In September 2008, I had an external antenna installed by a local installer. Reception was good using indoor rabbit ears, but I decided to get an external one to reduce clutter and to ensure that I am getting the best reception possible. Unfortunately I've had issues since day one as audio and video stutter and break up during the daytime, for SC Ten and Prime. All other channels are fine during the day, and ALL channels are fine at night.

I do not believe the issue is due to interference (as suggested by the installer) at particular times of the day - since daylight saving and the longer days the audio and video stutters are there for longer, for example I get poor reception during the evening news now but this was fine back in September/October as it was dark by that time. We have gone back to using rabbit ears, as it was too frustrating watching tv during the day over the Christmas break.

I live in Rivett, and have direct line of sight to Black Mountain tower. There are 2-3 trees in the way, but I do not believe these are a factors as the signal is fine at night, and even on days with no wind the stutters happen (for SC Ten and Prime). I am using Topfield STBs and they both work great with indoor antennas, so I am surprised that an external antenna does not work as well. Signal strength for the problem channels is fine (according to the Topfield's signal bar) and at the same levels as night time during periods of stutter. The installer put in a UHF/VHF antenna.

Does anyone have ideas as to why I'm having these problems? I've called the installer, and he claims that this is not a problem with his work, and that it's my equipment or interference that's the problem.

Try using the rabbit ears again for a couple of days to see if the problem continues. If not then you have discounted your PVR and the problem must be the antenna. Sometimes the problem can be too much signal which can be reduced with an attenuator from Dick Smith or Jaycar. Either way the installer is required come out to check it if you are having problems as he should provide warranty service on his work.

I would ask the installer if he used a digital meter capable of measuring bit error ratios when he did the install.

If he didn't, then I would negotiate with the original installer on the basis that the work has not been done in a professional manner, and that a second opinion will be obtained with a claim to be made back if it can be shown the original installation is deficient in some way.

If he did use a meter, then he should have no trouble in demonstrating that you should not be having a problem as a result of his work, based on the measurements he made at the completion of the installation, even to the extent of calling back to show this to you.

A competent technician should be able to sort out why the interference occurs at certain times of day, even if this requires calling back when the problem occurs.

If your invoice mentions the type of antenna, and you can post that here, that could be helpful.

davidw_au,
You have a 10 km clear path. It may be worthwhile inserting an attenuator between the antenna cable and the receiver. I say this because too much signal is just as bad as too little. The attenuator will also reduce the level of interference.

What is around which is likely to cause interference?
High voltage power lines, industry, radio transmitters?

AlanH

Davidw_au

My first reaction is too much signal, if you have a combination uhf/vhf antenna in your area I would expect to see mid 90's (dBuV) from the antenna, loss in a two way splitter and cable in a normal domestic house would see a level at the outlet somewhere near the mid 80's. This is quite high and could easily cause your problems.
The weather conditions change in the evening here in Canberra and this could be why you are noticing a difference in signal quality.
With our installs I ask my techs to record the signal readings, channel power, mer & margin, for digital and channel power & c/n for analogue. If we did this work I should have a record of it and am happy to review it for you. I had a look through our September work and could not see any jobs in Rivett so my assumption is we did not but let me know if I can help.
A normal install for us involves a site survey on the roof testing for both analogue and digital reception using a field strength meter capable of measuring both signals, once located we install the antenna, note the levels, install the cables (RG6 quad) fit the F Type wall plates and install a coupler rated at the correct loss to provide the appropriate signal levels at the outlet. If a splitter is used in place of the coupler then an attenuator is inserted to the input of the splitter to provide the correct loss, again to achieve the correct signal levels at the outlet. A test is done once the job is near completion and these are the recordings provided on the job risk assessment form and returned to the office.
It is interesting that you are having trouble with SC Ten (VHF 6) and Prime (VHF 12), we have noticed some transmission hiccups with Prime but I can’t recall any with SC Ten.

