Can the 'customer' re-tune/trim the receiver easily?
The standard AAVSO SID receiver requires considerable tuning
that assumes an experienced person working with an oscilloscope.
Because our SID is designed as an Education and
Public Outreach project,
we chose to provide "plug & play" right out of the box.
We did not want to require that high schools (especially those in
underserved or developing nations areas)
purchase oscilloscopes and DMM's and then have to find ham radio
expertize to tinker with an RF tuning
procedure that neither we nor they could assure was done properly.
Nor would we be able to provide tuning support to hundreds of
monitor sites. We needed something that a novice could readily
set up and get to work.
In the Stanford design, The 'customer' does not tune anything.
If the students wish to change the frequency then they
exchange a prefabricated frequency board that is
pre-tuned for them. Stanford provides frequency boards for
each of the VLF transmitters.