21 replies to this topic

[alanh]

V4

Channel range: 27 – 36 (519 - 589 MHz)
I would have noted which antennas comply with Australian Standard for TV antennas AS 1417.1(Int)-2011. However none have done so, so far.

A guide to antenna selection
Please note that within this category antennas come in different sensitivities which I have tried to match to the colours used in the DBDE’s “My Switch” map.
From the manufacturers’ websites, I have selected the antennas which are designed for the above channel range. This maximises the reliability of the received signal. I have not included antennas which are designed to receive a wider range of channels.
Caveats:
The DBCDE has not released the signal strength range represented by each colour
1. Antenna specifications supplied by manufacturers often quote a maximum sensitivity  for a particular channel  and for other channels there is less sensitivity
2. With one exception the manufacturers do not specify If there sensitivity is referenced to an antenna which is equally sensitive in all directions in 3 dimensions or one which is sensitive in a figure of 8 direction pattern. This makes the first reference 2 dB less sensitive to that for a dipole.
3. The height of the antenna above the ground (up to 10 metres)
4. Surrounding obstructions and reflecting surfaces.
If there is any doubt the signal strength, carrier to noise ratio, uncorrected error rate and modulation error rates need to be measured with a digital field strength meter. All Digital Ready Endorsed installers have these meters. For reliable reception under virtually all conditions the readings must be better than the values in section 9 of Australian Standard 1367:2007 (ignoring the analog TV requirements).
Pink
Hills Hunter Mk2
Matchmaster 02-MDU18/url]
ANTPA05MINI
ANTLPA16B
Digitek 01CUPA1

Dark Blue
Hills Ultimax 36
Matchmaster 02-MM-EE06
ANTPA2
ANTL32P
ANTM-EE06
ANTL32SS
2ANUPA2
Fracarro PU8F
Digitek 01CUPA2
AcademyTV ATVUltimate

Light Blue

Hills TMX18B4
Digimatch 02MM-DR18A
ANTSMU418
Digitek 01BU418

Diagrams
Masthead Amplifier
Firstly get the maximum signal from the antenna. You can then add a masthead amplifier to overcome the signal loss going down the cabling.
Amplifiers need to contain a filter to remove all signals except the ones you want.
Kingray MHU24FS
KMU32FSDP
Kingray MHU34FS
Kingray MHU42FS
Digimatch 10MM-MA24UP

Filters
These filters are unnecessary if the above amplifiers are used because they already contain the appropriate filters.
Matchmaster 10MM-J40BF, 10MM-J40DF or 10MM-J34BF
GME Kingray FL3BPMH Switch it to exclude V_L
09MM-HL12F Diplexer Domestic catalog section 9.2 Use input 2 for band 3 and input 3 for band 4 & 5. Input 1 is not used.
The antenna signals are fed into one of the above filters/diplexers and then into a wideband amplifier such as
GME Kingray MHW34FE, MHW34FS or MHW42FS  
Hills A2A

Multiple outlets
In single dwellings splitters with F connectors are used to feed multiple outlets. A two way splitter halves the signal to each outlet as well as a small extra loss for the splitter itself. To overcome this loss a distribution amplifier can overcome this loss. For this channel range use a
[url="http://www.gme.net.au/products/matv/matv-distribution-amplifier/MDA20U"]MDA20U . If the distribution system is also carrying band 3 as well use the MDA20H instead
This amplifier is powered through the antenna cable, so the power inserter which is placed between the TV and the wall, must be connected to the splitter’s outlet called power pass. The above amplifier is then connected between the antenna and the splitter.
Note:
1. The need for this amplifier can be identified by using signal strength measurements above.
2. The signal strength meters in receivers are not very accurate.


AlanH

Edited by alanh, 31 October 2011 - 11:38 PM.

[alanh]

.

