Coax cable spec for VM

swinster · 07-08-2011, 23:42

Hi

Does anyone know the specification of the coax cable for VM installations, and or where any decent cable may be purchased (approx 20-25m)?

Background info -
I installed some PH100 cable in part of my build around 5 years ago, but we're only now getting around to completion. Hooking the V+HD box today I saw some problems with a high signal loss so will need to replace. Maybe the cable is pinched or something.

The V+HD Box shows a 32 dB Signal to Noise Ratio (SNR), through a 6.1dB 3-way splitter at the wall and a 34 AGC signal level. However, at the end of the cable (direct to the wall) I'm seeing 22dB SNR and 58 AGC. This is only enough to view SD channels and the box will not go online, in fact if I try though a 3dB 2-way splitter, even the SD picture breaks up. Through the 3-way (which will need to happen) i get nothing.

Please only post with regard to this specific question.

Cheers,

Kymmy · 08-08-2011, 09:49

With most 6-7mm cables the attenuation at 20-25m in going to be a few DB's at least..

Probably PF100 is your best option though don't use it to extend the existing cable from the splitter, instead use it to replace the cable.

swinster · 08-08-2011, 22:16

Quote:

Originally Posted by Kymmy

With most 6-7mm cables the attenuation at 20-25m in going to be a few DB's at least..

Probably PF100 is your best option though don't use it to extend the existing cable from the splitter, instead use it to replace the cable.

Replace All cable in the whole house?

There is a short fly lead (approx 20cm) from the wall socket to the splitter. Then 3 outs.

travels 15-20m to the cable modem,
20m to downstairs (the cable I'm talking about in this post),
and a short 0.75m cable to where the current V+HD Box is positioned.

We are going to move the box from its current position to reside at the end of the 20m cable.

As mentioned, with the cable that is in place and NO splitter at the wall, the box will only just about work, but not fully. The cable modem is fine upstairs, so I might take the box upstairs and see how it behaves. The cable runs are similar in length.

Am I right in thinking that RG6 cable still gives slightly higher losses (even at the 600--700 MHz) region than 100 type cable?

Came across this stuff - hopefully better than what's in at the mo - http://www.satcure.co.uk/accs/page8.htm#WF100

swinster · 10-08-2011, 10:15

Interestingly, I plugged in the V+ Box into the cable run to upstairs used for the Cable modem. This is approximately a 15m (actually 3 separate cables joined), and I left the 3 way splitter in place. The results were identical to those I have seen with the V+ box plugged in close by the wall (this morning SNR 35dB, 30 AGC)

The unit went on-line immediately and all channels including HD ones showed no signs of pixelation.

swinster · 17-08-2011, 19:50

Well, I received the 30m of WF100 from SatCure today. Unravelled it and added the twist on F type connectors, and plugged it into the V+ HD box. Everything worked faultlessly.

SNR = 35 dB, AGC = 34, which is the same as the when the box is plugged in via the short cable.

I have no idea why the other cable gives such a poor result, but I obviously done something to it when installing. I can certainly recommend the stuff from satcure.