At what length of cable run should i consider an inline booster

J

jdseasider

Regular Member
My Satellite Setup
english sky, spiderbox 7000, 1.1m triax dish with tm2600 motor, Acer Aspire 5542
My Location
Blackpool, Lancashire, North West England
Got a couple of cable runs coming up which are potentially 30-50m would i be better using an inline booster or just a higher gain lnb?
 
Just check the signal on your meter at the end of the run and if it is low put an inline midway along the run.
 
If using decent cable 50 metres should not be a problem.
 
From personal experience ...
Cable runs 30 mtrs and under should not require an in line amp ..
30 > 50 mtrs again ..shouldn't be neccessary if your signal is already sufficient ...
but would recommend good quality cable ...and the best lnb you can afford to fit.
rgds
VS
 
That's on the cusp.

I'd try it without an Amp first, providing you use low-loss cable.

It's not just the LNB gain which is important, but the noise. If you fit an amp, that also adds noise, so only compensates for actual loss but possibly degrades quality.

A fine balancing act, best resolved by experimentation.
 
Ha!

The three wise (?) men ...................... :D
 
Tivù said:
Ha!

The three wise (?) men ...................... :D
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Ok Gordon ..who's the odd man out ..??
There are 4 of us including yourself ...

Doh ...its me ..aint it ....
;)
 
All my cable runs are well over 30m and I use the cheapest coax going, and have joints and heaven knows what in them. All but one all work fine - and seeing as thats the one connected to the Duo its no loss from the little use it gets :D
 
@VS: Three simultaneous (near as damn it) respondents :-righton


Edit: Whoops, you're right - there were four Mousketeers. Life is too fast for me, I'm afraid.
 
cheers chaps. Im going to use wf100 and its for viasat so want to makesure everything is hunky dory
 
jdseasider said:
cheers chaps. Im going to use wf100 and its for viasat so want to makesure everything is hunky dory
Click to expand...

You mean the pub owners and their customers wont be very pleased with you if there are problems? ;) :D
 
Use WF125 if you want to be certain.
 
While I do not consider myself as worthy of the wise mean club, I can chip in with this:

Even using relatively cost-effective cabling, anything under 50m shoud not be a problem. Unless cable passes next to something like a radio-transmitter, you only get a loss in signal strength, not signal-to-noise ratio. Personal experience showed that 50m of single-shielded low-cost coax (7mm) still gave good resuilts for quality, but with some reduction of signal strength (about 5-6 db).

Colleague/friend of mine who has been meddling with fringe reception for 25 years gave me a good tip: Don't joint cables, as each join will loose 3-6 db depending on join type. So two joins on a 10 meter cable is potentially much worse than a 50m unbroken cable. If possible, use a single run on cable to receiver. If signal then gets to weak, consider an amp, but only then.
 
It also depends on how strong the signals are to begin with - a few years ago I was tinkering with our 60cm Sky dish and just for the hell of it put a whole 100m reel of cheap coax onto it. I could see no difference whatsoever in signal levels :)
 
:D
Analoguesat said:
... put a whole 100m reel of cheap coax onto it. I could see no difference whatsoever in signal levels :)
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:D Of course there would have been some though. 100M!, I'll have to try that, most Ive done is about 70m made up of lots of offcuts with loads of joins.
 
st1 said:
Don't joint cables, as each join will loose 3-6 db depending on join type. So two joins on a 10 meter cable is potentially much worse than a 50m unbroken cable.
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That's myth, as any decent meter will demonstrate. The only problem with joins is that if they not well sealed they will allow water and other things that may degrade the cable to enter.
 
Receiver signal strength meters are not to be relied on, but you can pretty much guarantee that if you connect 100m of RG6 type cable, that you'll get attenuation in the region of the figures below.

Attenuation:
100MHz - 5.90 dB/100m
470MHz - 13.3 dB/100m
860MHz - 18.3 dB/100m
2150MHz - 30.3 dB/100m

A join using a barrel connector and two "F" male connectors can lose perhaps up to 3/4db depending on the frequency and as low as 1db at the lowest IFs.
 
Huevos said:
That's myth, as any decent meter will demonstrate. The only problem with joins is that if they not well sealed they will allow water and other things that may degrade the cable to enter.
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Yeah - I found that out a couple of years ago - I hadnt sealed any of the connections on the lnbs & one of the cables the to disecq switch filled up with water. The copper had gone a lovely green colour & the plasticized foil a mucky grey colour. (Told you I did things cheaply!) :-rofl2.

All the others were fine :D

Now I just try to have lnb's with pull down shields on them, but there are still some legacy lnb's in use
 
I've just done a quick test. I made a short fly lead using a barrel connector and two cheapo 'F' male connectors and took some readings with and without it inline.

First test at 11680V (IF 1930 MHz):
without the flylead: 70.7dBuV, MER 15.2dB
with the flylead: 69.1dBuV, MER 15.2dB

Second test at 11740V (IF 1140 MHz):
without the flylead: 73.3dBuV, MER 17.4dB
with the flylead: 72.3dBuV, MER 17.4dB

So going on Rolf's figures, at 2GHz a barrel connector and two cheapo 'F' male connectors and a foot of cable has the same loss as about 5 metres of virgin cable, and what's more has zero effect on MER which is what really counts.
 
Like Analoguesat I have some long runs with ancient cables and all sorts of (well waterproofed) joins without any problems.

The error correction on digital signals and the fact they are all either 1 or 0 makes them robust compared to any form of analogue signal.
 
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