i dont put down "others", i put-down idiots. So if you felt put-down, then I did my job correctly. ...and, FYI, no need to announce your departure because 1) this is not an airport and 2) nobody cares what you do.
I was at the motorcycle shop and one of the techs was having trouble with a CB installation. Being a Happy Ham, I offered my assistance. I noticed that his antenna was about 10 inches long. 10 inches may be good for some things, but not CB antennas. He said that he had read that he should “trim” the antenna until he had minimum SWR on channel 20. He kept trimming, but the SWR indicator needle stayed pegged at max. Note: He did not have a cool digital FARSOMETER. Being a “Radio Expert”, I suspected a feed line problem. We removed the seat. He had not only coiled the coax, he had tie wrapped it into a dog bone. The ends of the dog bone were as tightly bent as he could make them. We got another antenna kit an coiled the coax into a 6” diameter coil. A couple snips on the antenna and it was at an SWR of 1:1 on channel 20. As you have said, it is fine to coil coax, as long as the radius is not too small. A radius of 10 x coax diameter is what we use in aircraft installation. A coil of coax will act as an RF choke to signals on the shield, not the signals on the center conductor. As hams we will often have a few turns coil just below the antenna connector. This prevents RF energy coming into your radio shack via the shield. Finally, if coiling the coax damaged it, it would be bad when you bought it off the spool at the store. 73, Happy Ham
All I can say is that I worked with everything from HF to XHF and all the frequencies in between during my 17+ years in the Air Force and most of the time our cables were coiled both during use and in storage. Never had an issue.
Good test. I am always reconfiguring my antennas and taking them portable. I have pre-cut coax cable lengths. I always make a couple of coils at the base of the antennas as an RF choke. Sometimes the coax is too long between antennas and radio. I just coil up the excess coax. I usually use resonant antennas. Sometimes I have an auto tuner mounted at the feed point of the antenna. I have never had an SWR problem based on coax that was "too long" or coiled up. So much for "the experts." It is not the SWR that could be a problem but attenuation, ie loss of signal strength between radio and antenna. The attenuation is more critical for UHF and VHF frequencies depending on type of coax used and its length. You can find attenuation charts on the internet, or they are included in coax manufacturers' specs. Coiling a coax cable does not appear to affect attenuation in any signifcant and critical, at least in real world situtions like you describe.
I come here for the Sad Ham Trolling and almost always laugh a GREAT deal. Learn a little sometimes, laugh a lot all the time! Good Results and not surprised by the results or the Sad Ham reactions.
Thank you for the video. Coiling up your extra cable not cause high SWR which you just proved. I have built a lot of antennas and have coiled up close to the antenna connection with certain antennas to prevent RF from coming back to the radio on the outer shield. I have never heard coiling up the cable caused high swr or lowered the power output. Keep up the good videos.
this noun is a new one to me... that being said... i wrote it down and will now practice using this noun... thanks for expanding my knowledge!!!! P.S.... this should really piss off the wife...lol.
Confucklement , i hope there is no censorship laws on this noun, as i am going to be using this a lot.. hell i may even get it to take hold down here and if i get enuf followers, maybe it will make Websters Dictionary.....Love this guy. i have learnt so much...
Maybe you coiled it the wrong direction? Sort of like how water flows clockwise or ant-clockwise, down the toilet, depending on the hemisphere? I think you should have stated the direction of the coil!
Awesome. I love it when the video description has so much detail. I had no idea LMR400 existed and can be used for mobile application. Though one would have to think out the routing a bit better than when using the cheap stuff. Thank you again for your awesome presentation and fact producing.
The excess cable in my truck on my ham radio that I hacked to also work on GMRS has talked many many fars and it is in fact coiled. One day I talked 85 miles to a repeater. Folks that's in Florida. Not like King Randy's perfectly perched paradigm of power packing phase pinching fars producing propagation punch!
