Hello
I thought I would pass along some info on replacing a Radio Shack
49-535A
Digital Key Switch unit. Radio Shack no longer supports this item and
current alarm system users are left in the cold if one of these goes
bad, as mine did.
The replacements will NOT be cheap, but are much more versatile than
the original units.
Try Google searches for "access control kepad". These units are
normally used to control electric / magnetic locking doors, and are
well suited ( or can be adapted) as a replacement for the above unit.
I replaced mine with a International Electronice Inc.; Door-Guard;
Command and Control series (212i)interior, (212w)exterior.
Other possible options include Visonic CL-80 type units.
Again, these are not cheap (USD $100 each) but sure beat replacing the
entire system.
Hope this post helps someone else.
Dialtone