Sync issue with Master + Panasonic Viera TV

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LordVaderUK
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Sync issue with Master + Panasonic Viera TV

Post by LordVaderUK » Wed Mar 04, 2020 6:05 pm

Hi all

Getting to know my lovely new (old) Master. I'm trying to connect it to a (ridiculously large) Panasonic Viera TV. I bought the TV on Ebay (for a tenner!) because it has lots of input options, including SCART RGB.

However when connected to my BBC Master via a proper, decent DIN -> SCART cable the image appears but won't sync, it keeps whizzing from right to left (see video on link below). I can't see any settings on the TV menu which are relevant. And I have no idea what to look at on the Master either!

Can anyone suggest a fix? I can post specific details of the TV if that would help...

Video: https://www.dropbox.com/s/xpvmx5x0zg8ze ... a.mov?dl=0
Loving my BBC Master 128

Kazzie
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Re: Sync issue with Master + Panasonic Viera TV

Post by Kazzie » Wed Mar 04, 2020 6:53 pm

No instant solutions from me, but I noticed that the text was inching downward while it was whizzing across. So it's probably an issue with vertical sync as well as the horizontal. (The RGB socket outputs a composite sync, of course.)
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Re: Sync issue with Master + Panasonic Viera TV

Post by marcusjambler » Wed Mar 04, 2020 7:05 pm

Are you able to test the SCART input on the tv with something else?
A speccy +2 or amstrad say...

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Re: Sync issue with Master + Panasonic Viera TV

Post by LordVaderUK » Wed Mar 04, 2020 7:19 pm

marcusjambler wrote:
Wed Mar 04, 2020 7:05 pm
Are you able to test the SCART input on the tv with something else?
A speccy +2 or amstrad say...
Unfortunately my Master is my only bit of retro kit...
Loving my BBC Master 128

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Re: Sync issue with Master + Panasonic Viera TV

Post by marcusjambler » Wed Mar 04, 2020 7:27 pm

Try testing it on another tv because some modern ones just dont like old computer signal levels...
Have you tried the composite video?

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LordVaderUK
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Re: Sync issue with Master + Panasonic Viera TV

Post by LordVaderUK » Wed Mar 04, 2020 7:49 pm

I’ve tried it on two other LCD tellys, neither of which see the BBC at all - I suspect their SCART socket doesn’t support RGB?

I haven’t tried composite as I don’t have the right cables to connect... maybe I need to buy some...
Loving my BBC Master 128

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Re: Sync issue with Master + Panasonic Viera TV

Post by LordVaderUK » Thu Mar 05, 2020 1:41 pm

Does anyone know of a cable which goes from a 6 pin DIN to three phono connectors (see photo of an Atari compatible cable) for connecting to the rgb input of a TV? Have searched but can’t find one, which says to me that it can’t be done...?
F8136A66-B6D3-4982-8EE8-95859151E026.jpeg
Loving my BBC Master 128

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Re: Sync issue with Master + Panasonic Viera TV

Post by Kazzie » Thu Mar 05, 2020 1:48 pm

LordVaderUK wrote:
Thu Mar 05, 2020 1:41 pm
Does anyone know of a cable which goes from a 6 pin DIN to three phono connectors (see photo of an Atari compatible cable) for connecting to the rgb input of a TV? Have searched but can’t find one, which says to me that it can’t be done...?

F8136A66-B6D3-4982-8EE8-95859151E026.jpeg
If you want to use phono connectors, you don't want to start from the RGB connector. Those three leads are composite video, left audio, and right audio. So all you really need is a cable to go from the composite connector to the yellow input on your TV. Any BNC to RCA video cable will do the job nicely; here's one random example off eBay to get you started.
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Re: Sync issue with Master + Panasonic Viera TV

Post by LordVaderUK » Thu Mar 05, 2020 2:08 pm

Kazzie wrote:
Thu Mar 05, 2020 1:48 pm
If you want to use phono connectors, you don't want to start from the RGB connector. Those three leads are composite video, left audio, and right audio. So all you really need is a cable to go from the composite connector to the yellow input on your TV. Any BNC to RCA video cable will do the job nicely; here's one random example off eBay to get you started.
Thank you. I knew I was missing something bleedin’ obvious! Ordered 👍
Loving my BBC Master 128

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Re: Sync issue with Master + Panasonic Viera TV

Post by johnkenyon » Fri Mar 06, 2020 9:07 am

Kazzie wrote:
Thu Mar 05, 2020 1:48 pm
LordVaderUK wrote:
Thu Mar 05, 2020 1:41 pm
Does anyone know of a cable which goes from a 6 pin DIN to three phono connectors (see photo of an Atari compatible cable) for connecting to the rgb input of a TV? Have searched but can’t find one, which says to me that it can’t be done...?

F8136A66-B6D3-4982-8EE8-95859151E026.jpeg
If you want to use phono connectors, you don't want to start from the RGB connector. Those three leads are composite video, left audio, and right audio. So all you really need is a cable to go from the composite connector to the yellow input on your TV. Any BNC to RCA video cable will do the job nicely; here's one random example off eBay to get you started.
Or make the BNC problem go away by replacing the connector on the conputer with a chassis mount RCA socket. (got that t-shirt).

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Richard Russell
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Re: Sync issue with Master + Panasonic Viera TV

Post by Richard Russell » Fri Mar 06, 2020 9:31 am

johnkenyon wrote:
Fri Mar 06, 2020 9:07 am
Or make the BNC problem go away by replacing the connector on the conputer with a chassis mount RCA socket. (got that t-shirt).
Hmm, as a (once) professional video engineer I can't say I like the idea of replacing a high-quality constant-impedance BNC connector with a cheap phono connector, however 'convenient' it may be! We (the BBC) insisted on a 75Ω BNC socket so that the machine would be compatible with professional video infrastructure, e.g. in a TV studio, and not suffer reflections from the connector which might show up on the final picture, especially with the cable lengths that are typically encountered in such an environment.

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