Interference every KHz!

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  • Problem
  • Updated 2 years ago
I have a 6300 that is a couple months old and it has an odd problem. About 9~10 pm every night I get a radio station that spikes the display about every KHz mostly on 20 meters although it does it on 40 as well. It sounds foreign with music and an announcer. It raises and falls and I can't make out what station it is. If I tune past the ends of the band it instantly disappears but tune back and it appears again. Using SmartSDR v1.7.30 and I have an 80 meter loop and a ZS6BKW modified G5RV and both have their own DX current balun. It does it with either antenna. I also have a 5000A and if I switch over to it the spikes aren't there. It's driving be batty!
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Wally

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  • I hope it's not broke...

Posted 2 years ago

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Bill W2PKY

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Looks like your ANT Preamp is on. That will cause overload at night when using big antennas such as yours.
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Wally

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Yes it is...I'll turn it off tonight and see. Thank you!
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James Whiteway

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I see you have the Preamp on. You might turn that off to see if it helps. I have a local AM broadcast station less than 10 miles from me (50 KW!) that does the same thing at times. I lowered my inverted V ant a few feet and no more problems. ( well, other than something my neighbor is using that is every 60 Khz)
Good luck.
James
WD5GWY
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Ri

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Please let me know if you find out what your neighbor is using that is giving you problems about every 60 as I've got the same problem which is confounding me. Rick, W2JAZ
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Ken - NM9P, Elmer

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Do you have the WNB turned on?  If so, does the interference go away when WNB is turned off?
If it is ON, what is the level setting?

Have you expanded the panadapter to try to find the station?  If so, what frequency and how strong is it?  

Is there something different in the connection to your 5000 than to the 6300?  i.e. additional antenna switch, different jumper, etc?


BTW:  The 6300 "Preamp" is actually a gain-contoured preamp/attenuator.  It is just about unity gain at 14 MHz, and adds gain at frequencies above that.  It actually functions as an attenuator at frequencies below 14 MHz.  So activating the preamp on 20 meters doesn't get you much on the 6300.  You get some gain at 17 Meters, more gain at 15 Meters, and still more gain on 10 and 6 Meters.  You will be getting some attenuation at 40 Meters, more attenuation at 80 Meters, and still more at 160 Meters.

This is a bit confusing for first time users who are used to the standard settings on other rigs that may have  -20. -10, 0, +10, +20 dB settings.

The 6500 and 6700 have a more traditional selection of attenuator / preamp gain in different stages. 

As others have said, I would suggest you try both 20 and 40 Meters with and without the Preamp setting and see what happens.

Ken - NM9P
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Phil m0vse

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I have a similar problem on 20m but my spikes are every 3kHz or so. I also may be imagining it but they seem to get worse if I transmit, i.e. when I first switch on, they are probably 3dB above the noise level but if I hit tune, they seem to grow to about 6dB above the noise.

I do have a large broadcast station about 2 miles away (on 837kHz) but that doesn't seem to cause me other problems with the Flex (it completely overloaded my Elad Duo until I bought a high pass filter!)

Phil
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N4HY, Elmer

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If you have switching power supply leakage, it often gets worse as the amperage draws goes up (like transmitting).

73s
N4HY
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N4HY, Elmer

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What switching power supply are you using and have you confirmed continuous electrical contact between all mechanical interfaces in the case of the switching power supply?

This looks like switcher leakage.

Easily confirmed if you have another power supply.

73s
Bob
N4HY
(Edited)
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Wally

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I'm sorry...I thought I posted a reply thanking the members that told me to turn off the ANT Preamp. As soon as I turned it off the spikes went away. I had been fighting with this problem for weeks and they fixed it very shortly after I posted on the forum.