Original Message -----
Subject: [softrock40] Re: softrock40
I have long since removed the attenuator from the two low ranges just so I could use the RXII for such measurements. As you can see, the sensitivity is within 2 dB across this range. This is a standard build with no heroics other than removal of the attenuators.
Roger, Warren,
These attenuators are there because the Softrock is too sensitive on the lower bands when used with a good TX antenna. In fact I've put an attenuator in a LF RXTX.
I don't think you are going to find a substantial fault in the design that contributes to insensitivity. It is much more likely that the title of your post is correct and there is a soldering issue somewhere. :-)
But there are not any in the higher bands on an Ensemble RX because antenna noise is (should be) lower on the higher frequencies.
The fact that the snsitivity is the same over the whole range does not mean it's sensitive enough on the higher frequencies.
Yes, I remember Warren, you think your Softrocks are sensitive enough on 10m:)
Maybe my Softrocks are different.
Personally I do not think a soldering issue is likely to make a few dB difference, more likely a few tens of dBs?
73 Alan G4ZFQ
The MFJ is a great diagnostic tool. It's output is a little rich and will overload the receiver (but will not hurt it) if you connect it directly. But if you can put a 20 dB pad in the ouput then, as you tune across the bands, you should see pretty close to the same levels. It is a great tool for the RXII to check as you cross band boundaries and be sure your filters are ok.
Hope that helps. Let us know how you make out.
