Split one feed into two

[Smithy99]

Originally Posted by Junty Mcfadden

you sense a wind up? i sense a numpty, look it is really very simple, you need TWO cables into a sky+ box because you are feeding to TWO seperate independant decoders within the box - this is what allows you to watch and or record TWO different channels at the same time (the ability to watch an ANYTIME or RECORDED propgramme whilst recording TWO channels is due to the streaming video coming from the harddrive within the box, it's a very clever bit of kit in so much as it allows three active streams - OK so at SKY we have kit that can have 6 active streams (see EVS broadcast equipment if you are an anorak for some very funky tech)

So all you pretendo-techs don't talk BS when there is an adult in the room - your just making yourself look more of a numpty - 2 cables, 2 decoders and some very clever data management - but i guess that's why i work as an engineer at sky because i can understand that

Love and kisses (but don't tell the misses)

Junty

Oh dear, I honestly didn't think you could look anymore foolish until I read this. If you are a Sky engineer I feel really sorry for anyone whos system you install. How long have you been there?

Please answer me this, if you can just split satellite feeds, why would Sky or anyone else bother fitting multipoint LNB's? can you point me to a bit of equipment that you would reccommend to do what you say?

I must admit, I have never worked for Sky but have been running a satellite and aerial company since the days of BSB (the squarial) and installing aerials before Sky were ever born so I have some understandiung on how things work.

[Brian69]

The longer I spend on this site, the happier I am that I always installed my own dish etc (no offence intended to anyone... just an observation)

[SatDish]

Originally Posted by Proppinupthebar

look up the specs for a universal LNB

These ones?

RF frequency range:
10.70 - 12.75 GHz

Lower band range
10.70 - 11.70 GHz

Lower band local oscillator frequency
9.75 GHz ± 5 MHz

Upper band range
11.70 - 12.75 GHz

Upper band local oscillator frequency
10.6 GHz ± 5 MHz

IF frequency range (minimum)
950 - 2150 MHz

Small signal gain over RF frequency range
40dB Gain 65dB

Max. amplitude variation over IF frequency range
2.0 dB (within any 36 MHz bandwidth)
1.5 dB (within any 27 MHz bandwidth)
8.0 dB (over entire IF range - DTH)
5.0 dB (over entire IF range - SMATV)
Max. group delay variation over IF band
20 ns (within any 36 MHz bandwidth)

Multi-carrier intermodulation ratio
>=35 dB.

Local oscillator intermodulation products at lnb output
< -60 dBc
(in the frequency band 950 - 2150 MHz)
Local oscillator phase noise

-50 dBc (1 kHz)

-75 dBc (10 kHz)

-95 dBc (100 kHz)

Spurious components at LNB output
-60 dBc (in frequency band fc ± 120 kHz)

LNB isolation
> 26 dB

LNB input RF interface:
(optional, if waveguide is employed):
PBR 120 (rectangular), or C120 (circular) with gasket groove

Antenna feed RF interface:
(optional, if waveguide is employed):
UBR 120 (rectangular), or C120 (circular)
without gasket groove

Output IF connector
IEC 169-24 type F, female

IF output characteristic impedance:
75 Ohm

LNB output return loss (this is the recommended value in the ETSI BSS and FSS specifications)
>=8 dB
(over the frequency range 950 - 2150 MHz)

Recommended switching control signals
DiSEqC2.0 e

DC supply voltage
(assuming conventional switching method)
+11.5 to +19 V

maximum current
(assuming conventional switching method)
250 mA (single-band)
300 mA (dual-band)

[pagga1]

Thank you all very much for you comments.

So there's no solution then ? I can't believe I'm the only person to have suffered this problem.

And I can't believe there's no provision for this scenario in the digibox software - it would be useful if there was an option to disable tuner 2. I'd like to think that if this were possible, tuner 1 would change the channel and record stuff without having to be preset to the appropriate channel....

nice one sky.....

[sagarhshah]

hey pagga

I recently moved house and it had the same thing u talking about single communal dish.
I managed to use a neighbours feed as he didn't have sky and had no intention of getting it.

try and talk to the neighbours to find out if they all have sky and are using it. you might be able to to use one their feeds.

if theres no extra feeds then try and talk to the company who installed the system. they might be willing to upgrade the system so that people can use sky+ digiboxes.(although this one will probably cost more)


btw junty is talking absolute b*****ks. he doesn't seem to have a clue how sky broadcast the channels. don't won't to into technicals but junty if you still believe you are right and a number of us on here who aren't sky 'engineers' are wrong you are more then welcome to come over to my place and work your magic out and get two channels using one lnb feed by splitting it.
if you can then wow you might have discovered a way to save sky some money man!!!
we can patent this system of yours and make millions I tell you!!you can work out the technicals I'll handle the marketing whadayaa say junty?

loves and kisses (couldn't give a damn if you tell the missus)

sagar

[Sam Radford]

I'd just like to confirm that "Proppinupthebar" knows his stuff. The Sky+ box has two tuners and one decoder and works exactly as he described. I am an engineer, by the way; I have a degree in Electronic Engineering, which is more than most Sky installers have. Please don't insult me by calling them "engineers". You don't get an engineering degree by doing a 2 week training course that tells you how to climb a ladder and how to wire a telephone socket. (No offence to the competent Sky installers but some of the dummies think a "link budget calculation" is what the chancellor does each year!)

Anyway, getting back on topic, you can use the Sky+ box in a somewhat crippled fashion with one LNB feed if you connect up an SPS1 switch.
How can I split the signal from the LNB on the dish so I can run two receivers?

[Proppinupthebar]

Originally Posted by Sam Radford

I am an engineer, by the way; I have a degree in Electronic Engineering, which is more than most Sky installers have. Please don't insult me by calling them "engineers". You don't get an engineering degree by doing a 2 week training course that tells you how to climb a ladder and how to wire a telephone socket. (No offence to the competent Sky installers but some of the dummies think a "link budget calculation" is what the chancellor does each year!)

BEng(Hons), MSc here, both in Electronics after spending 5 years at University drinking, erm I mean studying Plus since then over 10 years of working specifically with digital TV compression systems across Europe.

[pagga1]

Thanks very much gents.....the SPS1 looks interesting...

I was about to blow a tenner on this - LNB switch amplifier polariser adapter

and then read about the scart lead requirement and got scared does anyone know of a ready to go scart lead that I can just buy and plug in ? Then I guess assuming that that doesn't work, I'd need to get the amplifier and try that.....

Still, it sounds like it might be a solution. Thanks again.....

Saw this as well - PULSAT - SMART PRIORITY SWITCH SPS1

Which one might be best ?