Broadcast station on 40m spilling into 40m Ham Band

Don Weeks

On my 6600, I am hearing a SW AM Broadcast station out of South Carolina at 40 over S9 and above. When they play music and in some cases talk, the entire ham band down to 7.150 noise floor raises up and down with the music. And in many cases stations at 7.260+ are drowned out or there is additional signal coming in over or with their voice distorting it. Someone online suggested adjusting the VFO and bandpass but I don't see a way to do that or I have not dug deep enough in the manual for this? 

John KB4DU

Don;

A few things to check.

1) Is the Flex in WIDE mode, if so close the other panadapters so that there is only one open. This will enable  the bandpass filters, greatly increasing the selectivity of the 6600.

2) Enable the TNF filters and set one over the offending signal. Procedure is in the manual.

3)  Click on the mode (LSB) and select a narrower bandwidth for the slice, maybe 1,8.

Let us know if any of these make a difference.

John

Don Weeks

John,

I will look at this when I get home. TNF is something I can add for sure. The LSB mode is narrow but the signal coming from the SW station is narrow. I believe it is coming in around 7.320. I will look into WIDE mode.

Ken Wells

A few things to check:

1) If the offending station is overmodulating, or has extremely sharp crossover transitions, these will mimic an impulse interfering signal.  This can trigger your WNB (Wideband Noise Blanker) if the WNB setting is high, which will pump the noise floor, and often send pseudo spurs up and down the band.  I have experienced this with Radio Havana.  Turning WNB OFF or down, may help.

2) Be sure that you are not using preamp gain on 40 Meters.  It is unnecessary, and only reduces your dynamic range, which could make you vulnerable to extremely strong signal interference.
This combined with zooming in your panadapter a bit and making sure that your radio is not in "Wide" mode can help.

WX7Y

Build or buy a Broadcast filter and install it in the Antenna lead, Much better to get rid of the RF at source getting into the radio then to put a band-aid  or try to filter it out if it is that strong.
Unfortunately the 6600 doesn't have a receive loop to install a Low power Broadcast filter like the 6700 has so the filter you build or buy needs to switch out of line during Transmit so you'll probably have to build a Relay switch that runs off the PTT Keying output.
73's
Bret
WX7Y

here are some on Amazon https://www.amazon.com/Flamingo-AM-Broadcast-Bandstop-Applications/dp/B079CMB44V/ref=sr_1_2?keywords...
or https://www.amazon.com/Broadcast-Reject-Filter-RTL-SDR-Blog/dp/B01N9SHS7P/ref=sr_1_4?keywords=AM+broadcast+band+filter&qid=1578669759&sr=8-4
or the great looking 11th order filter https://www.amazon.com/broadcast-reject-filter-order-enclosure/dp/B074S6X9HF/ref=sr_1_6?keywords=AM+...

Doug Hall

More sources. Neither of these requires bypassing on transmit - just put them in line with the Flex.

Buy:
https://www.kf7p.com/KF7P/Morgan_Filters.html

Build:
https://www.qsl.net/wb5wpa/Filter/AM%20Brick-Wall%20160%20Meter%20Filter.pdf

73,
Doug K4DSP

Craig_KØCF

Won't help. His interfering station is a 40 meter Shortwave broadcast station, probably just above the top of the 40 meter ham band. These filters are for the 500 kHz to 1.7 MHz AM broadcast band.

Bill -VA3WTB

And if the signal is going into the band pass, not much you can do. The 6600 has about the best filters around for signals out of the band pass.

caroline

The 6600 has better filters for out-of-bandpass signals than other antennas that's for sure, I even listen to certain radios like this, for example. https://www.radiofmdance.com