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King of the toroid

Discussion in 'General Ham Radio Discussion' started by Mudfoot, Mar 14, 2019.

  1. Redbeard U812

    Redbeard U812 Sr. Member

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    Think my F.A.S.S. would reject any ionic disturbances, even though ferrites may look like a magnets they are not. They do decent job of stopping some of the RF interference along that coax, used to run one between radio and leeenyer, and one or two between leeenyer and antenna before I changed my coax to BuryFlex. Had done all the bonding possible and the only resort was TOROIDS.



    Now if I do get some diesel contamination due to spurious RF emotions :p, I may give that a try. Also could try using a choke method on that return line there........just try tying it a knot. Wouldn't want any those spurious RF emotions returning to the fuel tank and contaminating the rest of the diesel population.....:whistle::whistle::whistle:
     
    Slowmover likes this.

  2. Redbeard U812

    Redbeard U812 Sr. Member

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    I'm sorry, I misread your comment.

    Probably due a little lack of punctuation.
    Kind of like ......
    "Helping my Uncle Jack, off a horse." .and........"Helping my uncle jack off a horse."
     
    543_Dallas likes this.
  3. Redbeard U812

    Redbeard U812 Sr. Member

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    That there my friend is called bonding. Using braid is the preferred method for taking all body panels to the frame. But I just use #6 stranded.
     
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  4. 543_Dallas

    543_Dallas Sr. Member

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    I ran a 6 foot piece of wire from the antenna mount to the frame. That's not really bonded at 27mhz. I thought I knew what I was doing because the symptoms went away.
     
  5. arc1

    arc1 Guest

     
  6. arc1

    arc1 Guest

    Captain kilowatt, what do you mean by my attitude? Have you quizzed any other members on this in regard to this discussion? I don't like to see this kind of culture anywhere. That is namely the one where people ridicule a defenceless person and pretend to know everything. I don't claim to know everything, but what I do know is that there were a couple of good examples of effective use of ferrites in his vid. Sure, there were quite a few you may question, however, is it so simple as to say ferrites are a band aid solution and that's it! For instance, my friend was having issues with the neighbours solar panels, they were generating a lot of rfi. Do you think he offered to replace his entire solar system to solve the problem? No, it was fixed quite simply, you know how, and it works both ways. I employ well designed ferrite chokes to prevent common mode current, I do not have all of these rf grounding crap that you all seem to talk about a lot, and I do more than well without any problems. I have some grounding at the base of my antenna purely for lightning, some members seem to be confused by this. So you mention your grounding and shielding, care to enlighten me on this?
     
  7. Slowmover

    Slowmover Sr. Member

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    On the big truck?
     
  8. Slowmover

    Slowmover Sr. Member

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    Ferrites have worked for me.

    On radio power leads as well as on a portable refrigerator/freezer where the RF was so bad during compressor run-time I’d turn off the radio.

    Maybe in a stationary base other approaches are better. And on a vehicle I own. I’m free to try everything.

    On a company truck there winds up being limitations in access, etc. so I’ll try ferrites. If it doesn’t work, on to the next idea.

    At present I’d like to have the power leads under 25’. 6-ga. They go past all sorts of devices.

    Bit by bit, piece by piece.
     
  9. 543_Dallas

    543_Dallas Sr. Member

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    I've had the most luck using them for common mode chokes. Especially in mobile installs. There isn't enough room to wrap a coax choke in the headliner when installing a puck mount. I'll use a stack of them around the coax right at the feed point. Probably not necessary for a few hundred watts but a few kilowatts is a different story.

    I have some on my xlr mic cable where it connects to the audio gear. They aren't needed at less that a kw carrier. It wasn't an issue with a condenser mic but had issues when I switched to the pr40. I suspect it was because the mic preamp level had to be increased and the preamp doesn't play well with rf.

    Some amplifiers don't have enough power cable isolation and you'll have stray rf from the power cables. Ferrite works well here also.
     
    Shadetree Mechanic likes this.
  10. loosecannon

    loosecannon Sr. Member

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    Who's got their knickers in a bunch?

    I didn't make fun of his video to make myself feel superior, i made fun of it because it was funny.

    If his intention was to teach someone how to wrap wires around a donut, then he did that.
    If his intention was to teach people what wrapping wires in ferrite actually does, or why you would or would not choose that method to solve your rfi problems, then he did not do any of that.

    This guy is not running dirty CB amplifiers and clipped modulation limiters, he is running amateur radio gear, and he is getting into everything in his house, and even his neighbor's house.

    nowhere in the video does he describe his station, his grounding setup, or his antenna, nor does he show us why he didn't start there to solve his problem.

    he could just be doing something dumb like operating from his 2nd floor and running 30 feet of wire down to a ground rod, or not tying his station ground in with his home electrical ground.

    If he was doing either of those things and thought that he had solved his rfi problems just because he's not bleeding on the telephone anymore, then he is the one who needs a lesson.

