RFI?

[awyeah]

I'm a ham radio operator, and my current Rexing V1 causes enough RFI that I can't hear on certain frequencies. Obviously this won't work!

Are there any amateurs on this forum that have used the SG9555GC? Did you have problems 2 meters?

Thanks!

- Dave/KD8TWG

 

[jokiin]

what frequency do your radios run at?

 

[awyeah]

The 2 meter band (in the US, anyway) covers 144-148MHz. The Rexing creates a bunch of noise right around 146-148. Interestingly, it only generates the noise when it's recording. Not when in playback mode.

 

[Nigel]

Presumably you have tried using a really good shielded power cable?
It is often the power cable that radiates the noise, even if the camera is running on battery, it is worth using a good cable even with a good camera.

 

[jokiin]

The 2 meter band (in the US, anyway) covers 144-148MHz. The Rexing creates a bunch of noise right around 146-148. Interestingly, it only generates the noise when it's recording. Not when in playback mode.

the sensor and storage interface both run at 108MHz which shouldn't be close enough for it to cause an issue but it possibly comes down to something else that is interfering, the reference design is generally a bit noisy, we had to do a bit of work with ours to get the levels down lower to avoid DAB issues and pass CE etc, HAM radio is not something that comes up much so not really sure to be honest

 

[lacibaci]

I'm a ham radio operator, and my current Rexing V1 causes enough RFI that I can't hear on certain frequencies. Obviously this won't work!

Are there any amateurs on this forum that have used the SG9555GC? Did you have problems 2 meters?

Thanks!

- Dave/KD8TWG

I noticed significant RF noise in GPS band. Enough to make my Garmin Nuvi to lose the GPS lock when placed near SG9555GC.

 

[jokiin]

camera doesn't run anywhere near the GPS band either, I have Garmin navs in 3 of our cars and have never noted any interference even with multiple cams running in each, I don't place a GPS next to the cameras though as that's not a practical application but perhaps if you get them close enough you could cause interference, the CMOS sensor can cause signal loss to GPS if close enough which is one of the reasons why we stick with external GPS antennas so you can get a bit of distance between them, about 6 inches of space is all it takes for that to be a non issue

 

[Deacon]

I listen in at the 155MHz range all the time with my GC V3 running, no issues with interference. I don't have anything 146-148 to compare to, though.

 

[domechrome]

Just got one today and will be installing it. I will check to see how it operates on the bands as well. My Icom is hard wired to the battery and all the panels bonded so that should help as well. Ill let you know - 73's

 

[domechrome]

Just installed it today and I didnt hear any extra noise. I was mostly on 2m, Ill test against 440 later. Unfortunately I had to take my HF rig out so cant see on the low bands.

 

[MorkdeNY]

Hi Dave et al

I'm a beta tester for Uniden scanners and my call is WB2EQE. I have a BCD536HP scanner in my '16 Acura RDX and use an NMO roof mount antenna. I'm running the GC V3 for the past 2 months and have not noticed any RFI nor spurs throughout the bands.

-doc

 

[domechrome]

Hi Dave et al

I'm a beta tester for Uniden scanners and my call is WB2EQE. I have a BCD536HP scanner in my '16 Acura RDX and use an NMO roof mount antenna. I'm running the GC V3 for the past 2 months and have not noticed any RFI nor spurs throughout the bands.

-doc

By your call I see your not far from me. Odd to see a region 2 in a region 1 area.

 

[MorkdeNY]

Lived in Region 0 and Region 4 -licensed since 1972

 

[Marc Onrust]

I noticed significant RF noise in GPS band. Enough to make my Garmin Nuvi to lose the GPS lock when placed near SG9555GC.

Same here. With my V2 running, the built-in navigation in my car (2007 Volvo V70) loses GPS lock too. It's a crappy system anyway, so I'm using navigation on my iphone (which doesn't seem to be interfered) even before I bought the cam. Therefor it doesn't really bother me nor did I try to solve it by relocating the cam's GPS receiver, but I guess that should make a difference somehow.

 

[Edgardo]

Hi Dave et al

I'm a beta tester for Uniden scanners...

I know this is OFF TOPIC but I have to ask ... will Uniden ever come out with a scanner that deals with the Harris P25 digital system which has obsoleted all my old trunk trackers?

Sorry for the diversion!

 

[Hex]

Hi there,
interestingly I had exactly the same problem with my SG9665GC V1.
Mine had two main causes for RFI:
1. The 12V to 5V converter
2. The SG9665GC itself
At the moment the cam no longer in use and this car sold, but back then I took some measurements.

The converter
The converter alone caused the DAB+ receiver to stop (VHF-Band III, ~178 MHz). This is what happened when I connected the included power supply:

These videos have poor quality (recorded with a GoPro in low light) but you can see the reception stopped when the power supply is plugged in.
Here you can see the output on the spectrum analyzer ( R&S FSH3) when measured with a magnetic probe on top of the converter.

Reference level, converter is not powered:

Converter on, but no load (0A):

Converter on, resistive load (0,4A):

Converter on, connected to SG9665GC:

Measurements at the cable with running SG9665GC:

As you can see, the converter itself is jamming everything up to 300 MHz. Above the SG9665GC produces nice peaks, which leads to the second point.

The SG9665GC
When connected to a clean power source (Anker 24W USB converter, verified with SA and scope) the DAB reception ends as soon as the cam starts recording:

.
And the measurements:

SG9665GC powered on, span 500 MHz like above:

SG9665GC powered on, full 3 GHz span:

So much for the measurements. When normal FM-Radio was used, the reception got noisy. Also amateur radio bands (2m & 70cm) were blocked with strong S9++ signals. A bunch of ferrite filters and shielded USB-Cables did not improve the RFI.

The Law-Stuff
The camera was purchased in the EU and had a CE-Marking attached by the seller. This marking must be on every "finished" product sold in the EU and declares some basic conformity. When someone declares CE conformity (you don't need to take measurements for this, only if something happens you are better off with measurements), they need to ship a copy of the certificate with the product or make the certificate easily accessible (download, email etc.). Of course the seller could't provide the certificate....

regards

 

[jokiin]

the power adapter was changed to a different one (actually we changed several times before the current one which we have been using for almost 2 years now) due to some DAB interference issues reported by customers in the UK