Scart/AV questions

Darby OGill

I'm still a bit confused about what's happening with the various options and what some of the terms mean. I have the digibox connected to the tv on AV1, with scart ON and RGB selected (AV1 is the rgb enabled input). I have the TV aerial signal connected through RF in, as usual.

Some questions, and all help appreciated.....

1. When I press SKY, I understand that I am automatically watching the satellite input from the digibox through AV1, with RGB signal. Is this correct?

2. If this is correct, what is happening when I press AV1 on the TV remote after doing the above? The picture is still the sat. channel, but the sound is significanly louder. Why is this?

3. If I press TV after 1 above, the digibox channel remains on (with slight change in picture- left-jump). Where is this input coming from? Is it PAL or Rgb?

4. If I press TV, and then choose a TV (non-satellite) channel, I am still watching through the AV1 connection, but I am watching PAL pictures. Is this correct?

5. What is S-video on AV2?

Sorry if these are unclear or stupid questions.

slave1

what make is your tv
have you the sky box looped through a vcr and do you have the vcr hooked up to a possible 2nd av input on your tv

watty

1) Assuming that in Setup:
SCART ON
RGB ON
ALSO
if the Sky remote is properly set up for your TV..
(press TV then 3 on Sky remote
Press Sky on Sky remote.
You should have Ch3 then Sky, unplug aerial on TV, you should still have Sky)


2) Dunno, unless the Sky remote is NOT correctly set for your model of TV set (There is a way to change what command is sent to TV when Sky button is pressed).

The Digbox BOTH sends TV AV command and asserts 6V (ws) or 12V(4:3) when pressing Sky, and ALSO enables 12V on RGB out pin of SCART too.

3) Press TV should switch off the RGB voltage pin to 0V. The AV1 then works by composite PAL, which will result in a slight sideways jump due to luminance delay line to match composite PAL to RGB processing delay. (or somesuch). In RGB mode the composite pin of SCART is the H/V composite sync instead of picture.

4) If you press TV and then 1, 2 ,3 4 etc, then you ought to be watch via aerial. Unplug it at TV set. NOT the AV1 connection. It ONLY has either the Satellite or possibly whatever is plugged into the Digibox VCR SCART connector if it is on and playing (VHS or DVD). AV1 would NEVER have the TV Channels, if your Sky remote is programmed to change TV channel when TV is pressed, which would be normal if correct TV model is programmed in the Sky Remote.

5) S-Video is a type of composite where the Black & White part (luminance or Y) is on one pin and the Coloured part (Chroma or UV) is on a separate pin. The advantage is that on NTSC, pAL and Secam the colour signal is normally overlapping the B&W signal on the Analog RF signal or on a single wire.

The TV or VHS thus can't perfectly separate them. This means solid strong colour is interpreted also as a fine pattern and fine B&W patterns generate false colour. S-Video solves this.

A TV has to take the NTSC, PAL or SECAM colour signal and decode it to raw U and V components (These are mathematically B&W - Red and B&W - Blue). The B&W or Y signal is then mixed as
aprrox (I might have the u and v wrong also a fraction is used)
U + Y = Blue
V + Y = Red
Y -(U+V) = Green
To get RGB to drive the screen.

A VHS can't record fine detail, so can't record the NTSC, PAL or SECAM either (the frequency is too high). So the VHS records the B&W part (all VTRs originally B&W) and seperately Shifts the 3.579MHz NTSC or 4.43 MHz PAL/SECAM to about 800KHz (=0.8MHz) and records it "under" the frequency used for the Video. The video is recorded via an FM carrier of about 4MHz for VHS and 5MHz for SVHS (Can't remember the exact figures).

This is why some VHS can record and play PAL or SECAM as long as the TV understands it. Also why on playback on PAL VHS an NTSC VHS tape can easily produce a "faked" PAL signal for a PAL TV. True NTSC playback needs an NTSC TV!

So it was realised that if a connector with the Y and UV (B&W and Colour) was used between VHS and TV with B&W on one wire and the Colour on the other, only one stage of separation and mixing would be needed, not two.

The MPEG signal on DVD and DVB does not uses PAL, NTSC or SECAM or composite as such, but digital B&W samples (Y) and less samples for colour (UV) hence 422 for professional Digital recording.

Some Grundig Digboxes can do Y+ UV out on S-Video connection.

S-Video can use a miniDIN plug with 4 or 6 pins or an extra UV pin on SCART (The Y uses the Composite PIN).

Component Video is Y, U and V on 3 RCA connectors, it is just the same quality as RGB. The USA never really used SCART so dson't have RGB in very often, S-Video and Component are more common.

S-Video (as long as the source is digital) is a BIG improvement on Composite, and only a miniscule bit worse than RGB and Component.

There is no effective difference in quality between RGB and Component. All display technologies use RGB. So although the Digital transmission is YUV component it is going to be changed to RGB someplace.

S-Video
Even an ordinary VHS would give a better playback to TV via S-Video, but usually only SVHS have s-Video in/out.

Again if the Digibox had s-video (no VHS records RGB) a VHS or s-VHS would record a higher quality picture as the colour and B&W parts would be separte if you used S-Video to playback into TV.

You can buy a RGB to S-Video convertor. Then an S-VHS recording of Sky1 or ITV played via S-Video to TV will be better than Tivo by far, but not quite as good as Sky+


There is no point whatsoever in a Composite to S-Video adapter plug other than pluging Composite into something with only s-Video in. A TV set or VHS will separate the Y and the UV better than any adaptor plug.