I'm no expert! But I'm thinking: unwanted inductance? I always uncoil because I have been told it can fry the radio! I always uncoil extension leads as my test and tag teacher always said! But with Radios? That S why I'm watching your videos! Btw my youngest son loves your channel. He's always watching ever since I got 2 baofeng uv5r iii. Nice to see someone doing real tests! Not throwing myths around. Cheers from Australia 🙂👍👍👍
You’re sense of humor is 100% perfect 🤣🤣🤣. You missed your calling as a “heckling back at the crowd comedian” , don’t ever change !! Always enjoy your videos 😎
Watching this prompted me to test it for myself. I used a Nagoya UT-72G antenna on a pie plate and a Baofeng AR-5R radio. I tested with the coax straight and then coiled the coax in a neat coil about 5" in diameter. I tested on GMRS 6 and GMRS 16 and just for the heck of it, I also tested it on MURS 3. I repeated the experiment 3 times and discovered to my surprise that it did seem to make a difference. The difference ranged from 0.02 to 0.1 but it was consistent. The larger difference was on MURS 3. I can only guess that it's because the UT-72G isn't a dual-band antenna and didn't handle VHF as well as UHF. I don't know why my results were different from Randy's, and to quote Paul Harrell (RIP), it's not enough difference to make a difference. Maybe induction? I don't know. But it doesn't matter.
Hey, I started as a ham a few years ago and got turned off by sad hams. Have found a better group and am back in it again and got my GRMS while I am at it so i can convince my friends to get radios too. Thanks for being no BS and showing me GMRS
5 หลายเดือนก่อน
CB radio was the top gateway drug to getting people into the ham radio community.. Now it is FRS, people much prefer the quieter FM mode and once they find out that a licensed ham can use an HT and talk to someone on the other side of the world their small FRS bubble looks far smaller.. Well like any hobby you get those that are like that, even the radio clubs can and do become cliques for snobs.. Since most people have real lives outside radio it may be hard to find the kind of people that are amiable..
In fact it's common among hams to coil up the coax to limit stray RF on the outside of the braid. Or "hot mike" as some older hams would call it. There is no danger involved coiling up coaxial cable, except for mechanical reasons as "minimum bending radius". In fact a big roll of e.g. RG58 with infinite length will be a perfect 50 ohm load. But of course the longer the coax cable between the radio and antenna is, the greater is the loss of RF energy. Best 73 from Ham Anonymous.
higher SWR - albeit by .04 for the higher spec cable ? dafaq? & it went down after coiling??!! lol I tried using my TV antenna with my feng (on 63 cm) a it worked a treat - SWR of 1.01 (Surecom)..... but when I took the antenna off the roof & ran it with only a short length of coax, the SWR went up to about 2.37.... a buddy did same & got 4.3 - still worked.. Re tried the test with a long cable - swr 1.01. My point being, I don't fully understand why, but feel a longer cable might hide a high swr - pure speculation on my part but possibly more of the reflected signal is happening further from the meter, than the meter is able to detect? .... Dunno? but any & all thoughts much appreciated.. 🤔
Good video, good real-world data. Another data point: you should avoid kinking coaxial cable (or any kind of cable such as ethernet). This can cause impedance issues. Minimum bend radius is 5x cable radius.
Good one randy ... next do the oh but you cant cut your coax it has to be an exact length ...ive watched a dozen or more vids on installs on 4wd and almost all of them say cutting your cable will effect the swr .. i laugh ive installed hundreds and cut cabes to fit never effected the swr ..
I'm trying to get into making antennas (for UHF CB - 477mButtHertz) & trying to have prove you don't have to spend a princes ransom on shop bought antenna, I was trying to figure out how to increase fars & lower SWR with chokes, baluns & ugly baluns, aka coils of co-ax. Still only vaguely understand the theory, but strongly suspect that's how you scored the SWR of 1.00 Keep up the great edutainment.
Randy That means I have to go buy longer cable so I have enough to coil. Thanks for the step-by-step help applying for my GMRS lic. Your right (as always) the FCC web site is a trip. Now waiting for both Radio and call sign.
Coiling the cable can help on some radio bands. It is called a balun, and helps to keep unwanted RF emissions from travelling back down the coax to the radio. I do this on my CB dipole. It lowered the SWR. It also helps balance the ohms. Not going to harm the radio.
