On Sat, 04 Jul 2015 11:01:29 -0700, RogerDoger
wrote:
Harbor Freight Wireless Security Alarm System Item 93068
Been working for years indoors only.
Recently the range has diminished.
new batteries installed but still does not regain original range.
It works but distance between unit is less.
Was 40 feet now only works at 30 feet.
Using both inside between rooms.
What can cause this lose in range?
Item 93068 9V at transmitter, 3 C at receiver.
http://www.harborfreight.com/wireless-driveway-alert-system-93068.html
The advertised range is 400ft. At 433 MHz, that's rather optimistic.
50-100 ft would be more likely.
My guess, based upon the rather limited information that you've
provided, is that you have some obstruction between the transmitter
and receiver, which may have changed. Interior walls may have
aluminum foil backed insulation, which blocks RF. Same with
metallized wallpaper. Concrete walls will also block RF.
If it's been working for "years", it may have accumulated some
corrosion inside, even if it was only used inside. Open and clean
with household cleaner (409) and a clean paintbrush.
Are you using real C batteries or plastic adapters with a NiCd insert?
Some devices (as I've found out the hard way) expect the 1.5V from an
alakline cell instead of the 1.35 from a NiCd. Try using what the
instructions recommend. Same with the 9v battery. Don't use a
rechargeable NiCd 9v cell, which can be as low as 7.2v:
http://michaelbluejay.com/batteries/9v.html
Remove both units. Put the receiver in a tree and start walking with
the transmitter. Measure the line of sight range. If it remains at
20ft one or both units are sick, sick, sick. It it magically
increases to 100ft, relocate them so that there's no RF eating
obstruction in between.
Hint: Read the Harbor Fright reviews sorted by lowest priority first.
There are some rather irate complaints about the lack of range. You
might have received a lemon years ago, which finally died.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558