I have a question/answer system that works via usb on a computer. A base station is plugged into a computer, and answers are sent to this base station using battery operated remotes in the 915mhz range.

I've encountered issues with interference from other devices using the same range, so I'm looking for a way to increase the reception power of the base. It has a screw on tnc connector (female on the antenna).

I've got basic knowledge of electronics but antennas are just out of my range (sorry for the pun).

Can anyone guide me in the right direction?

 

I would begin by looking at the ARRL site and other Amateur Radio resources online. There is a ton of information regarding antenna theory and design. Here is one of them. If you are receiving interference from a certain direction, you could build a directional antenna to provide some gain in the desired direction and nulls in others.

Since there is an external connector, the interface to the hardware is easy. Hope this helps get you going.

Cheers!
- Shawn

 

You are aware, I hope, that the 900 MHz band is cluttered with all kinds of devices and users. Most commercially available 900 MHz receivers have little or nothing in the way of selectivity, so if you up the sensitivity of the receiver (e.g. by connecting it to a better antenna) you also up the level of extraneous (for your purpose) signals. In the 902-928 MHz amateur portion, most ham users employ PL tones to reduce the effect of unwanted signals, but the receivers are still vulnerable to baby monitors and other household devices. (They can effectively jam the receiver if they are close enough.)

So, I don't know that improving your antenna will resolve your problem. Providing selective front-end circuits might involve expensive and bulky tuned cavities. There is a ton of useful information in the various 900 MHz oriented web sites, which see.

 

I am unfortunately aware of how prevalent the ~900mhz band is among consumer electronics.

This base station is being used in tradeshow environments and most recently, RFID antennas seemed to have been the biggest problem in reception for my base station.

Its usually in a relatively small space - the remote signal never has to travel more than 10 feet.