I continue to enjoy your demonstrations. You may know of Gordon West the Ham radio teacher. For HF antennas he suggest you make a coil in your cable to reduce the reflective power returning to your radio. W8KSC
Depends on the shape of the door, really. In my truck it's a gentle curve so no troubles, but in my GF's car it'd wreck the coax in just a few closings.
I have 3 coax's running from the roof through the top of the doors to get inside of the car, been that way for 8 years, no problems. Heck, since the beginning of time truckers have been running coax through the wing windows on the doors to get from the antenna to the cb, no issues!
i thought it was about the current causing too much heat on the cable and shorting it out. the midland micromobile cables are so thin they recommend uncoiling them
I'm not sure about this, Randy. For me, this subject hits home, emotionally. See, back in the mid-80s I used to pal around with these two guys; Ray and Peter. Both guys were really smart, both had multiple PhDs in various fields of science. One day, my friend Ray decided that he was going to coil up some RG58 and attach it to a ground plane antenna WITH NO GROUND PLANE WHATSOEVER. I think both of them had been drinking heavily that day because they had just lost their grant at the college they were were working at. The dean at the college, dean Yeager firmly believed that if you coiled up coaxial cable and transmitted a radio signal through that coil to an antenna, a portal to another dimension would be opened up. Well, anyway, Pete thought that was total bunk and so did Ray, which is most likely why they lost their grants and their jobs. The next thing you know, everyone is drunk, unemployed, depressed and throwing caution to the wind by coiling coaxial cable, attaching it to antennas and transmitting through it. Sure enough, a portal to another dimension opened up and a demon named Goser came through it and tried to destroy the world as we know it. Ray and Pete knew that the wouldn't be able to battle Goser by themselves, so they enlisted the help of the smartest man they know; a colleague by the name of Egon. Egon had a radical idea about how to defeat Goser. He theorized that if they all crossed their antennas and directed their radio signals in unison towards Goser, the SWR would flow both backwards and forwards at the same time, thus closing the interdimensional portal, sending Goser back to her dimension of origin and saving the world as we know it (starting with lower Manhattan). The plan wasn't without risks, however. Egon cautioned them that if their timing was off in any way, their radios would melt down in their hands and everyone would be killed at the speed of light. After Egon was through speaking, Peter jumped up and exclaimed "I LOVE THIS PLAN!! I'M HAPPY TO BE A PART OF IT!!! LET'S DO IT!!!" He then picked up his Boefang UV5R (knowing full well that it's illegal to transmit on GMRS frequencies with a UV5R) pointed it at Goser and grunted "Let's show this pre-historic bitch how we do things downtown." Ray and Egon and I joined in, crossing our antennas and directing the crossed radio streams right at our nemesis. Luckily, the plan worked perfectly. There was a tremendous explosion and we were all thrown back about 20 feet and severely burned. Goser vanished and the world was safe from the trouble we caused. Other than that, the only other consequences for the recklessness of coiling coaxial cable and then transmitting radio signals through it, was the fact that the FCC jailed all of us for 8 years for transmitting on GMRS frequencies through a Boefang UV5R. I have to tell you, every day of those 8 years in Leavenworth all I could think about was how stupid we were to violate the FCC rules about the Baofeng UV5R, how incredibly stupid we were for coiling our coaxial cables and how lucky we all were that the outcome wasn't any worse.
True, but that only affects RF electricities on the OUTSIDE of the shield where none is supposed to be. RF signals on the inside of the coax shield is mostly uneffected. Coiling coax does help a little but you are hiding a problem with either the cable or the antenna because there is not supposed to be any electric currents traveling down the outside of the shield in the first place. The more 'non resonant' your antenna is - the higher swr will be on the inside of the coax and that means the energy tries to travel down the outside of the shield instead.
Many radio books do suggest doing that because a balanced aerial such as a dipole when fed with unbalanced coax can induce r.f. on the outer of coax. G4GHB
Back in the day (probably 25 years ago...) I coiled up coax a LOT for my CB rig. Not going to cut a perfectly fine cable, just because it would mean I wouldn't have to coil it up when using that antenna in that specific car. And I never had any difference in SWR. Never even had to re-tune the antenna is I switched cars, and just had an SWR of 1,05.
