On Fri, 09 May 2014 11:25:30 -0700, Jim Thompson
wrote:

Suppose I simply made a dipole half inside and half outside? Would
that improve my reception?
...Jim Thompson

Well, it has half a chance of working, and half a chance of making
things worse. It depends on which side of the dipole you poke through
the wall. Half-baked is usually the result of half-way solutions and
half-ass kludges. The reason I can only offer half a reply is that I
have not seen anyone build a working antenna like that, which should
be a clue as to how well it might work. If you're going to drill a
hole in the wall, you might as well put the entire antenna outside.
However, if you insist on doing it wrong, just make sure you put the
half of the dipole that goes to the coax center conductor outside the
garage, and the grounded half of the dipole inside the garage. With
foil backed insulation in the wall acting as a ground plane, no RF
will radiate from the grounded half of the dipole, giving you a better
than half-way possibility of making this technical abomination work.
1/4 wavelength at 433 MHz is about 17.5 cm.

Incidentally, the problem with attaching a bigger/better/outside
antenna is that it MIGHT detune the receiver. If it's a crude TRF
(Tuned RF) receiver, where all the selectivity is one tuned circuit
connected directly to the antenna, any changes in antenna
configuration is going to create a problem. As Mike K suggested,
you'll need to look at the schematic to see if there's any isolation
between the antenna and the tuning.

Beware of engineers bearing screwdrivers (and tuning tools).

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558