[James T Kirk]

alanh, on Jul 9 2011, 08:49 PM, said:

V4

Channel range: 27 – 36 (519 - 589 MHz)
I would have noted which antennas comply with Australian Standard for TV antennas AS 1417.1(Int)-2011. However none have done so, so far.

Caveats:

AlanH

Such a long list of caveats indicates an illconsidered premature post.
A relentless zeal to prolifically post first is again a waste of time for the reader.

James

Edited by James T Kirk, 09 July 2011 - 09:55 PM.

[DrP]

This thread mentions a survey, but I see no survey here.  Will the topic author please present his list of questions.  

[James T Kirk]

Dear All

It appears AlanH has editing privileges beyond the rest of us.
Again, the moderators of this forum should be condemned for supporting this privilege, effectively condoning the errant AlanH.

The AlanH July 2011 post above was reduced to a dot and the May 2009 edited with the July 2011 deleted post.
I consider it very dishonest to change a post when another has responded to it.

Such activity dictates an increased responsibilty on our part to scrutinise and correct the errant AlanH as regularly as possible to minimise the reader being misled or given incorrect information or advice.

James

Edited by James T Kirk, 10 July 2011 - 09:09 PM.

[mtv]

James T Kirk, on Jul 10 2011, 08:58 PM, said:

Dear All

It appears AlanH has editing privileges beyond the rest of us.
Again, the moderators of this forum should be condemned for supporting this privilege, effectively condoning the errant AlanH.

The AlanH July 2011 post above was reduced to a dot and the May 2009 edited with the July 2011 deleted post.
I consider it very dishonest to change a post when another has responded to it.

Such activity dictates an increased responsibilty on our part to scrutinise and correct the errant AlanH as regularly as possible to minimise the reader being misled or given incorrect information or advice.

James

This post from DrP (in reply to evidence of alanh editing posts without the 'edited' line being displayed) is relevant, with forum mods denying alanh has that editing privilege, which is proven to be factual that he does have such a privilege and it is clearly being abused by him.

What is the relationship between alanh and the owner/moderators of this forum, that they permit him to continually abuse such a privilege?

http://www.dtvforum....&...t&p=1717187

[andrewlace]

Facepalm; Hi Alan, What testing did you do of these products?  Thanks. "Firstly get the maximum signal from the antenna. You can then add a masthead amplifier to overcome the signal loss going down the cabling. Amplifiers need to contain a filter to remove all signals except the ones you want." Um, all amps have some sort of filtering.  Something like a channel selective filter or a K series headend will do channel filtering.  What you've mentioned here is totally wrong.  The amplifiers that you recommended that I bothered to look at in the Kingray range do not have the feature set you have defined as necessary.  Dig around you'll see that the features you've mentioned are not built into a basic masthead amplifier.  I'm not familiar with the other (non GME Kingray) amplifiers you have listed here but I wonder if other installers would be familiar of the features.
What if amplifying is unnecessary or causes amplifier or tuner overload?

Channel range: 27 – 36 (519 - 589 MHz)
I would have noted which antennas comply with [url="http://infostore.saiglobal.com/store/Details.aspx?ProductID=1452023"] Australian Standard for TV antennas AS 1417.1(Int)-2011 [/url]. However none have done so, so far.

A guide to antenna selection
Please note that within this category antennas come in different sensitivities which I have tried to match to the colours used in the DBDE’s “My Switch” map.
From the manufacturers’ websites, I have selected the antennas which are designed for the above channel range. This maximises the reliability of the received signal. I have not included antennas which are designed to receive a wider range of channels.
Caveats:
The DBCDE has not released the signal strength range represented by each colour
1. Antenna specifications supplied by manufacturers often quote a maximum sensitivity  for a particular channel  and for other channels there is less sensitivity
2. With one exception the manufacturers do not specify If there sensitivity is referenced to an antenna which is equally sensitive in all directions in 3 dimensions or one which is sensitive in a figure of 8 direction pattern. This makes the first reference 2 dB less sensitive to that for a dipole.
3. The height of the antenna above the ground (up to 10 metres)
4. Surrounding obstructions and reflecting surfaces.
If there is any doubt the signal strength, carrier to noise ratio, uncorrected error rate and modulation error rates need to be measured with a digital field strength meter. All Digital Ready Endorsed installers have these meters. For reliable reception under virtually all conditions the readings must be better than the values in section 9 of [url="http://infostore.saiglobal.com/store/Details.aspx?ProductID=357890"]Australian Standard 1367:2007[/url] (ignoring the analog TV requirements).
Pink
[url="http://www.hillsantenna.com.au/cattleprod/products/A1303PHA"]Hills Hunter Mk2 [/url]
[url="http://www.matchmaster.com.au/domestic/vhf-antennas/phased-array-antennas"]Matchmaster 02-MDU18/url]
[url="http://www.naspl.com/uploads/media/screen-catalogue_01.pdf"]ANTPA05MINI[/url]
[url="http://www.toplineaerials.com.au/Products/StockInformation.asp?stockNo=7443"]ANTLPA16B [/url]
[url="http://au.digitek.tv/images/Docs/01cupa1%20specs.pdf"]Digitek 01CUPA1[/url]

Dark Blue
[url="http://www.hillsantenna.com.au/arbitrage/pages/47/FB608542%20Hills%20Ultimax36.pdf"]Hills Ultimax 36[/url]
[url="http://www.matchmaster.com.au/domestic/vhf-antennas/phased-array-antennas"]Matchmaster 02-MM-EE06[/url]
[url="http://www.naspl.com/uploads/media/screen-catalogue_01.pdf"]ANTPA2[/url]
[url="http://www.toplineaerials.com.au/Products/StockInformation.asp?stockNo=7165"]ANTL32P[/url]
[url="http://www.toplineaerials.com.au/Products/StockInformation.asp?stockNo=1026"]ANTM-EE06 [/url]
[url="http://www.toplineaerials.com.au/Products/StockInformation.asp?stockNo=7687"]ANTL32SS[/url]
[url="http://updates.clipsal.com/ClipsalOnline/Files/Brochures/D0000064.pdf"]2ANUPA2[/url]
[url="http://www.laceys.tv/files/files/catalogue/CAT105_FINAL_D1_lowres.pdf"]Fracarro PU8F[/url]
[url="http://au.digitek.tv/images/Docs/01cupa2%20specs.pdf"]Digitek 01CUPA2[/url]
[url="http://www.academytv.com.au/products/ATV-ULTIMATE-UHF-Phased-Array-Alternative-to-Hills-Ultimax-%28Digital-%26-Analogue-UHF-ONLY%29.html"]AcademyTV ATVUltimate[/url]

Light Blue

[url="http://www.hillsantenna.com.au/arbitrage/pages/47/Hills%20TMX%20Range.pdf"]Hills TMX18B4[/url]
[url="http://www.matchmaster.com.au/domestic/vhf-antennas/digimatch-antennas"]Digimatch 02MM-DR18A[/url]
[url="http://www.naspl.com/uploads/media/screen-catalogue_01.pdf"]ANTSMU418[/url]
[url="http://au.digitek.tv/images/Docs/01bu418%20specs.pdf"]Digitek 01BU418[/url]

[url="http://www.dtvforum.info/index.php?showtopic=78408"] Diagrams[/url]
Masthead Amplifier
Firstly get the maximum signal from the antenna. You can then add a masthead amplifier to overcome the signal loss going down the cabling.
Amplifiers need to contain a filter to remove all signals except the ones you want.
[url="http://www.gme.net.au/public/pdf/manuals/mhu-w24f-fs-2_im.pdf"]Kingray MHU24FS[/url]
[url="http://www.gme.net.au/products/matv/matv-masthead-amplifiers/KMU32FSDP"]KMU32FSDP[/url]
[url="http://www.gme.net.au/public/pdf/manuals/mhu34fs_insman.pdf"]Kingray MHU34FS[/url]
[url="http://www.gme.net.au/public/pdf/manuals/mhu42fs.pdf"]Kingray MHU42FS[/url]
[url="http://www.matchmaster.com.au/domestic/amplifiers/digimatch-masthead-amplifiers/10mm-ma24up"]Digimatch 10MM-MA24UP[/url]

