Thetis Diversity Display

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KA5KKT
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Thetis Diversity Display

Postby KA5KKT » Sun Jan 03, 2021 7:08 pm

I'm expecting the arrival of an 7000DLE MkII before too long.

Is there an opportunity to display the two receivers in a single Pan / Waterfall window?
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w-u-2-o
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Re: Thetis Diversity Display

Postby w-u-2-o » Sun Jan 03, 2021 9:42 pm

Not when using Diversity. Diversity essentially forms a single, composite receiver. You can look at each one in turn, but not both at the same time when using Diversity.

When not using Diversity you can, of course, see both at the same time, like this:

Capture.JPG
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KA5KKT
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Re: Thetis Diversity Display

Postby KA5KKT » Mon Jan 04, 2021 12:11 am

Thanks, Scott.

I'm not sure my question was well phrased, but I think I understand.

Using an external (analog) antenna phasing unit with two antennas, I get a single display on my non-Anan system that utilizes an early variant derived from PSDR for Pan / Waterfall display. With only a single receiver the single view I get is, I would say a composite of what the two antennas are providing.

You posted 'composite,' so I think you mean the two receivers can display as one, with what the two receivers-antennas are each getting combined. This would be approximately the same view as I might see wtih my single receiver fed by external antenna phasing unit and two antennas. Additionally, one can look at one receiver or the other in the Thesis display while using diversity RX. Thus one can get the 'whole picture' of two antennas in diversity mode in a single window and need not split between two windows.

I should add for context, perhaps both receivers on the same frequency or portion of the same band.

Do I have this right?
w3ub
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Re: Thetis Diversity Display

Postby w3ub » Mon Jan 04, 2021 1:32 pm

My experience with diversity: when turning on diversity, both receivers are activated and combined into the RX1 display and demodulator. Just like using an external amplitude and phasing unit.

But, you can enable RX 2 and view the second receiver, and also independently demodulate with it.

In my case, with a new 7000DLE this diversity mode is not stable and will fail readily, I have been falling back on non-coherent diversity.

Doug
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w-u-2-o
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Re: Thetis Diversity Display

Postby w-u-2-o » Mon Jan 04, 2021 3:08 pm

KA5KKT wrote:Using an external (analog) antenna phasing unit with two antennas, I get a single display on my non-Anan system that utilizes an early variant derived from PSDR for Pan / Waterfall display. With only a single receiver the single view I get is, I would say a composite of what the two antennas are providing.

Yes, that's correct. More technically, it's the vector sum of the two receivers. What is being done in the dual-ADC ANAN hardware is exactly the same as what is being done in the external "phasing units", except it is done digitally.

You posted 'composite,' so I think you mean the two receivers can display as one, with what the two receivers-antennas are each getting combined. This would be approximately the same view as I might see wtih my single receiver fed by external antenna phasing unit and two antennas. Additionally, one can look at one receiver or the other in the Thesis display while using diversity RX. Thus one can get the 'whole picture' of two antennas in diversity mode in a single window and need not split between two windows.

Essentially correct. The provided controls allow you to switch quickly between RX1, RX2 and RX1+RX2. Each selection is only displayed/received one at a time, i.e. you can't see/hear two or three of these choices at once.

I should add for context, perhaps both receivers on the same frequency or portion of the same band.

By definition, this type of "diversity" (poorly named, it is actually two element coherent beamforming) only works on a very narrow range of frequencies at a time. VFO A drives the frequency assignment of both RX1 and RX2 when Diversity is active.

If you haven't already, you might want to read this topic: viewtopic.php?f=21&t=2362

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