Tektronix 145 Pal Gen Lock test generator: What is it and what is inside?

[TheUnnamedNewbie]

There is a local guy that is selling a Tektronix 145 Pal gen Lock test generator. For the price he is asking I'm thinking of getting it just to see what is inside and if there are any usefull components I can harvest (seems to have a lot of BNCs that are 50 ohm, rather to my suprise. Would have expected everything to be 75 ohms).

Anyone have any clue what this thing actually does or what I will find inside? I can't seem to find much information on the net.

[iainwhite]

My guess would be that it generates PAL signal test patterns for Television sets

[ogden]

You can see what's inside w/o buying it (loads of metal-can opamps or transistors):

https://produto.mercadolivre.com.br/MLB-709641140-tektronix-145-m-generator-signal-pal-m-gen-lock-test-_JM

[vk6zgo]

"Gen lock" is so that you can switch sources without the receiving device losing syncs momentarily due to the two source syncs being out of phase.
This was used a lot in the days before frame stores, & was still important for inline devices such as the Tek 145, well after that time.

Analogue TV used "50 Ohm" sockets with a 75 Ohm system because they were cheap, plentiful & durable, whilst not causing any appreciable mismatch at low HF frequencies like 5MHz.

With the advent of "digital video", Studios racks were rewired with "true 75 Ohm" sockets.

[Alex Eisenhut]

Can I harvest those little gray caps on the ends of the levers?
These commonly fall off from vintage Tek stuff.