Gadget

Thanks for the suggestion regarding the attenuator. The installer said he measured the signal directly from the aerial, and from one of the points, and said the signal was "romping in", so it could be too much signal. We've had the rabbit ears plugged in for almost two weeks now, and the problem has gone away, so I'm pretty sure it's the antenna. And we have two different PVRs, both Topfield but different models, and the antenna affected both.

He had a gadget that he used to measure the signal, he mentioned the signal strength, but nothing about bit error ratios. He took a measurement on the roof direct from the aerial, and said the signal was great from there. A second test was done from a point, after I plugged the antenna in and noticed the picture and audio was skipping and breaking up regularly, up to a few times a minute for a few seconds at a time for the problem channels. But I noticed he ran it twice from the point, and told me to ignore the first reading (not that I knew what to look for) before saying there was no problem with the signal. As he offered a one year warranty I thought I'd see how it went and let him go.

It was installed on a Saturday, and I did call him up on following Monday. The immediate response was he has done this many times and the signal strength was great, so there was not a problem with the installation. But he eventually agreed to come back, after I got some signal strength readings from the Topfields. As I don't feel confident about his willingness or capacity to solve the problem, and also because weeknight tv reception, when we watch most of our tv, was fine in the months following because it was night, I've left things until now.

He said the antenna is similar to a Hills, I don't have a brand but I'll take a photo tomorrow morning and post a link to the photo.

Hi Alan,

I live in a residential area (Tristania Street) so I don't believe there should be any interference. And the rabbit ears were fine, if there was interference I would think I should have problems with these too, unless indoor antennas are less resistant to interference?

Thanks for the suggestion regarding the attenuator - I am a little disappointed that the installer has never mentioned that I might need one - should he have known when he measured the signal?

David

Hi Gadget,

I used another installer - since having these headaches I'm regretting I didn't do my research beforehand, as I've had a few people recommend Kaz.

The installer didn't seem to be as thorough as what you outlined. He took a reading from the roof, and only took the reading from one of the 3 points after I tested the picture and noticed it was very poor. From my observations, I'm disappointed that so many steps were skipped for my install. I know he used quad shielded cables, but I have no idea whether a coupler or a splitter was used. Two of the points are very close the the antenna, and the 3rd is about 10 metres away. There was no systemic measurement of signal from the outlets.

SC Ten is definitely the worst channel, followed by Prime. There are times when SC Ten is stuttering and Prime is ok. With the rabbit ears, I've only rarely noticed transmission hiccups with Prime too, SC Ten has always been fine.

I want to give the installer one more go to fix the issue - if he can't, I'll contact you. I haven't called him in sooner as I've been dreading the situation where he turns up, and for the 10 minutes he's here the signal is fine, as some days are better than others. But I've stuck with the antenna for long enough to know it's just not working properly. Should professional antenna installers be able identify problematic installations, even on days when things work ok, by taking measurements?

David

Gadget,
It is nice to see you are keeping records of the received signal strength, mer etc. if only this happened in other places.
Along with beeblebrox and MTV using purely digital installs (band 3 & 4 only) and putting a caveat on about poor analog performance gives me a little hope that at least small parts of the antenna installing industry are doing the correct thing for the consumers and the environment.

Since Canberra has its digital and analog transmissions in the same respective bands you do not have to worry about caveats.

Keep up the good work

AlanH

"I want to give the installer one more go to fix the issue - if he can't, I'll contact you. I haven't called him in sooner as I've been dreading the situation where he turns up, and for the 10 minutes he's here the signal is fine, as some days are better than others. But I've stuck with the antenna for long enough to know it's just not working properly. Should professional antenna installers be able identify problematic installations, even on days when things work ok, by taking measurements"

If the system is not in spec, yes you can. If everything is in spec then it's harder but i use a process of elimination, looking at the local environment, testing for specific interference on the freq's you mentioned, earthing the system, even looking at your equipment to see if anything in the room could be creating the interference. Earth potential between appliances can cause unusual faults with DTV. Sometimes it's not a ten minute job.

