335 replies to this topic

[Electronicman]

svEngineer, on Dec 12 2007, 12:05 AM, said:

Hi, I'm new to this forum but any help would be appreciated.

NO ABC-41 signal in BRIDGENORTH. 18km W of Launceston.

I'm having trouble getting ABC Ch41 & SBS Ch44 digital reception at Bridgenorth from Mt Barrow.

......
svEngineer
...........

Check the thread titled  "Low ABC/ABC2.......Devonport" in the Forum Topics below.

This will answer your question svEngineer  

[M'bozo]

Yes, there does seem to be a problem with ABC/SBS transmissions from Mt Barrow.

Not sure of the cause.

Can only hope Broadcast Australia work it out and resolve it.

So best you can do svEngineer is sit on your hands and wait - or - is your antenna correct?

The Fracarro model you need is a 20BL45 - the BL5 response drops off below C39, and in a weak signal area this can compromise SCTV reception on C38. Since you mention SCTV is OK, then I'm guessing you have a 20BL4 or 20BL45.

How do you tell? Look at the dipole - where the cable connects - somewhere on one of the flat portions there will be the channel range it covers - find that and post it here. Then more functional advice may be forthcoming

[svEngineer]

Thanks for the advice.

There is problems with the ABC West facing transmitter on MtBarrow- my father-in-law from George Town has been speaking to the tech's working on it- Electronicman- I will post on the Low/abc forum with more details on the conversation.

mtv & Mbozo.
The only numbers I can find on the FR-20 antenna I am using is 154_1 stamped in fine print on the cable clamp assembly board.  I assume it is the 20BL45 model, as it was purchased from Active Electronics to improve my UHF reception.  Prior to going digital.

The mast I was roaming around the garden with was only a 2mtr fiberglass fishing spear- sorry not very tech.

I am setting this up for digital now as we have bought a new Sharp LC-37D53X last week.  About a year or more ago with the FR antenna set up I bought a cheapy DVD-STB combo unit from Harris Scarf.  It received the commercial channels day and night and SBS only during the day but not ABC at all so I took it back and didn't progress digital again until now.  

Prior to that we have had problems with the analog signal ghosting, so I bought the new FR-20 antenna and tried it, however the only way I could remove the ghosting and get the best signal was by taking it INSIDE the house tin roof, facing Mt Barrow out through the hardiboard gable end.  It worked! Then ran it through a mast head amp.

.......svEngineer.........

[mtv]

A somewhat odd setup, but hey... if it works.

I think you'll find your reception will be ok once the repair work on the tower is completed.

[Electronicman]

mmm........... Maybe if you had ghosting problems with analogue why would Active recommend a yagi? In that situation I would have used a phased array to attenuate the ghosts. Inside the roof will alleviate the ghosts but you where lucky to have the gable in the right direction - good work!

As Col said...... a somewhat odd set-up, but if it works - why change!  

And just for the record, I have had no problems with the ABC/SBS reception at Wynyard (so I have not measured it as yet), but do have customers that are having problems with the ABC/SBS in lesser reception areas!  

[M'bozo]

The markings are usually like this: clicky

In your case they are probably a frequency range.

Edited by M'bozo, 13 December 2007 - 06:44 PM.

[alanh]

M'Bozo,
Looks like channels 47 - 53 which is equivalent to Australian channels 50 - 57
At UHF, Europe/NZ use 8 MHz channel width where as we use 7 MHz
AlanH

[mtv]

alanh,

I think the image posted by M'bozo is that of the dipole marking on a Fracarro antenna model 20/4753 which is a 20 element 'narrow-cut' UHF antenna, which Fracarro state as being for Australian Channels, 40 - 57.

My understanding of the image posted was only an example of where to locate the markings on the dipole and not intended as a recommendation of the antenna to use for digital reception from Mt Barrow, which of course, it's not.

[M'bozo]

mtv is correct, the image is for illustrative purposes only. Couldn't find a 20BL series dipole when at Laceys yesterday, so took a piccy of one that was lying around.

I realised from an earlier response that svEngineer might be looking in the wrong spot on the antenna so was trying to clarify.

btw GI for ABC ( & SCTV) is 1/16 which I find can be problematical in really poor reception areas ie with multiple reflections or adjacent channel interferers. I find in this case, although it is fairly rare, a yagi with narrower horizontal acceptance angle is better than a single phased array, which have been termed "garbage collectors" (?) elsewhere in this forum.

A site test with appropriate instrumentation, practical knowledge, and a range of antennas to select from is usually the best way of solving reception problems.

[svEngineer]

Mbozo & mtv, I've had another closer look,  on the antenna dipole I have are the markings FR on the left and DELTA on the right. No channel numbers.

The FR antenna is now (temporarily) in the living room on two wooden chairs looking out the east facing window, good digital signal on 38,50,52,  No ABC or SBS, the analogue ABC & SBS is ok- no ghosting but there is slight sound distortion on ABC.

I'll be trying to mount is back up on top of the roof, this weekend.

