[Yaesu] Good rigs for power line noise

Wed, 26 Mar 2003 21:02:01 +0200

John

I hold the RFI portfolio in our radio club and have been involved in many
cases to locate and rectify interference problems.  There are many radios
with very good noise blankers and other devices to eliminate or reduce
interference.  However, the only effective solution is to remove the source
of interference.

Your and my local conditions are very different regarding city laws and
technical installations and I can only offer guidelines to locate and
identify interference sources.

Walk and drive around your neighbourhood with a cheap portable AM radio to
locate the interference source.  The interference may even originate several
km from your house.

The following are cases in which I have been involved:

*  TV antenna masthead preamplifier became faulty and caused interference
for an entire city block.  This problem was difficult to trace, as the
interference was intermittent when the preamp heated up during the day and
cooled down at night.  (Owner replaced amplifier.)

*  Switch mode PSU of neighbour's TV wiped out several HF bands.  (Owner was
ordered by our 'FCC' to repair TV.)

*  Cable TV decoder caused very strong interference on one HF band.  (Cable
company replaced decoder.)

*  VCR RF output module caused interference around one HF frequency.
(Retuned RF module to a different channel.)

*  Neon sign at a petrol filling station caused wide interference on three
HF bands several km away.  This problem was difficult to locate, due to the
distance involved.  (Filling station owner had the sign repaired.)

*  Transformer on a residential sidewalk caused HF interference.  (Power
company repaired the fault.)

*  Insulators on high voltage lines caused HF inteference on various bands
in different cases.  (Power company cleaned insulators and replaced cracked
insulators.)

Experinece shows that one should investigate all options and be patient.
The TV preamp problem took 6 months to identify, yet the long distance neon
sign problem was located within two weeks.

I must add that I never operate any radio or computer installation without
mains conditioners/filters.  I obtained superb mains filters from an ICL
mainframe computer, which are used in the supply to my radio station and
another to my computer system.

The results are remarkable on the radio equipment and it is interesting to
observe the amount of noise that enters the station via the mains.  I have
some unidentified mains borne noise and the mainframe mains filter reduces
the noise from S8 to S0, literally.

I would not waste money looking for a radio with a good noise blanker.

I wish you success with the interference story and good luck with the
ST0RY story.

Deon ZR1DQ

----- Original Message -----
From: "John Geiger" <[email protected]>
To: <[email protected]>; <[email protected]>; <[email protected]>;
<[email protected]>
Sent: Monday, March 24, 2003 6:14 AM
Subject: [Yaesu] Good rigs for power line noise

: I have been chasing the ST0RY dxpedition for the last
: couple of days, with frustration.  The best band for
: propagation to ST seems to be 30 meters, but I have a
: high noise level on that band, so they are very rough
: copy.  I think it is power line noise, and have been
: contacting the power company, but they have been no
: help so far.  I am also in touch with the ARRL to try
: and get their help.  Of course there is always the
: possibility that the noise is coming from elsewhere.
: It seems to be a constant S6 on 30, and about the same
: on 40.  80 is usually a little quieter.
:
: I also have this noise on the higher bands, but bought
: a Yaesu FT100D based on the reputation of its NB.  It
: does take out the noise on 20-6 meters, lowering it
: from S5 to nothing most of the time.  However, it
: doesn't seem to touch the noise much on the lower
: bands.  I used to have an Icom 746 (original model)
: and it didn't do anything against the noise.  I also
: used to have a Kenwood TS2000, and I seem to remember
: that it handled it pretty well on all bands.  Guess
: the IF DSP or Kenwood NB was worth it.
:
: Does anyone have a suggestion as to what rigs really
: handle this type of noise well, other than the TS2000.
:  My budget is a little tight right now, so cannot
: afford an Icom 756PRO or 775, although someday hope to
: have one of those. Looking for any rigs that are a
: little less expensive that knock out power line or
: other noise really well.  Any suggestions?
:
: This ST0 deal so far has me considering giving up
: DXing and sticking with satellites or 2 meter FM (not
: really but it feels like that at times).
:
: 73s John NE0P