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I know lots of folks hate this antenna. But I was really shocked today when I was comparing the CHA-250B to that of my ATA120A screwdriver antenna on my truck and trying to access a 6M repeater north of me. My truck with the ATAS could hit the repeater just fine with about S9 and full...

In regards to RFI, I'm sure many of you have already found this reference, but this is a great reference for those who have not read this. Jim Brown's paper here: http://audiosystemsgroup.com/RFI-Ham.pdf

Tallman, I found lots. I've been slowly trying to eliminate them...or at least identify them so I can shut them off when I operate the radio. But moving the antenna made a huge order of magnitude of difference. -J

So, I've identified some of the major RFI generators in the house. Some addressed; some not sure how I'm going to address (like the electro-static air cleaner for the HVAC). Down the street, I do hear power line noise that the power company is investigating. But I did move my vertical antenna...

The more I search, the more I find. Laptop switcher...big time noise maker. I bought this charger that I use for my ATV to keep the battery charged. Huge Noise maker. At some point, I need to just go camping and take the HF radio with me :-)

ok. Fixed the alarm panel. The ground on the alarm panel was not connected; once I grounded the main board, all the noise from the panel is gone! Now another big noise source; the electro-static air cleaner for the furnace blower. Not sure out to fix this one... -J

We've had a long dry spell...so I'm waiting for the rain to see if there is a difference in noise. As far as the alarm panel, the noise is only when my RS232 cable is plugged in. If I disconnect that, then the RFI stops. this is the biggest noise maker on site. Not sure how to address this...

Not sure how this is going to help. I'm running the radio for this test on battery power and we're still getting *huge* amounts of RFI. What is a power conditioner going to do under this test scenario? Maybe I'm misunderstanding the use case. Please correct me if I am. BTW, power company came...

I'll work on doing that, i.e. replacing with linear power supplies. After additional testing, I found that the Raspberry PI noise was really coming from the USB to serial adapter which I have that goes to my alarm panel (alarm panel is RS232). I don't know why, but the twisted pair cable from...

So, I know I've got other threads somewhat related to RFI - or at least antenna issues and trying to deal with related RFI issues. But, I took some time this afternoon to shut down the breakers and run the radio on battery power to see what I have for on-premise noise and what is off-premise...

nomadradio, your comment is making me think that maybe that is why I had a much lower noise floor when the antenna 30' away was because the feedline was laying on the ground. I guess the ultimate test would be to move the antenna and test the difference between feedline on the ground and...

I follow you. But when I tested the antenna horizontally away from house about 30' the noise dropped off substantially. So I was hoping that 50' would even be better. Some of the noise sources are work equipment that I can't shutdown. They use switching power supplies that appear to be the...

Folks, I'm thinking now to get away from all the noise sources in the house, that I need to get the antenna as far away from the house as possible. That being said, because of retaining walls in the way, I want to go overhead with LMR-400 cable from the house roof eave to a Pressure treated...

Its a mix of PC and Ethernet switches I use for testing for work. Some of it is fan noise based on the RPM of the fans which is variable depending on temperature; when the fans are running full speed, the noise is much greater. there is also some switching power supplies/wall worts that are...

So, I did some testing and there are definitely some noise generators in my office. I've identified several that I was able to power down and my noise dropped. Unfortunately, I can't power the equipment down regularly because its for work. What is weird though, is when I had the antenna mounted...

Thanks. I'll give them a shot. The coax run to the top of the house is a couple of feet from the meter and antenna is directly above this (under ground power, but meter/service entrance is near shack). I'm really starting to wonder if that is why the noise appeared when I took the antenna from...

Mudfoot, I got a copy of the sound of the noise. Any ideas to pin point the noise source? Its AM on 3.8Mhz. I haven't shut down the power yet as I need to buy an AGM battery that I want to get long term for backup power for the radio. Thanks, -J

I'll have to move it again and test - wish I had two of the same antenna to test with an A/B switch...for a true comparison. The noise is more white noise, like the noise floor increased by by a couple of S units. Additionally, signals are more buried under the noise. It doesn't sound like...

No, just a stand alone T post. No fencing.

That makes me think...maybe I should shut down the main circuit breaker and see if things improve measurably. If so then, process of elimination on a per circuit basis. -J