251 replies to this topic

[alanh]

James,
You are not game! as your lack of knowledge would laugh you out of the room or worse

With Mt Tambourine and Currumbin in the same coverage area and all sharing the same channels. Why did the ACMA make Mt Tambourne horizontally polarised with Currumbin and Bilbrough Lookout Springbrook vertically polarised?

AlanH

[James T Kirk]

alanh, on 06 May 2012 - 12:22 AM, said:

James,
You are not game! as your lack of knowledge would laugh you out of the room or worse

With Mt Tambourine and Currumbin in the same coverage area and all sharing the same channels. Why did the ACMA make Mt Tambourne horizontally polarised with Currumbin and Bilbrough Lookout Springbrook vertically polarised?

AlanH

Again rotating a transmitting antenna is so stupid, so impractical, so impossible that no one other than a fool who pretends to have knowledge of television transmission would suggest this.

I invite the reader to check out how many times in the past it has been explained to AlanH that digital television antenna polarity from Currumbin is vertically polaried and Tamborine horizontally polarised and that it is simply because the analogue services had this polarity originally and in the real world, something that AlanH is blissfully unaware, no sane broadcaster would have the 500000 residents of the Gold Coast change this.

All too often AlanH makes it easy to debunk anything he says, even his short irrational response above contains misquoted, misunderstood information from the ACMA website, he has misquoted the transmit antenna polarity for the Mt Springbrook site serving the Gold Coast.
Unfortunately AlanH not only has little knowledge in this area but when this is combined with an inability to faithfully comprehend information he sources on the web, he ends up making repeated mistakes. In the case of Mt Springbrook, it is a site that transmits horizontally to the Gold Coast of course.

Sadly it is glaring errors such as these that causes those of us who are actually in the industry to decide we need to correct what this individual does here. As for the moderators, they have been already proven ineffective since they have no knowledge of this field.

Again for the reader please be warned, AlanH is a master poster on this forum but by no means is he anywhere near being a master of the subject matter.

James

[DrP]

Come now JTK.  alanh has dismissed a country of 53 million people because it didn't fit his view of things.  Do you seriously believe a trivial 500,000 people even registers on his radar?

[Chopsus]

James T Kirk, on 06 May 2012 - 10:39 AM, said:

Again for the reader please be warned, AlanH is a master poster on this forum but by no means is he anywhere near being a master of the subject matter.

James

Perhaps put that last line I your sig as a warning to others?

[alanh]

DrP,
I gather you have not found any 'real' SFN installations using ATSC otherwise you would have posted the name of the commercial broadcaster and the channels and locations of the transmitters.

You need to read the SFN post I included recently to find out how its done

AlanH

[James T Kirk]

alanh, on 06 May 2012 - 07:00 PM, said:

DrP,
I gather you have not found any 'real' SFN installations using ATSC otherwise you would have posted the name of the commercial broadcaster and the channels and locations of the transmitters.

You need to read the SFN post I included recently to find out how its done

AlanH

AlanH

You misjudge DrP, you yourself are the one who is afflicted with the need enter into verbose retorts.
Re SFN's and how it is done, I suspect DrP will prefer to choose reference material from reputable sources.

Again for the reader please be warned, AlanH is a master poster on this forum but by no means is he anywhere near being a master of the subject matter.

James

[DrP]

It is quite hillarious to see alanh try to back-pedal his way out of his silly remarks and in typical fashion too.  When he is caught out, as in this thread where he has once again failed to comprehend reality regarding antenna polarisation, rather than accept his error he attempts to deflect it off onto another topic.

Unfortunately for alan, all he does is further embarrass himself by exposing his almost complete lack of knowledge on a broad range of topics.

For ages he dismissed the small mountain of technical documentation regarding ATSC SFNs trials because 'there weren't any live examples of an ATSC SFN therefore it does not work'.  Never mind that he in effect called many reputable names in the broadcast world such as Rhode and Schwarz liars.  Never mind that reality in conjunction with Thomson stood up and gave him the ultimate backhander by demonstrating a live in use ATSC SFN.  Like 53 million people in Korea watching ATSC, this didn't disuade dear alan.   Oh no, not at all.  He just declared that this was not a 'proper' or 'real' SFN.

Some call him stuborn.  No, this isn't stubornness.  This is sheer commedy entertainment at it's best.

