, as that would simply be recreating the input fed to the Aurora.

If all you wish to do is what you describe in the second sentence, there are many devices around that include a 625-line modulator to convert baseline video/audio to a UHF signal suitable to feed into a television set's aerial socket. Alternatively, just use a television or monitor with video/audio input such as a SCART socket.

edit: Nicklyons2 posted while I was typing.

[G6Tanuki]

Truth is, each and every 'conversion' of frame-rate or resolution invariably involves a loss-of-image-quality.

So if you can stick with what the original source provides - it will always be the path-of-least-degradation.

Get the Aurora to provide a 625 signal!

[Brigham]

This must be in readiness for the new Alexandra Palace Television Society transmissions in Band I.

It would be easier to find a 405-line receiver, surely?

[Dave Moll]

For the sake of accuracy, I believe that the proposed transmissions will be by Heritage Broadcasting Ltd, rather than the APTS, although the latter is closely associated.

[winston_1]

Certainly the BBC has (maybe had) a 405 to 625 converter for playing old 405 videotape. But it was not small or cheap. There would be no market for an Aurora size one.

[Panrock]

A 405 to 625 converter would actually be quite useful for me. I have a large collection of old 405-line VHS recordings that were made in the '80s using an ex-Sutton Coldfield digital converter. It would be nice to incorporate these into my main system of today - the hard drive of a Panasonic HDD/DVD recorder and an Aurora.

In practice, all the re-pluggery involved means I hardly ever see the old VHS recordings. These sometimes exhibit mis-timed 625 dropout compensation that I tell myself is 'ignition interference'!

Didn't David Looser once build a 405 to 625 unit, or am I imagining it?

Steve

[Radio Tech]

Thanks everyone for the info, I did not know the auroa could provide a 625 line, but yes, I do have an old KBEV40 all but trouble with EHT output or the lack of and can not find out what the real trouble is, I even sent the transformer away but this did not solve the problem when I got it back, I am as it happens still looking for another 405 line TV (if I can get hold of one) and I am certain around here where I live there must be someone who has got one in the loft they don't know what to do with but it is finding them, I am going into Maplins and see if they can oblige with some device.

Best regards

Ken

[Brigham]

I'm getting more confused as we go along. What are we putting into the Aurora?