"beerbarrel" wrote in message
...
On Sun, 09 Jan 2005 23:12:13 GMT, Telamon
wrote:

In article ,
"Arthur Harris" wrote:

"HankG" wrote:

In my recent SWL experience, I found that most AM signals could be
detected at less than +/- 10 khz (usually 5) from the broadcast
frequency. He's on 12.172 (I think). My meter seems to be resting
on +30. His lower sideband is unclear, being interrupted by other
powerhouse stations.

It's not easy to determine the bandwidth of a station by using a
receiver. For instance, just because you can hear "something" from a
station as you tune your receiver over a 20 kHz range doesn't mean
the station is 20 kHz wide. You have to take the bandwidth and shape
factor of your receiver's i.f. section into account. The strength of
the signal will also affect what you observe.

For instance, a steady unmodulated carrier has essentially zero
bandwidth. But if you tune across it in lsb or usb mode, you will
hear the heterodyne over at least a few kHz. That's a funtion of your
receiver, not the transmitted sugnal.

The correct way to characterize a station's bandwidth is with a
spectrum analyzer.

Spectrum analyzers are generally expensive items. Got a source for a
modern one that covers 1 to 30 MHz that does not cost a lot?


O.K., guys, I got it. Don't really need to know the station's bandwidth.
It's just that I've never heard a station sound exactly like that.

How about my question modulation (limit ?), and any idea what DAB
stands for?

HankG