The most common and most likely answer to this crossword clue is the 8 letter word AIRWAVES
I've seen this crossword clue in The Guardian
A
I
R
W
A
V
E
S
Buddy explains!
The straight part
We know that "They bring us a broadcast" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they bring us a broadcast = airwaves.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does AIRWAVES mean?
AIRWAVES noun- Radio-frequency electromagnetic waves, usually used in the context of wireless communication; radio waves.
- Radio or television broadcasts.