[RFI] High Pressure Sodium Street Light

[Mike @ RFI Services]

HPS Lights aren't normally detectable at 130 mhz. However, if you think it
is the source of your RFI, triangulate. Back away from the light post until
the RFI is detectable. Set your sensitivity to minimum or attenuate to the
point of a barely receivable noise signal. Now move around the suspected
source rotating 360 deg. If the lamp is your source, you will have it all
the way around. If the noise is only detectable from one angle, look beyond
the lamp at what is further away.  With your signal at minimum sensitivity,
either the noise level will increase or disappear. The highest level is
always from the strongest radiator and the strongest radiator is always the
source. Remember, you will have peaks and nulls every half wave length of
the frequency being used. The lamp could be radiating or reflecting the
signal and seem to be the strongest because the source is too far away for a
direct signal to be received. This is called conduction. This is the most
common means of noise signal reception. The noise source is too far away to
be received by direct line of site from the source. So your receiver picks
up the noise after it is conducted along the line, overhead or underground,
until it is  close enough to be received from your antenna. This reradiated
signal is where you must start your search.
Good luck,
Mike Martin
RFI Services
6469 Old Solomons Island RD
Tracy's Landing MD 20779
301-855-5961 Tel
410-741-5153 Fax
21*29180 Nextel
mike@rfiservices.info
www.rfiservices.info