Finishing notes
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If you are using external antennas, you'll need to solder on RP-SMA or SMA connectors. Antennas come in either flavor so get 2 of each and then when you know what antenna you're using, solder the proper connector in.
Now that everything is up and running, assemble it using the standoffs. You may want to try a bunch of different sizes depending on how big your battery is.
Now play around with different bands! Note that the gain stage is 'tuned' to respond to certain frequencies so you may have to adjust parts to get good performance.
Finishing parts
| Part # & Datasheets | Description |
Distributor |
Qty |
Cost |
Total |
|---|---|---|---|---|---|
| SMA or RP-SMA edge launch | If using external antennas | 2 |
$2.00 | $4.00 | |
| 4-40 x 1/4" aluminium M/F standoff | Assembly standoff | McMaster-Carr |
4 |
$0.73 | |
| 4-40 x 3/8 " aluminium F/F standoff | Assembly standoff | McMaster-Carr |
4 |
$0.27 | |
| 4-40 x 1/4" machine | Assembly screws | Digikey |
8 |
Antennas
| ANT-868-CW- QW | 1/4 wave whip antenna for GSM 850 band (RP-SMA, straight) | Digikey | $6.78 |
| ANT-868-CW-HW | 1/2 wave dipole whip antenna for GSM 850 band (RP-SMA, straight) | Digikey | $7.64 |
| ANT-868-CW-HWR-RPS | 1/2 wave dipole whip antenna for GSM 850 band (RP-SMA, rotating) | Digikey | $8.98 |
| 1/2 wave dipole antenna for 1.9GHz (RP-SMA, rotating) | Hyperlinktech Sharper Concepts |
$9.00 | |
| 900 Mhz | Helical antenna for 900mhz bands (SMA, straight) | Saelig | $8 |
| Stubby 900Mhz | Helical antenna for 900mhz bands (SMA, straight) | Saelig | $3 |
| Dual 900/1800 | Helical antenna for 900mhz and 1800Mhz bands (SMA, straight) | Saelig | $6 |
| "Quad band antenna" | Helical antenna for all GSM cell bands (SMA, right angle) | SparkFun | $4.95 |
| 1/4 wave 2.4GHz antenna | Digikey pretty much everywhere |
~$5 |
Cell bands
| Name/Description | Freq. Band | Notes |
|---|---|---|
| GSM 850 Downlink | 870-894MHz | Starting to become more popular, but used more in rural areas in the US. |
| GSM 900 Downlink | 925-960MHz | Original & most common frequency band used in Europe. |
| GSM 1800 Downlink | 1805-1880MHz | Starting to become more popular in Europe. |
| GSM (PCS) Broadband 1900 Downlink | 1930-1990MHz | Original & most common frequency band used in the US. |
Other bands
| Name/Description | Freq. Band | Notes |
|---|---|---|
| Cordless Phones | 900-910MHz (handset) 920-930MHz (base) | 900MHz band cordless phones |
| Bluetooth | 2400-2483MHz | Headsets, small electronics |
| 802.11b/g | 2400-2483MHz | Generic WiFi |
| ZigBee | 868 (Europe) 915 (USA) and 2400-2483MHz | Some home automation stuff |
| GPS | 1575.42 MHz and 1227.6 MHz (civilian) 1227.6 MHz (military) |
Global Positioning System |