[Elecraft] Wireless Router Recommendations

[ron]

Thank you Jim for that very informative and helpful message!

Ron, wb1hga

Jim Brown wrote:

  > Proximity to the radio is meaningless. The following comments
> apply to virtually ALL Ethernet devices, including your computers. 
> What matters are:
> 
> 1) The antennas connected to the Ethernet device -- their length, 
> and their proximity to YOUR antennas (but NOT to your radio). 
> 
> 2) The design of the device with respect to SHIELDING of its own 
> internal wiring
> 
> 3) The design of the device with respect to the internal 
> generation of RF trash
> 
> 4) The design of the device with respect to keeping whatever trash 
> it produces off the antennas connected to it. 
> 
> 5) The directivity of the ham antennas and the Ethernet antennas. 

> MOST of the noise in the equipment I've tested comes out of the 
> box as a COMMON MODE signal, and is radiated by those cables as if 
> they were a long wire antenna. The good news is that the noise can 
> be greatly reduced by winding some turns of both the Ethernet 
> cables and the power supply cables around the RIGHT ferrite 
> toroids. Once you do that, you're left with what comes out of the 
> box due to poor shielding. And, of course, whatever is radiated by 
> your neighbors systems that are close enough to your radio 
> antennas to be loud enough to hear. [You can identify 10BaseT 
> Ethernet as the source by listening around 10,106 kHz, 10,120 kHz, 
> 14,030 kHz, 21,052 kHz for strong carriers with some subtle 
> modulation. While we buy 100BaseT gear, it carries both 10BaseT 
> and 100BaseT traffic, and most routers and modems talk 10BaseT. 
> These carriers are not based on a clock with a tight frequency 
> tolerance, so every system is running on a slightly different 
> frequency. That's why, for example, you will hear carriers between 
> about 14,029 and 14,030.5 kHz.]  

> 
> There is a detailed tutorial on ferrites on my website, along with 
> presentations I've done to a couple of ham clubs. All can be 
> downloaded as pdf files. No cost, no cookies. 
> 
> http://audiosystemsgroup.com/publish
> 
> BTW -- shielded Ethernet cable doesn't help -- for the shield to 
> do anything, it would need to be connected at both ends, and you 
> would be hard put with these boxes to find a connection that meant 
> anything.