Dave wrote:
"R. Scott" wrote in message
...
with no problems until the recent storms and the station has multiple
birdies and its in Wide FM rather than
AM ... makes me wonder.

go mobile. use a small antenna and an attenuator, maybe the one in the rig
will be enough with just a 6" antenna or something like that. if it is
indeed local to your shack it should be obvious when you get a few blocks
away, then start hunting for rectifiers. it should also be obvious if it is
from the transmitter as you drive around it. that might also find it if it
happens to be from a 3rd party, like a bad ground wire on a power pole or
something.

Also, do the test of shutting off everything at the breakers in the house...
there is an outside chance, especially with the FM symptom and extreme
width, that the AM station is getting picked up by some other device and
modulating it... it could be getting into a TV and modulating the color
burst, or a computer monitor, a old cordless phone, etc.

also check their fundamental and see if you can detect the fm on it, that
should be obvious enough also and something you could go demonstrate to the
engineer that may show him they have a problem that developed after their
certification.



Phew! That's a lot of stuff!

However, if all that fails, call Ghost Busters!

Regards,
JS

also check their fundamental and see if you can detect the fm on it, that
should be obvious enough also and something you could go demonstrate to the
engineer that may show him they have a problem that developed after their
certification.

Bingo, I just went to thier fundimental and in FM and WFM I can
understand the radio perfectly ... Nice and clear.

Weirdness.

Scotty W7PSK.

(Michael Black) wrote in
:

"R. Scott" ) writes:
80 is basically useless. 3400 and 4000 I have a Pegged meter WFM
signal from 1380kc station here. I have mini harmonics ever 200kc
that basically makes 80meters unusable Its really annoying and the
station says they had their equipment recertified 2 months ago

This is hardly an antenna issue.

You do realize that it may not be the transmitter?

If your receiver (and you don't specify what it is) hasn't got
good strong signal-handling, the station may be overloading it
and causing the junk. And at first glance, it wouldn't be
obvious whether it's the receiver or the transmitter.

Try a different receiver.

Put an attenuator between your receiver and antenna, and see
what happens to those signals when you increase attenuation. If
it's overloadig, there will be a point where the unwanted signals
go away that can't be accounted for by the actual attenuation.

An attenuator is the best and easiest test. Lots of ham receivers
actually have attenuators in the front end, so it may be just a
measurement thing. Basically if an in-band amateur signal is attenuated
significantly less than the spurs, then they are, indeed generated in the
receiver. The quick cure for that is to put a filter in the line to
remove the big signal on its own fundamental. Just make sure the filter
is either ONLY in the receive line or is capable of handling the output
power of the transmitter on any ham band.

Borrow a spectrum analyzer, which should stand up well to strong
signals since it wouldn't be much use otherwise, and see what signals
are arriving at your antenna. If you do see signals that are
traceable to the broadcast station, then likely they do have a
problem. But if not, it's your receiver.

Even then, there could be rectification in nearby clotheslines, fences,
etc., etc. I've cleaned up a couple of problems just by bonding a fence.

And it may not even be the receiver. There could be something acting
as a rectifier, that is picking up the transmiter signal and
generating harmonics for your receiver to pickup. A rusty rain
gutter, or a bad connection on an antenna, obviously something nearby.

Yep...usually that type is from a fairly nearby source.

Of course there are genuine spurs from broadcast stations. I remember
once, we had a big wide-band FM signal on 2182khz. DOC (at that time the
relevant authority) quickly tracked it down to a station running many KW
about 12 miles from our receive site (and made them fix it--interference
with hams is one thing, interference with a marine distress frequency
totally another thing in their books).



--
Dave Oldridge+
ICQ 1800667

On Tue, 23 Jan 2007 21:10:38 -0800, "R. Scott"
wrote:

80 is basically useless. 3400 and 4000 I have a Pegged meter WFM signal
from 1380kc station here. I have mini harmonics ever 200kc that
basically makes 80meters unusable Its really annoying and the station
says they had their equipment recertified 2 months ago

Hi OM,

Sounds like IF images from a front-end overload. Build yourself a 6
or 8 pole Hi pass filter to the antenna input.

73's
Richard Clark, KB7QHC

80 is basically useless. 3400 and 4000 I have a Pegged meter WFM signal
from 1380kc station here. I have mini harmonics ever 200kc that basically
makes 80meters unusable Its really annoying and the station says they had
their equipment recertified 2 months ago


Perhaps it is different in the US, but are not MW stations AM?

Jeff

On Wed, 24 Jan 2007 08:44:11 -0000, "Jeff" wrote:

Perhaps it is different in the US, but are not MW stations AM?

Hi Jeff,

Some are digital (but still AM ..um perhaps)

73's
Richard Clark, KB7QHC

"R. Scott" a écrit dans le message de news:
...


I solved such a problem by receiving on separates antennas: two center
loaded verticals 3meter high and about ten meter between them.
By adjusting attenuation and phase delay between the two antennas i got a
null in the spurious direction (ground wave), but no nul for incomming
signals from correspondants because the phases after ionospheric propagation
were not constant and identical on the two antennas.
Unfortunatly I have forgotten the phasig system I used, it was lengths of
coax (WL/8) and a variable capacity, found on QST or Ham Radio at the end of
the sixtees or at the beginning of the seventees.
For attenuation it was a simple linear double pot.

73

André F5AD
http://f5ad.free.fr/.

"R. Scott" wrote in message
. ..
80 is basically useless. 3400 and 4000 I have a Pegged meter WFM signal
from 1380kc station here. I have mini harmonics ever 200kc that basically
makes 80meters unusable Its really annoying and the station says they had
their equipment recertified 2 months ago

Is there a place I can report this in the FCC?

The antenna is about 10 miles from me. And they are running 5kw.

They are planning and have approval for 50KW now and Im worried that 160
and 80 and possibly 40 could me useless.


Thanks
Scotty W7PSK.
1 800 CALL FCC

Get the AM Brickwall Filter by PAR... It will attenuate the AM signal
-40dB at the front end of the radio will should go a long ways towards
cleaning up your receiver...
Since you have a single station to contend with, talk to Paul at PAR
and he will build you one with specific tuning for that station...

denny / k8do