A friend of mine passed this onto me in a clear-out, they had no idea of its actual intended use, perhaps someone out there in VRAT-land might know.
Observations:
It appears home brew and It states on the front TV line selector. It would appear to have a signal level meter much like an aerial installed might have used back in the day to assess your local reception level. An RF input socket at the rear which feeds into a Thorn ELC1043 tuner. There is also what appears to be a can from a VCR. Quite clearly there is a TX9 SAW/IF PC991 module employed.
To the front, a channel selector with the variable tuning connected up to a high end multi-turn Amphenol pot with analogue readout, which is also in-circuit with 3 additional Amphenol multi-turn pots to the rear. Mounted to the back of the mA meter is a PCB soldered across its terminals.
Switches on the front for AGC and AFC plus plus two selector banks (A) & (B) which would appear to suggest selecting lines, each having a BNC out for triggering to a scope. The main PCB has a whole raft of logic chips I assume to do with the line selection side of this. Finally on the front a video out BNC for monitor.
So what on earth would this have been used for and why would you wish to be able to interrogate lines and to what purpose, anyone? Someone clearly went to a lot of trouble. It needs some checking over before plugging in, after which I will connect it up to the museum signals rack and a scope to see what I get.
I would suggest that it was built for looking at ITS (Insertion Test Signals) on off-air feeds - or indeed, Teletext lines.
As you rightly say, someone went to a lot of trouble to make that.
Even now in HD land you check to see if the video starts on line 21 to make sure the video is correctly timed.
There was a design for a TV line selector in Television magazine, I can picture it in my head but can't remember the year but I think it was 1970s and I am pretty confident it's in the smaller magazines.
There was a design for a TV line selector in Television magazine, I can picture it in my head but can't remember the year but I think it was 1970s and I am pretty confident it's in the smaller magazines.
Is this the one?
Ah a delay timebase for examining VITS and Teletext lines, as usual @cathovisor was on the money.
This looks to be the basis of what I have before me but with some chaps further enhancements/mods. Back when scopes that could look at this level of detail were way too expensive.
Pretty obsolete now with our modern digital scopes, Oh well, mystery over, a curio for the museum shelf, a minor diversion, now back to my ITT 80-series TV repair.
My scope has a TV line selector that works very well.
Very useful when looking for video content related sync faults.
What's wrong with your ITT 80 Chris?
That's the one Frank, Looks like it appears in the larger style magazine so I got that wrong.There was a design for a TV line selector in Television magazine, I can picture it in my head but can't remember the year but I think it was 1970s and I am pretty confident it's in the smaller magazines.
Is this the one?