Some TV sets have Digital Comb filter DSP and do a huge improvement of reduction of patterning on solid colour and colouring of fine patterns. These work differenty and have different "benefit " for NTSC, PAL or SECAM composite.


When we talk of PAL or NTSC DVD or DVB, we don't really mean the colour system as used by Composite or S-Video at all.
PAL DVD/DVB = 576 lines by various resloutions
NTSC DVD/DVB = 480 lines
(NTSC refers to the Pre Colour US and Colour US 525 lines systems). Europe had 450, 625 anfd 819 lines.

525 lines = 480 picture lines
625 = 576 picture lines

Darby OGill

slave1- tv is a Mitsubishi (11 years old). VCR is connected, but has died and is not used (will switch on but keeps going back to stand-by immediately- display stays on. Also Mits. and same age).

Watty, thanks- I'm studying your reply! How do you remember all this stuff?

donhughberto

I have a bush 28" widescreen and my sky remote doesn't work at all with the tv, just the minibox so i have to use two remotes and i hate it, annoying!

ShaneOC

Two remotes...

Ah, to only have two remotes.

1 Sky+
1 Sky (Regular)
1 Amp
1 Video
1 DVD

:rolleyes: :rolleyes: :rolleyes:

Greenman

Two remotes...

1 Amp
1 Video
1 Humax Sat RX
1 $ky
1 DVD
1 Positioner
1 Wife's Tv

watty

I realy do have NINE in the Living room
TV, Sky, DVD, HiFi, PC Sat, AnalogSat1, Analogsat2, PCD player, S_VHS.

But the project to have One device to rule them all is well advanced. (The PC based version works, needs tranferred to PIC micro base station).

But there are NOT three hidden ones and a bunch of destroyed ones (well the workshop has 2 desmembered and two in use plus the ones for all the archived analog receivers. I have one NTL Digital remote but never had NTL )

Owenw

If you're looking for the Ruling Remote of Power and have a deepish pocket, might I suggest the Philips range of Pronto remotes?

These are fully customisable touchscreen learning remotes (they look like PDA's) which not only let you control all your AV gear but can also be used with X10 home automation.

Prices range from less than £100 to about a grand(!) for the latest full colour screen model (due for European release in 2004).

www.remotecentral.com is the best site on the web for all things remote based. www.letsautomate.com sells a few of these remotes and other home automation gear.

watty

Yes I know about such stuff. Also a neat customisable program for Palm Pilot (works out a lot cheaper).

Our idea is a basic NON-programmable remote. (light, small, good battery life, not complicated)

A basestation with illuminated 2 line text LCD. It has slots for card to dim lights etc. Connect to RS232 (set timer recordings from PC etc).

Also solves problem of gear that:
* Needs no user so can go in ventilated cupboard with no glass door
* stuff that reacts to same controller.

The base uinit has sockets for IR Leds and in programming you can specify which IR LeD to operate. Equipemtn can be in cupboard or have a plastic sucker over its IR Rx window with LED in it etc. Or whatever.

A panel of backlit lables on base unit shows which device is active to be controlled by remote. Two keys scroll up/down this list.

For "learning" you point the new remote and the normally controlling remote both at the base unit. You can also download defintions from PC.


A PC simulation works (It has a virtual remote handset on screen, workin picture of base unit (with buttons and displays) and actually works with real remotes and equipment via a small home-brew board connected to serial port HandShake pins. This was written and debugged by my eldest son for his Final Year project (It got full marks due to mix of research, design, simulation, examination of market potential and that on the final review day he used a real photo CD player remote via the PC SW to control a Satellite receiver, VHS, TV and camcorder.)

I have HW for PIC based base station working with working routines for LCD, keypad, IR Receiver, IR Transmitter, NVRAM r/w etc. I have "translated" a VB6 simulation from PC to PIC micro once before (fairly easy). I just can't fine the time right now to finish it!

parsi

Originally posted by ShaneOC
Two remotes...

Ah, to only have two remotes.

1 Sky+
1 Sky (Regular)
1 Amp
1 Video
1 DVD

:rolleyes: :rolleyes: :rolleyes:

1 Sky,
1 Analogue Sat,
1 remote for power socket for analogue sat box (it doesn't have an actual power switch)
1 Tv,
1 DVD,
1 Stereo,
1 Home Cinema,
1 Video
1 multi-function which does a lot of the above badly..
1 Drawer for them all.

Capt'n Midnight

Not to mention one of those keychain beepers - so when you loose the remote you just Whistle. (Though I know several people who are deaf in one ear - and setting off beepers is just cruel to them)

Yeah the main trick is to put the branded remotes away - so they can't get broken - use only to retune the stations etc. Still the SKY remotes are good for d'ol TV - and many TV's will switch over when the Scard is activated...

slave1

remotes
sitting room
1X Sky
1X TV
1X DVD
1X VCR
1X AV Amp
1X CD player
livingroom/kitchen
1X Sky
1X TV
1X DVD
1X VCR
1X Midi HI Fi
Bedroom
1X Sky
1X TV
1X DVD
1X VCR
1X Amp
1X CD player
1X Minidisc
1X Tape deck
1X Tuner

I cant understand these universal remotes, I think remotes are things of beauty, the more the merrier