Topics

RFI sources finding

Martin Kratoska
 

I plan to use my Antuino for RFI sources finding. My QTH is very noisy, full of LEDs with dimmers, switching PS etc. like another mid-city location. What will be the appropriate sensing antenna, do I need any additional attenuation/amplification etc.? Any experience?

73,
Martin, OK1RR

John Bucsek
 

You would want an antenna tuned for the frequency you want to examine.  Basically its the same process as transmitter hunting.  Typically a yagi is a good choice for VHF and above.  
Do a little research on Transmitter hunting if you need to get up to speed on the process.
I would think that using some variety of an SDR receiver along with software that lets you see the waterfall for an extended period (up to hours in some cases) would be an easier way to figure out what is causing the noise and then use the Antuino to find the actual source.
HDSDR is a good program for this application as you can change the waterfall duration to monitor the frequency span all day.  Seeing when a noise source appears and disappears can give one a good idea what the noise source is.

Andy_501
 

If you have a dual band 2M/440 handitalkie and can get something like a CF-416 Duplexer and combine that with an Ioio dual band home brew yagi antenna usually used for satellite work that should get you going. connect the antuino in between the HT and the duplexer and you should be able to use the antuino for displayed visual signal indications of the noise and the HT should give you aural indications; although using an HT is just FM usually so maybe an old refurbished radio shack handheld scanner might be better so you can select NFM, FM, AM , AMN or SSB modes to suit the noise you are working with.


I would start with a car AM radio on 530 KHz then if you spot something tune to 1710 KHz and see if it is still there then switch the the yagi to pinpoint the culprit.
cheers & Gud DX
73 Andy VE4PER

Andy_501
 

As an extra help if your RFI is broadband on HF maybe go to sdr.hu and check their map of registered stations and see if there is on ein your area that you can tune in to the RFI source at the lowest freq (select best mode AM, AMN, LSB, USB etc then click on the drop down list labelled "extensions" and select TDoA and it will pop open a window that will let you add two or three more stations from the map in your general vicinity and allow the system to triangulate the pinpoint location of the RFI source. Save a lot of time and gas then use your portable yagi system to pinpoint the faulty component accurately.

I wound up in a neighboring apartment complex with a portable AM/FM Tape player tracking down RFI that only occurred during NHL hockey playoff games. When the game was on , of course Dad was in the LR watching the TV game and Mom was in the bathroom bathing the children for bed and a faulty transformer in an electric razor outlet was wired to the bathroom light switch so when kids were bathing RFI reigned supreme.  Took some sleuthing to finally pinpoint that one.

Good Luck with yours.

On 2020-01-17 10:18 p.m., Andy_501 via Groups.Io wrote:
If you have a dual band 2M/440 handitalkie and can get something like a CF-416 Duplexer and combine that with an Ioio dual band home brew yagi antenna usually used for satellite work that should get you going. connect the antuino in between the HT and the duplexer and you should be able to use the antuino for displayed visual signal indications of the noise and the HT should give you aural indications; although using an HT is just FM usually so maybe an old refurbished radio shack handheld scanner might be better so you can select NFM, FM, AM , AMN or SSB modes to suit the noise you are working with.


I would start with a car AM radio on 530 KHz then if you spot something tune to 1710 KHz and see if it is still there then switch the the yagi to pinpoint the culprit.
cheers & Gud DX
73 Andy VE4PER

Andy_501
 

On 2020-01-18 2:53 p.m., Andy_501 via Groups.Io wrote:

As an extra help if your RFI is broadband on HF maybe go to sdr.hu and check their map of registered stations and see if there is on ein your area that you can tune in to the RFI source at the lowest freq (select best mode AM, AMN, LSB, USB etc then click on the drop down list labelled "extensions" and select TDoA and it will pop open a window that will let you add two or three more stations from the map in your general vicinity and allow the system to triangulate the pinpoint location of the RFI source. Save a lot of time and gas then use your portable yagi system to pinpoint the faulty component accurately.

I wound up in a neighboring apartment complex with a portable AM/FM Tape player tracking down RFI that only occurred during NHL hockey playoff games. When the game was on , of course Dad was in the LR watching the TV game and Mom was in the bathroom bathing the children for bed and a faulty transformer in an electric razor outlet was wired to the bathroom light switch so when kids were bathing RFI reigned supreme.  Took some sleuthing to finally pinpoint that one.

Good Luck with yours.

On 2020-01-17 10:18 p.m., Andy_501 via Groups.Io wrote:
If you have a dual band 2M/440 handitalkie and can get something like a CF-416 Duplexer and combine that with an Ioio dual band home brew yagi antenna usually used for satellite work that should get you going. connect the antuino in between the HT and the duplexer and you should be able to use the antuino for displayed visual signal indications of the noise and the HT should give you aural indications; although using an HT is just FM usually so maybe an old refurbished radio shack handheld scanner might be better so you can select NFM, FM, AM , AMN or SSB modes to suit the noise you are working with.


I would start with a car AM radio on 530 KHz then if you spot something tune to 1710 KHz and see if it is still there then switch the the yagi to pinpoint the culprit.
cheers & Gud DX
73 Andy VE4PER