radio waves on an oscilloscope

[chapi]

Hi guys.

I can view the waves from my transmitter on the scope, inc frequency, when the scope's probe is really close to the transmitter (up to 20'). But how can I do it from 20 miles? Is there any way to get a reading of the rf from a receiver? maybe using a bandpass filter?

I need to have it exactly like the probe, ie that when I start the transmission I will see the waves on the scope, and when I end it, the waves will disappear.

Any ideas how to do it?

Thanks.

 

[WA0CBW]

First you need an oscilloscope with a bandwidth capable of looking at your frequency of interest. Next your signal of interest needs to be strong enough to be picked up by the oscilloscope. There are other ways of doing this but will require additional equipment as others will probably describe.
BB

 

[slicerwizard]

Hi guys.

I can view the waves from my transmitter on the scope, inc frequency, when the scope's probe is really close to the transmitter (up to 20'). But how can I do it from 20 miles?

Use a real radio receiver. Like a $20 dongle. That's how you do it.

Your scope doesn't have an RF amp or filtering or an RF tuner, nor the required bandwidth. Ain't happening.

 

[zz0468]

What exactly are you trying to accomplish? Like slicerwizard alluded to, it takes a considerable amount of filtering and amplification to pull a single desired signal out of the air, enough so that you would have 90% of a full receiver to do it.

The closest you're likely to come is tapping the IF of an AM superhet receiver, with the AGC turned off.

If you're a bit more specific about what your end goal is, maybe we can actually help you.