The common mode choke is one of the most useful devices around. Most EEs do not understand magnetics, at all. This is a great device. I usually install directly into switchers. Could NEVER ship a military PS, without these versatile devices. Have spent 25 years designing these in. Look in a Tek 1A2 plug-in for the venerable Tek 547 scope. Guess what? you will find these designed in, in about the mid 50s by very capable engineers.
When I glued mine together, I just used the cardboard tube from a roll of toilet paper and cut it up the length and then squeezed it down to the diameter I needed and taped it to hold the size I needed for the toroids. It worked really well. :)
Thanks Paul! I saw you give the part number of the cores in an online forum message recently so I ordered mine (16 qty. cores) from Newark Electronics a few days ago. They have a large stock of the correct ones, and are just $1.25 per core. 73, Guy
Again, another interesting video Paul, keeping my attention for every single minute (no, I did not fall asleep, with or without the music ;o)) Thanks for all the work you put into making these video's. Looking forward to part 2 ! Best 73 !
Thank you so much for sharing valuable information. I'm really into baluns and chokes. I'm so happy I found your videos. Can ask a question. Is there any way I can do the attenuation test at home without buying a tracking generator? Can the antenna analyzer do the test or the VNAs do the test?
360 / 5.000 Risultati della traduzione Risultato di traduzione Hi Paolo, you actually skipped winding the cable on the toroids, could you kindly explain to me how they should be wound? From what I understand, mark the middle of the cable and from there do how many windings with the first half and then should the second half be wound in the reverse direction of the first or in the same direction? I thank you and always compliment you on your videos.
thank you for this helpful video. So, I am guessing when you solder the Rg-178 to the BNC, you're attaching it to the 'ground' connector part of the BNC??
Hi W1VLF - how did yiu connect the choke to the VNA to measure attenuation> I di nit see that detail. Is the VNA in just the transmissiion mode> Thanks, Chuck
The fundamental difference between the operation of a nanocrystalline core and a ferrite core lies in the absence of a resonance characteristic of ferrites at frequencies of 0.5÷2 MHz, and work on the absorption of RF interference, in contrast to the reflection of interference characteristic of ferrites, which is associated with a change in the inductive nature of the ferrite choke to capacitive and can create problems in the work of the IIP. Increase in impedance and attenuation by 2 - 6 times, High resonant frequency and wide bandwidth (up to 5 times), Absence of many resonances in the frequency response of the impedance, Reducing the leakage inductance by 2.3 - 3 times, High saturation induction (1.17 T), Excellent temperature stability (in the range from -60°С to +155°С the change in permeability is less than 15%), Low active losses in the wire, Wide operating temperature range: from -60°С to +100°С, Reduction of volume and weight by 2 - 3 times.
@@W1VLF you kidding me> I had the next urinal to him in Portsmouth NH when he did a gig there....Man I tell ya....im 6 '2 and he towered over me ....had to be 6 7' -6 8' lol I listen to that entire mascre of movemont and the 27 8x10 colot glossy photographs with circles and arrows on the back of each one and how it was to be used against us ! lol Then he looked at the seeing eye dog ! lmao
I live in a home in a HOA with restrictions on antennas...so I have a multiband dipole 40-10 in the attic....I have a high noise level of S-5 on 20 and more on lower frequencies. I operate with an IC-2610. I have placed some chokes on the AC-lines to the power supply (Astron) and on the 12v power supply leads...but levels remain constant. I know you were speaking about much lower frequencies....but do you have a suggestion for noise in the 20 M range. Since its a transceiver...if something needs go to the 52 ohm coax line ..it would be great to have something that will tolerate the 100W output of the transceiver. Thanks Ron KO4QCX
If you only build 1, I would say at the receiver. This would reduce conducted noise from propagating out to your remote antenna. If you build 2 I would at one on each end of the feed line. The one at the antenna, reduces the the noise pick up of the long feed line. This chokes work only on noise conducted along your feed line.. Not if the noise actually being received by the antenna.
@@W1VLF Thanks Paul, I have been trying to listen well the 20meter band. I have a 1/2 wave horizontal dipole and recently Installed a Delta loop which I cant see any Difference in the Noise level. I expected at least 1s unit low but unfortunately can't see any difference. On the line of your work I will do some experiment and if I achieve any good results will share here
It performs the same function yes. The current balun keeps provides a high impedance to RF getting onto the feed line of a say dipole for instance. The RF on the feed line causes your dipole to have a 3rd leg, IE the coax cable The CMC keeps noise currents that are on the ground system of your home, from getting onto the feed line, and propagating out to the antenna. Good question!!
