C-MAC on Scandinavian channels in the late 80s?

[timo_w2s]

I'm just going through some old What Satellite magazines from 1989 and I've noticed in the channel listings they list SVT 1 & 2 on Intelsat VA F12 (1W) and NRK on Tele-X (5E) as being in C-MAC. I know later on the channels were in D-MAC and D2-MAC but does anyone know if they did actually start off in C-MAC in the late 80s? Or was C-MAC just planned but never broadcast?

I remember B-MAC for the SIS feeds and AFRTS and of course D/D2-MAC for the Scandinavian stuff in the early 90s but I just don't remember anything about C-MAC which is why I'm wondering if it was ever used in broadcasts.

 

[PaulR]

Nope, never heard of it either.

Like you I had dabbled with D/D2-MAC and had heard of B-MAC but that was about it. Anyway here's what Wikipedia has to say about it-

http://en.wikipedia.org/wiki/C-MAC

Which mentions yet another variant I'd never heard of - E-MAC!

 

[timo_w2s]

The September and December 1989 issues of What Satellite list the Scandinavian channel as being in C-MAC but then in July 1990 they start to list them as being in D-MAC. By then BSB had also started using D-MAC on Marcopolo 1 at 31W (before that it had been doing a few D-MAC tests for STB manufacturers via Eutelsat 1 F2 at 7E).

 

[Captain Jack]

Hm yes, I remember B MAC for SIS feeds - weird diamond shaped images, couldn't see anything behind the format. At least with unencrypted D MAC broadcasts you could see what was happening (a bit like the sync removal on RTL4 channel).

I have never seen any other MAC formats, including C, but I only got into satellite stuff in 1993, with my first MAC decoder in 95.

What I would like to get my hands on a D MAC *encoder*.... But have never seen one.

 

[C0re]

a bit like the sync removal on RTL4 channel

LuxCrypt?

 

[Captain Jack]

That's it. RTL5 also inverted colours for some reason...

 

[Analoguesat]

And another one I havent heard of - A-MAC

http://en.wikipedia.org/wiki/A-MAC

 

[PaulR]

And at the bottom of the Wikipedia page is reference to another - S-MAC!

 

[Topper]

And at the bottom of the Wikipedia page is reference to another - S-MAC!

It all S-MACks of specifications that never entered mainstream broadcast encryption schemes to me

 

[bema]

SVT1/2 was re-transmitted by "Telenor", Norska Televerket for many years.. They were not "public", only for cable TV networks in different parts of Norway. I think the "stole" the signal from the Sunne transmitter in Värmland which also gives good signal into eastern parts of Norway..
And yes, they did use C-MAC for a while...

 

[Captain Jack]

Analogue formats and its associated encryption systems fascinate me. Much more fun that the "Malevich" we get in the digital world.

 

[Pride Of Cucamonga]

Analogue formats and its associated encryption systems fascinate me. Much more fun that the "Malevich" we get in the digital world.

Did the process of analogue encryption / decrpytion cause any loss in picture quality?

 

[Captain Jack]

I never noticed any deteriorations.

A good quality D2-MAC, Eurocrypt encrypted transmission, such as those from FilmNet+ on Astra (and later Canal+ on Thor 1) would give a run for more of today's SD broadcasts. They really were a pleasure to watch.

Unencrypted D-MAC NRK on Intelsat was also of very good quality.

Some, admittedly, were rubbish - TV1000 and TV3 were visibly poorer but this had nothing to do with the format.

 

[timo_w2s]

SVT1/2 was re-transmitted by "Telenor", Norska Televerket for many years.. They were not "public", only for cable TV networks in different parts of Norway. I think the "stole" the signal from the Sunne transmitter in Värmland which also gives good signal into eastern parts of Norway..
And yes, they did use C-MAC for a while...

Thanks! So you think it could be possible that they where C-MAC satellite transmissions pre-1990. Did they later change to D-MAC for public use? (Rather than just for cable headends)

 

[timo_w2s]

Did the process of analogue encryption / decrpytion cause any loss in picture quality?

I never liked Videocrypt, on all the receivers (and separate decoders) I used over the years the encrypted Sky channels always used to have faint horizontal lines on the picture as if the brightness or contrast wasn't decoded quite right. Other encryptions where fine.

 

[Anonymous_1]

About TeleX, This is not the main subject, but do you remember how strong was this satellite ?
more than 64dB

The antenna for TeleX by Swedish Microwave and its Feedhorn (circular) :

 

[timo_w2s]

I could get a weak signal from Tele-X just by pointing an LNB in the air in the general direction of 5E in Finland. It was stupidly strong. I think it was 61dBW in some parts of Finland. I remember seeing some of the dishes in Sweden back then and they made BSB's Squarial look big.

 

[Kveys]

The antenna for TeleX by Swedish Microwave and its Feedhorn (circular) :
View attachment 77750

 

[Analoguesat]

When we get a nice weekend afternoon Im going to try and get a stable picture from the 28E UK spots on a metal pan lid

 

[Analoguesat]

I shall also borrow the OH's wok - when shes out of course