Jim,
Two more quick comments.
When using the TinySA Utlra it’s best to keep the maximum signal level into
the TinySA Ultra mixer below -25dBm to prevent internal generation of
spurious emissions due to mixer overload (you can use internal attenuation
or external attenuation to accomplish this).
Also regarding TinySA Ultra sensitivity you will have maximum sensitivity
(lowest noise floor) when using the smallest RBW setting but this will also
slow down the sweep time.
Don wd8dsb
On Wed, Sep 13, 2023 at 9:46 PM Don Kirk <wd8dsb@gmail.com> wrote:
> Hi Jim,
>
> The TinySA Ultra has a LNA (low noise preamp) that you can enable for best
> sensitivity. With the LNA turned on you should be in good shape regarding
> sensitivity for very weak signals when used with the portable flag and the
> DXE preamp that was designed for use with the portable flag. I suggest
> having the AM filter selected on the DXE preamp unless you are trying to
> see signals below 1.8 MHz. You probably will typically not need more than
> 20dB of gain on the DXE preamp which provides 30 dB of gain and you can
> therefore often select the -10db attenuator on the DXE preamp and still
> have adequate sensitivity.
>
> I have the TinySA as well as the TinySA Ultra and one thing you might want
> to play with on the Ultra is the VBW setting as a form of averaging.
>
> I love the TinySA and the TinySA Ultra but I hardly ever use them for
> tracking down RFI as I have found they are much less useful due to their
> slow response time compared with the SDR receiver I use which is really
> like a real time spectrum analyzer versus a swept spectrum analyzer which
> is what the TinySA models are.
>
> You will see even on higher end modern swept spectrum analyzers they now
> include a real time spectrum analyzer mode which is the way of the future
> as it captures events/signals that are often missed with a swept spectrum
> analyzer.
>
> If the RFI you are trying to see is a constant discrete signal then a
> swept spectrum analyzer is adequate assuming you have settings configured
> appropriately but you just can’t beat the performance of an SDR receiver
> for capturing things “real time” and with much better RBW capabilities
> compared with the TinySA Ultra.
>
> The TinySA Ultra is handy if you want to view a very wide spectrum (large
> frequency range).
>
> Just FYI,
> Don wd8dsb
>
>
>
> On Wed, Sep 13, 2023 at 9:12 PM Jim Miller <jim@jtmiller.com> wrote:
>
>> I've got a TinySA Ultra and recently purchased the DXE Flag by WD8DSB and
>> Preamp. I'm wondering if the combination will be adequately sensitive or
>> should I use some other receiver?
>>
>> Thanks
>>
>> Jim ab3cv
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>>
>
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