I’ve heard this debate for 25 years I don’t see and difference . I’ve never did a test but I personally operate mostly on 10/11 meter SSB . I’d be interested to look at the differences between straight and coiled excess coax on a Bird setup for a reflect comparison just out of curiosity Anyway ,, good video man 👍
Love your videos, as a tech person I have to agree that winding and unwinding cables continually is not good for the cable. With network and power cables we extended the life of our cables by not twisting the cable as it was coiled them up.
I am so glad you made this video because I am dealing with this right now I installed a cb in my jeep and bought a antenna with a long coax cable so I needed to watch this 😀 thank you
I was tuning my buddies antenna that he ran through his old satellite TV cable in his walls. He had a coil of about 4ft and it actually made it worse if he uncoiled it lol. Oh BTW thank you very much for the step by step on how to get your GMRS license, that website is horrendous.
Great content, man! The SWR dropped because the coil made a load, a small load but a load non the less. I would be curious if it affected the forward power, and if so, by how much?
Before doing these tests could you state your null hypothesis? Some people need to know. My null hypothesis is that more fars is better especially when transmitting without an antenna.
It’s fairly common practice to deliberately coil coax to form a choke whenever connecting to a balanced antenna, or to create a drip loop to stop water coming indoors.
Can you answer this. I have my Tram 1177 tuned to 1.2-1 for the car mount AND magnet mount . I installed it on the tram ground plane adapter with a short section of cable and it goes up .3. When I used lmr400, it jumped to 2.2 to one. The coax test good,. All coax lengths are about the same.????
Antennas are very sensitive to their surroundings and how the cable is attached to the feed point so we would need to see some pictures of your installation to know anything for sure. But, remember, there is no need to worry about anything below 2.0 swr.
Will tying excess cable into a Hangman's Noose increase SWR? What about a standard Bowline Knot or the mighty Sheepshank? I smell a playlist! Awesome video debunking the straight coax purists out there. You are doing the Lord's work, even if it's Lord Xenu.
I do have a question ' on my Ford pickup, since I'm mounting a gmrs antenna on the roof, I was told that I could shorten my coax by 3ft and the extra coax I would wind up and hide somewhere, can this be done???? Please advise me
How about you do a test where you shorten the cable. I would be interested as to what the results would be. It would be nice to cleanup a Jeep install. Thanks for all you information!
You should never ever roll up your coax cable. Having the electrons go around in a circle slows them down. That is why top fuel dragsters are much faster than NASCAR cars. Top fuel dragsters go in a straight line, whereas NASCAR go around in circles, slowing them down. Not only does it slow them down, but the electrons going in circles might get them dizzy and disorientated and they may lose their way. So always run your coax in a straight line, even if it means you have to put your antenna in your neighbors yard.
You mentioned that LMR 400 isn't the best coax, what do you suggest for a base antenna installation with a length of approx 60 ft for VHF use GMRS and/or 2 Meters?
I suggest LMR400, because its plenty good enough for normal people that arent rich. I only say "its not the best" because if i dont say that, 100 sad-hams will leave comments saying that I dont know what I'm doing because LMR400 is not "the best".
My radio has plenty of FaRs and my coax is in a big pile up out side the shack because it is about 25ft too long. My SWR is >1.5:1 across 10-30MHz. What is the big deal?
I appreciate this.. Since I coil my extra CB antenna coax under the seat, I will sleep better knowing the radio doesn't give a F! OTOH... there are a few (ham radio) antenna experts on here on YT that could give you a one-word answer... with a 20-minute explanation! 😁😆
For sure, standing waves occur when you have an impedance mismatch (varies from 50 ohms at your alternating current frequency, when your line to load have a reflection from a "discontinuity," kink in the line or other factors that change the distance from the center conductor to the other conductor, moisture/vapor/water/dust/bugs... or other stuff in-between), loose or otherwise nasty connections, extraneous electromagnetic waves penetrating through the shielded connector, or worst of all - EMPs and/or direct hit by a nuclear detonation!
