Re: [Make-wifi-fast] Wiring up a wireless testbed

["Toke Høiland-Jørgensen" <toke@toke.dk>]

Aaron Wood <woody77@gmail.com> writes:

>> As for cross-talk between antennas, I'm not sure this setup removes it
>> completely; there's probably leakage around connectors, and possibly in
>> the cables attaching the outwards-facing SMA connectors on each machine
>> to whatever the tiny connectors on the cards are called. Don't have the
>> equipment to measure any of that, though, so for now it remains a hunch...
>>
>
> Yeah, that's going to depend on the noise-floor of the receivers.  I've
> found that -105dBm receive radios (other technologies) needed physical
> separation and cables rated at 60dB of shielding in order to keep
> cross-talk down.

Yeah, I've heard similar reports from others. And I'm not really in a
position to set that up; nor do I really need that much isolation
between the nodes (I think).

> The cables from the SMA connectors to the boards are likely pretty
> leaky (the board connectors are probably u.fl connectors)

Ah, yes, u.fl is what those are called. Indeed they are. So yeah, those
cables don't exactly look like they have a lot of shielding on them... :)

-Toke