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| DVB-T - few questions... http://forum.linhes.org/viewtopic.php?f=15&t=15891 |
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| Author: | Warped [ Sun Jul 15, 2007 2:41 pm ] |
| Post subject: | DVB-T - few questions... |
Hi all, Guys - want to start receive DVB-T. My system is: r5f1, 2xpvr250+1xNOVA-T. After setting up hardware I can receive DVB programs with room antenna - but only in one multiplex (QAM16,8k,1/2). Second one (QAM64,8k,3/4) - not. On working multiplex OSD is showing: Signal 15% | S/N:4,8dB | BE:11 | (LMS) Lock On non-working multiplex OSD is showing: Signal 15% | S/N:4,8dB | BE:11 | (L_S) Partial Lock and I receive dialog "You should have gotten channel lock by now. You can continue to wait..." My questions are: 1.How signal meter in r5f1 works. I assume FE reads it from DVB card. In case hauppauge NOVA-T is it based on tuner AGC or... In other words is it linear or exponential ?. 2.Signal about 15% - it is acceptable or should I forget about stable DVB TV with such low signal ? 3.I always have S/N=4,8dB. Is it normal or something is wrong in my setup ? 4.What means (LMS). In well working multiplex I have (LMS) Lock. On wrong one I have (L_S) Partial Lock or (L__) Partial Lock. What L and M and S means ? 5.Is in r5f1 a toll for helping positioning antenna (constantly on-line showing signal strength) 6.Is it possible that I have wrong transport setup and by this always receive (L_S) Partial Lock or (L__) Partial Lock ? Sorry for maybe silly questions but I haven't idea where I should explore for resolution - is it problem of signal strength or transport setup ? thx in advance for help. |
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| Author: | Mephi [ Sun Jul 15, 2007 2:46 pm ] |
| Post subject: | |
Whereabouts are you based? Where I live in the uk, there is no chance of picking up DVB-T with a room antenna, I've got a large wideband aerial on my roof, with some decent cabling, and that just about picks up everything. You've got to be in a very high signal area to use a room antenna. |
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| Author: | Warped [ Mon Jul 16, 2007 1:19 am ] |
| Post subject: | |
@Mephi, I'm living in Poland. Hause is 20km from transmitter. We have 2 multiplexes: EMITEL (QAM16,8k,1/2,1/32) and POT (QAM64,8k,3/4,1/32). Both are broadcasted with 1,35kW ERP. My antenna is wideband room anntena with 23dB amplifier. First multiplex usually I'm receiving with 0 BER - but sometimes not. Generally it is acceptable. Unfortunatelly second multiplex is simply immposible to see. Probably signal is too weak when QAM64 is used. br |
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| Author: | bruce_s01 [ Mon Jul 16, 2007 7:20 am ] |
| Post subject: | |
Are you splitting the output of the antenna to the PVR250s? Quote: My antenna is wideband room anntena with 23dB amplifier. Room based antennas are not good for many reasons, but as they are usually small and is being attenuated by the room walls. Amplification is not usually the answer as this amplifies the ambient noise as well as signal.
So I think you are not picking up an adequate signal. To improve your current setup, firstly raise the antenna as high as possible, and have it pointing through a window towards the transmitter. The best way though, would have a roof mounted external antenna, so you can have a decently large antenna with minimal local attenuation with a good quality (CT100) downlead. You may need some kind of masthead amplifier as well, but your aerial supplier/fitter should be able to identify if you need this. BTW is your area being supplied by the transmitter? I know in the UK some transmitters are directional and supply a service towards an area. Does Poland have an equivalent to this or this? Bruce S. |
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| Author: | Warped [ Mon Jul 16, 2007 12:51 pm ] |
| Post subject: | |
@bruce_s01 Thx for replay. Indeed room antennas are usually are worst solution, but I simply try simplest solution and when failed - go for more advanced... Transmitter is working with 1,35kW ERP - comparing to 50kW used for analog channels gives rather low signal strength. DVB-T in Poland just started tests phase - so no nice support like pointed on Yours links yet exists. |
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