1/4 Wave Shorting Stub

The Ultimate in Coaxial Lightning Protection!
          Nothing else even comes close.
1/4 wave shorting stub
3 1/8 fixed frequency stub
tuning portion of a 1/4 wave shortiung stub
Tuning section of a 1 5/8 tunable stub

The 1/4 Wave Shorting Stub also referred to as a 1/4 wave shorted stub, connects between your transmitter and your antenna system to short the center conductor to ground providing an extra degree of lightning protection for your transmitter. The stub is virtually invisible to your transmitter offering 0 db of insertion loss and an input VSWR <1.01 with return loss values typically >50db. The stub is custom made to your frequency, coax size and connector requirements and can be made tunable which allows for fine antenna matching in the field. The frequency agile stub can be tuned across the band it is made for. EX: FM stub is tunable from 87 to 110 Mhz. Custom frequency requirements are welcomed as well as various connector options.

  • Capable of handling very high discharge currents.                                                      

  • Excellent transmission characteristics.      

  • Maintenance free, no parts to replace after a discharge event.                              

  • Acts as a broadband filter and reduces AM signals by >30db at sites where an AM and FM are co-located.                          

  • Stubs can be made for all power levels and frequency requirements including STL and RPU applications and in a variety of connector options.                                         

  • Excellent protection for both transmitters and receivers.                                              

  • Handmade here in the USA

netwok analyzer sweep of tune-able 1/4 wave shorting stub

Here is a sweep of frequency agile stub built in 1 5/8 rigid coax tuned for 95.9Mhz. Input VSWR 1.0036 and return loss -54db at center frequency. Insertion loss is lower that the "bullet" used to calibrate the instrument for the measurement.

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