Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.




340 posts

Ultimate Geek
+1 received by user: 32


# 210546 1-Apr-2017 15:08
Send private message

Hi GZ

 

I'm having issues with reception of the channels on UHF Ch36 (Maori, Prime etc).

 

Three images are posted here:

 

https://imgur.com/a/diuMA

 

The first is Ch34 signal information, which is all OK and these channels work without any issues.

 

The second is Ch36, which has 100% strength, but very poor quality. As you can see on the TV, this results in lots of blocking and all channels in this block are unwatchable.

 

The third image is what my antenna looks like.

 

I'm in Christchurch in an area that Freeview tells me should be fine for signal.

 

I'm now annoyed with the situation enough to start troubleshooting.

 

Where should I start? Is there something specific to Ch36 that might explain why only these channels aren't working? Would a new antenna solve this issue?

 

Thanks in advance!


Create new topic
2262 posts

Uber Geek
+1 received by user: 470

Lifetime subscriber

  # 1752702 1-Apr-2017 15:18
Send private message

The Lincrad is a poor choice of antenna but should be good if you have LoS (line of sight). What suburb are you in??





Ross

 

Spark FibreMAX using Mikrotik CCR1009-8G-1S-1S+

 


Speed Test




340 posts

Ultimate Geek
+1 received by user: 32


  # 1752710 1-Apr-2017 15:34
Send private message

Thanks for the quick reply. Yeah the antenna is a relic and has been on the house for years. Suburb is Russley. There is a reasonably bushy big tree (Japanese Maple) about 5m from the aerial so not clear LoS to the hills. I'm happy to replace the aerial, I just need some guidance on what type, and (hopefully) an understanding of why it's only Ch36 that's the issue.

 
 
 
 




340 posts

Ultimate Geek
+1 received by user: 32


  # 1752711 1-Apr-2017 15:37
Send private message

Here's a pic looking toward the transmitter showing relative location of aerial and tree:

https://imgur.com/prMUSNw

919 posts

Ultimate Geek
+1 received by user: 46


  # 1752873 1-Apr-2017 20:19
Send private message

Try this...

 

 https://www.matchmaster.co.nz/digital-tv-antennas/02mm-mdu36/




340 posts

Ultimate Geek
+1 received by user: 32


  # 1752880 1-Apr-2017 20:52
Send private message

Thanks a lot, I was recommended that unit on the Matchmaster website. Is this one pretty much the same thing?

http://www.freeviewshop.co.nz/large-phased-array-aerial-freeview-p-595.html

I'm also keen to try and understand the physics at play here. Is my current aerial not doing well because it struggles at the higher frequency of the Sky/Korda channel, or because the tree is attenuating more signal at this higher frequency than the lower frequencies of the Mediaworks and TVNZ channels, or something else? It seems a bit strange that two out of three channels work perfectly, that's all.

1134 posts

Uber Geek
+1 received by user: 82

Trusted

  # 1752900 1-Apr-2017 21:43
Send private message

ashtonaut: Is my current aerial not doing well because it struggles at the higher frequency of the Sky/Korda channel, or because the tree is attenuatig more signal at this higher frequency than the lower frequencies of the Mediaworks and TVNZ channels, or something else?

 

In my opinion...

 

The second guess likely explains more of what's going on than the first. I expect you'd get a fair amount of signal disturbance - reflections and/or partial blockage - as the signal passes through/around the tree and its leaves, particularly on a windy day.

 

That aerial is a general purpose, fairly wide-band UHF/VHF aerial. It doesn't have particularly high gain. As Spyware said: it can be okay if you have line-of-site, but may not be satisfactory (due to insufficient gain and/or its reflection handling) for more trying conditions.

