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static on one freq.
- Thread starter egp8111
- Start date
Static on one freq.
This kind of thing often originates from some piece of equipment that incorporates a poorly designed switching regulator in its power supply. A poor design or one with inadequate filtering can radiate at a whole range of frequencies and interfere with your radios. Many items, including EFIS units and radios now have switching regulators in their power supplies. A give-away is if the unit is rated to run from 14 to 28V without any mods or settings.
With the radio on, try selectively turning off other items and see if the static disappears with one of them. I had an early GRT MiniX that splattered RF noise at 1mHz intervals throughout the aviation comm band, but they have fixed the problem a few years ago. Another item can be a device charger, such as the kind you plug into a cigarette lighter. These often are RF noisy. It can also be caused by many kinds of LED lighting.
I have an LED hand work light that generates so much RF noise that I can't use it in the plane!
This kind of thing often originates from some piece of equipment that incorporates a poorly designed switching regulator in its power supply. A poor design or one with inadequate filtering can radiate at a whole range of frequencies and interfere with your radios. Many items, including EFIS units and radios now have switching regulators in their power supplies. A give-away is if the unit is rated to run from 14 to 28V without any mods or settings.
With the radio on, try selectively turning off other items and see if the static disappears with one of them. I had an early GRT MiniX that splattered RF noise at 1mHz intervals throughout the aviation comm band, but they have fixed the problem a few years ago. Another item can be a device charger, such as the kind you plug into a cigarette lighter. These often are RF noisy. It can also be caused by many kinds of LED lighting.
I have an LED hand work light that generates so much RF noise that I can't use it in the plane!
The walkman came out after most of our aviation electronics were designed.
Larco
Well Known Member
I think Stein sells a modified unit so to illuminate to noise?
Noise free USB chargers
Garmin makes their GSB panel mount charger. Unfortunately it runs around $275. Stein likely sells it. Sporty's also has a couple that are meant for the cigarette lighter. I assume if Sporty's is selling them, they have been vetted for RF noise. Aircraft Spruce also has a bunch - you might have to check their reviews or do some research to see how quiet they are.
Garmin makes their GSB panel mount charger. Unfortunately it runs around $275. Stein likely sells it. Sporty's also has a couple that are meant for the cigarette lighter. I assume if Sporty's is selling them, they have been vetted for RF noise. Aircraft Spruce also has a bunch - you might have to check their reviews or do some research to see how quiet they are.
Couple of years (4-5 maybe more you how time gets away) ago at Oshkosh at the ATS tool sales booth they had some of what I would call small profile cigarette lighter double USB charges. Bought 2 of them for about $17-$18 each they have been totally RF interface free. Might be worth checking to see if they still have them. Also they kept pace with power required for a first generation iPad running GarmiPilot for hours on end. Very pleased with them, wish I'd kept the package it came in. Both are still working.
CHT jump
Do you have just a single CHT? Or if all 4 or 6, do they all jump? Basically, CHT and EGT are very low level signals which can be interfered with by the transmitted RF. Typically a dis-similar metal interface in the wiring will rectify picked up signals and generate erroneous readings. Proper shielding is usually the first thing to look at on the signals in question.
Do you have just a single CHT? Or if all 4 or 6, do they all jump? Basically, CHT and EGT are very low level signals which can be interfered with by the transmitted RF. Typically a dis-similar metal interface in the wiring will rectify picked up signals and generate erroneous readings. Proper shielding is usually the first thing to look at on the signals in question.
