Centralised TV System Problem

[mtobe]

Hello every one ,

I hope im in the right place,

im repairing an old hotel tv system , and im trying to get as many channels as possible

as far as I did was getting 22 channels working , i had to skip 1 frequency to avoid channels interference .

for example i have first channel on bg 21 , 2nd channel on bg 23.

if i add channel on bg22 both bg21 and bg 23 get high interference (you cant see a thing)

also ,

on UHF 2 if I kept skipping 1 frequency i use ( 31 ,33 ,35 ,37 ,39 , 41 , 43 , 45 ) , but thats the limit of the splitter , if i added 2nd splitter on same port all channels get bad picutres.

i have multiple amplifiers if there is a setup where i can use 2 amplifiers to get at least 30 channels it would help me great

thanks

 

[Channel Hopper]

If the satellite RF outputs are analogue then the usual rule is to avoid 'CH + 5' and 'CH + 9' otherwise the harmonics will cause interference.

 

[mtobe]

Thank tou for your response .

Yes the output is analog . Please explain it further i didnt get it fully

 

[mtobe]

If the satellite RF outputs are analogue then the usual rule is to avoid 'CH + 5' and 'CH + 9' otherwise the harmonics will cause interference.

thank you for your response ,

the output is RF , but plz explain this +5 +9 further i didnt get it

 

[Channel Hopper]

On top of using adjacent channels, 43 and 44,

'BG' 39 - 44 gives a figure of 5.
'BG' 35 - 44 gives a figure of 9.

 

[mtobe]

I will try it thanks

 

[mtobe]

now i only connect 3 Channels . configured as BG21 , BG 22 , BG 23

no channels work

If i connect 2 channels as BG 21 , BG 23 they work crystal clear .

Is there a way to not skip 1 frequency , at this rate i will end up with 24 channels only my target is 30 channels .

is there a way to connect 2 amplifiers together to get the best of it ?

thanks

 

[mtobe]

On top of using adjacent channels, 43 and 44,

'BG' 39 - 44 gives a figure of 5.
'BG' 35 - 44 gives a figure of 9.

please explain it further , i tried something but i dont think it was what you meant .

u get to 30 channels i need at least 5 spliiters , how do i connect them and which channels on which splitter .

thank you so much

 

[Analoguesat]

When you are setting RF analogue channels up you are recommended not to use + or - 5 or 9 channels from any one in use.

So if you use say channel 30 you should avoid 21, 25, 35, 39 So you wont get anywhere near 30 channels into the standard rf channel system. Plus as you have found bleedover from adjacent channels means you cant use them either.

There are online calculators that allow you to play around with tv rf channel allocations so you can see what will work & what wont, but you realistcally will probably get about a dozen channels in at best.

If you REALLY need 30 channels consider going for a DVB modulator or whatever the standard is in your country & setting our own mini multiplex up.

 

[mtobe]

When you are setting RF analogue channels up you are recommended not to use + or - 5 or 9 channels from any one in use.

So if you use say channel 30 you should avoid 21, 25, 35, 39 So you wont get anywhere near 30 channels into the standard rf channel system. Plus as you have found bleedover from adjacent channels means you cant use them either.

There are online calculators that allow you to play around with tv rf channel allocations so you can see what will work & what wont, but you realistcally will probably get about a dozen channels in at best.

If you REALLY need 30 channels consider going for a DVB modulator or whatever the standard is in your country & setting our own mini multiplex up.

thank you for your response ,

with the current equipment , how many channels i can get ?

can you give me link to such calculator ?

thank you

 

[Analoguesat]

Dont know how many you will get in & Im not doing the calculations for you.

Link - www.google.com

 

[mtobe]

is there any advantage of connecting 2 headend amplifier in terms of quality ?

 

[Channel Hopper]

now i only connect 3 Channels . configured as BG21 , BG 22 , BG 23

no channels work

If i connect 2 channels as BG 21 , BG 23 they work crystal clear .

Is there a way to not skip 1 frequency , at this rate i will end up with 24 channels only my target is 30 channels .

is there a way to connect 2 amplifiers together to get the best of it ?

thanks

'On top of using adjacent channels'

as I mentioned earlier, so you cannot step up one number only.

The problem will also increase if this is not a closed system, any locaL transmission will also need to be filtered from the modulator frequencies.

 

[Channel Hopper]

is there any advantage of connecting 2 headend amplifier in terms of quality ?

Sort out the existing issues first.

 

[mtobe]

Currently I reached my max as below :


i got no ideas to get pass 22 channels without losing the quality of the current channels

 

[Channel Hopper]

You could fit two more in if you redesign the frequency split equally between the three splitters ie. 21-36, 37-52, 53-69.

 

[mtobe]

You could fit two more in if you redesign the frequency split equally beteween the three splitters ie. 21-36, 37-52, 53-69.

if I add channel 33 to first splitter it won't work .

If used another splitter on 2nd amplifier input the whole channels ( 31 - 50 ) will go bad .
same for 3rd amplifier input .

I cant find splitter with more than 8 outputs in my country .

i tried to connect 2nd amplifier to use ( 22,24,26,28,30) channels on it , and then use both outputs and send it to the rooms but was terrible idea.

i dont know what to do ....

 

[Channel Hopper]

Only because you have a channelised amplifier in the system.

Change it for a wideband amplifier and get a good quality three way splitter (or a four way and terminate the spare input with a resistor)

 

[Channel Hopper]

Correction, the ALCAD can be used on one input only

http://www.alcad.com.au/wp-content/uploads/2014/05/CF-511-Multiband-amp-V2.pdf

 

[Terryl]

From what I see and read in this thread, it looks like your trying to make up a small local CATV system.

Your going to have troubles with intermod when trying to add odd and even channels in the same frequency band (UHF) to the system, when channels 21 and 22 (or any two adjacent channels) are combined the intermod (frequency A + frequency B = frequency C) will wipe out a third channel higher (or lower) in the system.

What is done in the CATV business is to put the channels in different bands, this will separate out the odd and even channels so all adjacent channel intermod problems are eliminated.

I don't know if you can use the VHF band or get channel converters/ modulators to do this, but there is no way to use all the odd and even channels you want to in a single UHF setup, (channels 21 to 69) not with out some very expensive channel combiners, modulators and IM filters.