Thank you for the instructions, Paul! To me is not clear how the RG cable is connected to the BNCs: it seems that only the screen part of the cable is soldered to the screen part of the BNC. So, were goes the central of the cable? Sorry for my bad english :-) 73
Hello Andrea The coax cable connects to the BNC or other connector if you choose just like it would normally connect. The center conductor of the cable goes to the center pin on the BNC and the shield of the cable goes to the ground connection on the BNC . Remember that the shield from one BNC and the other need to be isolated. This is why I use a PVC enclosure. Let me know if you have any other questions
Could you be more specific about this ferrite 75? E.g a friend of mine suggested me an NT-45/19/16-6000-IP12E (Painted). What is the complete name of this 75? 73
That's some very specific part number from a Brazilian manufacturer. You don't need to be so specific. Just google "ferrite rings 75 toroid" and chose a 1 inch ring. In the USA, several ferrite manufacturers use a code like SS-DDD-MM where SS is the shape of the toroid, DDD the external diameter in 100th of a inch (100 = 1 inch) and MM is the material. They add other numbers or letters arbitrarily. For instance, FT-100A-45 would be a ferrite toroid of 1 inch with material 45 made by a company named Amidon Corp.
I always use a second common mode choke on my remote antennas. Typically they are 300+ feet from my house.. That means thee is 300 feet of coax laying on the ground picking up signal s I don't want to reach my antenna
The common mode choke is one of the most useful devices around. Most EEs do not understand magnetics, at all. This is a great device. I usually install directly into switchers. Could NEVER ship a military PS, without these versatile devices. Have spent 25 years designing these in. Look in a Tek 1A2 plug-in for the venerable Tek 547 scope. Guess what? you will find these designed in, in about the mid 50s by very capable engineers.
When I glued mine together, I just used the cardboard tube from a roll of toilet paper and cut it up the length and then squeezed it down to the diameter I needed and taped it to hold the size I needed for the toroids. It worked really well. :)
Thanks Paul! I saw you give the part number of the cores in an online forum message recently so I ordered mine (16 qty. cores) from Newark Electronics a few days ago. They have a large stock of the correct ones, and are just $1.25 per core. 73, Guy
What is the Newark part number? I just searched, "FT140-75" and it did not show up?
Barry
This is the third video I've watched and I'm learning a lot. Thanks. 73 from PY5WHO.
Thank you Julio I appreciate your comments. I am trying get more time to make videos. W1VLF
Nice music Paul, good choice.
Again, another interesting video Paul, keeping my attention for every single minute (no, I did not fall asleep, with or without the music ;o)) Thanks for all the work you put into making these video's. Looking forward to part 2 !
Best 73 !
Hi Patrick... Glad you could stay awake ! LOL Thank you for taking the time to comment. W1VLF
love the test fixture. Very handy. Thanks for your videos
Great video - many thanks.
Thank you so much for sharing valuable information. I'm really into baluns and chokes. I'm so happy I found your videos. Can ask a question. Is there any way I can do the attenuation test at home without buying a tracking generator? Can the antenna analyzer do the test or the VNAs do the test?
Duck Tape the handy mans Secret weapon
What is the core material that the ferrite toroids are made of please? For example might they be type 43 or type 31?
360 / 5.000
Risultati della traduzione
Risultato di traduzione
Hi Paolo, you actually skipped winding the cable on the toroids, could you kindly explain to me how they should be wound? From what I understand, mark the middle of the cable and from there do how many windings with the first half and then should the second half be wound in the reverse direction of the first or in the same direction? I thank you and always compliment you on your videos.
PS...how much above 3 mhz would you think the choke in the cylinder would be effective cheers Brenton VK3CM
thank you for this helpful video. So, I am guessing when you solder the Rg-178 to the BNC, you're attaching it to the 'ground' connector part of the BNC??
What network analyzer are you using?
Hi W1VLF - how did yiu connect the choke to the VNA to measure attenuation> I di nit see that detail. Is the VNA in just the transmissiion mode>
Thanks, Chuck
Could I use an old ferrite from an old TV, to make this project for 27MHz. TKS 7351.
Arrow is the best. Once I discovered them I have never bought cores from anyone else.
The fundamental difference between the operation of a nanocrystalline core and a ferrite core lies in the absence of a resonance characteristic of ferrites at frequencies of 0.5÷2 MHz, and work on the absorption of RF interference, in contrast to the reflection of interference characteristic of ferrites, which is associated with a change in the inductive nature of the ferrite choke to capacitive and can create problems in the work of the IIP.
Increase in impedance and attenuation by 2 - 6 times,
High resonant frequency and wide bandwidth (up to 5 times),
Absence of many resonances in the frequency response of the impedance,
Reducing the leakage inductance by 2.3 - 3 times,
High saturation induction (1.17 T),
Excellent temperature stability (in the range from -60°С to +155°С the change in permeability is less than 15%),
Low active losses in the wire,
Wide operating temperature range: from -60°С to +100°С,
Reduction of volume and weight by 2 - 3 times.
greats video ..how about HF freq?
