[Elecraft] K3: PRE/ATT Bug or feature?

[drewko]

Actually, you will probably LOSE a couple of db by switching on both
preamp and attenuator compared to having both switched off. (Measure
your MDS and compare results if you don't believe...)

Regarding weak signals, one factor that is overlooked is the ATU. By
switching it to bypass you can gain 5 or 6 db in MDS. Of course, you
would want to switch it back on when you transmit. 

I wonder if the ATU could be programmed to automatically be bypassed
on receive? You would perhaps not want the ATU to be switched in and
out at break-in speeds, but after a suitable semi-breakin delay. I
think that would be a handy option for weak signal work for those of
us who must use the ATU.

73,
Drew
AF2Z



On Tue, 10 Aug 2010 13:28:01 -0400, Tom W8JI wrote:

>> This is NOT a bug, this is working EXACTLY as it should.  Some time you 
>> want to have a little extra gain, but not as much as the Pre does alone. 
>> In this case you will run the Pre ON, and the ATT on at the same time.  No 
>> bug there.  Just another way Elecraft has made the K3 a versatile rig for 
>> finding weak signals in a loud noise floor.
>
>
>The question is not gain, because 2 dB of additional gain is not 
>significant.
>
>The question is how running both the preamp and attenuator affects dynamic 
>range. It probably decreases dynamic range.
>
>I guess no one has measured it. 
>