I had to ponder this one a while.
Yes you're right, Larry.
Technological advances could be very dramatic
over a very brief historical period. A 45 year period
could see an extraterrestrial culture progress from crude-telegraphy
over copper wires to sophisticated radio transmissions.
For example the technological advances from 1900 (horse & buggy age; experimental spark-gap wireless telegraphy) to 1945 (Atomic bomb;
jet-aircraft; television) are nothing short of astonishing.
cheers.