Search String: Display: Description: Sort:

Results:

References: [ +from:k9ma@sdellington.us: 120 ]

Total 120 documents matching your query.

61. Re: [RFI] RFI Measurements (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Sat, 23 Jan 2021 17:09:11 -0600
No, they are not "meaningless". They are a relative measure of noise levels in various locations, which was my purpose in making them. I would gain absolutely nothing more from measuring absolute fie
/archives//html/RFI/2021-01/msg00118.html (8,777 bytes)

62. Re: [RFI] RFI Question (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 12 Feb 2021 14:43:28 -0600
This works in both directions, of course. I once had a neighbor with a wall-mounted telephone with a long coiled handset cord. The usual filters just couldn't keep the RF out of that phone, unless I
/archives//html/RFI/2021-02/msg00016.html (10,440 bytes)

63. [RFI] 20 Meter Interference (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Tue, 23 Feb 2021 19:46:21 -0600
I've recently started seeing this signal on 20 meters, probably local, as it is present late at night when the band is dead. It is a swept signal, typically starting at about 13.625, sweeping upward
/archives//html/RFI/2021-02/msg00021.html (7,336 bytes)

64. Re: [RFI] 20 Meter Interference (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Tue, 23 Feb 2021 20:25:09 -0600
The spectra images didn't come through, so here are the links: http://sdellington.us/hr/RFI/20m_K9MA.jpg <http://sdellington.us/hr/RFI/20m_K9MA.jpg> http://sdellington.us/hr/RFI/20m1_K9MA.jpg <http:/
/archives//html/RFI/2021-02/msg00022.html (8,324 bytes)

65. [RFI] Fwd: 20 Meter Interference (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 26 Feb 2021 12:04:41 -0600
It turned out to be a wireless doorbell extender, right in the shack. Once again proving that one should check your own home first. I'm not sure if it's the wall wart or the device itself. It seems t
/archives//html/RFI/2021-02/msg00024.html (10,253 bytes)

66. Re: [RFI] Fwd: 20 Meter Interference (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 26 Feb 2021 12:40:56 -0600
No. "Safeguard Supply" It was very cheap. 73, Scott K9MA  On 2/26/2021 12:21 PM, Michael Aust wrote: Interesting. Was it a Ring Doorbell Extender ? 73 Mike WB6DJI Sent from the all new Aol app for iO
/archives//html/RFI/2021-02/msg00026.html (11,955 bytes)

67. Re: [RFI] Fwd: 20 Meter Interference (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 26 Feb 2021 13:03:34 -0600
Half a dozen or so turns of the wire from the wall wart to the device on a Radio Shack 2730104 "Snap-On" ferrite core completely eliminates the interference. These cores generic. MFJ used to sell the
/archives//html/RFI/2021-02/msg00027.html (11,085 bytes)

68. Re: [RFI] Fwd: 20 Meter Interference (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 26 Feb 2021 13:07:39 -0600
Sorry, I spoke too soon. Shortly after I sent the last message, the interference returned, eve with the choke. It appears to be getting onto the power wiring via the wall wart. I try a different one.
/archives//html/RFI/2021-02/msg00028.html (11,216 bytes)

69. Re: [RFI] Fwd: 20 Meter Interference (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Fri, 26 Feb 2021 16:36:30 -0600
Yes, I discovered it by running the radio on a battery and turning off circuit breakers. The culprit definitely was the wall wart. The cyclic pattern apparently was due to the device intermittently l
/archives//html/RFI/2021-02/msg00030.html (11,626 bytes)

70. Re: [RFI] Difficult power line RFI find. (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Tue, 9 Mar 2021 23:07:26 -0600
I presume that you know that was the right source because the problem went away after it was fixed. However, you don't say how you knew you were tracking the right source earlier. I've also tracked a
/archives//html/RFI/2021-03/msg00016.html (12,195 bytes)

71. Re: [RFI] Difficult power line RFI find. (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Wed, 10 Mar 2021 14:14:30 -0600
Hi Don, I've had some of those very constant sources, which makes tracking harder. Usually, they eventually go into some kind of fluctuations, often subtle ones. In my case, identifying the right sou
/archives//html/RFI/2021-03/msg00029.html (20,022 bytes)

72. Re: [RFI] Difficult power line RFI find. (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Wed, 10 Mar 2021 14:21:26 -0600
If your local utility is cooperative, they may share with you maps of their distribution lines. 73, Scott K9MA Thanks for sharing your very similar story, and very interesting based on the configurat
/archives//html/RFI/2021-03/msg00030.html (13,675 bytes)

73. Re: [RFI] Difficult power line RFI find. (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Thu, 18 Mar 2021 00:07:20 -0500
Hi Don, Aside from the safety issue, any time you find metal on metal contact near a power line, without secure bonding, you have a potential noise source. One example I found was a lateral guy touch
/archives//html/RFI/2021-03/msg00044.html (23,061 bytes)

74. Re: [RFI] New Interference at kk0sd (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Mon, 22 Mar 2021 09:10:05 -0700
Even without a spectrum display, just tuning across the band may tell you whether it's likely to be power line or electronics. Line noise will be nearly constant over hundreds of kHz, while that from
/archives//html/RFI/2021-03/msg00080.html (12,778 bytes)

75. Re: [RFI] New Interference at kk0sd (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Mon, 22 Mar 2021 09:12:45 -0700
The MFJ-852 is very sensitive. You might find it useful to put a shorting strap across the receiver input as an attenuator. 73, Scott K9MA -- Scott Ellington -- via iPad _____________________________
/archives//html/RFI/2021-03/msg00081.html (13,381 bytes)

76. Re: [RFI] New Interference at kk0sd (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Tue, 23 Mar 2021 18:08:09 -0700
See September 1995 QST for an article I wrote on a very simple way to match a small tuned loop. It takes just two capacitors. Email me off list if you don't have access to QST archives. 73, Scott K9M
/archives//html/RFI/2021-03/msg00102.html (38,515 bytes)

77. Re: [RFI] New Interference at kk0sd (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Tue, 23 Mar 2021 20:16:31 -0700
Although I built the first loops as fixed receiving antennas, I've since built a couple smaller ones for RFI tracking. Note that the series resistor is just to increase bandwidth for phased arrays. I
/archives//html/RFI/2021-03/msg00104.html (41,662 bytes)

78. Re: [RFI] Update -- New Interference at kk0sd (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Sat, 27 Mar 2021 08:25:39 -0700
You now know that the source is probably outdoors. 73, Scott K9MA -- Scott Ellington -- via iPad _______________________________________________ RFI mailing list RFI@contesting.com http://lists.conte
/archives//html/RFI/2021-03/msg00125.html (7,408 bytes)

79. Re: [RFI] Wireless Power Transfer with electric vehicles - politics is over (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Mon, 12 Apr 2021 22:43:32 -0500
Some years ago, I was asked to advise some EE graduate students on using an RF amplifier for wireless charging.They were completely  clueless about RFI issues,. That said, is suppose it's conceivable
/archives//html/RFI/2021-04/msg00131.html (8,622 bytes)

80. Re: [RFI] Further data on my weird RFI problem (score: 1)
Author: K9MA <k9ma@sdellington.us>
Date: Thu, 6 May 2021 16:24:07 -0500
Hi Pete, Is the frequency stable, or does it drift around? 73, Scott K9MA -- Scott Ellington -- via iPad _______________________________________________ RFI mailing list RFI@contesting.com http://lis
/archives//html/RFI/2021-05/msg00005.html (8,654 bytes)

Current List: 61 - 80
Page: [1] [2] [3] [4] [5] [6]
This search system is powered by Namazu