On the poor receptions front- a friend in Legana with an in roof antenna is experiencing poor ABC digital reception problems that started a few weeks ago.  They were blaming the building next door.  Could be Mt Barrow's fault.

svEngineer

[mtv]

svEngineer ,

The Fracarro 20 Element 'DELTA' is designed for Australian UHF channels 28 - 36 (actually, it goes down to Ch 24, but we don't transmit ch 24 here).

The important factor is it's highest channel, being 36, so it's the wrong antenna for your area.

All the digital signals from Mt Barrow are UHF Band 5, so you need either a Band 5 antenna (channels 36 - 69) OR a wideband UHF antenna (channels 28 - 69)

The channels you require are 38, 41, 44, 50 and 52.... so the Band 5 'should' be ideal, however, as M'bozo is more familiar with your area, he recommends a wideband (Bands 4 & 5).

If in doubt, a wideband will usually work well on either Band 4 or 5.

Obviously, if the transmitter antenna still has a fault, your reception on those channels (ABC/SBS) wont improve until it's repaired.

If you want the wideband Fracarro, the model number is 20BL45

[Electronicman]

The Delta was ideal for analogue UHF though mtv - UHF 29, 32 & 35 (SBS, ABC & WIN) but how did you receive Sthn on VHF 9 svEngineer? Have you another, larger antenna in the system?

btw I was working at Rocky Cape today (Smithton end of Montumana Rd) and on doing a site survey both ABC and SBS was down about 9db (after boosting) compared with the three commercial channels. Problem was crap wiring to the TV sockets - just paralleled together, not split or tapped - causing the headaches with the digital reception!  

[svEngineer]

mtv, much obliged.  I will hold off until the abc MtBarrow  transmitter is repaired. Given that I have not got the right antenna it is curious how the CH 50 & 52 signals are coming in ok. But if a new antenna will get ABC & SBS CH 41/44 I am willing to give it a try.  Or even call in the pro's to do a sweep with the right gear.

My suspicion was that the ABC and SBS antenna arrays were on a different tower from the commercial stations on top of Mt Barrow, or that they are at a lower height on the tower.  Having driven up there a few times for the view, there are the towers that are on the northern escarpment closest to the public road, and the southern tower, from Google earth there is 1.7 kms between the two locations.  You can see the shadow from the southern tower quite clearly on the ground when zoomed in on google earth, must be a morning photo.

....svEngineer....

[svEngineer]

Electronicman,  There was a combo antenna on the roof that I disconnected to remove the ghosting when I installed the FR-Delta but it is still up there. The set up had a Kingray mast head amp driving a mile of cable in the roof space T-d off to about 4/5 outlets all over the house.  I tidied up a few and ran the (in roof) FR-Delta into the masthead amp back into the distribution.  I think the Sthn VHF signal was picked up from the C-C cable joins in the roof space and older cable.   We don't watch much Sthn and were mainly interested in getting the ABC/SBS watchable.

For this round of digital tuning I have one length of new quad RG6 cable & F connectors direct to one TV , & the Sthn VHF signal is very poor on Analog. ABC and SBS analog are watchable with very mild snow, and some sound distortion on ABC when people say "esses".

Thanks for the FR antenna identification.  What do you think is the best digital replacement? I'll wait until ABC Mt Barrow is repaired.  Though the misses is not impressed by sharing the lounge room with the FR-delta-20 sitting on a couple of chairs in front of the Christmas tree.

svEngineer.

[M'bozo]

svEngineer,

Yes, 10 & 20 element deltas. Installed hundreds of them in the analogue days. Fortuitous reception of non specified channels could be expected if the local signals are strong enough.

Suggested antennas from my experience:

Fracarro log periodic: LP45HV (LP45F for F connect version)

Hills yagi: TMX18B5 (part number FB607081B)

Phased arrays: Hills ULTIMAX 36 (part number FB608542) or ALCAD AP369. Since I have no experience of signals in your area, I'd be plumping for a phased array, since almost without exception that is what I use in poor areas.

The commercial/national towers at Mt Barrow (if SBS can be called national) are 300m apart with an antenna height difference of 17m favouring the commercials. (according to ACMA records)

EDIT:

Quote

INSIDE the house tin roof, facing Mt Barrow out through the hardiboard gable end.

Well, that is not so unusual. I've done that. The antenna's in the middle of the roof, looking out the front. Come to think of it, over the years I've mounted antennas in many places other than on the roof of the building. Whatever works, and works as well as can be expected.

Edited by M'bozo, 15 December 2007 - 04:23 PM.

[svEngineer]

Anyone know whats happening with the Low signal from Mt Barrow ABC/SBS tower west facing array?  I've just got back after 4 weeks away and there's no improvement to the signal at Bridgenorth.  The Commercial's 38/50/52 signal strength is still booming in , but no Ch 41/44.  Is this to do with the 7LA-Fm install or the antenna failure?  The guys at Active said that it was all still very tight lipped about what was going on up there.

I'm thinking of buying one of the phased arrays as suggested and trying that.

svEngineer..

[alanh]

All,
For Mt Barrow, I would not buy a band 4-5 antenna unless its a phased array where you have no choice. This is because the Minister for Broadband, Communications and the Digital Economy, Stephen Conroy says there will be an analog switch off startomg in December 2009. Since Tasmania has the highest proportion of digital receivers I will bet you will not be much after that.