Newly subscribed here and I got to say, I'm loving your videos, I've been personally interested and currently am studying to get my license and finally get into HAM radios, ect. Used to be a CATV Technician for a while and have been curious about experimenting and trying out and see how different coaxial types can affect attenuation, signal loss, signal gain, ect. Keep rolling out great content!😀
i read the title and i thought NO. isn't the wire inside a shield, hence the name COAXial?... you could have imperfect shielding and stuff like that, but not thaaat bad... Thank you for these videos. Some practical tests teaches us a lot, if not more than theoreticals.
Could you possibly compare your current setup on your jeeps SWR to what it would be with a ground plane mount? Looking at your setup (mounted in front of the windshield) I’m confused as to how it gets a good ground plane. Keep in mind that I’m an idiot that is just starting into GMRS, and so far your videos BY FAR have the most useful information
The antenna location on my Jeep doesn't have a "good" ground plane.. But it is "good enough". Dont let the "experts" fool you into thinking that you must have a perfect groundplane.. Perfect is better, but anything below 3:1 is just fine for normal people.
@@TheNotaRubicon I’m still thinking about the mount for my side by side. I worry that a magnet mount on a plate on the roof will get knocked off continuously, but I’m concerned that a roll cage mount won’t have enough ground plane. I’m trying to avoid buying an SWR meter if I can help it but I don’t want to damage a brand new radio
The choke will stop r.f. on the outer of the cable and may therefore reduce the s.w.r. For example a dipole is a balanced aerial but coax is unbalanced so to stop r.f. a choke is used, a ferrite ring is more effective.
The length would be important, and longer would probably be better (although, the cable loss/return-loss in the smaller cable would certainly make the indicated SWR actually better). Also, in order to perform a valid test, a load with a known poor SWR would be needed... i.e., a "badly" matched antenna, or an intentionally un-matched dummy-load (e.g. a 75-ohm resistor of sufficient wattage). This would then present a higher VSWR along the line, and may show a more noticeable change in any "choking effect" and SWR change of a coiled cable (in similar fashion to an "ugly" balun) vs. an uncoiled cable. Otherwise, somewhat interesting but really meaningless. A similar test at higher-power HF would be interesting... 73 from west Texas!
I have Ben Into Radio's for almost 40 Years & I Remember Hearing That Saying To When I Started back then & Of Coarse I believed It until i got older & Tested it my self & i Found Out That it Did not Really make any Difference on 10 ,11Or 12 Meter Either ! But i know from First Hand Experience That Buying Good Coax Online Is Very Hard to Do Now Days so take that with a Grain of Salt
OMG I love your videos! Best on the inter webs! But, more importantly, I need that T-shirt. LOL. Please share where you got it. And thank you for the great content.
I replaced a 3 year old Cobra 29lx on my Kenworth rig that had a display issue with a brand new 29lx ..now I cannot get my SWR to calibrate ..old one was fine ..new one will not calibrate ..it’s especially high on the low channels ..I’m running a dual setup using Wilson 2000 model antennas ..anyone have any thoughts? ..thanks in advance for any help
SWR is a ratio of reflected power, so no matter how much you push in (to a point), it should not make any [significant] difference as that ratio would stay [mostly] the same.
I would be curious to see how it affects other bands, and I wonder if it does make a difference there and that's where the advice came from. I know you're just gmrs, so that's not your thing, but now I'm curious.
It may not affect SWR, but if you use digital modes you should not coil your cable. High radius bends can cause the 1's to get stuck in the corners while the 0's slide on through, causing massive confuckulation.
Not a fan of his put downs to others. I will be avoiding his videos in the future.
i dont put down "others", i put-down idiots. So if you felt put-down, then I did my job correctly.
...and, FYI, no need to announce your departure because 1) this is not an airport and 2) nobody cares what you do.
When a cable is shielded well enough, one would't expect any difference in SWR. And you proved it in the test. Great video.
I was at the motorcycle shop and one of the techs was having trouble with a CB installation. Being a Happy Ham, I offered my assistance.
