Only 3 radar stations were out of action for any significant length of time, and the gaps in the radar coverage were made good by neighbouring stations and mobile units.
The widespread belief is that the Germans were on the brink of destroying the RAF before they switched to London, and that they switched to London on Hitlers orders. That isn't really true.
Goering and Kesselring had both wanted to attack London for some time, believing they could draw the RAF into an all out defence of the capital, and destroy the British fighters in a few large battles. Hitler merely released them to carry out this plan.
Much is made of the unsustainable losses the RAF was suffering at the end of August and begining of September, during the Luftwaffe's attack on their airfields.
The fact is, the Luftwaffe was still losing as many fighter pilots as the British, and training fewer replacements.
The RAF began the BoB with huge reserves, over 110% of front line strength in reserve, and was producing fighters at more than twice the rate of Germany. RAF reserves shrank during the Battle, but from late July on, there were never less than 1000 Hurricanes and Spitfires available.
The RAF also began with many pilots in reserve, a total of around 1300 pilots, compared to around 1000 for the Luftwaffe.
The Luftwaffe began the Battle with almost no reserves, and aircraft production lagged so badly front line fighter strength declined throughout the battle. From a high of nearly 1000 109s at the start, by early September the Luftwaffe had around 700 109s operational.
So, the figures for early September were RAF: 1100 Hurris and Spits, 1300 pilots.
Luftwaffe: 700 109s, similar number of pilots.
The Luftwaffe put on an all out effort in the last week of August, flying 3900 109 sorties, sompared to the previous high in a week of 3000. By the first week of September, serviceability had dropped to around 75%, and the number of 109 sorties declined
to 3200.
The following week they switched to attacks on London, and sorties went down much futher.
The RAF in the same period maintained a sortie rate of 5000 per week, and actually improved serviceability rates during the period, from 90 to 92%.
The Luftwaffe were on the verge of winning the battle much the same as a marathon runner who puts on a sprint is on the verge of winning his race. If he can keep up the sprint for 10 miles he will win, but of course he can't sprint for that long.
and the brits stolen decoder ring (Enigma machine) they used in WW2 which gave them the same info as top GE generals got in real time, the RL BOB would have ended differently. Those two items gave the Brits the upperhand without which history would have been changed...
Radar was vital, but Enigma intercepts played verry little part in the BoB. Most German traffic from airfields went by landline, not radio, so couldn't be picked up anyway, and what little was sent by radio and decrypted played no real part.