Good luck
Gadget

Thanks Alan, we are rather spoilt here in Canberra, in 95% of our installs we can provide an analog and digital service for our customers without any dramas what so ever. It's really only when we get into the outer regions that we focus on digital only. There are a few areas in town (I can count them on one hand) that analog is poor and DTV is the only option. But in the main our customers want both services so that's what they get.

Record keeping is a basic fundamental, without it you just don't know what's going on. I have 14 guys out there, without records I'm blind and ignorant to the facts, I'm afraid I'm too much of a control freak, I have to know.

Cheers
Gadget

Here is a picture of the antenna: http://www.users.on.net/~david.w.au/DSC01340.JPG

The antenna appears to be a Clipsal 2ANUV14, or facsimile thereof. Click

I do not use Clipsal antennas, in fact when I come across them in my work, I replace them owing to their lesser performance compared with the ones I would normally use. They only seem to be used by electrical contractors supplying a package installation deal.

That is not to say your particular antenna is unsuitable, as I have not come across that particular model. Others with experience in your area can comment more appropriately. (The area I install in is all UHF.)

Since the installer is coming back to have a look at it, I would wait to see what he reports.

Not quite, it's a Digitek CDX14 supplied by Bitek Pty Ltd. Widely used here in Canberra and a very good performer. I won't be drawn into comparisons with other brands as the Digitek brand is too close to home and I could well find myself in the poo.
We use them and are successful with our installs, the installation method in the photo is different to ours.
Good luck with the revisit, try to get some channel power, MER and margin readings from him and let us know the results.
Gadget

Gadget,

Thanks for that. I have not come across these in Tasmania, and I had noticed a difference between the posted picture and the one I put up.

I shall add that to my data base.

Local knowledge to the fore again.

Marc.

Hi Gadget,

Thanks - will let you know how it goes, I'll organise a time with him next week or the week after and post the results here. I'll also find out if he fitted an attenuator or coupler. By the way, for the channel power, MER and margin readings, are these for each channel, or for the digital signal in general? Also, what is the c/n reading (for analogue) and abbreviation for, and should I get the analogue channel power and c/n for each channel?

I'm glad to hear that the aerial I got is ok, so I won't have to start again from scratch if I end up cutting my losses with this installer.

David

Readings for each digital channel.
= Carrier to Noise
Yes

In short, if one of our installs had the trouble you mentioned I would be checking all of these readings and depending on the results checking elsewhere for faults or reasons why.

Gadget

Hi All,

Sorry if this is the wrong thread, but I have a similar problem. I have 1 TV at the living room, 1 at the bedroom, and a digital tv card on my desktop. A week ago, I was having problems with Prime TV on my main TV (living room). I rerun the autoprogram and I can't get Prime on that TV. The digital card and the TV at the bedroom have no problems (beside the freezing of image and audio), but at least I can see prime digital on both places. To add up, I have a Homecast PVR conected to my main TV, and it works perfect even with no freezing. I can't tell what kind of antenna I have, it's an apartment, rented. But I can tell that I haven't had any problems until a couple of weeks ago. The PC and the bedroom are conected straight to the wall. The living room is a different story. When I bought the PVR, it comes with a loop through for the TV. But this wasn't working for me at home (it worked at the store perfectly). I assumed that my signal was a bit weak, so I decided to get a splitter. I plugged the splitter (simple one, not with booster or anything) to the wall, and connect the PVR and the TV to the splitter. The PVR is connected to the TV using HDMI. I know it looks weird, but it works for me. Or it worked until last week. Does any of you have any idea what could happen? is Prime TV testing their signal? Also the strangest thing happened. When I rerun the autoprogram, I got SC 10 on channel 5 plus Prime 3 View on the same channel (yes, if I go from 5 to 5, I switch between both channels). Except that Prime 3 is no longer available....

