[TowerTalk] RF Quiet Router

Jim Lux jimlux at earthlink.net
Sun Sep 3 13:08:19 EDT 2006


At 09:06 PM 9/2/2006, Jim Brown wrote:
>On Sat, 02 Sep 2006 16:47:15 -0700, Jim Lux wrote:
>
> >At least, I don't hear any new birdies on the radio that's connected
> >to the equipment that's connected to the module.
>
>I wouldn't expect RF noise to be coupled to the radio via the radio's
>power port -- I would expect our radios to do decent RF filtering on
>it's own power input (or perhaps I live in wonderland). But I WOULD
>expect trash produced in the power supply to leak onto its own power
>cable and be RADIATED by that power cable and picked up by the
>receiving antenna(s).


I wasn't particularly clear on this.  I had a short whip connected to the 
radio, so it would definitely have found radiated noise.

But, in the actual intended application, the radio's connected to some 
coax, which (hopefully) goes some distance away

And, for what it's worth, several recent radios I've fooled with don't have 
all that great a filtering on the DC input. I think they rely on a stiff 
power source with low RF source impedance. So perhaps, while you're not 
totally in wonderland, you might be looking down the rabbit hole.


Jim W6RMK
>




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