66 replies to this topic

[Jeffry]

alanh, on Jan 21 2008, 10:16 PM, said:

Jeffry,
The power consumed by the transmitter increases as the channel number increases particularly at high powers. The coverage range is also less for the same radiated power. The losses in cabling is greater. So band 3 is the best compromise for large areas of Australia except where a local repeater is required. Then using the upper end of the UHF band is ok because the total power is small.

We are vacating 45-52, 54-70, 83-108 and 137 - 144 MHz (channels 0-5 & 5A) when analog is switched off.

AlanH

Quite so but Band 1 and Band 3 are subject to much more interference, especially for fringe areas like here -particularly power line interference in hot windy weather. Also FM interference with the proliferation of local transmitters -Pub Tab/2KY especially around here where frequency is exactly half of Prime 6.
UHF subjective picture quality is always much better.

When aggregation occured everyone had to buy a UHF antenna, possibly new masthead amplifier and many also got a new VHF aerial because all the old 5/6 regional specials didn't work on the new ABC channel 11 (unless turned sideways! and then they didn't work on Prime 6). So, it would have actually been cheaper for most viewers in regional areas (not just here) if all UHF was organised.

When analogue is switched off here we will have one only VHF digital on channel 12

Jeff

[M'bozo]

Whatever it takes



100K from main tx behind blocking terrain.

Very quiet (electrically) rural environment.

AP369 into MHU44G. (Hello alanh)

Measuring at flylead end: (No wallplate to minimise connector discontinuities, incoming cable straight into power injector via PAL female crimp):

Best channel:   C38  599.5MHz  76dBµV  cBER 7x10^3  aBER 9x10^5  MER 26  near C/N 36  far C/N 48
Worst channel: C50  683.5MHz  68dBµV  cBER 9x10^4  aBER  <10^6  MER 31  near C/N 28  far C/N 41

Subtract masthead gain of 44dB + cable/connector losses of 5dB gives 3/5 of 5/8ths of **** all signal: but it works. No safety margin of any kind, obviously.

To top it off, I had 2 more of similar in the same area, but these at least had minimum levels around 35dBµV which was nicer. I would get about 2 of these a month, and call after a couple of weeks to see how they are faring.

Last year 2 of these types of installs failed, one has been mentioned elsewhere in this forum, the other the local vegetation re-arranged itself in winter and the customer had to go to Aurora. I probably shouldn't have persisted with that one as it bit me big time.

These types of jobs are so much more fun than join the dots bread and butter installs. Now if they could only enclose Tasmania in a Faraday shield to prevent problems originating from mainland interference - but I digress.

Edited by M'bozo, 22 January 2008 - 07:34 PM.

[beeblebrox]

M, on Jan 22 2008, 08:33 PM, said:

These types of jobs are so much more fun than join the dots bread and butter installs.

Provided the customer's prepared to fork out the $$ for it.

M, on Jan 22 2008, 08:33 PM, said:

Now if they could only enclose Tasmania in a Faraday shield to prevent problems originating from mainland interference - but I digress.

maybe they should just tow it a bit further away like they did to NZ!!!

[Jeffry]

M, on Jan 22 2008, 08:33 PM, said:

Now if they could only enclose Tasmania in a Faraday shield to prevent problems originating from mainland interference

Is the proposed Farady shield going to be tall enough to include Optus C1? If they can't receive Aurora could start a revolt down there.

Jeff

[bellotv]

M, on Jan 22 2008, 08:33 PM, said:

Best channel:   C38  599.5MHz  76dBµV  cBER 7x10^3  aBER 9x10^5  MER 26  near C/N 36  far C/N 48
Worst channel: C50  683.5MHz  68dBµV  cBER 9x10^4  aBER  <10^6  MER 31  near C/N 28  far C/N 41

Marc
It would be hard to say which is the "best" channel.
C38 has the higher level and therefore more fade margin but it has lower Bit error ratio and MER than C50.

Still ,we DO do what ever it takes  .
Today I scraped the side of van on a fence post .DOH! and then got bogged at next job and got towed out by tractor but finally got the job done .
The  beaming smiles on the customers after watching 20 years of analog crude was worth the days shite.

