But yes, it is too bad it can't reach beyond 2.5 GHz where all the modern communication standards sit. That makes the SVA1015 obsolete straight away.
Not obsolete, it just has a narrower target market. I can imagine plenty of uses for a 1.5GHz VNA.
Like what? Because it is a 50 Ohm device you can't use it for systems with an impedance very different to 50 Ohm without losing accuracy. So this does limit it to 'radio stuff'.
When it comes to network analysers there are basically two types: the HF 50 Ohm types which are primarily useful for HF (radio) work and the LF types which also have 1M Ohm inputs and various methods to do the analysis to offer a wide range of useable impedances. The LF network analysers are much more useful as a general purpose tool. Siglent should make one of those (just like the Omicron 100 you reviewed recently).
So you think corrections can't be applied for alternative usages ?
From the manual:
2.1.3.8 Correction
Correct the displayed amplitude to compensate for gains or losses from external devices such
as antennas and cables. When using this function, you can view the correction data table and
save or load the current correction data. When amplitude correction is enabled, both the trace
and related measurement results will be mathematically corrected. Positive correction values
are added to the measured values. Negative (-) correction values are subtracted from the
measured values.
1. RF Input
Set the input impedance for numeric voltage-to-power conversions. To measure a 75 Ω device,
you should use a 75 Ω to 50 Ω adapters to connect the analyzer with the system-under-test
and then set the input impedance to 75 Ω.
2. Apply Correction
Enable or disable amplitude corrections. Default is Off. The analyzer provides four correction
factors that can be created and edited separately, but they can be applied independently in any
combination.