Alignment

Simplifying the Process:

We have laid the groundwork for establishing the Path Align-R™ test set as a viable and effective solution for thepath alignment process. We will now describe how this process of aligning the microwave link is greatlysimplified.

1. Review the Engineering Profile to determine the expected RSL (received signal level, or path loss)for the link under test (this should include the free space path loss and the gain of the antennas). Notethat the loss exhibited by the installed cable or waveguide transmission lines are not included in thisvalue because the Path Align-R™ test sets are connected directly to the antennas with a short coax cablewith minimal insertion loss to impact the test.

2. Both tower climbers (technicians) should go over their check lists, prior to climbing the tower, toassure that, included with the Path Align-R™, they have:

• A charged battery installed (possibly a spare if you are planning to be up for over 4–5 hours);
• The proper waveguide-to-coax adapter for the antenna;
• A coax cable (SMA to coax connector on the coax-to-waveguide adapter);
• The supplied headset; and,
• A carabiner and a nylon runner, strap, or lanyard of appropriate length to attach the back-pack's'D' ring to the tower.

3. Set one Path Align-R™ unit to ‘Master’ and the other Path Align-R™ unit to ‘Slave’ (it doesn’t matter whichis which, as long as they’re different).

4. Using the front panel thumbwheel switches, select the proper link frequency (Note: both units mustbe set to the same frequency, e.g. 6.2 GHz).

5. After reaching the antenna, check that the antenna polarization is properly setup.

6. Locate each Align-R™ unit near the back of the antenna, with its weather-resistant instrument backpack’s‘D’ ring attached to the tower structure using a carabiner and a nylon runner, strap, or lanyard.

7. Attach the coax-to-waveguide adapter at the back of the antenna’s waveguide flange.

8. Connect the coax cable from the appropriate output connector on the Path Align-R™ to the adapter.

9. Connect the headset to the Path Align-R™.

10. Turn the Power Switch ON. An LED will indicate which output connector is active (make sure thecable is connected to that connector) and begin talking. Typically, the antennas can be off alignmentby as much as several beamwidths and the voice channel will still operate.

11. While one technician simply observes the reading of the path loss meter at his/her site, the other sitecommences Azimuth (horizontal) adjustment. As the voice channel is full duplex (FM), eachtechnician can communicate with the other during the alignment process. Check for both side lobes aswell as the main lobe response to ensure that the antenna is being aligned to the main lobe and notone of the side lobes. The Path Align-R™ test sets have enough sensitivity (-100 dB) and update speed(300 ms) to quickly check for side lobe and main lobe response.

12. Once Azimuth has been optimized, the Elevation adjustment is performed.

13. When steps 11 & 12 have been completed at the first site, the technicians switch roles and steps 11 &12 are repeated by the other technician at the second site.

14. Once step 13 is completed, for both Azimuth and Elevation, the link is aligned. As a record, note thefinal path loss value displayed on the meter.

Summary:

The difficulties of scheduling an antenna alignment test with the radios can cause significant delays, asdescribed earlier. Furthermore, traditional test methods can produce significant costs in mobilization,deployment and testing of the antenna system. If the transmission lines (waveguides, etc.) connecting theantenna to the radio were to have a problem, the test is in jeopardy until they are corrected. If the path undertest is questionable (due to site choice, obstructions, etc.), the Path Align-R™ can step right in with minimaleffort to verify if there are any problems. Using the Path Align-R™ test set, the overhead associated with offeringpath alignment services (cost of equipment, level of expertise required, and training time) has been greatlyreduced. Offering path alignment services with the Path Align-R™ translates to providing more revenue opportunities for your company.