Filters
These filters are unnecessary if the above amplifiers are used because they already contain the appropriate filters.
Matchmaster 10MM-J40BF, 10MM-J40DF or 10MM-J34BF
[url="http://www.gme.net.au/products/matv/matv-filter/FL3BPMH"]GME Kingray FL3BPMH [/url] Switch it to exclude V[sub]L[/sub]
[url="http://www.matchmaster.com.au"]09MM-HL12F Diplexer[/url] Domestic catalog section 9.2 Use input 2 for band 3 and input 3 for band 4 & 5. Input 1 is not used.
The antenna signals are fed into one of the above filters/diplexers and then into a wideband amplifier such as
GME Kingray MHW34FE, MHW34FS or MHW42FS  
Hills A2A

Multiple outlets
In single dwellings splitters with F connectors are used to feed multiple outlets. A two way splitter halves the signal to each outlet as well as a small extra loss for the splitter itself. To overcome this loss a distribution amplifier can overcome this loss. For this channel range use a
[url="http://www.gme.net.au/products/matv/matv-distribution-amplifier/MDA20U"]MDA20U[/url] . If the distribution system is also carrying band 3 as well use the MDA20H instead
This amplifier is powered through the antenna cable, so the power inserter which is placed between the TV and the wall, must be connected to the splitter’s outlet called power pass. The above amplifier is then connected between the antenna and the splitter.
Note:
1. The need for this amplifier can be identified by using signal strength measurements above.
2. The signal strength meters in receivers are not very accurate.


AlanH[/quote]

Edited by andrewlace, 12 July 2011 - 12:16 AM.

[alanh]

Andrew,
You will note that every entry has a link to the manufacturers' website so that you can read it for yourself. It is upto you to decide if the often inadequate specifications are accurate.

Remember that most antennas are tuned to a range of frequencies. The narrower the range of frequency the greater the output. This does not appear in specifications because, the gain figures (dB) is the increase in sensitivity over a dipole or a 3 dimensionally equally sensitive antenna. It does not compare the output of antennas of different bandwidth.

See Q I know that the phased arrays specified here are for a wider bandwidth, however there is none available of the restriced bandwidth.

Masthead Amplifier

If you used the link ot the amplifiers you will find the ones recommended in this post remove all signals below 520 MHz and above 860 MHz. This reduces the noise, interference from impulse noise, two way radio transmitters and mobile phones towers.

I have not recommended wideband masthead amplifiers unless they are preceeded with a filter for the band required for the viewer.

All amplifiers have intermodulation distortion. This is why separate tuned channel amplifiers are used in MATV systems. An internal or external filter prior to amplification can prevent strong interfering signals from modulating the TV signal you are trying to receive. If this is not done the interference cannot be removed down stream.

Reducing the bandwidth of amplification also reduces noise amplification as well.

AlanH

[andrewlace]

Hi Alan, with due respect, no amplifier removes interference from impulse noise.  As for filtering out the unwanted channels, none of these products do that at all.  Certainly using a UHF only amplifier can be a better option than amplifying VHF when it is unnecessary. However getting the signals right and using the right size amplifier rather than over or under driving the system is far more important.  I know what these amps do and they cannot remove all the signals you don't want because they are wideband UHF.

alanh, on Jul 12 2011, 12:13 PM, said:

Andrew,
You will note that every entry has a link to the manufacturers' website so that you can read it for yourself. It is upto you to decide if the often inadequate specifications are accurate. I'm aware of the benefits of band selective antennas.  Fracarro still stock narrow band antennas yagi antennas.  I'd suggest you read their catalogue to see for yourself.  The point is that this is not the be all and end all.  

