Power Line Carrier ____________________________________________________________________
RF-MCGARDPRO
Hubbell Power Systems, Inc.
–
RFL™
Products
July 1, 2022
©2022 Hubbell Incorporated
5-58
5.6.3 TX Filter
The HPS/RFL 9508 TX Filter is a plug-in module consisting of two PC boards and two air core
inductors. It plugs into the left side of the RF chassis.
CONNECTOR
(Plugs Into Mother Board)
PC BOARD
107828-2
PC BOARD
107828-1
AIR CORE
INDUCTOR
L2
AIR CORE
INDUCTOR
L1
Figure 5-36. TX Filter, Top View
The function of the TX Filter is to filter out harmonics and noise that is out of the bandwidth of
the filter. The bandwidth of the filter can be set to either 8kHz or 16kHz using two programmable
jumpers, J1 and J45. The filter center frequency is tunable from 24kHz to 496kHz using
programmable jumpers. The outer edges are 20kHz and 500kHz. The 8kHz bandwidth is used
for most applications.
Setting Jumpers on the TX Filter
The TX Filter consists of two PC boards that are mounted at right angles to each other and are
supported by an aluminum frame. The TX Filter has a total of 44 jumpers that must be configured
for proper system operation. Two of these jumpers (J1 and J45) are used to select the bandwidth
of the filter which can be either 8kHz or 16kHz. Jumper J44 is used for system testing, and the
other 41 jumpers are used to tune the center frequency of the filter from 24kHz to 496kHz. The
outer edges are 20kHz and 500kHz. Tuning the filter is done from the 9508 TX Filter
Programming Sheet supplied by HPS/RFL on the Customer CD. 27 of the jumpers are located
on the 107828-2 board. This is the board with the two large air core inductors shown on the next
page with the location of the jumpers. The remaining 17 Jumpers are located on the 107828-1