Oh I love Rural NSW

[alanh]

Jeffry,
These allocations were made by the ACMA. There are only a few regions using horizontal and vertical polarisations. They include Goulburn Valley, Vic, Manning River NSW, ACT/Southern Tablelands NSW.

AlanH

[M'bozo]

bellotv, on Jan 23 2008, 07:53 PM, said:

Marc
It would be hard to say which is the "best" channel.
C38 has the higher level and therefore more fade margin but it has lower Bit error ratio and MER than C50.

Still ,we DO do what ever it takes  .
Today I scraped the side of van on a fence post .DOH! and then got bogged at next job and got towed out by tractor but finally got the job done .
The  beaming smiles on the customers after watching 20 years of analog crude was worth the days shite.

Oh I love Rural NSW

Richard,

you are correct, it probably is splitting hairs, and the fade margin is the reason I plumped for it as "best".

And to top it off, had almost a repeat of that one today in another bad spot.

Yep, scraped my previous van on a power pole & a star dropper, got bogged, etc etc, even had fun this afternoon getting out of a steep pot-holed dirt driveway with deep ruts by the gate where people spin their wheels after they've opened the gate, and the gate had a bloody bend just before it- aaarrrrrgh!

No worries, off for a week's holiday in sunny Adelaide, that'll burn the fog off for sure  

Marc.

[M'bozo]

bellotv, on Jan 23 2008, 07:53 PM, said:

Marc
It would be hard to say which is the "best" channel.
C38 has the higher level and therefore more fade margin but it has lower Bit error ratio and MER than C50.

Still ,we DO do what ever it takes  .
Today I scraped the side of van on a fence post .DOH! and then got bogged at next job and got towed out by tractor but finally got the job done .
The  beaming smiles on the customers after watching 20 years of analog crude was worth the days shite.

Oh I love Rural NSW

Richard,

you are correct, it probably is splitting hairs, and the fade margin is the reason I plumped for it as "best".

And to top it off, had almost a repeat of that one today in another bad spot.

Yep, scraped my previous van on a power pole & a star dropper, got bogged, etc etc, even had fun this afternoon getting out of a steep pot-holed dirt driveway with deep ruts by the gate where people spin their wheels after they've opened the gate, and the gate had a bloody bend just before it- aaarrrrrgh!

No worries, off for a week's holiday in sunny Adelaide, that'll burn the fog off for sure  

Marc.

[TV4FREE]

mtv, on Jan 21 2008, 12:18 PM, said:

Good concept. (had a giggle at the English translation)

The noise figures are a bit high.

Who's the Australian distributor?

We are Col. At least the noise figures are real.

On the flipside they do make a 40db masthead with 0.8 noise figure. Not Pots. Yes, thought it was bull dust until we actually tested it.

[bellotv]

TV4FREE, on Jan 24 2008, 10:42 AM, said:

We are Col. At least the noise figures are real.

On the flipside they do make a 40db masthead with 0.8 noise figure. Not Pots. Yes, thought it was bull dust until we actually tested it.

Is it cooled with liquid nitrogen  

[bruiser333]

alanh, on May 15 2006, 12:58 AM, said:

Filtering
To remove all non Digital TV signals Kingray fl3bmh. Use the configuration on page 4 bottom left, position A

It removes interference from impulse noise, AM, FM and CB radio (27 MHz and UHF), pagers and mobile phone repeater signals.

If someone could please confirm (and not to doubt Alanh!); can these high pass filters dampen the effect of impulse noise (cars, light switches etc), or are they typically used for removing AM, FM, CB, mobile etc signals?

Many thanks,

Bruce

[mtv]

bruiser333, on Feb 20 2008, 09:59 AM, said:

can these high pass filters dampen the effect of impulse noise (cars, light switches etc), or are they typically used for removing AM, FM, CB, mobile etc signals?

Bruce,

The filter is designed to remove/reduce RF signals at particular frequency ranges, typically those which are outside the required TV bands, as you mentioned, but not electrical impulse noise.

Impulse noise isn't removed directly by the filter, but it does help the problem by filtering out the RF bands that are most susceptible to being affected by impulse noise.

