Cheap way of verifying radio transmitter tx frequency (to avoid interference) ?

[e100]

I was thinking of buying the 902 to 928 MHz United States ISM version of the Xbee and flashing the firmware for the Australia ISM band which has a much narrower range  from 918 to 926 MHz.
We have cellular carriers operating either side of this range so I'd like to be extra sure that I'm not accidentally transmitting where I shouldn't be.
Is there a cheap way of verifying the transmit frequency without buying a spectrum analyser. I'm probably only need to do the check once, so a breadboard solution would be OK.

Mike

[tggzzz]

What makes you think you can flash just that parameter?

If you want to do a proper job, you'll have to measure not only the carrier frequencies, but also the amplitude of sidebands and harmonics.

Almost certainly cheaper and more defendable to just buy the right device in the first place.

[e100]

What makes you think you can flash just that parameter?

Digi makes the Australian specific firmware.
http://ftp1.digi.com/support/firmware/pcn.xbp900.20110119.pdf
Most resellers just sell the default US version or don't specify the version.
Digi provide a utility for flashing the firmware.

[Kelbit]

In a pinch, I've used an RTL-SDR stick as a makeshift spectrum analyzer when caught without one. Not nearly as good as a real spectrum analyzer, but it costs $20 and fits in a laptop bag.

[kripton2035]

In a pinch, I've used an RTL-SDR stick as a makeshift spectrum analyzer when caught without one. Not nearly as good as a real spectrum analyzer, but it costs $20 and fits in a laptop bag.

+1