Webro WF100 - Length For Strength ?

M

moonbase

Small Dish Man
Messages
2,483
My Satellite Setup
2.0m Precision
My Location
UK
Hi,

What length of Webro WF100 cable can be used before the signal strength in Ku band starts to weaken? I need to install a couple of cable runs that are longer than the usual ones I use and wondered if I should use Webro WF100 or WF125. If I can get away with WF100 I prefer to use it as the WF125 is not as "friendly" to work with.

It's just for a normal setup, nowt out of the ordinary, two cables from LNB, one to a satellite receiver, the other to a TBS DVB device.
 
S

s-band

Contributor
Messages
842
My Satellite Setup
1.5m IRTE PF, Octagon OSLO external Ref., TBS6983,
Various L, S, C, X & Ka bits. 1.2m S/X/Ku/Ka Prodelin on Az-El
My Location
SE UK
It depends on the LNB gain. As long as you can see a significant increase in noise, across the whole IF band, when you connect the cable, you probably won't be losing any SNR. Looking at the specs, 125 is only a couple of dB better than 100 for a 100m length at 2050MHz. It won't make any difference what band the LNB is on the same applies (you're only interested in the IF loss). Coaxial Cable Specifications WF100 CT100 WF65 RG6

For really long runs I'd include a gain slope equaliser with a bit of gain. In my case, I put it where there's a divider in line, about 1/3 the way. The 1st bit is about 10m and the 2nd is about 25m. It' not ideal but it works.

If you got some attenuators, try putting the calculated loss in line with what ever you have at the moment and see what happens. I'm sure others will have rules of thumb for this.

<edit> A further thought: When using a TBS69xx, you should see around -70 to -50dBm noise. If you see a straight line where the noise should be, you've lost too much.
 
Last edited:
jeallen01

jeallen01

Specialist Contributor
Messages
4,185
My Satellite Setup
See Signature
My Location
Somewhere in England (possibly?)!
@s-band
FWIW that satcure site page is well worth downloading as I did some time ago. OTOH, I have no idea from where Martin P & co got the info to put it together (& no idea if/when it might be deleted if the site is deactivated!).
 
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