SDRSharp Spectrum Analyzer - how wide?

[mccuistion]

I'm having fun with my NooElec and SDRSharp (as well as the version for my Android).

But I'd really like to have it 'zoom out' further so I can see more spectrum displayed. I haven't figured out how to do that. Maybe I'm just missing the right option, but my question is

How do I get SDRSharp (or other similar software) to display
a wider range of frequencies on the screen?

My real purpose is I've built a couple FM Transmitters (9volt batteries and antennas less than 1 foot, so they are within legal playing limits). The one works great and I can tune it within the 88-107 normal FM range. But the other one is off the chart, that is, I don't know where it broadcasts. So if I could get SDRSharp to display a wider range of freqs, say 70 - 120 mhz, I might spot the signal as I turn it on and off and then thus be able to modify the coils to behave in the normal FM range.

Thanks for any clues on wider fequency displays.

 

[DSheirer]

How do I get SDRSharp (or other similar software) to display a wider range of frequencies on the screen?

The displayable bandwidth is determined by the sample rate of your R820T dongle. With the R820T, you'll only be able to display 2-3 MHz of bandwidth.

If you want to see 70 - 120 MHz simultaneously, the new Ettus B200 displays 56 MHz of bandwidth and tunes 70 - 6,000 MHz:

Ettus Research - Ettus Research News

 

[mccuistion]

With the R820T, you'll only be able to display 2-3 MHz of bandwidth.

I feared as much.

But, are there any apps that sample multiple batchs of 3Mhz and then patch them togeather? Of course, it would be less than live, but it would be useful ...

 

[br0adband]

The one way to do what you want to do (apparently monitor a very large swath of bandwidth at one time, whether it's taking place live or even "patched" together) would be:

a) use multiple RTL (or whatever you're using) sticks at the same time, using different copies of your SDR program, and each stick assigned a portion of the bandwidth spectrum you're trying to monitor up to the usable point of each stick which tends to be about 2.4 MHz (before they start dropping samples severely) for devices using the Rafeal R820T tuner/Realtek RTL2832U controller which are by far the most popular devices out there. If you wanted to cover that 50 MHz spectrum mentioned in the OP that would require literally 20 RTL sticks, and while USB technically can handle 128 devices on a controller, I don't seriously think you'd go that far. Even the most powerful machine you could build today would choke having 20 copies of SDR software to cope with all at the same time.

b) get a far more capable piece of high end SDR hardware like the one that DSheirer just provided a link for. Yes it's more expensive, but you get what you pay for, obviously. 56 MHz of bandwidth at one time, good lord, I can't even imagine the storage requirements for such a device if you tried to do a raw baseband recording of any length with that hardware... Terabytes upon terabytes.

<and yes I wish I had one, just finished watching the video demo of that newer hardware and it's awesome as expected...>

 

[slicerwizard]

But, are there any apps that sample multiple batchs of 3Mhz and then patch them togeather? Of course, it would be less than live, but it would be useful ...

c) (hopefully, an actual useful and practical answer) You should look into rtl_power.

New utility: rtl_power : RTLSDR

 

[KC1UA]

The Airspy is a forthcoming device based on the R820T but with a bandwidth of 10 MHz. Check airspy.com | A tiny and efficient software defined radio . Tentatively it appears that it may be available in a few months.

The Ettus devices, to my knowledge, to this day are problematic running in Windows. Also, to see 56 MHz of spectrum requires successful connectivity to a USB 3.0 port. Which, as I can confirm....can be a flipping nightmare.