    Now here you are assuming that we are just a bunch of jerks who make fun of people that are trying to fix their problems, and that we don't know what we are talking about.

    you should do yourself a favor and start searching around the past posts in this forum.

    we have covered grounding for lightning, rf grounding, vehicle bonding, NEC conformation, and just about anything else that involves copper, and we have run those subjects right into the ground. pun intended.

    If you would like some specific help with an issue you are having at your station, there are many of us who love to help, just start a thread and ask.
    LC
     
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  11. 543_Dallas

    543_Dallas Sr. Member

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    CB fight!!!!

    Didn't we used to have a popcorn emoji on this forum? I need one for this post.
     
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  12. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

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    Aluminum foil is not just for making hats anymore. Here is the section on ground system testing from Radio Works.

    http://www.radioworks.com/nbgnd.html

    A ground system test

    OK, so you have a good ground system set up, all the ground wires are short, all the ground loops have been minimized. Can the system be improved? Probably, and here is a quick and simple way to find out. This test is especially good for checking out radial systems for verticals and ground systems on boats.

    First, purchase two, inexpensive, 75' rolls of aluminum foil. Unroll about 8 feet of foil from each roll and lay in on the ground, the rolls forming a 90 degree angle to one another. Twist the first foot of foil into a thick, aluminum wire. Then twist the two twisted ends of the foil together. Use a short clip lead or other attachment method and connect the foil to the ground system. Even better, connect a length of ground braid and route it directly to the point on the transmatch in the shack. Measure your antenna's SWR with and without the foil ground hooked up. It shouldn't make any difference. If it does, then you need a better ground system. Repeat this procedure for each band, unrolling the length of the foil so it is 1/4 wavelength long for the band being tested. If your ground system is working well, there will be no difference in SWR readings.

    There are other ways to make this measurement beside looking for changes in SWR. If you have an RF ammeter, (the MFJ-931 has one built-in) connect it in series with the station ground at the transmitter. Use the aluminum foil procedure outlined above. Any change in RF ground current indicates an inadequate ground system. The MFJ RF 'Current Probe' should work as well and does not have to be placed in series with the ground systems.

    The foil technique works well with vertical antennas. Roll out a coupe of lengths of foil for a particular band, connect to the base of the vertical in parallel with the radial system. If the SWR changes, the radial system could use some improvement.

    Note: With an improved ground system, you may see the SWR rise slightly. Remember, a properly installed 1/4 wave vertical with low I2R losses will have a feedpoint impedance around 30 - 35 ohms. The lowest SWR you will see if everything is working perfectly is 1.5:1. Trap verticals are certainly no better than a good, full-size, 1/4 wave vertical. So, don't be surprised to see the SWR increase as the ground losses are reduced.
     
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  13. kopcicle

    kopcicle Sr. Member

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    'bout time somebody got it right.
     
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  14. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Oh please.....spare me the "you're only picking on me and nobody else" routine. Apparently you have not seen much in your 2 1/2 years here and only 3 posts as of the other day. If you don't like "to see this kind of culture anywhere" you are going to have a REALLY hard time on the internet discussion forums and social media then. That's the problem today......nobody can make a joking comment about something without offending someone. Too bad. Well I don't like the comment you made referring to grounding and shielding as "crap". I guess that's the former occupation I had for 22 years coming out in me. I saw for myself what PROPER grounding and shielding does when I was in commercial broadcasting dealing with everything from audio up to 1.7GHz. We had large toroids on the incoming coaxial and hardline cables for lightning protection as well as on the power lines for the same reason. That was it. PROPER single point grounds using wide copper flashing were used along with shielded audio and control lines. No toroids anywhere else in the systems whether AM or FM transmitter sites and never an issue. Those very same grounding techniques used at an AM site can be implemented in a typical amateur station with minimal cost if you do it right the first time. It is far from crap to do it that way. My own amateur station has six ground rods at the tower base......two for each leg.....and all connected together at the base. Transmission lines are grounded at point of entry and the station ground is tied into the main electrical service ground to create a single ground point to eliminate current flow from one ground to the other during a lightning strike event where the charge flows outward thru the ground creating a difference in potential between two distant ground points. Any audio lines or control lines I use are shielded. The control line to the remote coax switch is shielded 6-wire. Again no toroids anywhere. Will I ever HAVE to install some? Maybe and if Ineed too I will but for now things are great and there is no RFI at all.
     
    Redbeard U812 likes this.
  15. Captain Kilowatt

    Captain Kilowatt Professional Amateur
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    Been trying to pound that into people's heads for years. A lot of amateurs stop adding ground radials when the SWR on their ground mounted vertical hit 1:1. I tell them to keep going until they see something more like 1.4:1 or so or better yet use an analyzer to watch the impedance and shoot for 32-36 ohms. The small SWR is nothing and the antenna will be much more efficient.
     

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