I noticed that his antenna was about 10 inches long. 10 inches may be good for some things, but not CB antennas. He said that he had read that he should “trim” the antenna until he had minimum SWR on channel 20. He kept trimming, but the SWR indicator needle stayed pegged at max. Note: He did not have a cool digital FARSOMETER.
Being a “Radio Expert”, I suspected a feed line problem. We removed the seat. He had not only coiled the coax, he had tie wrapped it into a dog bone. The ends of the dog bone were as tightly bent as he could make them.
We got another antenna kit an coiled the coax into a 6” diameter coil. A couple snips on the antenna and it was at an SWR of 1:1 on channel 20.
As you have said, it is fine to coil coax, as long as the radius is not too small. A radius of 10 x coax diameter is what we use in aircraft installation.
A coil of coax will act as an RF choke to signals on the shield, not the signals on the center conductor. As hams we will often have a few turns coil just below the antenna connector. This prevents RF energy coming into your radio shack via the shield.
Finally, if coiling the coax damaged it, it would be bad when you bought it off the spool at the store.
73,
Happy Ham
All I can say is that I worked with everything from HF to XHF and all the frequencies in between during my 17+ years in the Air Force and most of the time our cables were coiled both during use and in storage. Never had an issue.
But that was military cable... it was "special". It cost 5x too much. ;) TY for your Service.
@@TomRolfson It's the same cable, they just pay 5x more for it, LOL
I have to admit, sometimes my cable shrinks a little bit when it gets cold.
I just pull on mine to warm it up. much better transmission!!!
🤣
Then buy a thermal jock strap. 😝
@@toml.8210 Chestnuts roasting on an open fire........
Just squeeze it very hard at the base.
Thank you for being a calm voice in the wild world of so called experts.
Good test. I am always reconfiguring my antennas and taking them portable. I have pre-cut coax cable lengths. I always make a couple of coils at the base of the antennas as an RF choke. Sometimes the coax is too long between antennas and radio. I just coil up the excess coax. I usually use resonant antennas. Sometimes I have an auto tuner mounted at the feed point of the antenna. I have never had an SWR problem based on coax that was "too long" or coiled up. So much for "the experts."
It is not the SWR that could be a problem but attenuation, ie loss of signal strength between radio and antenna. The attenuation is more critical for UHF and VHF frequencies depending on type of coax used and its length. You can find attenuation charts on the internet, or they are included in coax manufacturers' specs. Coiling a coax cable does not appear to affect attenuation in any signifcant and critical, at least in real world situtions like you describe.
I come here for the Sad Ham Trolling and almost always laugh a GREAT deal. Learn a little sometimes, laugh a lot all the time! Good Results and not surprised by the results or the Sad Ham reactions.
Thank you for the video. Coiling up your extra cable not cause high SWR which you just proved.
I have built a lot of antennas and have coiled up close to the antenna connection with certain
antennas to prevent RF from coming back to the radio on the outer shield. I have never heard
coiling up the cable caused high swr or lowered the power output. Keep up the good videos.
I have been a Ham for 35 years and I really like the noun “confucklement”
You learn something new every day
this noun is a new one to me... that being said... i wrote it down and will now practice using this noun... thanks for expanding my knowledge!!!! P.S.... this should really piss off the wife...lol.
Me three! I love tongue in cheek sarcasm. Well done!!!
Confucklement , i hope there is no censorship laws on this noun, as i am going to be using this a lot.. hell i may even get it to take hold down here and if i get enuf followers, maybe it will make Websters Dictionary.....Love this guy. i have learnt so much...
I thought it was an adjective?
Maybe you coiled it the wrong direction? Sort of like how water flows clockwise or ant-clockwise, down the toilet, depending on the hemisphere? I think you should have stated the direction of the coil!
Awesome. I love it when the video description has so much detail. I had no idea LMR400 existed and can be used for mobile application. Though one would have to think out the routing a bit better than when using the cheap stuff. Thank you again for your awesome presentation and fact producing.
The excess cable in my truck on my ham radio that I hacked to also work on GMRS has talked many many fars and it is in fact coiled. One day I talked 85 miles to a repeater. Folks that's in Florida. Not like King Randy's perfectly perched paradigm of power packing phase pinching fars producing propagation punch!