Remember that most antennas are tuned to a range of frequencies. The narrower the range of frequency the greater the output. This does not appear in specifications because, the gain figures (dB) is the increase in sensitivity over a dipole or a 3 dimensionally equally sensitive antenna. It does not compare the output of antennas of different bandwidth.

See Q I know that the phased arrays specified here are for a wider bandwidth, however there is none available of the restriced bandwidth.

Masthead Amplifier

If you used the link ot the amplifiers you will find the ones recommended in this post remove all signals below 520 MHz and above 860 MHz. This reduces the noise, interference from impulse noise, two way radio transmitters and mobile phones towers.

I have not recommended wideband masthead amplifiers unless they are preceeded with a filter for the band required for the viewer.

All amplifiers have intermodulation distortion. This is why separate tuned channel amplifiers are used in MATV systems. An internal or external filter prior to amplification can prevent strong interfering signals from modulating the TV signal you are trying to receive. If this is not done the interference cannot be removed down stream.

Reducing the bandwidth of amplification also reduces noise amplification as well.

AlanH

[alanh]

Andrew,
This is a general topic
There are no masthead amplifiers with a band 4 only filter

AlanH

[andrewlace]

What do you mean by band 4 only filter?  Several products come to mind.  Some are current Alcad AM318, some are old school (fracarro js and es range).  You can even get some single channel masthead amps.  It depends on what type of filter and why.  The hassle with any narrow band products occurs when the broadcast authorities play with the broadcast channels.  As close to perfect as some narrow band products were, I still find myself removing and throwing some out in the rubbish because they are simply not suitable anymore.  These products are available but I get the feeling they are not popular and many importers and manufacturers won't spend lots of money promoting a product with limited appeal.  Limited production runs mean higher prices.

alanh, on Jul 14 2011, 03:07 AM, said:

Andrew,
This is a general topic
There are no masthead amplifiers with a band 4 only filter

AlanH

[alanh]

Andrew,
There is no point in stocking single channel filters except those used for MATV systems.

Band 4 in Australia is our channels 27 - 36 or 519 - 589 MHz EU channels 27 - 36 only.

I am pleased that the Lacey's new catalogue does quote the correct Australian channels due to our 7 rather than 8 MHz wide UHF channels.
All overseas antennas and filtered amplifiers allow channels 20 - 26 to be amplified. In Australia these channels are not used for TV but for two way radio. The use of these frequencies will increase because the ACMA will be issuing a lot more licences.

GME Kingray are made in Sydney and remove channels 20 - 27.

Keep in mind that in 2014 all TV transmitters will be reallocated channels so that all transmitters on one site will be in one of the following groups
Channel 6 - 8, 10 - 12
Channel 28 - 33 Part of band 4.
Channel 34 - 39
Channel 40 - 45
Channel 46 - 51

AlanH
Both horizontal and vertical polarisation will be used.

WA commercial country digital transmitters will be installed from now on using these groupings.

In the meantime virtually all installations now are for digital TV so no TV antenna equipment should pass channels 0 - 5A anymore. So in common with the rest of the digital world no transmitters are using any frequency below 174 MHz which is our channel 6, European channel 5 or ATSC channel 7.

AlanH

[andrewlace]

Agreed that UHF frequencies are amplified. And now you're telling me that filtering out the channels is not necessary.  Choosing the right amplifier for a job is essential (assuming one is necessary).  There is clearly more to this topic than the issues you raise and ironically then argue against. Have you actually tried out any of the products you list?  Such experience is vital with any product as well as a good quality spectrum analyser, to find out what interference is there.

alanh, on Jul 14 2011, 08:04 PM, said:

Andrew,
There is no point in stocking single channel filters except those used for MATV systems.