Sure... it will work as long as the noise is really on the feedline,and not being received on the antenna. W1VLF
Group w Alices entire mascre movement
LOL.. Thanks for noticing !!
@@W1VLF you kidding me> I had the next urinal to him in Portsmouth NH when he did a gig there....Man I tell ya....im 6 '2 and he towered over me ....had to be 6 7' -6 8' lol I listen to that entire mascre of movemont and the 27 8x10 colot glossy photographs with circles and arrows on the back of each one and how it was to be used against us ! lol Then he looked at the seeing eye dog ! lmao
Kid! I was 6 when this came out.
Deburring tool works well also.
If the core is only good for LF and MF what good are they on HF noise? I can't waste my time.
Paul do you install one at the antenna and one inside...same as the other or just one very close to the receiver.
Put one nearest the receiver input first , then if you still have problems nearest the antenna input.
Just use the right core for where you listen .
I live in a home in a HOA with restrictions on antennas...so I have a multiband dipole 40-10 in the attic....I have a high noise level of S-5 on 20 and more on lower frequencies.
I operate with an IC-2610. I have placed some chokes on the AC-lines to the power supply (Astron) and on the 12v power supply leads...but levels remain constant. I know you were speaking about much lower frequencies....but do you have a suggestion for noise in the 20 M range. Since its a transceiver...if something needs go to the 52 ohm coax line ..it would be great to have something that will tolerate the 100W output of the transceiver. Thanks Ron KO4QCX
You can use core type 43 for hf and add a 3 rd or 4th core. Should be better yet.
Chuck. AA4CP
The question is where to put this choke for best results...?
Place it close at the antenne in the coax feed cable. If you still have RFI or local QRM place another one next to the TRX. It might help.
Should this will be mounted near the Antenna or at the receiver end
If you only build 1, I would say at the receiver. This would reduce conducted noise from propagating out to your remote antenna. If you build 2 I would at one on each end of the feed line. The one at the antenna, reduces the the noise pick up of the long feed line. This chokes work only on noise conducted along your feed line.. Not if the noise actually being received by the antenna.
@@W1VLF Thanks Paul, I have been trying to listen well the 20meter band. I have a 1/2 wave horizontal dipole and recently Installed a Delta loop which I cant see any Difference in the Noise level. I expected at least 1s unit low but unfortunately can't see any difference. On the line of your work I will do some experiment and if I achieve any good results will share here
After you have used the glue - put the cap back on and put it in the fridge - you will not need to throw it away half used
Tony...!!! I have to try that. You have just saved me a bunch of money and aggravation !
Are you basically making a 1:1 current balun?
It performs the same function yes. The current balun keeps provides a high impedance to RF getting onto the feed line of a say dipole for instance. The RF on the feed line causes your dipole to have a 3rd leg, IE the coax cable The CMC keeps noise currents that are on the ground system of your home, from getting onto the feed line, and propagating out to the antenna. Good question!!
Thank you for the instructions, Paul! To me is not clear how the RG cable is connected to the BNCs: it seems that only the screen part of the cable is soldered to the screen part of the BNC. So, were goes the central of the cable? Sorry for my bad english :-) 73
Hello Andrea The coax cable connects to the BNC or other connector if you choose just like it would normally connect. The center conductor of the cable goes to the center pin on the BNC and the shield of the cable goes to the ground connection on the BNC . Remember that the shield from one BNC and the other need to be isolated. This is why I use a PVC enclosure. Let me know if you have any other questions
@@W1VLF Many thanks, Paul :-)
Could you be more specific about this ferrite 75? E.g a friend of mine suggested me an NT-45/19/16-6000-IP12E (Painted). What is the complete name of this 75? 73
That's some very specific part number from a Brazilian manufacturer. You don't need to be so specific. Just google "ferrite rings 75 toroid" and chose a 1 inch ring.
In the USA, several ferrite manufacturers use a code like SS-DDD-MM where SS is the shape of the toroid, DDD the external diameter in 100th of a inch (100 = 1 inch) and MM is the material. They add other numbers or letters arbitrarily.
For instance, FT-100A-45 would be a ferrite toroid of 1 inch with material 45 made by a company named Amidon Corp.
Sorry I meant a second one if needed at the antenna
I always use a second common mode choke on my remote antennas. Typically they are 300+ feet from my house.. That means thee is 300 feet of coax laying on the ground picking up signal s I don't want to reach my antenna
@@W1VLF Thanks a lot Paul over the years I have learned a lot of good stuff from you. GOOD JOB
OM 73'S AA4CP CHUCK
With heat PVC will pull apart.
Who noticed the white paper on the wall? 😅😂😅😉
Super glue always gets all over hands
I prefer Ballistol