Retune devices 13th March?

Forums › Freeview (DVB-T/DVB-S) › Retune devices 13th March?

1 | 2 | 3 | 4 | 5 | 6

481 posts

Ultimate Geek

#593238 10-Mar-2012 15:42

codyc1515: It should have never happened, they should have had the correct frequencies in the first place.

To take it a step further, they never should have had analogue TV in the first place - it should have been digital from day one?

codyc1515

1598 posts

Uber Geek
Inactive user

#593239 10-Mar-2012 15:45

Deev8:
codyc1515: It should have never happened, they should have had the correct frequencies in the first place.

To take it a step further, they never should have had analogue TV in the first place - it should have been digital from day one?

I think you all misunderstand, what I was saying was similar to saying well why don't we just rollout 4G now and then retune all the phones afterwards.

eXDee

4032 posts

Uber Geek

Trusted

#593643 11-Mar-2012 17:43

I'm curious, theres quite a significant drop in frequency.
we have 670mhz to 710mhz atm, and this is dropping to roughly 560 to 600mhz.

People often make comments about how telecoms 850mhz freq travels further and penetrates walls better than 900mhz. As that's how physics works, if i remember correctly :P

This is an even bigger difference of approx 100mhz. But will this actually cause a marked improvement in signal strength for some in fringe coverage? eg those who get shaky signal in bad weather for example? Or those picking up one mux and not others?

595mhz has a wavelength of 50.39cm.
705mhz has a wavelength of 42.52cm.

Edit: found http://www.afar.net/rf-link-budget-calculator/ in quest for some kind of answer.
I wish i knew what numbers to throw in here heh.

freitasm

BDFL - Memuneh
79250 posts

Uber Geek

Administrator

ID Verified

Trusted

Geekzone

Lifetime subscriber

#593659 11-Mar-2012 18:10

eXDee: People often make comments about how telecoms 850mhz freq travels further and penetrates walls better than 900mhz. As that's how physics works, if i remember correctly :P

Actually I think most comments on Telecom XT 850 MHz being better at penetrating walls were always in comparison to 2100 MHz, not 900 MHz.

eXDee

4032 posts

Uber Geek

Trusted

#593667 11-Mar-2012 18:14

freitasm:
eXDee: People often make comments about how telecoms 850mhz freq travels further and penetrates walls better than 900mhz. As that's how physics works, if i remember correctly :P

Actually I think most comments on Telecom XT 850 MHz being better at penetrating walls were always in comparison to 2100 MHz, not 900 MHz.

This is true. Would this mostly make such comments irrelevant when comparing to vodafone then, as they have 900mhz 3G? Is the difference between 850 and 900 insignificant?

Just read this
http://www.afar.net/tutorials/900-mhz-versus-2.4-ghz/

Radio waves continue to astound me. I'm just wondering if these freeview frequency changes will have any real world difference.

freitasm

BDFL - Memuneh
79250 posts

Uber Geek

Administrator

ID Verified

Trusted

Geekzone

Lifetime subscriber

#593670 11-Mar-2012 18:15

I believe the 850 MHz and 900 MHz won't be much different.

Behodar

10501 posts

Uber Geek

Trusted

Lifetime subscriber

#593672 11-Mar-2012 18:17

eXDee: Edit: found http://www.afar.net/rf-link-budget-calculator/ in quest for some kind of answer.
I wish i knew what numbers to throw in here heh.

I'm not sure exactly what numbers to put in there either but from a rough play it looks like a ~20 km increase in range (for the transmitter I tested, Te Aroha). I'm in fringe coverage myself and while it works most of the time I do get the occasional dropout so I'm looking forward to the changeover to see whether it fixes it for me.

Equinox IT

Cloud spending continues to surge globally, but most organisations haven’t made the changes necessary to maximise the value and cost-efficiency benefits of their cloud investments. Download the whitepaper From Overspend to Advantage now.

eXDee

4032 posts

Uber Geek

Trusted

#593673 11-Mar-2012 18:19

freitasm: I believe the 850 MHz and 900 MHz won't be much different.

Ah yes. I'd be curious to know whether 700 to 600mhz (ish) will be much difference.

Cyril7 signal methinks!

wilt64

246 posts

Master Geek

#593711 11-Mar-2012 20:05

Propagation wise the lower end of UHF will be better than the top end, to add to the equation coax and connector lossage will also be higher in the upper frequencies so in theory shifting to the lower end of UHF could increase signal by 3-4db (3db being twice the signal strength)

sbiddle

30853 posts

Uber Geek

Retired Mod

Trusted

Biddle Corp

Lifetime subscriber

#593731 11-Mar-2012 20:36

eXDee:

Radio waves continue to astound me. I'm just wondering if these freeview frequency changes will have any real world difference.

In some cases I suspect the answer will be yes.

knoydart

904 posts

Ultimate Geek

Trusted

#593793 11-Mar-2012 22:55

From the results of testing of UHF aerials available here in NZ that I´ve seen, most commercial aerials have slightly gain at the top of the UHF band compared to the lower frequencies in band, so possibly the shift in frequency downwards may not bring you much gain (if you pardon the pun).
The experience at other sites so far, has shown no noticeable improvement of reception to areas that have marginal coverage pre restacking, so try not to get your hopes up too much.

EDIT for spelling

wilt64

246 posts

Master Geek

#593934 12-Mar-2012 10:18

More info here regarding frequency changes and dates...

http://www.rsm.govt.nz/cms/policy-and-planning/projects/digital-terrestrial-television-frequency-restacking/timing-and-channel-information

Skolink

1081 posts

Uber Geek

#594008 12-Mar-2012 11:33

eXDee: This is an even bigger difference of approx 100mhz. But will this actually cause a marked improvement in signal strength for some in fringe coverage? eg those who get shaky signal in bad weather for example? Or those picking up one mux and not others?

I would have expected so, but my for my parents in Palmerston, receiving a signal from Mt Cargill (50km away), the signal got worse. Previously they could get the Kordia mux, which would break up a bit in bad weather. After the frequecny change they cannot receive any digital channels. It may be that the transmit power was lowered, antennas adjusted, or that my parents' UHF antenna has better gain at the higer frequency.

JimmyH

2886 posts

Uber Geek

#594371 12-Mar-2012 22:22

Skolink:
eXDee: This is an even bigger difference of approx 100mhz. But will this actually cause a marked improvement in signal strength for some in fringe coverage? eg those who get shaky signal in bad weather for example? Or those picking up one mux and not others?

I would have expected so, but my for my parents in Palmerston, receiving a signal from Mt Cargill (50km away), the signal got worse. Previously they could get the Kordia mux, which would break up a bit in bad weather. After the frequecny change they cannot receive any digital channels. It may be that the transmit power was lowered, antennas adjusted, or that my parents' UHF antenna has better gain at the higer frequency.

In my case I am looking forward to it. I take a signal off KauKau and can get the TVNZ and Mediaworks muxes, I can even get the TVNZ mux (which is the lowest frequency of the three) using a cheap set of powered bunny-ears in the bedroom. However, the Kordia mux is at a much higher frequency and I can't get it at all - even with a new rooftop UHF aerial cut for the correct frequencies, professionally installed with a masthead amplifier. The lower frequencies definitely propagate better in my experience.

Behodar

10501 posts

Uber Geek

Trusted

Lifetime subscriber

#594439 13-Mar-2012 08:03

In my area, the lower-frequency analogue channels look better than the higher-frequency ones, but it'll be interesting to see whether I get the same sort of results from digital.

1 | 2 | 3 | 4 | 5 | 6