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I'd start with 60db at the least, and go up from there.? 60db is 1000x voltage (loss or gain).? Those SDR dongles are quite sensitive (mine is down in the microvolts, maybe fractional microvolt range), and if the Bitx puts out 7 watts, that's roughly 53 v p-p in a 50 ohm setup.??

80 to 100 db would be better IMO.? That would help to not overload the dongle... and should get the signal level down to the point where you wouldn't be encountering any limiting in the signal.?? Put a t fitting on your dummy load - one side goes to the radio, the other to your attenuator.

If you have access to a step attenuator, even better.? That's the way I'd do it (I've got one 120db to 0).? Start with 120 and reduce the attenuation until you have enough signal to measure - I think the specs call for better than 40 or 45db down for unwanted signals, so you'd want your carrier to be higher than that.

I've done the "coax into dummy load, and then used a dongle to measure near the coax" method.? That also worked well enough for what I was doing.? It's a quick way to do it... without all of the extra components.? You just start moving the dongle closer and closer until you get enough signal.

Bob

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