Forum Home
PC World Chat
Thread ID: 136692	2014-04-02 04:37:00	TV Signal	Poppa John (284)	PC World Chat

Post ID	Timestamp	Content	User
1371806	2014-04-05 10:05:00	The wiring inside the the lounge is cat 5 or 6. The one from the roof down is older, black & thinner. Cat5/6 are data cables PJ and may not be suitable for UHF TV. While digital TV is effectively a 'computer' signal stream, the interface between your old cable (coax and unbalanced) and the Cat5/6 cable (balanced pairs) may not be passing through a balun (BALanced to UNbalanced transformer) and that may degrade the signal. There are a lot of cowboys out there capitalising on the analog/digital change-over. As to the appropriate signal source, I suggest that you look at the 'district average' in the surrounding streets and take note of the types of antenna used and the direction they are aimed. Those two factors represent the combined wisdom and experience of the local installation teams and are 'usually' a reliable indication of what you may need for a good result. Your old system may also be a combination of VHF and UHF antennas and they would (should) be interconnected via a combiner unit, which will also degrade the signal and it is best to get rid of the old TV1/2/3 lowband antenna. That said, I have found that the signal strength needed for reliable terrestrial UHF digital reception is much lower that was necessary for VHF/UHF analogue, and although my home has many TV outlets and an amplifier unit, I found that on a scale of 1-10 I could back the UHF amp gain down from 9 to 4 without degrading the signal at any of the outlests, including my garage/manshed which is about 35 metres of cable away from the amp. The amp itself is at least 15 metres from the antenna and it is still diplexed to a VHF antenna, so by all standards I should have a ratshlt picture, but in fact all five TVs are perfect. Feel free to PM me if you want to ask any questions, I was an antenna installation consultant in a previous life and installed/set up the current system myself. There are about 8 outlets in the house (maybe more) and one in the garage/workshop. Cheers Billy 8-{)	Billy T (70)
1371807	2014-04-05 23:27:00	Cat5/6 are data cables PJ and may not be suitable for UHF TV. While digital TV is effectively a 'computer' signal stream, the interface between your old cable (coax and unbalanced) and the Cat5/6 cable (balanced pairs) may not be passing through a balun (BALanced to UNbalanced transformer) and that may degrade the signal. There are a lot of cowboys out there capitalising on the analog/digital change-over. As to the appropriate signal source, I suggest that you look at the 'district average' in the surrounding streets and take note of the types of antenna used and the direction they are aimed. Those two factors represent the combined wisdom and experience of the local installation teams and are 'usually' a reliable indication of what you may need for a good result. Your old system may also be a combination of VHF and UHF antennas and they would (should) be interconnected via a combiner unit, which will also degrade the signal and it is best to get rid of the old TV1/2/3 lowband antenna. That said, I have found that the signal strength needed for reliable terrestrial UHF digital reception is much lower that was necessary for VHF/UHF analogue, and although my home has many TV outlets and an amplifier unit, I found that on a scale of 1-10 I could back the UHF amp gain down from 9 to 4 without degrading the signal at any of the outlests, including my garage/manshed which is about 35 metres of cable away from the amp. The amp itself is at least 15 metres from the antenna and it is still diplexed to a VHF antenna, so by all standards I should have a ratshlt picture, but in fact all five TVs are perfect. Feel free to PM me if you want to ask any questions, I was an antenna installation consultant in a previous life and installed/set up the current system myself. There are about 8 outlets in the house (maybe more) and one in the garage/workshop. Cheers Billy 8-{) Billy...thanks for that info. You are right of course, not Cat5/6. Inside the house is white/cream sheathed cable , the inner core is one solid strand of copper. The cable from the aerials is much older, black & thinner. The UHF aerial is just over a year old & is modern & similar to those around us. It is also pointing the same way. The bloke who installed the aerial walked around the roof with his signal meter & said where the aerial is, is as good as it was.He installed the new aerial & connected it to the old one. The TV picture was good. Since that time the picture dissolves into scrambled lines & colours. for periods. The installers opinion is that Reception in Wanganui is variable, not good. On the map by Asatttv above thread I can see that Springvale is in a Green/white area of poor reception. At the moment I have bypassed the signal booster & blueray recorder & this is a little better. SOOO... I either have to replace the downlink cable from the existing rig & see what happens or try a Sat Box. Thinking about it at the moment. PJ	Poppa John (284)
1371808	2014-04-06 00:09:00	PJ i too have been having similar problems........... but i live in the cliff........ so cannot face aerial to roberts ave if it is still going cos i have a hill directly behind my house. I have it set up to face palmerstong north. a lot of the time i get good reception, then for a few days we get crap reception, lines, and colours or sound and no pic or pic and no sound........... and i know its none of the gear cos it is all new. A large amount of people i talk to have freeview glitches in wangas apparently we do not have good covereage..... i never had problems before the switch over ......:( if i was a little more financial than i am id consider sky......... but do find them a bit overated for the price. I have one tv off each aerial.. i have 2 aerials. both the same.(I was told that to get best signal each telly needs its own aerial) and at times one can get signal and the other cant.. but mostly if signal is bad on one its bad on both. i have multiple tvs in house but only 2 that run tv channels on it, the others are for xbox and movie watching but i would like to be able to add them to tv able........... can i do this with a splitter box idea? at some stage no rush ...... i hate going on the roof and in the ceiling... lol	beetle (243)
1371809	2014-04-06 04:22:00	As I see it PJ you are going to need a man with the tools and test gear to set your aerial up properly. Poor reception areas are a real challenge and at the end of the day your Aerial is absolutely critical. You may also find a Masthead Amplifier helpful but you’re looking at another $100. And as Billy has already mentioned, get rid of any aerials and their appendages no longer in use. At the end of the day unless you’ve got the gear and the agility to scamper around rooftops you are going to need a Tradesman, and finding a good one of them is a challenge in itself. :2cents: Good luck.	B.M. (505)
1371810	2014-04-06 05:21:00	If ya going to do that agility thing - if you're in a covered area get a double phased array with a return policy at the wholesalers check with them first as I said and get that $30 meter thingy to get a strength reading. But then when you determined the spot and if it is different to your old aerial placement you need to install the metal stand on your roof - man that's hard for me just hope you don't get leaks :eek: If you are just far away get a super long one like a 90 something element one. Or pay $70 odd to get someone there to just test it out if you can get it at all ...	Nomad (952)
1371811	2014-04-06 05:42:00	BM & Nomad. Being 75, partly paraplegic, crook heart, half blind & 80% deaf...I am not going to attempt any roof walking. I would only end up "sky walking". First thing I want to do is borrow a Sat Box & try that. PJ	Poppa John (284)
1371812	2014-04-06 05:48:00	Beetle...Glad to know it is not just us with this problem. There was an article in the Chronicle about it. It is well known by the TV people in Wanganui that a Translater is needed for Wanganui. However it if for one of the TV stations to do & nobody wants to pay for it. I belive Roberts Rd is gone, when digital came in the old way was discontinued. All the aerials now point to P/N. What you arew experiencing is the same as us. PJ	Poppa John (284)
1371813	2014-04-06 05:54:00	BM & Nomad. Being 75, partly paraplegic, crook heart, half blind & 80% deaf...I am not going to attempt any roof walking. I would only end up "sky walking". Very wise PJ, that was my understanding, but I'm picking someone is going to have to do some roof walking at some stage. Fingers crossed for the Satellite Dish aye.	B.M. (505)
1371814	2014-04-09 12:07:00	Might be worth to get a real RG6 cable to plug the TV to the wall if you are just using a cheap cable. We did that to ours and it gave a much better reception. We are also in tricky location which we have a double phased array exterior aerial. +1 If your cable from the wall to the TV has 3C-2V marked along it, you are likely to have severe signal loss and susceptibility to interference. Replacing a 3C-2V patch cable with at least RG-59 or better, RG-6 cable can make an astounding difference.	wuppo (41)
1371815	2014-04-09 21:07:00	You mention the cable to the roof is older and thinner, if it's a low quality or wrong type of coax you can lose a lot of signal strength through it. What worked for older VHF aerials is not always suitable for UHF but it often gets used just because it's already there. Improving the coax, removing any older VHF aerials and splitters, using a masthead amp - all will add some signal strength and could improve things. If however it's just where you are causing the problem none of these may help. It's all a bit hit and miss but an experienced local installer really should be familiar with all the potential issues in your area and able to sort it out or advise you if it'll always be a problem. If not maybe they just aren't any good.	dugimodo (138)
1 2 3 4