Ask the Expert

Splitter causing power loss between sites

I have a wireless connection between two SMC2582WB 15 miles (24 km) away from each other. I have a T1 (ADSL) (1,536 Kbps) from Site 1 to Site 2, but in the Site 2 only I receive 200 Kbps.

Description of Site 1:

  • 1 SMC2582WB
  • 1 directional grid antenna (24DBi)
  • 1 outdoor amp (YDI Iwatt)
  • 4 feet of LMR-400 cable
  • The SMC is next to the antenna
  • 150 feet of LAN Cat 5 cable to the ADSL Cisco SOHO router
Description of Site 2:
  • Same SMC radio
  • Splitter 1 to 2, to an omni antenna of 14 DBi & the 24DBi antenna
  • Same 1 watt amp
  • 150 feet of LMR-400 cable
  • 20 feet of LAN cable to my switch.
The SMC is 150 feet from the antenna. Where are my missing Ks?

    Requires Free Membership to View

Assuming that radios at Site 1 and 2 have the same output power settings, there is clearly more loss in your setup at Site 2.

Your splitter causes insertion loss and divides available power between two antennas. Furthermore, Site 1 has just 4 feet of LMR-400 cable, while Site 2 has 150 feet, causing much greater attenuation. The power radiated by Site 2's directional grid antenna should therefore be significantly less than the power radiated by Site 1's antenna. Site 2's omni antenna might be useful to local stations, but probably not to Site 1's receiver located miles away.

Use a reference guide like the CWNA Study Guide and the actual insertion loss and attenuation ratings associated with your splitter, connectors, cables, antennas and amps to calculate your Equivalent Isotropically Radiated Power (EIRP). Then you can consider changing your Site 2 setup (for example, adding an amp) to increase the power aimed at Site 1.

This was first published in August 2004

There are Comments. Add yours.

 
TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to: