During the past weekends ARRL Field Day, we attempted to deploy a AC200P MAX as our primary power source to operate our HF Radios. The Bluetti created so much RFI noise as to make the radios unuseable. We were able to determine that the noise was coming from the 110 connection we were using (unable to check the DC connection as no adapters - yet). Our other power source an EGO generator had no detectible noise.
Are there any suggestions to reducing the interference or modifications to be made? Willing to work with engineering to resolve this. This was not isolated to just the Max, we had two bluettis deployed a 200P and a 200PMax and both exhibited the same noise. Like 7-9 dbi of noise.
Try adding an RF filter inline with the AC output. This includes two toroidal cores with the live and neutral wires wrapped in them, and two capacitors between each wire to ground. Other radio fans can help you buy or even build one.
Thank you, Raymond. That’s the thoughts we were having. We noticed it during ARRL Field Day and didn’t have much in the line of resources or time to figure it out. Although I was hoping that maybe Bluetti might have a solution that wouldn’t require lugging around another piece of gear. Stay tuned as we get closer to a solution and what it took.
At this point I’m guessing that this problem is related to an open Ground on the AC outlet. I have an EGO Nexus Power Station and when I check those outlets they show as correct. I further suspect the open ground because when I connect my radio to the 12v30a power source on the Bluetti, I’m only dealing with my normal noise floor.
You may find this interesting … I have a hi-end system with balanced cables - couldn’t find the hum insertion anywhere - did some research and was directed to my cable source - disconnected Cable TV and the hum was eliminated - total silence and total surprise at the source of the injection.
Note: there is no common point or connection to cable in my audio system which is also filtered with Furman isolation.
I found this post after searching for the same issue. I worked an event in which I decided to use the Bluetti 200. We were operating in the 2 meter band. At first I thought I was having antenna issues. I later found that the RFI was the Bluetti. Even when not connected to the DC or AC, AND with the DC and AC off and the unit only powered on, I was getting RFI. I confirmed this with both an HT and Mobile rig. Distance of the antenna with the Bluetti would diminish and eventually negate the RFI. Depending on how the device is designed, I assume this would eliminate the AC and DC outputs. Something internally must be acting as an accidental antenna and transmitting RFI. Like the poster MikeZ, I would also be willing to make any mods needed to eliminate the noise, especially since I purchased the unit for Ham operations.
I second the findings in the previous post, in that it is a radiated noise issue. I was able to observe with a 2m handheld radio that the AC200MAX emitting significant RFI. The FCC test report on cursory inspection looks good: https://fcc.report/FCC-ID/2AYT3-AC200MAX/5541039
I’m curious if @BLUETTI Engineering can help identify the source of the noise.