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.




4 posts

Wannabe Geek


# 251620 3-Jul-2019 12:33
Send private message quote this post

First a quick description of my setup...

 

A clear view of Mt Campbell transmitter across the width of Tasman Bay
- via UHF signal to
Phased array UHF antenna (https://www.jaycar.co.nz/heavy-duty-uhf-phased-array-tv-antenna/p/LT3154) with 24dB Masthead Amplifier (https://www.jaycar.co.nz/24db-masthead-amplifier-optimised-for-digital-tv/p/LT3254)
- connected with RG6 coax to
Panasonic DMR-XW380 DVD Recorder (twin tuner & HDD)
- connected from antenna passthru with generic coax cable to
Panasonic TH-L42E6Z LCD TV

 

I noticed that my antenna was mounted with Horizontal polarity, but Mt Campbell is Vertical (https://freeviewforum.co.nz/tip/rf). So I checked the signal levels on the TV, and all channels were Quality 10 Strength 10 except CH27 (mostly local Mainland TV programs), which was Q5 S10.

 

I rotated the antenna to Vertical, which improved CH27 to Q7 S10.

 

ISSUE: Sometime later I noticed ALL channels on the DVD Recorder had gone to Q0 S10 - No Signal! Running the auto-tune didn't detect any stations. But reception on the TV itself was still just fine.

 

It took me a while to make the connection, but when I returned the antenna to Horizontal, I could auto-tune the DVR, and all was well. I've repeated the antenna rotation a couple of times to confirm results.

 

The reason for correcting the polarity was an attempt to improve CH27 Mainland TV reception - in spite of good signal metrics, there is still quite frequent pixellation.

 

Can anyone offer a clue to what's going on?

 

 


Create new topic
6762 posts

Uber Geek
+1 received by user: 634

Trusted
Subscriber

  # 2269208 3-Jul-2019 12:36
Send private message quote this post

Hi, can you please post a photo of the current antenna showing us its orientation, polarity wise

 

Cyril


22263 posts

Uber Geek
+1 received by user: 4785

Trusted
Subscriber

  # 2269211 3-Jul-2019 12:41
Send private message quote this post

Somethings broken in the antenna connection when you moved it?





Richard rich.ms

 
 
 
 


24 posts

Geek
+1 received by user: 2


  # 2269309 3-Jul-2019 13:46
One person supports this post
Send private message quote this post

With those original high signal levels I'd guess it's quite likely overload of that masthead amplifier now..

 

The opposite pole was probably attenuating it enough for things to work ok before.

 

 

 

If you can try and get a direct connection to the antenna without the amp, it's always a better arrangement when there's sufficient signal level!


1953 posts

Uber Geek
+1 received by user: 132


  # 2269371 3-Jul-2019 14:34
One person supports this post
Send private message quote this post

Why use a masthead amp if you can see the Tx across the bay?  Take out the masthead amp and try again.


569 posts

Ultimate Geek
+1 received by user: 124


  # 2269373 3-Jul-2019 14:39
Send private message quote this post

I agree with removing the amp, probably way too much signal

DVB-T is a place about getting the right balance



4 posts

Wannabe Geek


  # 2269380 3-Jul-2019 15:11
Send private message quote this post

Thanks for your replies.

 

I installed the antenna Horizontal again without checking when I moved house, then added the pre-amp to get better signal levels. I thought maybe the distance was too much.

 

Click to see full size

 

Will remove the pre-amp as soon as this weather improves, and let you know!


6762 posts

Uber Geek
+1 received by user: 634

Trusted
Subscriber

  # 2269381 3-Jul-2019 15:14
4 people support this post
Send private message quote this post

OK, so just confirming that your antenna as shown in the picture is infact vertical, I just needed to ask as some folk get a little confused with arrays as to which way is what.

 

As others have said I doubt you need that preamp, how far does google maps say you are from the tx.

 

Cyril


 
 
 
 


317 posts

Ultimate Geek
+1 received by user: 78


  # 2269400 3-Jul-2019 15:44
Send private message quote this post

The picture you uploaded shows your antenna mounted vertically, (not horizontally). It is the driven elements that determine whether it's vertical or horizontal, not the antenna as a whole.

I also recommend removing the Masthead amplifier (and disconnect the power supply that feeds it) in case it is being overloaded with strong signal either from the TV station, or an unrelated nearby source.

1224 posts

Uber Geek
+1 received by user: 229


  # 2269432 3-Jul-2019 17:46
Send private message quote this post

You don't need the amp anywhere in Stoke, Richmond, Tahuna ,Atawhai etc

 

removing it should fix things.

 

 




4 posts

Wannabe Geek


  # 2269438 3-Jul-2019 17:59
Send private message quote this post

Well the weather didn't improve, but I went out & removed the pre-amp anyway.

 

Result? Magic Eye pictures on the TV's channels, and nothing on the DVR! I probably got some water in the connection :-(

 

Anyway, I grabbed the old rabbit's ears from the spare bedroom, and am running perfectly satisfactorily for now. So I'll get tonight's recordings done, and recheck connections in tomorrow's Nelson sunshine!


160 posts

Master Geek
+1 received by user: 37


  # 2270296 5-Jul-2019 10:02
2 people support this post
Send private message quote this post

looks like you got confused with the polarity.

 

also, if rabbit ears work, you definitely don't need the masthead amp.

 

 




4 posts

Wannabe Geek


  # 2270405 5-Jul-2019 12:29
Send private message quote this post

Strange, I thought I posted an update yesterday, but it's gone...

 

I rechecked reception yesterday when everything was dry outside, and was seeing Quality 10 Strength 10 on all channels except CH27, which is now Q10 S9 on the TV and Q10 S6 on the DVR. Everything's looking great.

 

The photo shows the new antenna position (Vertical), so you were right - signal overload from the pre-amp.

 

Thanks your your helps!


1224 posts

Uber Geek
+1 received by user: 229


  # 2270667 5-Jul-2019 19:23
Send private message quote this post

Mainland will always be lower as they are on Takaka Hill not MT campbell.

 

 


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 »

Dunedin selects Telensa to deliver smart street lighting for 15,000 LEDs
Posted 18-Jul-2019 10:21


Sprint announces a connected wallet card with built-in IoT support
Posted 18-Jul-2019 08:36


Educational tool developed at Otago makes international launch
Posted 17-Jul-2019 21:57


Symantec introduces cloud access security solution
Posted 17-Jul-2019 21:48


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



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.