First new tubes sometimes are bad or go bad soon.
Second a tube tester is NOT 100% especially when at high freqs.
If the EBF89 is the audio out find the G1 pin ind follow that back to
the driver. there will be a cap between the driver plate & output G1.
Change it.
For the tuning noise check the previous tips. Also there is a way the
shaft gets grounded, clean that real good. On TV UHF tuners that
was a big problem.
73 Zeno
LFOD !