Local interference

[dhardin53]

Been doing some investigation  work. found the reason why my KG935G when in scan mode keeps geting a spick and stops scanning.

My personal wirless weather station works on 915mHz, killing all Wi-Fi and LED lights, and still pulsing. The neighbor next door has a security gate topically use 316 and 415 MHz, Plane a wlaking over there tomarrow and see if signal increases. Sound a lot like a beacon  posable from the local county airport one mile away. will take a drive over there as well. Wireless gas meter and electric meter I believe is in the 800 rang?  the water meter has some type of Automated Meter Reading (AMR) of sending device as well. Not sure of its frequency. I think it is a drive my system or meatier readings. 

 

Fire up my HDSDR dongle and found this. Sound is not great but there is a click at the end of each burst.  Any suggestions. 

[Lscott]

12 hours ago, dhardin53 said:

Been doing some investigation  work. found the reason why my KG935G when in scan mode keeps geting a spick and stops scanning.

My personal wirless weather station works on 915mHz, killing all Wi-Fi and LED lights, and still pulsing. The neighbor next door has a security gate topically use 316 and 415 MHz, Plane a wlaking over there tomarrow and see if signal increases. Sound a lot like a beacon  posable from the local county airport one mile away. will take a drive over there as well. Wireless gas meter and electric meter I believe is in the 800 rang?  the water meter has some type of Automated Meter Reading (AMR) of sending device as well. Not sure of its frequency. I think it is a drive my system or meatier readings. 

 

Fire up my HDSDR dongle and found this. Sound is not great but there is a click at the end of each burst.  Any suggestions. 

 

20220313_235437.mp4 33.35 MB · 0 downloads

If you're lucky the signal exhibits a fair about of polarization, vertical or horizontal. 

If your radio has a signal strength indicator try rotating the radio 90 degrees. Then turn in a circle and see if the noise will null out completely or to a significant degree. Try to get a compass heading. The noise source should be in line with the axis of the antenna. Repeat at several widely space points. Hopefully you can plot the headings on a map and get a general idea where the location of the noise source might be located.  

If it's coming from a utility pole, wouldn't be surprised, it could be a bad insulator or loose connection. Each utility pole should have a tag on it with a number. You can report that tag number to the local utility and ask them to come out and investigate and repair as necessary.

[dhardin53]

Interesting insight, thank you so much. Interesting maybe not related. Sunday night around midnight one leg of the 200 amp breaker failed. After 20 minutes of investigating found one leg at the meter/main breaker and found it. I'm sure it is just a weak breaker and will be replaced today, this happened last year. Just wiggling the old breaker I head something inside the breaker ping sound the then returned the load to normal. Still working today but this breaker is 40 years old and if this is a utility componiee problem  that may have effaced the leg going to my house it is a good time to replace it. But them anagen i don't feel my weak old breaker is it issues. but on never knows. 

Great weather today to get out and program this exact frequency in the hand-held and do just as you said. Would be a nice time to have a small foxhunt mini beam. 

http://www.arrl.org/direction-finding

Thaks again, a little guidance means a lot.

WROQ912

  

[dhardin53]

Narrow it down some yesterday. Not a 100% but  I will soon. It is a good possibility a "Lamb wave" or some type of ultrasonic testing.

Go figure.

[flashover52]

Good luck! One of our ham folks tracked down some interference and it was a neighbors ceiling fan. Specifically the LED switch. Drove him nuts as the interference was sporadic. Had the power company come out and took a bit of trial and error to hunt it down.

[gman1971]

Interference that is that narrowband in nature can also be dealt with the use of a passband cavity for single channel, of if the interference is that narrowband (like a NOAA weather station) then you might be able to use a cavity notch filter, or if you need a range of frequencies to pass then you can use a preselector filter. 

Another option is to step up to a radio with a better front end. 

G.

[Lscott]

8 hours ago, gman1971 said:

Another option is to step up to a radio with a better front end. 

G.

A very good point for newbies out there. Power isn't everything. Having a bullet proof receiver that won't overload and maintains selectivity in a high RF environment is critical. This is why you'll see people like gman1971 spending big bucks on commercial radios, his favorite are Motorola models. I also have a collection but I'm mainly into the Kenwood stuff.

People get tempted by the cheap, or cheaper, Chinese radios. For some people they might be OK for their intended usage, occasional non-critical communications. I'll admit I have a few as "beater radios" and you get what you pay for, if you're lucky.  If you want something you're going to bet your life on look at buying a better radio. There is a reason why those radios carried by police and firefighters cost in the $1,000's, their life is on the line. Those radios CAN'T afford to fail.

[Radioguy7268]

9 hours ago, Lscott said:

This is why you'll see people like gman1971 spending big bucks on commercial radios

I laughed when I read that. The Gman does NOT spend big money on his radios. Most of his Motorola gear was acquired at prices well below dealer cost. I'd venture to say that every Moto radio he owns could be sold today at a profit. Not sure many CCR owners could say the same.

But, you're right about receivers.

[Lscott]

4 hours ago, Radioguy7268 said:

I laughed when I read that. The Gman does NOT spend big money on his radios. Most of his Motorola gear was acquired at prices well below dealer cost. I'd venture to say that every Moto radio he owns could be sold today at a profit. Not sure many CCR owners could say the same.

But, you're right about receivers.

Well he has spent more on his various high end Motorola radios than I have on my Kenwood stuff. Other than my D74A, and the D578UVIII Pro, I’ve paid maybe a bit over $200 for some of the digital radios. The analog stuff was well under $100, more like $30 to $80 range. I have a photo in the gallery showing most of my radio collection sorted out and boxed up in plastic tubs for storage. It’s grown a bit since then.

[gman1971]

Well, I've spent a lot b/c I've purchased a ton of XPR radios and accessories... most of my XPR7550e radios were acquired for an average well under <300 bucks.

I don't spend money on analog radios anymore, its just not worth it... but that is really besides the point. This is not a who has spent more or less thread.

Obviously, back on the thread, about interference, as stated: a radio like an XPR7550e, or an XPR5550e will have a very sensitive and selective front end, which will make it very resilient to interference; however, at this point in time, I simply cannot recommend anyone who isn't beyond serious about radios getting one due to the insane pricing....

With that said, if you are willing to sacrifice most of that bandwidth on your CCR VFO, then a good preselector will work well to improve most CCR's front end. Obviously, say goodbye to portability, but at least you'll have improved the RX capabilities substantially.

G.

[Lscott]

Talking about expensive for the XPR7550e’s…..

https://www.ebay.com/itm/354082232848?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=TlfnglliRoC&sssrc=2349624&ssuid=j_t98fioS_6&var=&widget_ver=artemis&media=COPY