Another Freecom USB DVB-T thread

[relkeel]

Hello all,

Have read through and tried everything suggested in the long Freecom USB DVB-T thread but still do not seem to get any channels.

I only recently bought it and have installed the bda drivers. GBPVR finds the stick but does not find any channels. I have run Chris Day's scanner the results of which I have attached. It seems to try and lock onto several channels but then reports 'scan timed out'. I am in North Yorkshire and believe I am served by the Emley Moor transmitter.

Can I now assume that it is my aerial that is not up to the job?
relkeel

[djtaylor]

Can I now assume that it is my aerial that is not up to the job?

Have you tried any other set top box to determine that you can receive anything?

Have you tried an all locations scan rather than restricting it to your area, if that's what you've done?

Does it work with the Freecom software?

Before bothering with anything else, if it were me, i'd be sure that I could receive DVB-T with a set top box or at least by some other method.

David.

[relkeel]

Haven't tried a set top box. I use a Sat dish for the FTA channels.
I'll see if I can find someone to borrow one from - don't really want to buy one if I'm never going to use it.

Yes I have tried all locations as well and I get the same results with the Freecom software and 2 other media centre software packages I've tried.

Does the scan I attached tell you anything? Do you know what the 'scan timed out' means?

Thanks for your help.
relkeel

[djtaylor]

To be honest I haven't even looked at the scan. To me it's not relevant at this stage.

Since you get the same result with the Freecom software and two other packages, it rather sounds like either you aren't in an area that's covered or quite possibly that your signal from the aerial is crap which is why i'm suggesting a Freeview box because they generally have a nice signal display of some sort. Although most software packages have something too, you want to determine whether it's the signal or software.

Please describe your aerial installation, how many TV's are fed off it, how are they split, mast head amp or passive splitters etc.

Aerials don't "wear out" despite what the adverts might want you to believe although your present aerial might not be up to the require gain and rejection properties of a more up to date aerial. What does kill signal is moisture in the downlead, corroded signals, kinked cables, poor shielding and also terribly bad, passive splitters. How long is the cable?

The more info you can provide, the better the response we can give.

David.

[relkeel]

mast head amp or passive splitters etc.

:confused: Blimey, your speaking a language I don't understand!
I only have one TV that is fed from a Sat dish to a digibox that is used purely to receive FTA.

There is an aerial feed into the house as well but it is not used at present (hence the purchase of Freecom stick). I should estimate it is around 15-20 metres in length. The aerial was only installed soon after we moved into the house about 3 years ago so I would have hoped it could have been able to receive freeview. My searches have confirmed we should but the transmitter (Emley Moor?) is almost 70km away.

I think the simplest thing to do is to beg/borrow/steal a set top box and see if that produces anything.

I'll also check the aerial lead for cracks, dampness, etc.

Thanks again for your help.
relkeel

[ArtificialIntel2]

Have you tried using a signal booster? These sticks need a stronger signal than other devices such as a tv, video recorder etc.

Regards

AI

[relkeel]

Have you tried using a signal booster? These sticks need a stronger signal than other devices such as a tv, video recorder etc.

No I haven't yet. I thought I'd read they didn't make a difference as you either have a digital signal or you don't. However, I'm sure you know a lot more than me about these things so I'll give that a try as well.
Thanks
relkeel

[djtaylor]

70km is a good stretch, you'll want good gain on the aerial for that but it should be very doable. I'm 60km from the Sutton Coldfield transmitter and a typical "standard 12dB gain" antenna worked fine even though I upgraded it to something more suited to the specific application.

If the aerial download is a few years old, it could well be "standard screened aerial lead" which can easily lose well over half the received signal by the time it gets to the TV.

Can you count the elements on the aerial "bars" or even post a pic?

The idea is to get as much signal as you can without amplifying at the end of the lead because you then amplify all the noise too which although it might help, isn't the best solution.

Typically, people use passive splitters to divide the output between two TV's and straight away, each one gets less than half the signal.

If you need an amplifier, the best place for it is right at the aerial mast as close to the aerial as possible, this way, you amplify the signal before it has a chance to pick up noise.

If you definitely are receiving analogue from a transmitter that broadcasts digital then it sounds like a signal strength issue (or interference which could be from many things, including kinked, mismatched cable etc.). If on the other hand, the transmitter isn't transmitting digital signals then yes, no end of amplification is going to help of the signal isn't there in the first place!

Of course, you could always pop to Argos (or any local retailer) to get a box and specify that you need it to be able to pick up Freeview in your house, if it doesn't it's not fit for the purpose you specified and they should take it back if you get my drift.

There's no getting away from the need to determine the signal strength as a starting point. In case you're not aware, this is what is really meant by digital TV. There are two states in binary, it either works or it doesn't.

David.

[relkeel]

That's really informative and made things clearer - thanks.

The analogue signal I receive is pretty good although Channel 5 is slightly 'crackly'.

Having just looked a bit more closely at the aerial it does look a little 'weedy' for the job compared with some I've seen. If I understand you correctly it has 8 pairs of elements, i.e., 8 bars each side of the central bar.

I'll go get a set top box to at least determine whether I get a signal at all.

relkeel

[djtaylor]

That's really informative and made things clearer - thanks.

The analogue signal I receive is pretty good although Channel 5 is slightly 'crackly'.

Having just looked a bit more closely at the aerial it does look a little 'weedy' for the job compared with some I've seen. If I understand you correctly it has 8 pairs of elements, i.e., 8 bars each side of the central bar.

I'll go get a set top box to at least determine whether I get a signal at all.

relkeel

If it really is an 8 element aerial is typically going to be a bit underwhelming for that type of service. Have a look here, see if it's like any of these:-

http://www.maplin.co.uk/search.aspx?Menu...&doy=25m10

DAT45 is a good aerial http://www.satcure.co.uk/accs/page11f.htm though you might still be able to make it work with a little amplification. Best if you can avoid it though, it's always better to improve the aerial/cable to receive the best signal prior to contemplating any sort of electronics as they will *always* introduce additional noise.

The other good practice is to have no connectors. Those wall plates where you plug the TV aerial lead into are handy and keep the wife happy but do nothing except bad for high frequency signals which treat the junction as a mismatch which results in reflections and losses. Ghosting is what you get when you get signal reflections and if you think of that in a digital signal, it will introduce errors in the bitstream as the same signal could be received again after it was expected. Result, receiver barfs, locks up for a moment, pixelates, sound carries on - general junk.

So, good cable, no breaks from one end to the other, good quality connectors with no stray bits of copper shield.

When looking at aerials, a gain of 3dB is a doubling of signal and 10dB is a multiplier of 10 times. So when you see an aerial that claims a gain of 12dB and one that has 15dB, the second one will deliver twice the signal that the first one will. Quite significant!

David.