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Hi All

I have a Anan-100d and when I look at the schematic on the PA & LPF I can see 2 fixed attenuator (se picture) but how / where can I control this attenuator ???? in Powersdr ???

If I remember correctly, it's been a while since I looked at this, this attenuator is used for Ext2/3 input. I believe it is 20db, if memory serves. I used to connect my low band Rx antenna to Ext2 until I found that this attenuator is switched in and there is no way I found to switch it out. I now use Ant 3 input for my Rx antenna which is not attenuated. Much better for a low signal Rx antenna.

Joe W4WT

This is controlled from the main console via the ATT control. 10dB selects the 10dB pad, 20dB selects the 20dB pad, and 30dB selects both. If you select more than that the software starts to add in attenuation from the step attenuator IC on the SDR board itself.

If you want finer grain control than that, simple double click ATT and it will change to S-ATT. Then you are using the step attenuator, which will provide between 0 and 31dB of attenuation in 1dB steps.

Scott is, of course, correct. My mind is just not right.

73,

Joe W4WT

Hi All

The reason why I aske is that when I use ANT1 my RX is very low sensitivity but if I change to BYPASS then the RX is at full sensitivity.

using hpsdr 3.4.9 and every time I startup I have to change the attenuator to 0 to get a good sensitivity.....have to figure out where det problem is becurse I realy like to have 3 antenna connected to my ANAN 100d

TNX fer help...Ben

I'm not understanding where the problem is. With appropriate (good) band conditions best sensitivity is always achieve with zero attenuation.

Hi Scott

The problem is that when I connect a antenna to ANT1 the rx sencivity is very lov ...if I change to BYPASS the the RX is Good so somthing is wrong ???

Ben

Not enough information here to debug your problem