Any help/ideas/explanations?

Thanks in advance

First of all, What appartment complex are you in?

Gadget

In O'Connor, around the O'Connor shops, it's called city edge complex. I'm on the first floor, and only one more level above me.

Yep, know it well, it's one of ours.
There were channel filters on the systems there, we have removed some to allow DTV through but I don't think we have done all the blocks. Let me know your block or unit number by PM and I'll check my records.
Being so close to Telstra Tower, ingress is a real problem, make sure you have quad shield flyleads otherwise your leads will be acting as an antenna and clashing with the antenna signal.

Gadget

44 Moorhouse St. Do you really need the apt number? is there any other way to contact you? what do you mean with "quad shield flyleads"? What does "ingress is a real problem" mean? I bought my antenna cables from Dick Smith, sure they aren't top quality but they have been enough so far. Thank's for your help.

Calichin

Each block has it's own unit plan number, if you know this let me know. Send any personal info via PM (personal message), if you're worried about sending me info my details are in my signature, contact me directly if you like. From my map of the complex I don't beleive we have removed the channel filters from your block, the dtv service you are getting will not be reliable.

Quad shiled flyleads have 4 different levels of shielding 2 foil and 2 braid, this type of lead will give you the best rejection of unwanted signals that can be picked up by poorly shielded flyleads.

Ingress is when poorly shileded leads pick up signals that then clash with the antenna signals.

Unplug your flylead from the wall socket and throw it on the floor, see if you still get a signal. If you do the lead is acting as an antenna and is not well shielded.

You have a 600,000 watt transmitter about 1 kilometer from you, it will cause problems if you don't have correctly shielded leads.

Gadget

Hi Gadget,
It's been a while since I replied. Busy times. I checked my cables as you mentioned and I didn't catch any signal when they are unplugged from the wall. So I guess they are "shielded".
To make things worse, now I can't get any signal from Prime or WIN. You mentioned earlier that you were aware of this problem, and that you were working on the complex?
Is there any way you can help me?

Thanks,
Calichin

If he did use a meter, then he should have no trouble in demonstrating that you should not be having a problem as a result of his work, based on the measurements he made at the completion of the installation, even to the extent of calling back to show this to you.

ok, it goes like this.

There is a analog channel filter in place. It passes analog VHF 7 & 9, UHF 28, 31, 34.
The DTV can sneak through in the following way, DTV 6 with analog 7, DTV 9a with analog 9, DTV 30 with analog 31. However DTV 11 & 12 miss out. Guess what channels Win and Prime are.

Call your Body Corp (ACT Strata Management if I'm not mistaken) and ask them to send me a work order request, I'll do the rest.

Gadget

Hi Gadget,

Have you done any work lately in the complex? do you know if these problems have been fixed? I'm still having some issues, but probably not as bad as it was before.

Pls let me know

Thanks,

No and no.

I have also been problems with my reception - which I suspect are due to external antenna (or cables).

My TV tuner (Sony W4500) only seems to pick up the digital channels intermittently - and I have not been able to work out a pattern to that. It also does not pick up digital ABC at all.

We are in Kambah, near Mt Taylor, with the Antenna pointing to Mt Tuggeranong. Overall there are a few trees in the way, but no structures or landscape interference.

I have an antenna as per attached here: [cancel that, don't know how to add attachments]

I don't know what type it is: it was installed when we moved in. In short it has 6 short elements and 6 long elements: all horizontal. There is also a Satellite dish that does not appear to be connected to anything but is fastened to the same pole. Also, one of the antenna elements - the longest one at the end is broken and only hanging on with the end of it leaning to the ground. Presumably that's not a good thing, but still does not make sense to me why I would sometimes get receptions and sometimes not. I have also noticed that the neighbours on either side have much smaller antennas (although I have no idea whether they are getting digital reception).