I'm no expert! But I'm thinking: unwanted inductance? I always uncoil because I have been told it can fry the radio! I always uncoil extension leads as my test and tag teacher always said! But with Radios? That S why I'm watching your videos! Btw my youngest son loves your channel. He's always watching ever since I got 2 baofeng uv5r iii. Nice to see someone doing real tests! Not throwing myths around. Cheers from Australia 🙂👍👍👍
You’re sense of humor is 100% perfect 🤣🤣🤣. You missed your calling as a “heckling back at the crowd comedian” , don’t ever change !! Always enjoy your videos 😎
This really clear things up for me... I have been concerned about this very issue for some time. Thanks for taking the time to make this video.
Watching this prompted me to test it for myself. I used a Nagoya UT-72G antenna on a pie plate and a Baofeng AR-5R radio. I tested with the coax straight and then coiled the coax in a neat coil about 5" in diameter. I tested on GMRS 6 and GMRS 16 and just for the heck of it, I also tested it on MURS 3. I repeated the experiment 3 times and discovered to my surprise that it did seem to make a difference. The difference ranged from 0.02 to 0.1 but it was consistent. The larger difference was on MURS 3. I can only guess that it's because the UT-72G isn't a dual-band antenna and didn't handle VHF as well as UHF. I don't know why my results were different from Randy's, and to quote Paul Harrell (RIP), it's not enough difference to make a difference. Maybe induction? I don't know. But it doesn't matter.
Hey, I started as a ham a few years ago and got turned off by sad hams. Have found a better group and am back in it again and got my GRMS while I am at it so i can convince my friends to get radios too. Thanks for being no BS and showing me GMRS
CB radio was the top gateway drug to getting people into the ham radio community.. Now it is FRS, people much prefer the quieter FM mode and once they find out that a licensed ham can use an HT and talk to someone on the other side of the world their small FRS bubble looks far smaller.. Well like any hobby you get those that are like that, even the radio clubs can and do become cliques for snobs.. Since most people have real lives outside radio it may be hard to find the kind of people that are amiable..
In fact it's common among hams to coil up the coax to limit stray RF on the outside of the braid. Or "hot mike" as some older hams would call it. There is no danger involved coiling up coaxial cable, except for mechanical reasons as "minimum bending radius". In fact a big roll of e.g. RG58 with infinite length will be a perfect 50 ohm load. But of course the longer the coax cable between the radio and antenna is, the greater is the loss of RF energy. Best 73 from Ham Anonymous.
Wow. I really hate cutting coax and soldiering pl239's on. I'm going to try this and see what I get. Thanks for the video
@@ZiggleFingers who makes them.
higher SWR - albeit by .04 for the higher spec cable ? dafaq? & it went down after coiling??!! lol
I tried using my TV antenna with my feng (on 63 cm) a it worked a treat - SWR of 1.01 (Surecom)..... but when I took the antenna off the roof & ran it with only a short length of coax, the SWR went up to about 2.37.... a buddy did same & got 4.3 - still worked.. Re tried the test with a long cable - swr 1.01. My point being, I don't fully understand why, but feel a longer cable might hide a high swr - pure speculation on my part but possibly more of the reflected signal is happening further from the meter, than the meter is able to detect? .... Dunno? but any & all thoughts much appreciated.. 🤔
Good video, good real-world data. Another data point: you should avoid kinking coaxial cable (or any kind of cable such as ethernet). This can cause impedance issues. Minimum bend radius is 5x cable radius.
Thanks for the video. I have coiled coax for years. I ran a Dentron 2kw and never had a issue. It works for me. Jmo
Good one randy ... next do the oh but you cant cut your coax it has to be an exact length ...ive watched a dozen or more vids on installs on 4wd and almost all of them say cutting your cable will effect the swr .. i laugh ive installed hundreds and cut cabes to fit never effected the swr ..
I'm new to all of this. When you speak of fars, is this a metric far or an imperial far?
