Is There a Thetis Diversity Basics Tutorial?

[ViolinTeacher]

The Thetis manual is quite brief in its description and instructions, I'm wondering if there's a better tutorial available? I'm not getting much (or anything) in the way of noise reduction or signal improvement. I've got a mag loop for RX1 and using an active whip on RX2. Sync is on and I've tried both antennas as reference source.

Further questions:
- What are the proper settings under General>ADC? Do the defaults settings work?
- Should AGC be set manually for both receivers? At what level?
- Should ATT be set for either receiver? I saw one YouTube tutorial that stated that was necessary. Unclear why.
- Will I only see results for specific types of local QRM? Maybe I'm hoping for too much?

[w-u-2-o]

You may indeed be expecting too much. Only interfering signals can be suppressed, not random atmospheric noise. And it will only work to suppress interfering signals if you are "lucky" in your arrangement of antennas. Did you read this post in the tacked topic at the top of this sub-forum?

https://community.apache-labs.com/viewtopic.php?f=21&t=2362#p2411

You need hardware with dual ADCs. I.e. an ANAN-100D or newer.

The default ADC settings should work. If you can't remember if you changed them use the reset to default button on the ADC settings tab.

AGC and ATT should be set on RX1 as desired for best reception of the signal you are interested in. They do not affect diversity performance. Those settings will be copied over to RX2. RX2 should NOT be specifically enabled in the UI.

[KA5KKT]

Hi Scott -

Please clarify -
"RX2 should NOT be specifically enabled in the UI."

Is that to say that 'Diversity' is operational while only RX1 is engaged on the display and via audio?


TIA,
Dick - KA5KKT

[ViolinTeacher]

Wow! I was not aware that RX2 should not be active in the UI.

What seems to make the most difference:
-RX2 not activated in the UI
-DDC1 set to ADC0 instead of the default ADC1.

With DDC1 set to ADC0 I get a lot of variation in the Phasing Control target. When it's set to default Phase seems to have little or no effect.

73 de Bill Alpert/ KG6NRV

[K1LSB]

From Thetis User Manual Revision 1.1 Section 5.7 Page 57:

Diversity improves the received signal for RX1, but is independent of the operation of RX2. RX2 can
be used on a different band if desired; the only constraint is if it is on a different band, its RX filters
will need to be disabled.

Mark

[w-u-2-o]

Thanks Mark!

Yeah, my answer was poorly worded and confusing. But then so is the naming of the various functions in our radios.

From the perspective of "diversity", which is really a poorly-named beamforming algorithm, RX1 is the RX1 you normally think of. But RX2 is, in fact, a separate DDC from the DDCs used for RX1 and RX2. That third DDC is dedicated only to making the second channel (confusingly named RX2) for the diversity beamforming function. And that third DDC is always associated with the ADC2 channel.

Meanwhile, the "normal" RX2 function continues to be fed by its dedicated DDC which may be fed from either ADC1 or ADC2 depending on your ADC assignment settings.

For more discussion of the entire naming issue (ADC, DDC, RX, VFO, etc.) see this topic: viewtopic.php?f=6&t=2644