Re: [Discuss-gnuradio] USRP/WBX DUPLEXER TUNING

[dave k]

ok thaks. I wasnt sure if i should add attunetion or simply decrease tx power. Now that im thinking about it, maybe its not really neccessary to sweep the feeq range? The usrp could just shoot a 8mhz wide signal (noise?) into the thing, and visualize in realtime the notches and pass bands change as i adjust the cavities. Rx and tx seperatly of course. Thoughts?

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From: Marcus D. Leech <address@hidden>;
To: dave k <address@hidden>; address@hidden <address@hidden>;
Subject: Re: [Discuss-gnuradio] USRP/WBX DUPLEXER TUNING
Sent: Thu, Dec 1, 2011 4:46:38 PM

On 1-12-2011 11:36 AM, dave k wrote:
> If i were to use a usrp to tune a repeater duplexer, could i just connect both WBX ports directly to the can's, and use one port to tx and the other to RX? Would i need to add some inline attenuation? For clarification i would be doing this with 1 WBX
>
The absolute maximum RX power on a WBX is about -10dBm, when turned up to maximum gain. Beyond that, and damage to
  the 2nd-stage LNA is almost guaranteed.

So, as a safety precaution, I'd put a 30dB to 60dB attenuator in-line in front of the RX2 port on the WBX, depending on what your
  expected TX power is going to be.

When you're "tuning cans", you're trying to maximum the isolation between TX and RX, with split-frequencies between TX and RX.
  And you can easily pass through a region where TX and RX isolation is zero while tuning them up.