Antenna problems

[rewguy]

I am having difficulty with a couple of antennas that I purchased. I am using a 315 MHz ASK RF receiver and transmitter from Laipac. If I use a piece of wire (~23 cm in length) as an antenna on both the transmitter and the receiver, the range is decent. However, when I replace either the receiver, the transmitter, or both antennas with a permanent, quarter wave 315 MHz LP antenna from LINX, I get no reception at all. Does this have to do with how far I place the antenna from the receiver / transmitter module? Right now both are in my breadboard with a piece of wire ~.5 inch long.

Any ideas? Thanks,

Andrew

 

[bmcculla]

If I had to guess I'd say that the problem was because you are using a bread board. Bread boards have extra capacitance in the interconnects. RF stuff is fairly sensitive to small changes in the impedance of the circuit - a little bit of extra capacitance would be enough to throw it off. Why the wire works is beyond me - might just be luck. In general the closer the connector is to the RF output the better.

Hope this helps
Brent