The filters are quite effective at reducing out-of-band RF signals, that often overload RF amplifiers and/or tuners, providing a cleaner digital signal to pass to the tuner. eg: less bit errors and a higher signal to noise ratio.

Whilst that filter may help a bit, the best way to tackle impulse noise is to ensure you do everything else to reduce\eliminate the problem first eg: correct antenna for digital (no elements for below band 3) the antenna should be one which is designed to capture a sufficiently high signal level with low BER, quadshield coax, including flyleads (installed as far away from electrical cables as possible) fully-shielded connectors, etc.

The antenna should be mounted at the best possible location providing the highest channel power (signal strength) and lowest bit error ratio (BER).

I have had success with the Kingray filter at tackling impulse noise, but have ensured I have done all the above as well.

Basically, anything that can assist in providing a higher signal to noise ratio, should help.

The key is to have a much higher signal level than the level of the noise.

This is often very difficult to achieve, especially if the source of the impulse noise interference is outside your control. ie: from equipment used in an industrial area.

[andrewlace]

Three amps that work very well on digital:
Fracarro JS2/RT, MAP106, MAP 206 and MAP 105.

Anyone else out there think these are good?

I have also heard good things about the Kingray MDA.

In areas where large gain 35+ dB are needed the MAP is essential.

Suggest that larger amps are problems waiting to happen and that in most cases a small amp is all that is needed (otherwise you risk overloading the amp and backing off a large amp is not the best solution).

Just know your levels before you amplify.

Also be advised that the noise figures for many amps are taken with two channels at the point where it works the best.

The MDA has the highest rated output (not gain but this feature alone can be very important) I've ever seen in a masthead amplifier and a very low claimed noise figure.

[alanh]

andrewlace,
Do any of the amplfiers you quote contain any filters? If so what frequencies

AlanH

[beeblebrox]

andrewlace, on Mar 3 2009, 04:01 PM, said:

Three amps that work very well on digital:
Fracarro JS2/RT, MAP106, MAP 206 and MAP 105.

Anyone else out there think these are good?

I have also heard good things about the Kingray MDA.

In areas where large gain 35+ dB are needed the MAP is essential.

Suggest that larger amps are problems waiting to happen and that in most cases a small amp is all that is needed (otherwise you risk overloading the amp and backing off a large amp is not the best solution).

Just know your levels before you amplify.

Also be advised that the noise figures for many amps are taken with two channels at the point where it works the best.

The MDA has the highest rated output (not gain but this feature alone can be very important) I've ever seen in a masthead amplifier and a very low claimed noise figure.

Hey Andrew, replying to a 12 month old post, gotta be a bit quiet down at laceys.    me I'm sitting here listening to cfa traffic on the vhf radio and waiting for the world to go back to normal....  plus it's too windy to get on a roof anyway.

For the bulk of digital jobs I still use the MDA20h or 20u...  or MHU34FS or the u44 if I really have no choice.

The problem with most mast head amps are they amplify Band 1 (and 2), have highish noise figures and very often are not chosen for the right environment.  So many saddle and screw cheapo amps still installed...  I don't get it, coz it takes a lot longer to do a saddle and screw connection than an f connection.

[bellotv]

andrewlace, on Mar 3 2009, 04:01 PM, said:

Three amps that work very well on digital:
Fracarro JS2/RT, MAP106, MAP 206 and MAP 105.

Anyone else out there think these are good?

I have also heard good things about the Kingray MDA.

In areas where large gain 35+ dB are needed the MAP is essential.

Suggest that larger amps are problems waiting to happen and that in most cases a small amp is all that is needed (otherwise you risk overloading the amp and backing off a large amp is not the best solution).

Just know your levels before you amplify.

Also be advised that the noise figures for many amps are taken with two channels at the point where it works the best.

The MDA has the highest rated output (not gain but this feature alone can be very important) I've ever seen in a masthead amplifier and a very low claimed noise figure.

