@ricnunes

I think after the experiences of Northrop with the XST program by the time of Tacit blue they had mastered their methods for geometrical stealth, especially because the Tacit blue traded most of its aerodynamics for stealth and was a tech demonstrator. We can be quite confident that the changes until today were rather small as the law of physics stay the same, today a Tacit blue would probably just have better flying characteristics. If overall dimensions would significantly grow to B2 size, we could expect a great enhancement of geometric stealth performance in VHF band. The threat situation back then was also not much different with huge numbers of metric P-18/12 available to the Soviets, so the Tacit blue design was optimized for VHF band stealth performance.
The changes should be foundin RAM and RAS and this mainly in x-band where the wavelengths are within the size of the RAM layers and RAS. In metric wave the tacit blue is a good RCS representer and in this case, after 35 years we are lucky to have declassified documents available, we might lack the scale but Hpasp's interpretation makes much sense at this point.

You doubt my value of 0,16m² for the F-35, understandable because we lack the scale for those declassified US origin charts, fair enough. Hpasp once stated that he believes that the difference of X-band to VHF is in the order of 10 DBSM. I extrapolated 22 DBSM with his scale interpretation (which sounds credible) of this declassified US chart:


If we would make the simplification of proportional decreasing the 22 DBSM X-band/VHF delta effect of the tacit blue from the 30 DBSM of the F-35 we would get that 0,16m² RCS as result, all assuming that our scale interpretation and the simplification of proportional DBSM decrease are right.
If this interpretation based on this US documents would be right, a Nebo-M would detect a 0,16m² RCS (in VHF band) F-35 at a distance of 320km.

As for jamming
I'm aware of dedicated jamming by systems such as the Growler but I question it in this debate where systems such as the S-300 and -400 could target those aircrafts at extended ranges if used in HOJ mode.
But this topic lead me to research a little on VHF band radars performance in jamming environment. I came across this website of a Belarus upgrade program for the P-18 with quite much information and RCS-range values.

http://www.kbradar.by/en/products/radiol...ooruzheniya/99/

I found the discrimination of RCS-range for the P-18 particularity interesting, the value for a F-14 is 175km. Assuming that they used a RCS value of ~8m² and that the Serbian SA-3 site detected the F-117 at ~28km, a calculated a RCS of 0,005m² for the F-117 in VHF band. Also interesting is the performance under heavy dedicated jamming at 500km distance. Giving the huge degradation for the original analogue system I think we can assume that the range performance of the P-18 was also degraded to some extend. Hence that engagement which suggests a 10 DBSM difference for X-band to VHF-band could be the result of jamming and the true difference could be in the order of 20 DBSM interpreted and extrapolated from those declassified Tacit blue documents.