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friendly data sheet The HEC-2000-V now
joins the line of single-channel Hum Eliminators manufactured by Allen
Avionics. Like the HEC-2000 and the HEC-2000-H, the HEC-2000-V stops all 50
Hz and 60 Hz hum. The HEC-2000 Series is designed to eliminate hum in video
applications caused by long cable runs or ground loops.
This new edition is a heavy-duty version,
like the HEC-2000-H, and features 1/4" thick, stainless steel guard rails to
protect the connectors when not in use.
With the addition of the HEC-2000-V to the
HEC-2000-H, the end user has a choice of connector location and protection,
plus the performance of the standard HEC-2000. The HEC-2000-H is designed
for optional rack mounting installation. (see below)
The HEC series works in circumstances where
interference is caused by small differences in ground potential (less than
20 volts) or by induced currents in long cable runs. When there are multiple
power panels in a building, or even a single floor, equipment and lighting
loads resut in small differences in potential which induce a ground loop
current flow and 60 Hz hum. (see Figure 1)
Electronically-induced current flows in
long cable runs also create hum. For 50 Hz and 60 Hz power systems, and
where induced currents are high, the HEC-2000, HEC-2000-H and HEC-2000-V
increase the attenuation at the power frequency.
Should a small amount of hum remain after
an HEC has been added to the circuit, a second HEC can be added in series,
without significant degradation of the video signal.. |