For those wondering, this is a 43 mix toroid. Generally speaking, the 43 mix will be slightly more advantageous on higher bands 10Mhz and up, where the 31 is better suited for the lower bands. Links in description for toroids and jumpers
@@Kody10538 personally I get more noise during the daytime on higher bands. Experiment and see which bands you're getting more noise on and use the appropriate toroid mix for your targeted noise
Put one on top, next to the antenna, and another on the bottom, next to the transceiver. I think that is how they work best to remove electrical noises
Great video. These chokes are so important yet easy to make. Absolutely a must especially for any end fed horizontal or vertical. I install one on every installation before I have issues.
These commercial Common Mode Filters are a Waste of Money. The One you built yourself makes way more Sense in Functionality + it saves you a Ton of Money too. Nice Video. 73 de Uncle Günter 💯👌🙋♂
The purpose of a choke is to reduce common mode current. But you do not meaure the R+/-JX of the choke- so do you know what you have built? If the choke is overall inductive and the length of your coax (outer shield) is net capacitive, you could actually be making common mode worse? If you don't measure it, you don't know what you have or how to improve it. Dale W4OP
Indeed, Dale. I do have a Rig Expert analyzer, so I know the end result with it inline my feed. Admittedly I don't have enough concern to test the choke itself. I have a CMC choke at the base of my vertical, and this one plugged into the back of my meter in the shack 125' away. Slightly capacitive/resistive on either side of 30m center on a multiband vertical
Ham newbie here…and this is very interesting. Thanks for posting. I’m learning, so let me ask this question: how does this differ from a couple dozen coax wraps around a PVC pipe (which is what I suspect is in the old MFJ thingy)?
@@elmoreglidingclub3030 it's really just a different version of the same thing, just much smaller. Ultimately you won't really know how any of them affect your application without testing. Coax coil wrapping is nice because you can "tune" resistive / capacitive characteristics with more or less coils. You can do that with different toroid mixes or # of wraps with these, just to a lesser extent.
thanks for the video instructional. i see that it is possible to get PL-259/SO239 RG8x jumpers now. that way you don't have to use an adapter to join the feed line. so, would this work ok at legal limit? i'm assuming that it would.
@@whiskeysix Actually, for a common mode choke, a Mix 73 ferrite core is better for the low bands (160-40M) and the Mix 31 is better for the high bands (40-6M). Mix 43 is better for HF Ununs or Baluns. KE6PO
You may have ground loops. Disconnect any ground connection on the rig’s ground log. It’s not necessary and can cause ground loops which occur when the gear in your shack are on a different potential. You may need ferrite on the PC USB cable and/or other cables.
My understanding is that the core type selection is dependent upon the freq of the interference and the freq of the transmission but the physical build is the same regardless.
For those wondering, this is a 43 mix toroid. Generally speaking, the 43 mix will be slightly more advantageous on higher bands 10Mhz and up, where the 31 is better suited for the lower bands. Links in description for toroids and jumpers
What if my goal is running 10 through 80? Is 31 the way to go in that sense?
@@Kody10538 personally I get more noise during the daytime on higher bands. Experiment and see which bands you're getting more noise on and use the appropriate toroid mix for your targeted noise
Put one on top, next to the antenna, and another on the bottom, next to the transceiver. I think that is how they work best to remove electrical noises
Great video. These chokes are so important yet easy to make. Absolutely a must especially for any end fed horizontal or vertical. I install one on every installation before I have issues.
These commercial Common Mode Filters are a Waste of Money. The One you built yourself makes way more Sense in Functionality + it saves you a Ton of Money too. Nice Video. 73 de Uncle Günter 💯👌🙋♂
Thanks for the video! Can you list which ferrite you used?
Love the throw on table skit ❤
Don't do this with foam dialectic the center conductor migrates through the foam towards the shield.
The purpose of a choke is to reduce common mode current. But you do not meaure the R+/-JX of the choke- so do you know what you have built? If the choke is overall inductive and the length of your coax (outer shield) is net capacitive, you could actually be making common mode worse?
If you don't measure it, you don't know what you have or how to improve it.
Dale W4OP
Indeed, Dale. I do have a Rig Expert analyzer, so I know the end result with it inline my feed. Admittedly I don't have enough concern to test the choke itself. I have a CMC choke at the base of my vertical, and this one plugged into the back of my meter in the shack 125' away. Slightly capacitive/resistive on either side of 30m center on a multiband vertical
Ham newbie here…and this is very interesting. Thanks for posting. I’m learning, so let me ask this question: how does this differ from a couple dozen coax wraps around a PVC pipe (which is what I suspect is in the old MFJ thingy)?
@@elmoreglidingclub3030 it's really just a different version of the same thing, just much smaller. Ultimately you won't really know how any of them affect your application without testing.
Coax coil wrapping is nice because you can "tune" resistive / capacitive characteristics with more or less coils. You can do that with different toroid mixes or # of wraps with these, just to a lesser extent.
thanks for the video instructional. i see that it is possible to get PL-259/SO239 RG8x jumpers now. that way you don't have to use an adapter to join the feed line. so, would this work ok at legal limit? i'm assuming that it would.
This is a choke only , correct ? Not a transformer balun ?
240 31 ??? or 240 43.??
This one is a 43 mix since I generally work the higher frequency bands. A 31 mix is arguably more suitable for 40-160m
@@whiskeysix Actually, for a common mode choke, a Mix 73 ferrite core is better for the low bands (160-40M) and the Mix 31 is better for the high bands (40-6M). Mix 43 is better for HF Ununs or Baluns.
KE6PO
What ferite should i use for 10 meters and 11 meters vertical wire antenna?
A 43 mix toroid is generally regarded as being more beneficial for those higher bands
What mix Toride?
He used a type 43. 240-43 is 2.4 inch diameter. Toroid, not toride.
It does not work for me on 27-28 MHz and the rod antenna. The RFI keeps coming. How to remove it? Won't adding a few radials help?
You may have ground loops. Disconnect any ground connection on the rig’s ground log. It’s not necessary and can cause ground loops which occur when the gear in your shack are on a different potential. You may need ferrite on the PC USB cable and/or other cables.
Without specifying the core mix, this is kind of meaningless...
My understanding is that the core type selection is dependent upon the freq of the interference and the freq of the transmission but the physical build is the same regardless.
Maybe I'll withdraw the word, "meaningless" and replace it with 'would have been helpful to discuss'.
🏆🇧🇷🏆🇧🇷
Can you show us how you tested it, to see how well it performs?