Duplexer Cavity and Filter Tuning and Alignment


A Duplexer is one of the most critical components in your Repeater System. Having a poorly tuned or misaligned duplexer, improper or damaged phasing cables, will destroy system performance and may even damage your receiver.


Northcomm Technologies can examine and align your Duplexer, Filter, Preselector or Combiner using our state of the art test and measurement equipment.


The Northcomm Technologies Difference:

  • Each device is physically and mechanically evaluated
  • All connectors are removed and inspected for damage under 5X magnification  
  • Your devices are returned with new metallic Brady ID labels indicating the desired frequencies
  • Device tuning components are sealed with red tamper indicating die, alerting you if the tuning elements have been altered 
  • Results are recorded and provided at no additional cost: spectrum analyzer screen shots of the final tuned measurements will be emailed for your review and records. This includes the observed Insertion loss at the Pass-Band, Notch Depth, and frequency accuracy on the day of alignment


Northcomm Technologies uses Times Microwave Silverline Coax Test Cables when testing your devices along with our cutting-edge testing equipment which provides unsurpassed accuracy, traceability, and precision. 


**Please note, that the phasing harness and the interconnect cables which connect your cavities are critical, frequency sensitive lengths. Certain duplexers such as the Celwave, EMR, and RFS have no problem being tuned from their original frequencies to a new frequency without replacing these cables. However, many duplexers will require new critical length cables, especially if your new frequencies are many Mhz away from the factory tuned freqs. If you are unsure if your device can be tuned to your channel, please call us and we will discuss any concerns you might have. This issue does not affect the typical Motorola preselector, band-pass filters, and notch filters.

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Perform Duplexer or Preselector Tuning Service

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