Basic Query regarding Australian TV standard

[Penny Lopez]

Hi all!

I've had great fun reading through the forum and investigating the Aurora (would never have found it if it weren't for your "sticky" thread!)

My vintage television is already capable of resolving an image from current analog broadcasts via it's antenna. I want customise a setup where this vintage B/W tube is the 'monitor' for a free-to-air set top digital receiver (and whatever peripherals I plug into that), once the analog tap is turned off.

Since I'm not sure which standards Australian TV used in the 60s, My question is this: Do I need a standards convertor? I'm beginning to suspect not. I just need someone cluey to whip up a Coax or Phono "IN" for me, right? At present this television has absolutely no input ports for anything at all, and the antenna is simply attatched to the back via two metal prongs with screw caps. Is creating an input hard?

Your wisdom and thoughts on this little project would be appreciated If I get it going, I will definitely be on the look out for more so-called 'obsolete' televisions, a colour 405-line model would be great and more challenging!

Yours,
Pen

[jjl]

Hello Pen

I believe that Australia has always used a 625 line TV system with 5.5MHz sound carrier. This is why your vintage set works with current analogue broadcasts.

You don't need a standards convertor such as an Aurora to allow your old set to be used with current Australian standard definition set top boxes or what have you.

What you need is an RF modulator that will convert baseband video and audio to the desired RF signal, you then would then connect the RF output to the antenna connections on your old TV.

You could use an old VCR as your modulator if you can find one that provides a composite video and audio inputs. In Europe such things are easy to find as we have the SCART socket where such signals are accessible.

Please note that this scheme won't allow you to show HD video on your old set.

Hope this helps.


John

[cmjones01]

I don't know about the Australian market, but there are plenty of digital boxes in the UK which have modulators built in, so they'll work with an aerial-only TV straight away. I've got two here in regular use: an ancient Philips OnDigital box and a Humax F2-Fox T.

Chris

[Penny Lopez]

Thank you for confirming my suspicions!

The problem is, there is no antenna input on this television at all. Just two spring-loaded pegs which you can clamp wire to.
The set is preset to various channels and so I guess I will need an RF Modulator aligned to work with one of those channels (1, say.)

Any more tips would be appreciated! and thanks again.


Penny

[Michael Maurice]

Your antenna might be a 300 ohm balanced input rather than a coax plug.

Though I've never been to Australia, I'm sure that there must be some way of tuning in the various channels.

[Synchrodyne]

As I recall, 1960s New Zealand TV receivers had only 300 ohm balanced antenna inputs, and I suspect that the same was true in Australia. What is needed here is a simple balun (readily available for a few dollars from Dick Smith and similar outlets) that will accept a 75 ohm coaxial input (Belling & Lee type seems to be the norm here in Australia, although the F-type is not unknown) and connect directly to the pair of 300 phm screw terminals. Thus any converting device, VCR, etc, with a 75 ohm RF output on one of the VHF channels may be connected. Probably many such RF outputs are UHF, but at least in the past VHF types were available. I haven't yet looked at the available digital-to-analogue set-top converters available in Australia, as I am postponing the change as long as possible. But one with an RF output on a VHF channel would be needed to work with a 1960s VHF-only receiver.

In respect of television transmision standards, Australia used the CCIR/Gerber 625-line system (later named as CCIR System B) from the start, albeit with a unique VHF channel set and with different receiver IFs as compared with European practice. PAL colour was added circa 1975, and much later, Zweiton stereo sound.

Cheers,

[Penny Lopez]

Excellent people, I thank you. I am familiar with baluns. I don't know why that didn't occur to me earlier.


DVD -----> Phono input/coax converter -------> balun -----> TV



Cool! I'm getting a guy who loves tinkering with valve radios etc to just give a look at the telly, see if he can fix up the V-hold which starts to roll a bit too frequently... and a bit of a clean up inside. Otherwise, it all works fine.

Can't wait

[cheerfulcharlie]

The simple 300 ohm connecting tags was probably because VHF traveled so well in comparison to UHF. When the UK had VHF in a few cases a bit of wire and a coat hanger was all you needed to pick up a good signal.

But obviously your dealing with an old set now so keep your fingers away from anything metal when its on - just in case - there is a grumpy old capacitor or something in there ready to growl and bite you

[AidanLunn]

Originally Posted by jjl

Hello Pen

I believe that Australia has always used a 625 line TV system with 5.5MHz sound carrier. This is why your vintage set works with current analogue broadcasts.

You don't need a standards convertor such as an Aurora to allow your old set to be used with current Australian standard definition set top boxes or what have you.

What you need is an RF modulator that will convert baseband video and audio to the desired RF signal, you then would then connect the RF output to the antenna connections on your old TV.

You could use an old VCR as your modulator if you can find one that provides a composite video and audio inputs. In Europe such things are easy to find as we have the SCART socket where such signals are accessible.

Please note that this scheme won't allow you to show HD video on your old set.

Hope this helps.


John

Please note also, that there are some set top boxes with in-built RF modulators.