 

You only notice problems for the one particular transmission, but if you checked with a spectrum analyser, you may well find that signal in that location for all of the transmitters is close to the receive threshold. In other words: you could say you're lucky to receive the transmissions that you do receive with that aerial rather than the other way around. wink




340 posts

Ultimate Geek
+1 received by user: 32


  # 1753002 2-Apr-2017 07:37
Send private message

OK, thanks, that makes sense. I originally expected to have to buy a new aerial for Freeview, but was pleasantly surprised when I didn't need one - sounds like that was 'only just' and I probably did need a new one.

I also vaguely recall that during winter last year (when the tree didn't have any leaves) that the reception was better on the Ch36 channels - this would further reinforce the tree theory.

I'll check out the aerials in the links above and see if I can get one of those up and running.

 
 
 
 


576 posts

Ultimate Geek
+1 received by user: 196


  # 1753009 2-Apr-2017 08:04
Send private message

The other thing to look at when replacing the aerial would be to also replace the lead from the aerial to the TV.

 

Link to the TM seller I bought our lead from.

 

Aerial lead




340 posts

Ultimate Geek
+1 received by user: 32


  # 1753232 2-Apr-2017 16:08
Send private message

So I spent a couple of hours today moving the aerial from one side of the house to the other. Now it's not pointing directly into the tree any more. It is still not perfect LOS as there are trees on other properties further away.

 

Unfortunately no change to the original issue. I realise it might have been a long shot, but it was worth a try. If a new aerial doesn't fix it then I will replace the lead as well (though that will be a real pain).


919 posts

Ultimate Geek
+1 received by user: 46


  # 1753266 2-Apr-2017 16:57
Send private message

 Did you have someone watch the signal information on the television when you were aligning the antenna? If not try moving the antenna to the extreme so signal is lost, then move antenna around slowly until the quality moves up. Less signal but more quality perhaps. 




340 posts

Ultimate Geek
+1 received by user: 32


  # 1753276 2-Apr-2017 17:14
Send private message

Yeah I might need to give that a go, I only had 2 minutes of patience by that point. I'm getting closer to pulling the pin and paying for someone who knows what they are doing to come around.

On that note, can anyone recommend a Christchurch antenna company that know what they are doing and won't charge a fortune?

Create new topic



Twitter and LinkedIn »



Follow us to receive Twitter updates when new discussions are posted in our forums:



Follow us to receive Twitter updates when news items and blogs are posted in our frontpage:



Follow us to receive Twitter updates when tech item prices are listed in our price comparison site:





News »

New Zealand government unveils new digital service to make business easier
Posted 16-Jul-2019 17:35


Scientists unveil image of quantum entanglement
Posted 13-Jul-2019 06:00


Hackers to be challenged at University of Waikato
Posted 12-Jul-2019 21:34


OPPO Reno Z now available in New Zealand
Posted 12-Jul-2019 21:28


Sony introduces WF-1000XM3 wireless headphones with noise cancellation
Posted 8-Jul-2019 16:56


Xero announces new smarter tools, push into the North American market
Posted 19-Jun-2019 17:20


New report by Unisys shows New Zealanders want action by social platform companies and police to monitor social media sites
Posted 19-Jun-2019 17:09


ASB adds Google Pay option to contactless payments
Posted 19-Jun-2019 17:05


New Zealand PC Market declines on the back of high channel inventory, IDC reports
Posted 18-Jun-2019 17:35


Air New Zealand uses drones to inspect aircraft
Posted 17-Jun-2019 15:39


TCL Electronics launches its first-ever 8K TV
Posted 17-Jun-2019 15:18


E-scooter share scheme launches in Wellington
Posted 17-Jun-2019 12:34


Anyone can broadcast with Kordia Pop Up TV
Posted 13-Jun-2019 10:51


Volvo and Uber present production vehicle ready for self-driving
Posted 13-Jun-2019 10:47


100,000 customers connected to fibre broadband network through Enable
Posted 13-Jun-2019 10:35



Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.


Support Geekzone »

Our community of supporters help make Geekzone possible. Click the button below to join them.

Support Geezone on PressPatron



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.