DCS Luftwaffe Radar Substitutes
At the moment, there are no period radar units in DCS. However, I've been doing some experimentation using combinations of modern units, buildings and other objects. Here are some example mock-ups in DCS with some historical counterparts. I did these quite quickly, so no doubt if we include these in the SoW DCS campaign, we will tweak them to get them even better. However, this should give at least a rough idea of what is possible.
Würzberg Radar

The Würzberg stand-in is not particularly convincing, but it is rather small and has a lower range. Therefore, it is rather unobtrusive. The modern substitute has a range of 90km and the historical unit was up to 70km, which is close.
Ref: https://en.wikipedia.org/wiki/W%C3%BCrzburg_radar
Freya Radar

The Freya stand-in is more convincing, although it scans quite quickly, which is not correct. That said, even the scanning version looks pretty convincing and it makes for a decent Freya site. The range match is better here (modern = 120km, historical = 200km). As the accuracy for the historical unit was poor, I actually think this is a good compromise. All the indications I have found suggest that there were 2 Freyas and sometimes a Würzberg Riese at each major site.
Ref: https://en.wikipedia.org/wiki/Freya_radar
Wassermann Radar

This looks the least contrived, although the broad antenna array at the lower part is not correct. Thus, this is sort of a hybrid between the FuMG.41 Wassermann L and FuMG.42 Wassermann S variants. An additional problem was that the Wassermann radar was not deployed in France (although they were planned) — there was a Mammut radar at Digullevillem, but that is quite different. The range of the modern stand-in (120km) is actually shorter than the historical one (300km), but this is probably okay, given the limited size of the map. Like the others, this has near-perfect accuracy.
Ref: https://en.wikipedia.org/wiki/Wassermann_radar
As these are all working units, they can be used for tracking aircraft. I've done some tests and they can certainly pick up TF-51D and B-17G units... even a single aircraft. They are all very accurate though. There is no "uncertainty" in their tracking capability.
It is also possible to destroy them. I did some testing on this too, and cannon fire (20mm), bombs (SC50s) and artillery (7,5cm) can knock them out pretty easily. And, once gone, their radar capability goes off too.
Of course, I would certainly prefer an historically-correct LW radar modelled directly into DCS. However, at least for the time being, these substitutes give some of the required functionality for the SoW campaign.
EDIT : This this post for an evaluation of LW radar sites viewtopic.php?f=56&t=6835&p=53198#p53198