Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

I echo Don's comment. My MC-60 mic used to be very sensitive to RF in the shack and my monitor used to click on and off, until I placed common mode chokes on the coax leaving the antenna tuner, and on the coax feeding a balun outside the shack. (Antenna is an open-wire-fed 80 meter doublet.)

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

To re-enforce what has been said already, I read the Contest Clipper Club report and then a few others, and to summarize, here is what I found: - I ordered a few dozen Mix 43 and Mix 31 chokes online. I think I ordered 24 of each type and used the model numbers in the CCC document I

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

PM Subject: Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI Thanks everyone for their replies to my problem. I read Jim Brown's paper this afternoon and have ordered some mix 31 Big Clamps. I'll try putting one at each end of the 40m coax feedline (RG8X) with the prescribed

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

Jeff and all, I see many hams reporting placing common mode chokes on AC lines, DC lines, AUX cables and other lines in the shack. I am of the opinion that the proper use of common mode chokes is on the antenna feedlines. With coax fed antennas, a choke right at the feedpoint and with

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

Hi Jeff does not suprise me. Read the link in Jims email single beads do not cut it. ~73 Don KD8NNU FH#4107 -.- -.. ---.. –. –. ..- On Sat, Feb 14, 2015 at 1:56 PM, Jeff Hall wrote: Thanks Jim, I'll give it a read and order up some mix-31 toroids. Does it surprise you the KAT500 is getting

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

Thanks Jim, I'll give it a read and order up some mix-31 toroids. Does it surprise you the KAT500 is getting power cycled as I described? Is it really that sensitive? 10 of the ferrite beads I got from DXStore (rated for 150MHz or lower) work fine for 10m-20m. But no dice on 40m, so I guess

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

Don't know what kind of ferrite beads you are using, but many are intended for VHF use and are not helpful at HF. Also, it is usually ineffective to just put a bead on the coax -- you should wrap multiple turns through a large toroid. Good ferrite materials for HF are #31 for 1.8-7 mHz and #43

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

On Sat,2/14/2015 9:48 AM, Jeff Hall, W6UX wrote: can anyone suggest some further experiments to try? Yes. The problem is that ferrite beads slipped onto a transmission line does NOT make an effective common mode choke. Those beads are inductive, and, depending on the length of the line and

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

Does this mean that your KAT is placed between the K3 and the KPA? OZ4UN Sendt fra min iPhone Den 14/02/2015 kl. 18.49 skrev Jeff Hall, W6UX w...@ymail.com: by directly connecting the K3 to the KPA500. __ Elecraft mailing list Home:

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

There are some great articles on common mode chokes http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf The other is K9YC's cookbook. Since I bought a VNA, I have been able to play with the choking value of some random chokes. Very interesting. Mike va3mw On Sat, Feb 14,

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

There must be something special about 40 meters and micro-controllers. My Aquarium Controller used to do a Reset when I transmitted on 40.The cure for me was to wrap the control cable leads through Some Snap on chokes I just installed my KAT500 today and considered taking thepower lead and

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

On Sat, 14 Feb 2015 23:57:18 + (UTC), Harry Yingst via Elecraft wrote: There must be something special about 40 meters and micro-controllers. I learned years ago that there is something special about 40 meter RF. I've gotten into more stuff when on 40 meters than anything else since 21 MHz

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

Thanks everyone for their replies to my problem.  I read Jim Brown's paper this afternoon and have ordered some mix 31 Big Clamps.  I'll try putting one at each end of the 40m coax feedline (RG8X) with the prescribed number of turns. -Jeff On Saturday, February 14, 2015 4:22 PM, Michael

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

: [Elecraft] My KAT500 seems very sensitive to common mode RFI Thanks everyone for their replies to my problem.  I read Jim Brown's paper this afternoon and have ordered some mix 31 Big Clamps.  I'll try putting one at each end of the 40m coax feedline (RG8X) with the prescribed number of turns

Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI

? From: Jeff Hall w...@ymail.com To: Michael Walker va...@portcredit.net; Harry Yingst hlyin...@yahoo.com Cc: Elecraft Reflector elecraft@mailman.qth.net Sent: Saturday, February 14, 2015 9:22 PM Subject: Re: [Elecraft] My KAT500 seems very sensitive to common mode RFI Thanks