Re: [Elecraft] Common Mode chokes to reduce noise

On 11/28/2021 11:05 AM, Ed Cole wrote: K, kind of what I was thinking.  So either go on search for noise source or try reducing the noise at the receiver.  K3 NB does not improve SNR on 6m. The K3 NB has lots of tweaks. Depending on the modes you use, it might help in some situations. On

Re: [Elecraft] Common Mode chokes to reduce noise

OK, kind of what I was thinking. So either go on search for noise source or try reducing the noise at the receiver. K3 NB does not improve SNR on 6m. On HF noise varies: 80m its S7 from an inverted-V; on 20m its S3 from a yagi (both have baluns). 6m noise at S5-S7 is the most troublesome

Re: [Elecraft] Common Mode chokes to reduce noise

While it is unlikely to make any difference, if you can source these ferrite sleeves in the USA they are excellent value and perhaps worth a try. A pack of 5 cost about $1.50 plus shipping and tax (£1.15 + tax in the UK). Two packs (10 sleeves) should make an effective choke for 6m and will slip

Re: [Elecraft] Common Mode chokes to reduce noise

I don't see how a common mode choke would help in that situation. If the noise changes that dramatically depending upon where you have the antenna pointed, that strongly suggests that the noise is being received by the antenna and is not riding on the shield of the coax.  If it is received

Re: [Elecraft] Common Mode chokes to reduce noise

On 11/27/2021 9:21 AM, Ed Cole wrote: I was reading the comments about combating mic noise and wondered if adding some ferrite beads to my 6m coax at the shack would have any effect on received broad-band noise. If it does, something is very wrong in your shack, like bonding. What DOES

[Elecraft] Common Mode chokes to reduce noise

I primarily work eme so band noise is a prime enemy of weak signals. I was reading the comments about combating mic noise and wondered if adding some ferrite beads to my 6m coax at the shack would have any effect on received broad-band noise. I definitely see the noise peak in one direction

Re: [Elecraft] Common mode chokes - FS RF meter

PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Common mode chokes W8JI also describes one and how to calibrate it. http://w8ji.com/building_a_current_meter.htm Eric KE6US On Tue,8/9/2016 1:56 PM, MaverickNH wrote: >> Just wondering - short of +/- RF Burns and Audible Noice, c

Re: [Elecraft] Common mode chokes

Here is a device I made to do that: 73, Vic, 4X6GP Rehovot, Israel Formerly K2VCO http://www.qsl.net/k2vco/ On 9 Aug 2016 23:56, MaverickNH wrote: Just wondering - short of +/- RF Burns and Audible Noice, can one readily detect/measure Common

Re: [Elecraft] Common mode chokes

es. Don't confuse them. 73 from Ian GM3SEK >-Original Message- >From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of >Josh Fiden >Sent: 09 August 2016 22:16 >To: elecraft@mailman.qth.net >Subject: Re: [Elecraft] Common mode chokes > >Add another wi

Re: [Elecraft] Common mode chokes

W8JI also describes one and how to calibrate it. http://w8ji.com/building_a_current_meter.htm Eric KE6US On Tue,8/9/2016 1:56 PM, MaverickNH wrote: Just wondering - short of +/- RF Burns and Audible Noice, can one readily detect/measure Common Mode Current on a coax antenna feedline?

Re: [Elecraft] Common mode chokes

Bret, Refer to the K9YC (Jim Brown) paper on RFI, Ferrites, Baluns and Audio Interfacing for "good" baluns. http://www.audiosystemsgroup.com/RFI-Ham.pdf. For common mode chokes (baluns), look particularly at Chapter 7 of that document. A stack of 5 FT240-31 cores and a length of coax

Re: [Elecraft] Common mode chokes

Add another winding to a choke and it magically becomes a transformer! 73, Josh W6XU On 8/9/2016 1:56 PM, MaverickNH wrote: Just wondering - short of +/- RF Burns and Audible Noice, can one readily detect/measure Common Mode Current on a coax antenna feedline? -- View this message in

Re: [Elecraft] Common mode chokes

e awful) may also be useful: http://www.ifwtech.co.uk/g3sek/clamp-on/mfj-reviews.pdf 73 from Ian GM3SEK >-Original Message- >From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of >MaverickNH >Sent: 09 August 2016 21:56 >To: elecraft@mailman.qth.net >Subje

Re: [Elecraft] Common mode chokes

On Tue,8/9/2016 1:56 PM, MaverickNH wrote: Just wondering - short of +/- RF Burns and Audible Noice, can one readily detect/measure Common Mode Current on a coax antenna feedline? Yes. A calibrated RF current probe coupled to the outside of the coax can easily measure common mode current.

Re: [Elecraft] Common mode chokes

Further (apologies, I should have thunk it through before posting): Based on http://www.karinya.net/g3txq/chokes/ which may or may not be well-accepted, which choke configuration would you choose for "Best"? I'm actually fond of two chokes in series to address the 1.8-30MHz range, but am still

Re: [Elecraft] Common mode chokes

Just wondering - short of +/- RF Burns and Audible Noice, can one readily detect/measure Common Mode Current on a coax antenna feedline? -- View this message in context: http://elecraft.365791.n2.nabble.com/Common-mode-chokes-tp7621305p7621430.html Sent from the Elecraft mailing list archive

Re: [Elecraft] Common mode chokes

Check Jim's tutorial on RFI.  You will need some clip on #31 cable ferrites, I think. Mel, K6KBE From: Cortland Richmond <k...@earthlink.net> To: elecraft@mailman.qth.net Sent: Sunday, August 7, 2016 2:54 PM Subject: Re: [Elecraft] Common mode chokes I had a similar p

Re: [Elecraft] Common mode chokes

I had a similar problem in 2005 when noise from a 2kW Honda got into my RV on FD. Lacking any ferrites etc I borrowed a plastic "milk bottle box" and wound about 30 feet of extension cord around it., which worked well as a temporary fix. Cortland ka5s On 8/7/2016 2:21 PM,

Re: [Elecraft] Common mode chokes

On Sun, 2016-08-07 at 15:50 +1000, Gary wrote: > Hi, > I have an inverter generator producing S9 noise on 3.5Mhz, and S7 > noise on 7Mhz. Higher frequencies are clear. > If I were to use a trifilar wound choke on the lead from the > generator, what would be the best mix...43, 77 or? > I can

Re: [Elecraft] Common mode chokes

On Sat,8/6/2016 10:50 PM, Gary wrote: I spent a lot of time searching the web but unsure still. k9yc.com/RFI-Ham.pdf See the Choke Cookbook and follow the guidelines for the bands where you have noise, and for coax the size of the power cable. Place the choke as close as possible to the

[Elecraft] Common mode chokes

Hi, I have an inverter generator producing S9 noise on 3.5Mhz, and S7 noise on 7Mhz. Higher frequencies are clear. If I were to use a trifilar wound choke on the lead from the generator, what would be the best mix...43, 77 or? I can source ferrite cores here in VK, whether I can obtain what