Diversity Receive Pre Amp

  • 1
  • Question
  • Updated 2 months ago

Hi,

I noticed on my 6600 that if I’m in Diversity Receive with no antennas connected, the noise floor between slice receivers is the same only if no pre amp or attenuation is applied.  I suspect that the pre amp setting for the first slice receiver is not being applied to the second.  This makes sense since characteristics between the two antennas will be different.  However, there doesn’t seem to be any way to control the pre amp selection for the second diversity slice.  Am I missing something obvious?

Chuck


Photo of W9WLX-Chuck

W9WLX-Chuck

  • 61 Posts
  • 16 Reply Likes

Posted 2 months ago

  • 1
Photo of Tom Warren

Tom Warren

  • 59 Posts
  • 24 Reply Likes
Hi Chuck, Just to let you know, I've also noticed the same thing and don't know what to make of it..
Photo of Bill W2PKY

Bill W2PKY

  • 528 Posts
  • 87 Reply Likes
Yes this is true even on the 6700.
On the 6700 have to have a second slice open on the alternate Diversity slice in order to control the preamp. No preamp selection when using Diversity on the second slice.
Photo of W9WLX-Chuck

W9WLX-Chuck

  • 61 Posts
  • 16 Reply Likes
Thanks.  I understand the limitation.  Since both slice receivers are on the same panafall, the pre amp/attn value is not being applied to the second slice even though the second slice is on a different SCU.  Not sure if the limitation is in hardware or software but the pre amp/attn is also applied to the panafall too, so that's where it likely gets complex.  If I open another panafall for the diversity receiver, then pre amp/attn values can be set independently, but I would lose the automatic slice VFO sync and audio split settings.  It's probably a rare occasion when that would be necessary, but good to know a work-around.
(Edited)
Photo of Bill W2PKY

Bill W2PKY

  • 528 Posts
  • 87 Reply Likes
Since the 6600 has 2 SCUs should be able to have separate values for the preamp on each slice. Flex needs to put the preamp selection on the slice flag rather than the panadapter when in "DIV" mode.
When I use "DIV" on 6M with a horizontal loop and HF vertical the vertical needs more preamp than the loop. It's interesting to hear the signal rock back and forth left to right on 6M Eskip signals.
Photo of Tim - W4TME

Tim - W4TME, Customer Experience Manager

  • 9186 Posts
  • 3548 Reply Likes
There is an easy workaround.  Before setting diversity on, open a 2nd panadapter and set the RX antenna to the same RX antenna as the child slice that you will create.  Tune the slice in the 2nd panadapter that is automatically created to the same band as the child slice and then delete the slice.  Enable diversity.  Now using the 2nd panadapter menu, set the preamp gain to your desired setting.
(Edited)
Photo of W9WLX-Chuck

W9WLX-Chuck

  • 61 Posts
  • 16 Reply Likes
Thanks Tim!  Much better workaround with no loss in functionality.