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Is this a Birdie?

 

It starts low then steadily rises in pitch then fades away.  Does not seem to be coincidental to anything going on at the house.

Is this QRO likely a local issue, or atmospheric?

Thanks for any help, I know it's probably a question I missed on the test. :)


- Jim Linch

randall krippner
 

Not a birdie - a birdie is generally considered to be something generated internally by your receiver and would show up as vertical line on your waterfall display that doesn't change in frequency. What you're seeing could be something like a variable speed motor with an electronic speed controller ramping up as it comes on-line, or even someone with a wonky transmitter. The fan motor on my furnace is one of those electronically controlled variable speed motors and when it comes on I can watch a similar display on my waterfall as it comes up to speed. Eventually it settles down down and leaves a few traces on 20 meters, but nothing I can't deal with.

There are so many devices that generate RFI these days that it's damned near impossible to figure out what's causing issues without a lot of detective work. The FCC hasn't exactly been diligent in keeping up with interference issues. Although to be fair considering new gadgets and equipment are being brought to market by thousands of different companies every year it would be impossible for the FCC to test everything.

Once upon a time I replaced the lights in the garage with CFLs only to find that as soon as someone flipped on the switch they totally obliterated the entire 20 meter band and more. Holy cow, that was nasty! They literally pegged the S meter on my receiver. Next day they all got tossed and were replaced with LEDs. 

 

Thanks for that response Randall, I had assumed it was atmospheric in nature.

My HVAC is very close to the sloper EFHW so harmonics is likely the reason.  I will have to experiment, not that it happens a lot.  


On Sun, Aug 4, 2019, 05:23 randall krippner <randallkrippner@...> wrote:
Not a birdie - a birdie is generally considered to be something generated internally by your receiver and would show up as vertical line on your waterfall display that doesn't change in frequency. What you're seeing could be something like a variable speed motor with an electronic speed controller ramping up as it comes on-line, or even someone with a wonky transmitter. The fan motor on my furnace is one of those electronically controlled variable speed motors and when it comes on I can watch a similar display on my waterfall as it comes up to speed. Eventually it settles down down and leaves a few traces on 20 meters, but nothing I can't deal with.

There are so many devices that generate RFI these days that it's damned near impossible to figure out what's causing issues without a lot of detective work. The FCC hasn't exactly been diligent in keeping up with interference issues. Although to be fair considering new gadgets and equipment are being brought to market by thousands of different companies every year it would be impossible for the FCC to test everything.

Once upon a time I replaced the lights in the garage with CFLs only to find that as soon as someone flipped on the switch they totally obliterated the entire 20 meter band and more. Holy cow, that was nasty! They literally pegged the S meter on my receiver. Next day they all got tossed and were replaced with LEDs.