My experience on UHF mastheads.
MAP105 is too noisy for use as a masthead amp where the signals are terminally weak,MHU34F/FS  is my preferred choice due to reliability.Alcad AM126 (UHF section used and terminator fitted to VHF input) has the edge over MHU34 in terminally weak situations  but I am scared of these after some early ones bit me on the bum.(I believe newer PCB material and QC have fixed these issues)

MAP105 are however excellent when driving long coax lengths when the received signal at the antenna is high to begin with (overcomes amp noise)
MAP105 seems to have a very noisy wideband amp stage with a very flat response and makes a great noise generator to use with a spectrum analyzer.Good for experimenting   cheap   

JS2/RT are also good amps if you need band 1 for analog as well.These amps have excellant overload ability.

[andrewlace]

Hi Bello TV - MAP 105 on High signal levels??
How low are we talking?

Should've mentioned the Alcad AM112 is also another option 24dB gain on UHF, <2.5dB although alanh probably did that, it is fixed gain though.

There are amps designed for super low signal levels such as pre balun amps, some mastheads work ok on low low signal levels.  The first time I did this I nearly fell over when close to 40dB signal strength (were talking years ago) on UHF went from acceptable to fantastic (am215 and pbu - now da5) on a blu920 running off arthurs seat transmitter from narre warren on analogue.  Failing that a masthead would be the way to go.

My point is that if you are on low signals, choose a good antenna and pbu combo running off a line or masthead amp.  Something designed for low noise not lotsa hoot (the two are generally diametrically opposed.

Things are actually really busy with some of the new gear (plugging new products warning) ESX200 and some other new cool gear coming through nudge nudge wink wink.

What can I say, google is great and so is this forum if you're trying to do market research.

Hi Alanh, (JS2RT is a wideband amp channel 0-69), the MAP105 is UHF only (can't comment on anything other than the results I've had with these on gippsland for the MAP105).

Please be aware that most mastheads contain some forms of filtering however, they are not designed with every filter under the sun, if you want that then get a single channel head end (K series).

In honest truth I can't be totally sure the filtering in each of these amps, I know some amps come with specific pager filters built in, but as far as I'm aware the more filters = more noise.  The less filters the better the return loss and the lower the noise figure (compared to the same amp depending on the addition of extra unnecessary filtering).  If filtering is not required (sans matv systems where harmonics will kill, huge output levels are required and balanced signals over long runs) then don't use it.  Filtering is most effective before amplification.  That said every amplifier is designed with some form of filtration inside of it.

That said the MAP 106 and 206 have FM traps because they need them (big vhf amps).  The JS2RT doesn't have an FM filter built in and in 99% of the time running VHF it is fine.

Hi Beeblebrox,  Will get killed for saying this - there is nothing categorically wrong with screw and saddle generally the problem is feedback from the amplifier (due to no shielding - which can still be an issue with some f type amplifiers with high output levels or even poorly shielded cable).
That said F connectors are nifty things and darned easy and I would choose an f connector due to the choice of good stuff out there with an f connector on it, but I hear it too often that an f connector makes something good and no f connector makes something bad (mainly from very nice sparkies).

Haven't had any problems with band one probably because much of my installation experience was using log periodic that rejected band 1 and were far less sensitive to noise than a combo (Alan will like me for saying that).

That said I agree with the logic of not amplifying what you're not using, the only issues I've ever experience with band 1 was when it was 20+ dB stronger than anything else and then for the sake of neatness (and getting analogue working) bang on a low band attenuator.  As you've rightly said people should be careful about the amps they use, but if people aren't measuring BER then how can they know if an amp's working or not?

Although generally speaking if something is screw and saddle it is pre digital as every man, his dog, his wife, his 2.3 children and even his maccaroni and tuna sandwich want f connector (that said I agree sincerely with the maccaroni sandwich).  This of course means that lots of screw and saddle stuff does not work on digital.  And, yes I have replaced in the past large quantities of old screw and saddle junk (and a few f type amps too).

Hey thanks for the posts guys, this is keeping things interesting

[alanh]

Andrew,
I have not been asking for single channel amplification because the only customers will be TV station off air monitoring. For the rest of us we want 5 channels simultaneously.

What I had in mind is the following band pass filters
Band 3 174 - 230 MHz (chAU 6 - 12) (chEU 5 - 12)
Band 4 518 - 590 MHz (chAU 27 - 36) (chEU 27 - 35)
Band 4+ 518 - 680 MHz (chAU 27 - 49) (chEU 27 - 45)
Band 5 590 - 820 MHz (chAU 36 - 69) (chEU 35 - 59)

chAU is Australian channel numbers
chEU is European channel numbers.

