PC based spectrum analyser a question ?

I have an external TV tuner for computer (Haupage with USB).
How can I use it as PC based spectrum analyser.
Has anybody a software to do this ?

thanks

mudrik

There are some LAN cards that can be used as 2.4-2.5 GHz spectrum analyzers. This is possible since they have a built-in signal strength function that can be accessed.

I am going to guess that a TV tuner can not be used effectively for the following reasons:
1) most tv tuners have AC coupled demodulators, ie they do not respond to unmodulated rf signals. So any output will be due to AM modulation on the received signal only. CW or FM modulated sources will not be seen. Unless there is a signal strength function already built in, this will be a major showstopper.
2) 125 channel tuning capacity sounds like a lot, but there is a guard band between channels where the internal filters will throw away the RF signal. You will have a hard time seeing signals between those channel frequencies, unless you have full access to the tuner's PLL to program many more channels than it is designed for.

Thanks biff for your respond.

At the beginning, in the process to set up all possible TV transmitters to be
received, we sweep the whole frequency intervall (i think VHF and UHF).
And the tuner says about, the received signal is strong or weak, so it is
indeed the primary job of a spectrum analyser.
I'am not sure about the access to the tuner for external sweeping and for
detecting the signal level, is it possible ?

regards