[alanh]

DrP,
If ATSC was so good why hasn't it got past the trial stage?? They certainly not covering 240 km in one SFN.
So I left out South Korea as a small proportion of the total ATSC receiver population its tiny. USA >300 million + Mexico and other central America countries and South Korea.

What you cannot admit is that SFNs are commonly used in DVB-T/T2 countries but the ATSC allows such a small SFN its not worthwhile.

This is your deflection to not admit that ATSC SFN is not practical for real broadcasters.

Alanh

[nbound]

What about WVPT / WVPY? (synchronised digital broadcasts on both 11 and 21 in their license area.)

[alanh]

WVPT 11 STAUNTON, VA, WVPY 21 FRONT ROYAL, VA, US

The FCC licence makes no mention of synchronised transmission
WVPT is a community broadcaster which is in the PBS. "SHENANDOAH VALLEY EDUCATIONAL TELEVISION CORPORATION"
The main transmitter is only 10 kW on their band 3 channel 11 horizontally polarised signals and the transmitting antenna has very deep nulls in particular directions.
Repeaters are on channel 11 horizontally polarised with an ERP of 8 whole Watts!
For an equivalent field strength the UHF power needs to be 4 times the VHF power.


WVPY is a community broadcaster which is in the PBS. "SHENANDOAH VALLEY EDUCATIONAL TELEVISION CORPORATION"
The main transmitter is only 100 kW on their channel UHF 21 horizontally polarised signals and the transmitting antenna has very deep nulls in particular directions.
4 Repeaters are on channel 21 horizontally polarised with an ERP of 39 whole Watts!

Considering the FCC doesn't even specify the carrier frequency there is no requirement for the main transmitter frequency to be identical carrier frequency which is required for SFNs and no attempt to use the receiving antennas to assist the directional characteristics of the transmitting antenna to minimise interference. Its more likely an on channel repeater

On-air repeaters are not SFNs.

http://www.tvtechnol...nab-show/205991

AlanH

Edited by alanh, 07 May 2012 - 11:33 PM.

[nbound]

http://transition.fc...n/tvq?call=WVPT

Quote

  Licensee: SHENANDOAH VALLEY EDUCATIONAL TELEVISION CORPORATION
  Service Designation: DD   Digital Television distributed transmission system (multiple transmitter sites)

  Transmit Channel: 11     198 - 204 MHz Construction Permit
  Virtual Channel:  51   (viewer sees this channel number)

  Network affiliation:  PBS

  File No.:   BPEDT-20120321ADL Facility ID number: 60111
  CDBS Application ID No.: 1480720

   38° 09' 54.00" N Latitude   
   79° 18' 51.00" W Longitude (NAD 27)

  Digital Television distributed transmission system reference point.

and so-on for repeaters and WVPY....


Wikipedia: distributed transmission system-

Quote

In North American digital terrestrial television broadcasting, a distributed transmission system (DTS or DTx) is a form of single-frequency network in which a single broadcast signal is fed via microwave, landline, or communications satellite to multiple synchronised terrestrial radio transmitter sites. The signal is then simultaneously broadcast on the same frequency in different overlapping portions of the same coverage area, effectively combining many small transmitters to generate a broadcast area rivalling that of one large transmitter or to fill gaps in coverage due to terrain or localised obstacles.

alanh, on 07 May 2012 - 11:31 PM, said:

only 100 kW on their channel UHF 21

Only 100kW?

alanh, on 07 May 2012 - 11:31 PM, said:

...with an ERP of 8 whole Watts!
...
...with an ERP of 39 whole Watts!

As for the low powered infill sites, yes as Im sure your aware, infill sites are generally quite low powered, why waste energy on broadcasting to either unpopulated areas, or area which already have signal from elsewhere.

Edited by nbound, 08 May 2012 - 12:01 AM.

[alanh]

Nbound,
I did not use the link used I used the actual engineering data for the current licence http://licensing.fcc...tion_id=1482575 No mention of distributed transmission System. I've checked them all and none of them mention DTS.

I do not use Wikepedia because you cannot guarantee accuracy

Since the FCC uses the term, their definition is http://hraunfoss.fcc...A-09-1153A1.pdf. Note that the definition was created a year prior to the NTSC switchoff.

The map of the coverage areas shows high mountains.

If you compare their 39 W transmitter on an directional transmitting antenna to SEQ's SFN from the the Sunshine Coast to the NSW border for SBS on channel 36
Bald Mountain 15 kW
Gympie 5 kW
Gympie Town 0.5 kW
Mt Cootha-tha 200 kW
Currumbin 1 kW
Mt Tambourine 25 kW
Springbrook 1 kW.

