# Diagnosing interference

**URL:** <https://discussions.flightaware.com/t/diagnosing-interference/70100>\
**Category:** ADS-B Flight Tracking\
**Created:** [October 18, 2020, 4:20am UTC](https://discussions.flightaware.com/t/diagnosing-interference/70100 "2020-10-18T04:20:20Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![abcd567](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/abcd567/32/113769_2.png) [@abcd567](https://discussions.flightaware.com/u/abcd567)\
**Post date:** [October 18, 2020, 8:38am UTC](https://discussions.flightaware.com/t/diagnosing-interference/70100/4 "2020-10-18T08:38:14Z")

</div>

> [@AussieMBW](#):
>
> I just wanted to know if there were instructions anywhere so I could get some nice pretty graphs showing what’s being transmitted.

**(1) Download Spektrum for Windows**

Direct Download Link for Current Latest release for Windows: [spektrum-win64.zip](https://github.com/pavels/spektrum/releases/download/2.1.0/spektrum-win64.zip)

Check Download page for Latest Release:  
[https://github.com/pavels/spektrum/releases](https://github.com/pavels/spektrum/releases)

(2) Unzip the file, and inside you will find a file named `spectrum.exe`.

 ![image](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/9/f/9f2f5611ba698acd701a78cac8ef6408b6fb51c4.png)

&nbsp;

(3) Plug the dongle in your Windows Computer. If you have a dongle without integral filter, it will show all the signal existing in your area.

(4) Connet the antenna directly to yor dongle (No Filter)

(5) Double click the file spektrum.exe and the program will start

(6) When the program starts, it will detect and list the dongle as shown below. Click on the dongle name, and wait few seconds for scan to start.

 ![image](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/7/1/7137d4988986c502b934377e8e6f25f08b792e09.png)

&nbsp;

(7) Click on the “Measure” button

 ![image](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/1/f/1fa4b31672baed9acc72f49bb7608cdedc2c7753.png)

&nbsp;

(8) On “Measure” window, “Gain” will be by default 50 (it is actually 5 dB). Adjust gain by bringing mouse pointer above 50 and turning mouse’s scroll wheel. Set it to maximum 496 (it is actually 49.6 dB).

 ![image](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/a/1/a133e90f02e4ae2c5d754891e5b66197575b9240.png)

(9) Leave her to run for 5 minutes so that it repeats scan several times.

(10) Repeat scan with a filter inserted between Antenna and Dongle.

Here are 3 scans I have done recently:

**NOTE-1:**  
The scans below were done in an urban area with strong Cell/Mobile, TV, FM, Fire, Ambulance, Taxi, and other communication signals at VHF, UHF and Microwave frequencies. Other locations may not have such severe RF interference.

**NOTE-2:**  
The scan 1 shows RF noise picked by antenna and processed _without any filter_, The scans 2 & 3 were done with filters, and show how filters remove this noise.

### Scan 1 of 3 - FA Antenna + Generic DVB-T (no internal or external filter)

![Thumb-Generic DVB-T](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/8/7/87fd6fa5183285e98a9dc5e32727d808fadedb1f.png)  
_CLICK ON IMAGE TO SEE LARGER SIZE_

 ![FA-ant+Generic-DVBT](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/c/5/c59c4cfe98dc40ca829a94cbf2fc7df343ecd0c3.png)

&nbsp;

### Scan 2 of 3 - FA Antenna + ProStick Plus (Only Internal filter of ProStick Plus. No External filter)

![image](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/e/e/ee99e5dd5f1b6dbd1dfbd90b0652333d15417372.png)  
_CLICK ON IMAGE TO SEE LARGER SIZE_

 ![FA-ant+ProStickPlus](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/7/4/749864a62ca8555af809e7ef8d345c75238e9047.png)

&nbsp;

### Scan 3 of 3 - FA Antenna + ProStick Plus (with internal filter) + External Filter (FA Light Blue)

![image](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/e/e/ee99e5dd5f1b6dbd1dfbd90b0652333d15417372.png) ![image](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/3/8/3829bdc7c24ccec188f62d1741ebb4871c331bda.png)  
_CLICK ON IMAGE TO SEE LARGER SIZE_

 ![FA-ant+ProStickPlus+FA-LightBlue-Filter](https://us1.discourse-cdn.com/flex019/uploads/flightaware/original/3X/5/2/5205d65161ddc5c34af981954b375f75e7c0fab0.png)

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_[View the full topic](https://discussions.flightaware.com/t/diagnosing-interference/70100)._