Band 4 in Australia is our channels 27 - 36 or 519 - 589 MHz EU channels 27 - 36 only.

I am pleased that the Lacey's new catalogue does quote the correct Australian channels due to our 7 rather than 8 MHz wide UHF channels.
All overseas antennas and filtered amplifiers allow channels 20 - 26 to be amplified. In Australia these channels are not used for TV but for two way radio. The use of these frequencies will increase because the ACMA will be issuing a lot more licences.

GME Kingray are made in Sydney and remove channels 20 - 27.

Keep in mind that in 2014 all TV transmitters will be reallocated channels so that all transmitters on one site will be in one of the following groups
Channel 6 - 8, 10 - 12
Channel 28 - 33 Part of band 4.
Channel 34 - 39
Channel 40 - 45
Channel 46 - 51

AlanH
Both horizontal and vertical polarisation will be used.

WA commercial country digital transmitters will be installed from now on using these groupings.

In the meantime virtually all installations now are for digital TV so no TV antenna equipment should pass channels 0 - 5A anymore. So in common with the rest of the digital world no transmitters are using any frequency below 174 MHz which is our channel 6, European channel 5 or ATSC channel 7.

AlanH

[alanh]

Andrew,
What I have been saying all along is to only allow the frequencies carrying the channels the viewer wants to watch should be amplified and all others should be removed. In fact in the Tuner within the TV there is a filter to only allow one channel to be amplified. The channel amplified is the one selected.

I am not proposing in masthead amplifiers that you have to have a filter for each channel, this is prohibitively expensive, particularly now when the channels are not consecutive. As a result antennas and masthead amplifiers pass groups of channels

Band 1 channels 0 - 2 Analog TV only
Band 2 channels 3 - 5A Analog TV and FM only
Band 3 channels 6 - 12
Band 4 channels 27 - 36
Band 4+ channels 27 - 49
Band 5 channels 36 - 69.

You do not have to use a spectrum analyser all the time. Use the antenna for the band in use, it has a filtering action of its own. If the MER, C/N and Pre BER specifications cannot be met then just pick a masthead amplifier which contains the appropriate filter. This will save heaps of time. It also ensures that if interference occurs after you leave the site it will not cause any problems for the customer.
The main issue is to measure the signal levels to prevent amplifier or receiver overloading. If the amplifier gain is too high an attenuator on the input can be used to prevent overload.

To make it clear
Use an antenna(s) for the band(s) to be received. This will maximise the TV signal and minimise interference
If a masthead amplifier is required pick one containing a filter for the same band(s) used by the antenna. This will allow you to use higher gains without problems particularly if interference is present.
Wideband masthead amplifiers should not be used unless preceeded by a filter for the band in use.

Yes I have used this principle in an area of very strong interference and it works.

"Choosing the right amplifier for a job is essential" It is made simpler by picking one with the appropriate filter. Determine the gain by adding the desired wall plate signal level to the cabling/splitter losses and subtract it from the measured signal level from the antenna. This will give you the masthead amplifier gain. Use the lowest noise figure amplifier for the above criteria.

The reason I quoted the restack channel groupings so that the industry can get the right filters and antennas organised for 2014 and to know what products can have restricted ordering.

AlanH

[DrP]

In a TV there is wideband input, a mixer/amplifier of some description and a band pass filter.  For an analogue TV, AGC is determined later on and fed back to the mixer amplifier stage.  If a certain person doubts this I can probably dig through some old service manuals and post images to demonstrate.  Of course, this is not the only method of RF signal level control, but it has been a very popular method.

As for industry advice, as hard as it might be for alanh to accept that he's not the first person to ever hear of the term 'restacking', the 'industry' is fully aware of what is coming and does not require the advice of an arm-chair expert who is simply regurgitating material he's found on the internet.

