HOW TO MAXIMIZE RADIATED POWER FROM AN ANTENNA Even if they were not "calibrated" for the particular frequency bands, it is easy to correct this problem. Here's how to maximize the efficiency of any antenna to a specific frequency band (I've done this for many types of omnidirectional antennas for WIFI routers - 802.xx class b/g/n ) This information is 100% accurate for this type of antenna. 1. Calculate the centre frequency of the band you want to cover; - Example, the 3G band is 2010MHz to 2145MHz 2145 minus 2010 = 135 (this is the bandwidth in MHz) Divide the bandwidth (135MHz) by 2, which equals 67.5 Add 67.5MHz to 2010MHz and you get 2077.5MHz Now, calculate the electrical wavelength of the antenna for the center frequency as follows; 234 divided by 2077.5MHz = 0.11263 Multiply this number by 12 (the number of inches in 1 foot) and you get 1.351 ! This is the length in inches you want the wire/radiating element to be for a 1/4 wave antenna (1.351") 2. Open the antenna and trim/add to the wire/radiating element to the proper length; - Score around the circumference of the antenna's plastic body, just above the flexible portion/joint to expose the antenna element. If the element is coiled, just cut it off, leaving about a .125" stub to solder to. Otherwise, you can trim or add to the wire as it can be accurately measured when straight. Use a precision scale or (preferred) callipers to measure the length (as directed above) and cut a piece of solid 16-14 gauge copper wire to the calculated length. Carefully solder this precisely measured and cut copper wire to the stub left from the old antenna. Now measure the overall length after soldering and trim if necessary to achieve the aforementioned length. 3. Re-Assemble the antenna; - Make sure the wire/element is straight Align the outer body of the antenna that you scored and removed in step 2 and use super glue (gel works best on this type of plastic) to secure the two parts back together. Next, cover this seam with a piece of heat shrink tubing to add strength. Two layers of heat shrink works very well and allows peace of mind. Label the antenna for the band it covers (if desired) and repeat the process for each antenna/band your device covers. That's all there is to it ! You now have a perfectly calibrated and frequency centred antenna which will deliver maximum output power and have minimal SWR's. Have fun !