See if you can find a US one like the above

AlanH

[MLXXX]

I must question why are we going through the details of an aspect of use of a broadcasting system that has not been adopted in Australia and which is unlikely to be used here for television broadcasting in the foreseeable future! This appears to be for no purpose other than to correct alanh, who in the past has tried to argue that SFNs do not work using the ATSC television broadcasting system. If he hadn't made that claim, we would not be having this current tangential discussion.

I note that a number of successful trials of ATSC SFNs have been reported over the years, such as one I mentioned myself in this forum last year [as part of my "enlightening alanh" activities] as follows:

MLXXX, on 15 May 2011 - 08:31 PM, said:

In recent years doubt has repeatedly been raised in this forum about the feasibility for digital terrestrial television broadcasting of using Single Frequency Networks that employ the ATSC standard (8VSB modulation). ATSC is used in the United States and Canada, parts of Central America, and South Korea.

This article caught my eye as an example of such a network recently put into operation (from http://www.thomson-b...fn-transmitters ):-

WMBC-TV Reaches New York Audiences With Thomson Broadcast ATSC SFN Transmitters

PARIS — March 29, 2011 — Thomson Broadcast announced today that New Jersey-based broadcaster WMBC-TV has successfully deployed an ATSC single-frequency network (SFN) to improve its coverage in New Jersey and New York City. The installation ― Thomson Broadcast's first implementation of an ATSC SFN solution — allows WMBC-TV to reach target viewing areas in New York that were not adequately served from the broadcaster's New Jersey transmitter due to interference from terrain and building profiles.

Thomson Broadcast upgraded WMBC-TV's existing DCX Paragon transmitter for SFN compatibility and provided a second Thomson Elite 1000 (ELT-3K80-ULA) solid-state transmitter located on the Empire State Building in New York. The addition of this second transmitter in SFN mode increased penetration into the targeted areas, significantly improving WMBC-TV's broadcast signal coverage.

Here is the topic description for a talk that was scheduled for 12th April this year at the Las Vegas Convention Centre ( http://expo.nabshow....iondetails.aspx ):-

Several ATSC Single Frequency Network (SFN) systems can be found operating throughout the US. Most of these systems include some sort of terrain shielding as part of their design. This paper highlights the challenges encountered and results achieved in implementing a "True SFN" system in New York City. An analysis of the design, implementation, and field test results, including receiver performance in this high multi-path environment, will be presented.

It would appear that despite the technical challenges, Single Frequency Networks have proved a feasible solution in some locations, to improve reception of ATSC digital TV.

The ATSC Recommended Practice for SFNs published in September 2004 was republished with revisions in September 2009. Here is the revised version: http://www.atsc.org/...dards/a_111.pdf

I note that currently a particular ATSC SFN is operated as follows (see http://en.wikipedia....gital_operation ):-

Digitally, WTVE is one of the first stations in the US to transmit using a distributed transmission system,^[7] having received special temporary authority from the FCC to operate WTVE-DT via eight (mostly low-powered) transmitters scattered across its coverage area rather than relying on one large signal.^[8]
The station transmits with on-channel boosters from sites in or near:

• WTVE-DTS1 Reading, Pennsylvania (225m 0.76 kW DA)
  
• WTVE-DTS2 Bethlehem, Pennsylvania (155m 2.8 kW DA)
  
• WTVE-DTS3 North East, Maryland (87m 0.11 kW DA)
  
• WTVE-DTS4 Quarryville, Pennsylvania (193m 1.0 kW DA)
  
• WTVE-DTS5 Myerstown, Pennsylvania (63m 1.15 kW DA)
  
• WTVE-DTS6 Lambertville, New Jersey (95m 0.6 kW DA)
  
• WTVE-DTS7 Philadelphia (378m 126 kW DA)
  
• WTVE-DTS8 Brockton, Pennsylvania (138m 4.25 kW DA)

This pattern effectively creates a tailored coverage area corresponding to one large main signal centered on Philadelphia, plus a series of boosters.

I don't see the purpose of discussing what is happening on the other side of the globe in relation to a digital television broadcasting system technically rather different to our own. There do not appear to be any learnings to be imported into Australia, suitable for discussion in this forum.

Edited by MLXXX, 08 May 2012 - 03:37 AM.

