YSTV's home-made Devices

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Revision as of 12:27, 2 January 2010 by Iain.cooke (talk | contribs) (→‎VT C-E switch: label and name)

http://old.ystv.co.uk/internal/docs/index.php?page=YSTVUserManuals

Links will be added slowly to YSTV's bodges. This page is only for the stations made-from-scratch, or heavily-altered equipment.

Currently I (Malcolm) am trying to fix new comms.

Composite to Scart

These are not quite as simple as they first appear. They send the composite video signal of up to four inputs to the correct pins of a corresponding Scart plug. Additionally they send 12 volts (from the DC input) to the appropriate pin of the Scart plug.

S-Video to Composite

S-video to composite pin and capacitor detail can be found here http://www.epanorama.net/circuits/svideo2cvideo.html

Three Composite along Cat-5

This was originally used at Woodstock 2007. It is a very convenient way of getting three camera video signals from approximately the same location to their common destination. It could also be used to send mono sound to the destination too.


Other Less Significant Devices:

Dirty Little Box

Dirty, in this case, because it's not very sophisticated. This will convert a 50Hz, interlaced RGB video signal (like the output of a Comodore / Acorn / BBC computer) to a composite video signal. It doesn't do any resolution changing or frame rate conversion, so if your input video isn't at the right rate (and most PC VGA cards won't do the right rate) then the output will go to pieces. As a result this isn't the most useful piece of kit in the station.

VGA DA

Does what it says on the tin - splits a VGA input signal into two identical copies to drive two monitors or projectors at full signal strength.

VGA to Composite Dongle

(Malcolm.chambers 03:31, 2 January 2010 (UTC)I don't think I've ever seen this)

A rather nasty widget that converts a VGA output from a PC (at any sensible low resolution) to composite and S-video outputs. It's powered from a USB plug (to get 5V), which can if necessary be put in another PC's USB port. It should be noted that as there is no USB data connection, the PC doesn't know that any power is being drawn from the port.

S-Vid switcher

A 4-to-1 or 1-to-4 passive switcher for S-video signals (although it can also be used on composite with the relevant adaptors). Being passive, it's not frame-synchronised, it just uses mechanical switches. Not clear whether the inputs are terminated when not selected or not. A-V switcher

S-Vid to Comp converter (and Comp to S-Vid)

A very nice active box for converting composite outputs into S-video, or S-video signals into composite. Avoids the signal loss and resolution loss associated with passive converters by actually extracting the relevant signals and sending them down the required cores, and actively combining the s-video signals to the composite output.

S-Vid DA

Splits an S-video input into three identical outputs. As well as the basic active splitting, also provides gain and HF boost controls for the chroma channel, to correct for colour loss on long cables. Can be used on composite video through the S-video luma channel as a 3-ouput DA (chroma channel is a bit oddly behaved).

VT C-E switch

(Malcolm.chambers 03:31, 2 January 2010 (UTC) I'm pretty sure this is the box which has a label "this now works as you'd expect [##/07/09]"" and merely selects which of the two inputs goes to the output. If so then it's not as simple as it looks as it has two resistors in, for termination I expect.)

(Iain.cooke 12:27, 2 January 2010 (UTC) This label referred to the switch position, which didn't match the inputs: switch left = right input and vice-versa. This was re-wired to make positional sense.)

A metal box with three BNC connectors and a switch in it. The switch picks either of the inputs to connect to the output. The unused input is supposed to be terminated, although this doesn't appear to work reliably. In the obvious sort of way, can also be used backwards. It is named the C-E switch as it was originally used to swap between VTC (Umatic) and VTE (VHS) due to a shortage of mux inputs.