No probs grafter.
That carrier list probably needs some of the older unidentified offsets removing. It's geting a bit cluttered now and those carriers can move around a little over time.
Some transmitters used to be locked to rubidium standards and were accurate to within a single Hz. I think they've all closed down quite recently which is a pity as they made excellent reference points. You really need accurate references in order to calibrate your receiver properly. Some stations drift a little. Some drift a lot. Some jump frequency. Some have temperature controlled offsets. Some warble. Some just spread everywhere and have unusual characteristics. These can all make up a distinctive footprint. When you take these things into account, add the audio, propagation, etc. you begin to see how the carriers can often be identified.
The offsets were assigned for a reason, probably to minimise co-channel interference. They aren't necessarily a sign of poor transmitter maintenance. We try to be accurate but it's probably unrealistic to expect our accuracy to be within the Hz. For my own calibration I use the Buxton repeaters on 50 and 70MHz. These are generally regarded as being spot on at 50.000.000 and 70.000.000MHz. This seems reasonable when you consider they are right on the edges of the bands. They would probably need to be carefully controlled to avoid them drifting outside the bands.
Transatlantic carriers sometimes have a more smeary appearance, but the real givaways are their visible 60Hz sidebands as opposed to the 50Hz carriers you get with European signals.
The DXer in Portugal is Hugh Cocks. He is a member of the Skywaves group and is well known in the TV DX world. Today, he posted that he received Brazilian TV on band 1. I think it was just audio though.
Amazing isn't it! But having lots of expensive equipment won't help if the conditions aren't right. There's a lot to be said for "being in the right place at the right time", even if you have a simple setup. There's hope for us all!
Cheers
John
Paul has pointed me towards a website that has some extra software for the card that makes it more useful with weak signals and if I get more adventurous some circuits to add reduced bandwidth onto it. The card that I've installed has the correct chipset for the additional software whereas the PCI-TV card didn't. As you are all TVDXERs you probably already know of his website http://www.ukdx.org.uk but I've added it to the T1 links page if anyone wants to take a look. At the moment the only problem I can see is this PC puts out a massive spike from the DVI adapter on 48.0MHz, it can be seen as an almost blank screen when I tune the card to 48.25. Adapting down from a N socket to a TV plug required some ingenuity, the gaggle of inline adapters probably looses half the signal 
Thanks for your continuing advice.
