one massively over priced ebay item

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VicGyver
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one massively over priced ebay item

Post by vic user »

my goodness this is expensive!

http://cgi.ebay.ca/ws/eBayISAPI.dll?Vie ... 23604&rd=1

chris
carlsson
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Post by carlsson »

I dunno - working RF modulators can be hard to find. $8 equals about 60 SEK, and I remember ten years ago when I paid 200 SEK or something like that to get hold of a working RF (ripped out from a still boxed, shrink wrapped VIC-20 that the former reseller still had in stock).
Anders Carlsson

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Post by vic user »

he must have changed the price

it was listed around $25.00 american

chris
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Post by Schema »

vic user wrote:he must have changed the price

it was listed around $25.00 american
Hehe, I saw that too. Maybe it's someone here? Image
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Post by carlsson »

Are RF modulators NTSC/PAL specific too? I realize US systems are broadcasting on channel 3 or 4 (VHF?) while European normally used channel UHF 36. However, I wonder if a such channel 3/4 RF would work on a PAL/European TV too.

Btw, those VHF/UHF definitions is something I never understood or bothered to look up. My old TV had VHF 2-4, VHF 5-12 and UHF 21-69, and channels above that would be super channels (90+ IIRC). I wondered where channels 13-20 and 70-89 went. Newer TVs operate in MHz, 48-999 where super channels should equal anything above 200 or so.
Anders Carlsson

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Leeeeee
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Post by Leeeeee »

This modulator would be useless in Europe. CH3 and 4 are VHF but, even if you have a receiver that can tune that low, there are other differences.

The Video bandwidth is less so the, sometimes not brilliant, modulated colour will look even worse, more washed out.

The sound subcarrier is different, at least from PAL I (6MHz).

If you want a modulator for a VIC go kill a video recorder, they have modulators you can easily adapt.

I'll do a web page or two on it if there's enough interest.

Lee.
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Post by carlsson »

Most TV systems today have composite, SVHS or SCART (at least in Europe), so it'd be a better solution to hack together a composite video cable instead of resurrecting a RF from an old VCR. At least I would find it easier (and give better picture!).
Anders Carlsson

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Boray
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Post by Boray »

I can't use RF modulators! Because they are transmitting digital TV on exactly the same frequency here.... :(

/Anders
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carlsson
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Post by carlsson »

Airborne digital TV on UHF 36? You mean that one will interfer the other, even if only one lead is connected to the TV/VCR?
Anders Carlsson

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Leeeeee
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Post by Leeeeee »

I can't use RF modulators! Because they are transmitting digital TV on exactly the same frequency here.... :(
Yes you can. A modulator can, usually, be persuaded to work anywhere in the whole TV band. You just need to know what to 'adjust'. 8^)=

Vic to scart or even S-video isn't too hard either, I can do that as well.

There are also some mods you can make to the Vic's colour circucits that can improve the colour significantly, trouble is you need access to a vectorscope to set it up properly.

Hands up anyone else who has access to one. 8^)=

Lee.
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Post by carlsson »

I suppose there is nothing internally in VIC-I from where you can drain a RGB signal?
Anders Carlsson

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Post by Mayhem »

Sadly not. I don't think you can get more than composite out of a Vic20 (S-video on a C64).
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Post by carlsson »

According to the specs (pin configuration and block diagram) of the 6560, and I suppose 6561 too, the chip seems to output "COMP COLOR" and "SYNC & LUMIN" as two separate signals. Probably they are merged somewhere on the way to the connector. However, I realize that to get more than composite, you would have to hack onto the chip/circuit board. I suppose someone in 20 years at least have attempted this?

I'm quite a technical noob when it comes to areas like this, how a video signal is generated internally and whether there even is an intermediate step which resembles RGB, or if each component is generated and added to the signal in order. On the block diagram, there is a magic box called "Color Decode" which takes a set of registers ("arguments") and puts out the two signals. I suppose any intermediate RGB signal would be inside that one. Is this what Lee refers to with the vectorscope?
Anders Carlsson

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