Having TACAN at least was an advance over the early B.2s and other variants...off the top of my head I think these may have only have had ADF at the time.
It was the same-same but different with the B.20.
When it was announced in late 1966 that 2SQN would deploy from Butterworth (Malaysia) to Phan Rang (South Vietnam) several mods had to be undertaken. TACAN had to be fitted, as all navigation in SVN to R/Vs was to a TACAN point. UHF was added to the VHF, as UHF was the tacair freq band (choppers and FACs also, of course, had FM). Armour plate was added under the pilot's bangseat and under the nav's prone bombaimer position. Also nitrogen purging was added to the fuel system to prevent tank fires if hit by groundfire.
ADF was retained, and later replaced in an early 1970s navcom upgrade. At that stage, there were many more NDBs in Aust than TACANs and VORs.
The other navaid was Green Satin doppler with a GPI (mk IV I think).