Sander Sweers wrote:
> On Fri, Apr 4, 2008 at 8:03 AM, Andy Walls <[EMAIL PROTECTED]> wrote: > > If you suspect you have signal strength or SNR problems, some steps you > > could take, if you haven't already, are: > > When you do not have the samsung tuners on the PVR-500 this very likely the > problem. Hans said the following in [1] which describes the same symptoms. > > > There are two possible causes: first of all the Samsung tuners are > > simply not very good, and secondly the PVR-500 needs a stronger signal > > than the PVR-250 (it splits the signal internally to both tuners, so > > this reduces the signal strength). In this case it sounds that an > > antenna amplifier will help. However, if there are some channels that > > work and others that do not (and often show a sort of herringbone > > effect), then there isn't a lot that can be done as that is a > > limitation of the Samsung tuner. But from the description of your > > problem I'd say that you need an amplifier. > > [1] http://www.gossamer-threads.com/lists/ivtv/users/37601#37601 > > Greets > Sander > > PS: Can we post the below to the wiki? Sure, with some edits as indicated below: > > 1. Ensure you are using 75 ohm splitters that cover your desired > > frequency range (55 - 802 MHz for US NTSC broadcast IIRC). Change the parenthetical to: (55 - 802 MHz for the current US NTSC broadcast allocation) > > > > 2, Ensure that all unused cable runs, wall jacks, or splitter outputs > > are properly terminated in a 75 ohm load. > > > > 3. Replace RG-58/U cables with RG-6/U cables. RG-6/U has about 3 dB > > less loss per 100 feet at 400 MHz than RG-58/U according to one > > manufacturer. "according to this source: http://www.rfcafe.com/references/electrical/coax_chart.htm " > > 4. Add a broadband TV amplifier as close as you can to where the signal > > comes into your location, ideally before any splitters or long cable > > runs. If you don't also use your cables to receive FM radio signals > > and the amplifier has an FM trap, set the FM trap to "IN" to reduce > > intermodulation products induced in the tuner by the FM broadcasts in > > the 88-108 MHz band. Set the trap to "OUT" if amplifying a cable television feed. Cable uses frequencies in the FM broadcast range for TV channels. > > > > 5. Make sure you have an in-line lightning protection/grounding unit > > installed in the cable close to where the signal comes into your > > location. Grounding the shield of the coax protects your gear from > > electrical transients induced by nearby lightning. (Full stop) "Grounding the shield of the coaxial cable using the lightning protector may also improve the signal quality in you location (especially if using a consumer-quality antenna amplifier. :) -Andy _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
