PAR Filter Information: The HT series feature unprecedented fast recovery from the notch frequency.
–3dB points are typically 1% of the notch frequency. These are asymmetrical
notch filters that employ a miniature toggle switch to allow the end user to
select which side of the notch requires fast recovery at a given time.
For example the VHFDN153HT has its notch nominally set at 152.5MHz. With the
switch set left ( receive DC-151 MHz) the loss at 171 MHz is only –3dB. With the
switch set right, the –3dB frequency is 154 MHz. This is in stark contrast to
other commercial notch filters whose 3dB points are typically +/- 10 MHz. |