Hi Mark K,.... Thanks for Info, Two different Freqs. Block 9B and 8A, Not a Single Freq. Network then?
Ofcom had some research done, as to Why DAB don't get into buildings, as well as the FM Band does...

Not found report yet, but it's because FM Band works by Reflection/ reradiation, this is a Two edged
sword, because reflections are what causes the MultiPath effect....In fact, if you look at an FM signal
using a Direction finder..(the ones with 4x switched aerials) you see signals from more than one direction
Whereas, at High Band 165-174Mhz, and DAB 174-240Mhz, you only get One signal, with little multipath

Although UHF 400-470Mhz is used for security inside shopping malls etc, you would think DAB would be
OK in buildings, but depends on the building construction, and size of rooms/ windows relative to W/length

Interesting about the Bus Comms. on Band 3, needing a huge number of TX to cover London with good signal
Made worse having to use the special Aerials on the Buses, That looked like a Huge upside down Dinner Plate
This was so, could put Bus through the giant car wash, so couldn't have a normal aerial, would damage easy

This is the effect with Band 3, Its Very first use was during the war, for tank to tank comms.(some No19 set)
Then of course, was used by 405 line ITV, Comms, and now DAB...Its interesting, having worked on High Band,
also Band 3 Comms, you noticed a Huge reduction in range, as you go up above 170megs (405 Anglia TV 176Mhz)

Rod Watts