[bearoutwest]

The history of No 600 Sqn "Gentlemen in Blue" notes the same Blenheim Mk If's being used for night patrols and fighter sweeps over Holland in May 1940. The aircraft used in the fighter sweeps had to have their radar equipment (Mk III and IV A.I. sets comprised of 2x approx 100kg boxes - modern microwave oven-size) removed prior to operations. The NF models were flown together with "regular" fighter Blenheim Mk If's and no reference is made to differing armament.

Graham Warner's book on the Bristol Blenheim notes (p.261) the forward firing armament was 4x in belly-pack and 1x in port wing for the Mk I NF. It's written as a commentary in passing, rather than a specific technical conclusion.

There does not appear to be any conclusive evidence, either, that the NF Blenheim Mk If's had the wing gun removed. There didn't appear to be any reason for it, as the radar boxes were mounted in the fuselage, and the wing receiver dipole aerial was clear of the wing gun port. The original intended position for the receiver was on the wing leading edge; but reception was better with a pair of dipoles above and below the outer wing surfaces.

...geoff