[arm-allstar] Video example of rfi getting into fob, and my setup.

[Terry Bethlehem]

#1 Yes it is greater than 10mhz for the repeater. The friend that helped 
with this said the duplexer is only used for rx filtering.

#2 Getting the tx antenna at point blank range is just to show the 
problem. It is the same noise when the repeater is in its normal spot. 
When the repeater is in its normal spot, the passenger floor, it is of 
course farther away. I had to have the AC cranked in the car during the 
recording. If it is quiet in the car, the buzz tone can be heard when I 
listen to my output on another radio. The repeater I'm linked to has 
mentioned they hear it too.


As for your tin foil idea, I was thinking along the same lines. I just 
found a altoids tin that isn't empty. It looks like it might be the 
right size to put the fob inside to see if that helps shield it better.


On 7/5/2017 5:46 PM, "Steve Agee via arm-allstar" wrote:
> My observations:
>
> #1 You say the duplexer is tuned to more than twice a normal split. 
> So, greater than 10 MHz? Does this duplexer spec out that far? Some of 
> them tell you 6 MHz or so maximum split, so be sure you are within 
> tolerances/specs of the duplexer.
>
> #2 You are ramming +35 dbm or so of RF straight down the throat of 
> your FOB. I don't know of any of them that wouldn't shudder under that 
> much RF. Try wrapping it with some grounded aluminum foil. If it 
> creates a ground loop then try it without grounding (as a reflective 
> shield only). Now if it still happens 50 feet away out of the near 
> field of the device, then perhaps you would have an argument. 
> Remember, the FOB is a Part 15 or similar device.
>
> N5ZUA
>
> On 7/5/2017 4:28 PM, "kd4ont via arm-allstar" wrote:
>> https://youtu.be/wSA7DscoiZM
>>      _______________________________________________
>>
>> arm-allstar mailing list
>> arm-allstar at hamvoip.org
>> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>>
>> Visit the BBB and RPi2/3 web page - http://hamvoip.org
>
> _______________________________________________
>
> arm-allstar mailing list
> arm-allstar at hamvoip.org
> http://lists.hamvoip.org/cgi-bin/mailman/listinfo/arm-allstar
>
> Visit the BBB and RPi2/3 web page - http://hamvoip.org