[andrewlace]

Hi Alan, I'm still confused by your lengthy post. "If the MER, C/N and Pre BER specifications cannot be met then just pick a masthead amplifier which contains the appropriate filter."
"Yes I have used this principle in an area of very strong interference and it works."
Are you saying that it is possible to make a signal that suffers from poor BER, MER and c/n work by placing a filter on it? Please keep you answer concise and on track.

Nettiquette Wikipedia

Edited by andrewlace, 16 July 2011 - 06:27 PM.

[alanh]

Andrew,
If you are in a strong signal area, the measured signal level from the antenna will after amplification will exceed the level for satisfactory Intermodulation distortion on the amplifiers' specification. So no amplifier should be used.

Yes, I am in an area with very strong AM signals, the TV signals are not particularly strong, so using a Kingray FL3bmh filter to remove any signal below band 3 and a wideband high gain amplfier mounted just underneath it,  has made reception meet the specifications in AS 1367:2007 and I have stable reception which was not possible before. The TV signal going down the Quad shielded RG6 is now much stronger than the interference.
By the way I used a Hills DY10 to minimise maximise the band 3 TV signals and minimise all other frequencies.


AlanH

[MLXXX]

This may be a liitle off-topic, but here goes...

I find it interesting to read about the the reported fragile performance of VHF/UHF antenna amplifiers in relation to medium wave broadcast band AM radio transmissions, and FM radio broadcast band transmissions, when I compare that with my own experiences of the robust performance of car radios literally in the shadow of a medium wave AM transmission mast.

Over the years I've owned a variety of motor vehicles. I've driven past the ABC's broadcasting site at Bald Hills, 17km north of the Brisbane GPO, many times, whilst listening in the early years to AM and in the later years either to AM or FM. On no occasion was the reception audibly affected by the extraordinarily intense field strength. (This was so whether the radio was tuned to one of the Bald Hills stations, or not.)

The mast is about 200 metres in height. I see from Google Earth that the highway in front of the site is a mere 550 metres from the mast. There is a constant stream of vehicular traffic past the site. I daresay a passive crystal set with a diode of sufficient current rating could drive a loudspeaker very loudly at that distance from the transmitter! In fact you could get a nasty electric shock if you were not careful, fiddling with a crystal radio.

The mast is used for the stations formerly known as 4QR and 4QG, now known as 612 ABC Brisbane and Radio National. 612 is a 50KW station. RN is a 22KW station. [In addition there is now a third medium wave band station, ABC News Radio.]

My experience of a lack of interference to reception for a variety of different car radios over the years is all the more remarkable when it considered that when a car radio is tuned to the AM band, the 50KW and 22KW stations constitute in band signals.

I'd also mention that a portable DAB+ radio of mine, with its rod antenna fully extended, and tuned to DAB+, did not miss a beat when driven past the Bald Hills mast.

[alanh]

MLXXX,
Car radios, DAB+ radios are not TV receivers. They do not have such wide bandwidth and such high gain at such a high frequency.

AlanH

[DrP]

TVs do not have "high gain".  I have no idea where someone could even begin to imagine such a concept.

[andrewlace]

Why aren't you using an MDA20H or a AM210 masthead amp?

alanh, on Jul 16 2011, 08:43 PM, said:

Andrew,
If you are in a strong signal area, the measured signal level from the antenna will after amplification will exceed the level for satisfactory Intermodulation distortion on the amplifiers' specification. So no amplifier should be used.

Yes, I am in an area with very strong AM signals, the TV signals are not particularly strong, so using a Kingray FL3bmh filter to remove any signal below band 3 and a wideband high gain amplfier mounted just underneath it,  has made reception meet the specifications in AS 1367:2007 and I have stable reception which was not possible before. The TV signal going down the Quad shielded RG6 is now much stronger than the interference.
By the way I used a Hills DY10 to minimise maximise the band 3 TV signals and minimise all other frequencies.


AlanH

[alanh]

Andrew,
I am using a MDA20H as well so I can have 8 outlets. This amplifier is well into the roofspace.

AlanH