AlanH

[cdn]

alanh, on Jan 26 2008, 01:15 AM, said:

All,
For Mt Barrow, I would not buy a band 4-5 antenna unless its a phased array where you have no choice. This is because the Minister for Broadband, Communications and the Digital Economy, Stephen Conroy says there will be an analog switch off startomg in December 2009. Since Tasmania has the highest proportion of digital receivers I will bet you will not be much after that.

AlanH

Sorry alanh but unless Win and Southern Cross get off their big fat A`s and start moving 2013 looks a better date for the closing down of analog in tassie

[M'bozo]

svEngineer, on Jan 25 2008, 12:41 AM, said:

Anyone know whats happening with the Low signal from Mt Barrow ABC/SBS tower west facing array?
svEngineer..

Just got back from a break myself.

The ABC/SBS signal here is improved from when I last checked around the first week of January.

Talking to the ABC reception advice line today suggests there is still work yet to be completed.

I'll be over your way when the MS Fest happens in Feb, might have time to drop in and have a look if you're interested.

Marc.

[svEngineer]

Mbozo & all,

SUCCESS with ABC/SBS reception at Bridgenorth.

I have now installed the Hills Ultimax UMX36 and a Kingray MHW34FS shielded masthead amp, Good signal strength on ABC/SBS and the commercials. F connectors used with quad shield.

Before sticking it back inside the roof space, I ran the new Ultimax direct to the TV from outside with about 10mtrs of coax which had a signal of 86% on ABC on the new Aquos LCD-tv.  When installed back the roof space I tried running the Antenna without the masthead amp but there was not enough signal strength due to the long run of coax, let alone another 5 outlets that I want to hook up.   It is also now hooked up to an analogue TV with good results, slightly snowy on SBS, and good signal on Southern VHF even.

Thanks to Mbozo for your help on antenna selection.  I must admit that I was a bit baffled with the good digital signal from the commercial channels with the older FR-Delta antenna.  However felt that it was time to bite the bullet and get a more appropriate antenna even with uncertainty about the Mt Barrow ABC west array.

I haven't touched the masthead amp gain setting- I've left it on the factory setting.

I will be going to pay Active Electronics for all the bits- they insisted on a Try before you buy approach, very generous of them.  The new set up has also just passed the heavy rain test with 20mm falling in the last hour and no interruption to the digital signal.

svEngineer

[M'bozo]

svEngineer,

That's good.

Don't know what signal of 86% on the Aquos relates to in real world terms, but as long as reception is reliable, that's all you require. From what you have described regarding operation without the masthead amplifier, it sounds to me as though the signal from the antenna is low to start with. Leave the UHF gain setting on maximum (that's the factory setting anyway)

The good signal on Southern Cross is fortuitous VHF reception from the Ultimax as the signal is probably quite high where you live. Ordinarily the combining link in the masthead would be removed when running UHF only, but if you do this, you will lose the Southern Cross reception. Also ensure the FM trap shorting link is on the IN position.

Marc.

Edited by M'bozo, 06 February 2008 - 06:31 AM.

[Vookie23]

Sorry about posting this here but am unable to start a new topic, just wondering if we get any HD programs in 5.1 DD on the NW coast??  Thanks

[mtv]

Can't help with the programs in your area, but you need 5 posts to start a new thread (which in this case, the "HD Programs" might be a better forum)

[Vookie23]

mtv, on Mar 17 2008, 06:23 PM, said:

Can't help with the programs in your area, but you need 5 posts to start a new thread (which in this case, the "HD Programs" might be a better forum)

Thanks (that's 5 )

Edited by Vookie23, 17 March 2008 - 06:56 PM.

[JackSprat]

Hi,

I am not sure if this is the right place to post, my apologies in advance if it isn't.

About 2 weeks ago I moved to the Sheffield area from Hobart. It took a couple of days to unpack, and then I found I could not get any television. In Hobart, all my digital channels were fine, however, when I set my televisions up here, I had no reception except for Southern Cross.

I contacted the previous resident, and he said he had to buy a booster box to get reception, which he had taken with him, and didn't want to give it me. I got him to read the number off his box, and he said it is a gme kingray psk02. He told me where to get one which I susequently did, only to find it is only a power supply only, and the booster box is up by the TV antennas. There seems to be 2 TV antennas up on a mast, and another one on the leanto part of the house at the back. The good people I bought the power supply from also told me I had to tune my TVs to uhf for digital in this area.

Much later I seem to have everything working. The analogue channels apart from Southern Cross are smoky and ghosty, but the digital channels are fine, with the exception of Southern Cross. I also seem to have a lot of ABC & SBS channels, although most of them have the same programmes.

With Southern Cross on digital, the picture occasionally breaks up or the sound squawks, mostly in the evenings. I have a 42 inch Panasonic Plasma and a cheap coles MTV set top box on the spare TV. I've spoken to my neighbor, and they say they have no problems with their reception. I'm just wondering what might be causing only one channel to break up when the rest are perfect all the time?

Is it the way I have tuned the channels in, or do I need to do something more?