Filters & signal quality, oh my!


#1

I bought the combo USB RF amp + filter.

Is there any advantage to the external filter as well? Seems as though I’d get more attenuation outside the bandpass, but perhaps at the cost of signal loss too?

I’m also considering replacing the smaller indoor antenna recommended on the build page with this one.

Should I expect either of these to be useful? (I imagine the most useful thing would be to get the antenna a clearer view of the sky, but in the interim…)


#2

Locations with lot of RF noise (Cell phone & other communications signals), do require an external filter both with ProStick (orange) and ProStick+(blue).

I live in a high rise building with lot of Cell Phone antennas on roof top of my building, as well as on roof top of many surrounding buildings.

My setup does not have an external amplifier, as the ProStic/ProStick+ have an integral amplifier. Adding an FA filter to both ProStick (orange) AND ProStick+ (blue) did improve performance. Here is result of a test I conducted last year. Gain setting was constant throughout the test:

ProStickPlus with and without Filter


#3

James,
I think you need to get the antenna outside and up high.
My basement window mounted antennas get about the same range that you do.

I would first search the posts on optimising gain. It costs nothing and can help significantly.

The antenna is good but need to good location to help it out.
You can also try putting the dongle and RPI in a metal case to reduce RF interference.

Jon


#4

(A) SWEEP/SCAN BY NOISE GENERATOR

Image 1 of 5 : SETUP

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Noise Source BG7TBL

Image 2 of 5 : Pro Stick (orange)


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Image 3 of 5 : Pro Stick (orange) + Filter

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Image 4 of 5 : Pro Stick PLUS (blue)

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Image 5 of 5 : Pro Stick PLUS (blue) + Filter

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(B) Scan of Existing Cell Phone and other RF Signals at My Location

Method used: Do I Need A Filter?

scan by rtl_power-1a

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scan by rtl_power-1b

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scan by rtl_power-1c


Help interpreting frequency scan results
Antenna height increased but range doesn't
Do I Need A Filter?
Range seems to have dropped
#5

To close out the thread, the filter was noticeably better, but the antenna really made a huge difference.


#6

Yes, this is my experience also,
The FA 26" antenna + FA filter + FA Pro Stick is a real good combo, as well as very reasonably priced.