Remember that all state capital city main transmitters are all band 3 & 4 only.

AlanH

[bellotv]

Andrew
My comments are from experience in areas where you get less than 30dBuV after stacking 20RD4 and comparing MER and BER on T40a .AM126,MHU34 and MAP105 were compared as they have similar gains  IE around 35dB +/- 1.

The MAP105 would have MER down at 19 or less while the Alcad was just holding at 24 .The BER was similarly effected although I can't remember exact figures now.,however I wouldn't proceed with any install if MER is averaging 21 or less.Infact I prefer 24 as the minimum without strongly advising customers that problems will most likely occurr  if we proceed

Many of my jobs in the country involve locating spots often 50-100 meters away and therefore require high gain amps especially if splitting to several rooms is required at the other end.MAP105 is fin in these situations if you've got around 50dBuV from the antenna.
I've used AM112 these are an excellent 24dB low noise UHF amp.

Am yet to try PBUs.

[webbiegareth]

Hi everyone,

Since this thread is very old, what are the main amps the installers are using today? Has anything new & improved come out specifically for Aust digital TV yet?

[mtv]

webbiegareth, on Oct 22 2010, 03:48 PM, said:

Hi everyone,

Since this thread is very old, what are the main amps the installers are using today? Has anything new & improved come out specifically for Aust digital TV yet?

Not really much has changed since the last discussions.

As per my reply in your other thread asking about amps... they should be avoided wherever possible.

Edited by mtv, 22 October 2010 - 07:02 PM.

[alanh]

webbiegareth,
When I edit the pinned "Get the best reception" and associated posts the editing date appears at the bottom of the post automatically. I do check these sites periodically and there has been no change.
I have tried to get the manufacturers to produce amplifiers which will remove any frequency below 174 MHz (channel 6) as well as 230 - 519 MHz (between channel the top edge of channel 12 and the bottom edge of channel 27). I am yet to have any success. You can however use a wideband amplifier preceeded by a filter which will do the job. If you are in a UHF area only then the Kingray UHF amplifier range is quite suitable.

Kingray also make the MDA20H which does remove interference from TV channels 0 - 5A, FM and two way radios.

AlanH

[HillsTas]

Has anyone tried the Hills Q-AMP and/or the LARA (UHF Only version of Q-AMP)

The Q-AMP has filters for Cellular, Pager, FM and Band 2. Picks up only 45-70MHz in Band 1
It also can be Local or remote selective (VHF Local 0-8dB, Remote 22-30dB, UHF Local 0-10dB, Remote 24-34dB)
AFAIK it is the only masthead which can be dialled down to 0dB, but please feel free to prove me wrong.

At a trade price of $60, they are pretty well priced too! (Includes either PAL or F injector)

Cheers

Dave

[alanh]

Dave,
Does Hills have any masthead amplfiers which will only amplify VH (174 - 230 MHz) and/or U (519 - 820 MHz)?

The SA Regional areas use analog channel 1 54 - 62 MHz for Spencer Gulf and SE SA they will be switched off on 15th December with the 7 Victorian Regionals (4 high powered)  about 6 months after that.

Tasmania only has ABT 2 is the only band 1 transmitter on the island.

AlanH

[beeblebrox]

HillsTas, on Oct 25 2010, 08:50 AM, said:

Has anyone tried the Hills Q-AMP and/or the LARA (UHF Only version of Q-AMP)

The Q-AMP has filters for Cellular, Pager, FM and Band 2. Picks up only 45-70MHz in Band 1
It also can be Local or remote selective (VHF Local 0-8dB, Remote 22-30dB, UHF Local 0-10dB, Remote 24-34dB)
AFAIK it is the only masthead which can be dialled down to 0dB, but please feel free to prove me wrong.

At a trade price of $60, they are pretty well priced too! (Includes either PAL or F injector)

Cheers

Dave

no as it amplifies band 1.

I asked hills to supply something better than a Kingray MDA20H from a noise and band perspective five years ago but haven't seen one yet.   until you can do that I'll stick with the kingray and Johansens and ikusi's (different amps for different jobs)