[DrP]

Let's not forget the real reason for this uhhh, tangent.  alanh's disconnect from the real world was demonstrated WRT antenna polarisation.  Rather than accept the error and move on he is attempting to derail the thread with ATSC SFN comments.  That ATSC SFNs have been demonstrated in the theoretical, in trials and in live use should, of course, be set aside as clearly alanh knows what he is talking about.

R&S, CRC, and even the broadcasters actually employing ATSC SFNs are all self deluded.  The viewers have all been taken in and are imagining they are seeing pictures on their screens.  In reality a man from the networks has broken in to their houses, hypnotised them all, and they are in fact sitting in front of screens displaying 'no signal'.

That or alanh really doesn't know what he is talking about.  I wonder which it is.  

[DrP]

Recap:  alanh does not understand why digital television transmissions in a given area have the same polarisation as analogue transmissions in that same area and wants to rotate the transmission antenna.

[nbound]

Sorry DrP - i took the bait... Yes where were we...

[mtv]

nbound, on 08 May 2012 - 06:45 AM, said:

Sorry DrP - i took the bait... Yes where were we...

Yes, in addition to being a Master Poster... alanh is a Master Baiter.

That's what forum trolls do..... incite arguments.

He's destoyed yet another thread (his own) by taking it waaaaaay off topic.

This is typical of alanh, but it has had some entertainment value..... especially his challenge to JTK...

alanh said:

I challenge you to rotate the transmitting antenna from horizontal to vertical and then explain it to all those who cannot receive the signal anymore!

That's just priceless...... certainly one to add to 'The Facts'.

Just when you think alanh has gone as low as he can go... he keeps digging.

[johndee]

I have just bought a USB tuner for my new laptop. Since I am intending to use it in various places I need a decent antenna I can take about with me. Are the so-called digital flat pannell ones any good, (Good for packing)  or are they just  hidden rabbit ears? I have searched the forum and found nothing on them, or misunderstood.
I was going to use rabbit ears but my son said his rabbits would object if I cut them off.
Thanks, JB

[nbound]

Generally the flat panel antennas are only as good as some of the various rabbit ears antennas about.  Where abouts are you considering using it?

[johndee]

nbound, on 19 July 2012 - 07:51 PM, said:

Generally the flat panel antennas are only as good as some of the various rabbit ears antennas about.  Where abouts are you considering using it?

It's for a laptop, which I intend to take round with me. The antenna which came with the USB stick only picks up SBS where I tried it, and the instruction manual says use a better one for TV  
I have a DSE powered rabit ears, but my wife collected up all the power packs she could find and put them away together, so I don't know what goes with what; the DSE is 12vbut power? polarity?
JB

[nbound]

Polarity is almost definately centre pin positive.

The reason I asked location(s), is that it may help identify a possible aerial.

[johndee]

nbound, on 19 July 2012 - 10:58 PM, said:

Polarity is almost definately centre pin positive.

The reason I asked location(s), is that it may help identify a possible aerial.

I mainly  expect to use it in Craigieburn, Melbourne. Mt Dandenong is almost visible from there, subject to smog.
JB

[nbound]

I dont know the area well enough to know if rabbit ears (with arms extended and laid flat) will pull in the stations there. Its unlikely SBS (as its UHF) will work with that setup though.

[alanh]

John,
Why don't you try the recommendations in the first post in this strand. You can buy one and some retailers will take it back if it's under 7 days.

If you have line of sight then the recommendations are likely to work.

AlanH

[matturn]

I have a computer based DTV tuner in a location with poor signal reception. I would like to recieve a channel on a horizontally polaraised channel 7 (184500 KHz) here. It would be difficult to mount an external antenna near the location.

I have tried a range of amplified and unamplified indoor antennas with no success (three sets of rabbit ears at various lengths and orientations, a high end Crest amplified model, an Antsig amplified model, "The Leaf", and a useless piece of coated wire that came with the tuner). They all seem to have poor VHF reception compared to their UHF reception (at least regarding the transmissions from Yatpool).

There is a window that roughly faces the right direction, but there is no line-of-sight to the tower, which is about 20kms away. There are no other remotely feasible sources of signal.

Another forum suggests www.winradio.com.au/home/ax31b.htm for a similar problem, but I was hoping for a cheaper solution.

Would I have a good chance of success mounting a caravan antenna indoors, or possibly even a rooftop style antenna this way? Is it possible to buy a single frequency (or VHF optimised) antenna?