I'm trying to get into making antennas (for UHF CB - 477mButtHertz) & trying to have prove you don't have to spend a princes ransom on shop bought antenna, I was trying to figure out how to increase fars & lower SWR with chokes, baluns & ugly baluns, aka coils of co-ax. Still only vaguely understand the theory, but strongly suspect that's how you scored the SWR of 1.00
Keep up the great edutainment.
Randy That means I have to go buy longer cable so I have enough to coil. Thanks for the step-by-step help applying for my GMRS lic. Your right (as always) the FCC web site is a trip. Now waiting for both Radio and call sign.
Coiling the cable can help on some radio bands. It is called a balun, and helps to keep unwanted RF emissions from travelling back down the coax to the radio. I do this on my CB dipole. It lowered the SWR. It also helps balance the ohms. Not going to harm the radio.
In catv we used a soda can as the minimum radius for bends not sure if same since catv coax is 75ohm and radio is 50ohm.
I’m a CB guy but this was helpful. I always heard mixed opinions on the subject and I need to do something with my excess cable.
I continue to enjoy your demonstrations. You may know of Gordon West the Ham radio teacher. For HF antennas he suggest you make a coil in your cable to reduce the reflective power returning to your radio. W8KSC
I have always wondered if closing a car door on a roof mount Magnet base antenna, will damage the coax? Something to test maybe?
depends on how bad it's pinching it, they will eventually short if it's too bad
No, but the door will leak rain.
Depends on the shape of the door, really. In my truck it's a gentle curve so no troubles, but in my GF's car it'd wreck the coax in just a few closings.
I coil my coaxial cable in knots. I also slammed the car door on it.
I have 3 coax's running from the roof through the top of the doors to get inside of the car, been that way for 8 years, no problems.
Heck, since the beginning of time truckers have been running coax through the wing windows on the doors to get from the antenna to the cb, no issues!
i thought it was about the current causing too much heat on the cable and shorting it out. the midland micromobile cables are so thin they recommend uncoiling them
The 'inexpensive' cable used in this test was from a Midland Micromobile MXT500.
Thanks for this, I was just going to install a GMRS antenna on my truck and wasn't sure how to handle the 4 feet of extra coax. Dig your shirts!
OMG 😲 you connected your HT to an aftermarket antenna, "GMRS ANTENNAS CAN NOT BE REMOVED," 🤪🤣🤭🤫😎 great video
I'm not sure about this, Randy. For me, this subject hits home, emotionally. See, back in the mid-80s I used to pal around with these two guys; Ray and Peter. Both guys were really smart, both had multiple PhDs in various fields of science. One day, my friend Ray decided that he was going to coil up some RG58 and attach it to a ground plane antenna WITH NO GROUND PLANE WHATSOEVER. I think both of them had been drinking heavily that day because they had just lost their grant at the college they were were working at. The dean at the college, dean Yeager firmly believed that if you coiled up coaxial cable and transmitted a radio signal through that coil to an antenna, a portal to another dimension would be opened up. Well, anyway, Pete thought that was total bunk and so did Ray, which is most likely why they lost their grants and their jobs. The next thing you know, everyone is drunk, unemployed, depressed and throwing caution to the wind by coiling coaxial cable, attaching it to antennas and transmitting through it. Sure enough, a portal to another dimension opened up and a demon named Goser came through it and tried to destroy the world as we know it. Ray and Pete knew that the wouldn't be able to battle Goser by themselves, so they enlisted the help of the smartest man they know; a colleague by the name of Egon. Egon had a radical idea about how to defeat Goser. He theorized that if they all crossed their antennas and directed their radio signals in unison towards Goser, the SWR would flow both backwards and forwards at the same time, thus closing the interdimensional portal, sending Goser back to her dimension of origin and saving the world as we know it (starting with lower Manhattan). The plan wasn't without risks, however. Egon cautioned them that if their timing was off in any way, their radios would melt down in their hands and everyone would be killed at the speed of light. After Egon was through speaking, Peter jumped up and exclaimed "I LOVE THIS PLAN!! I'M HAPPY TO BE A PART OF IT!!! LET'S DO IT!!!" He then picked up his Boefang UV5R (knowing full well that it's illegal to transmit on GMRS frequencies with a UV5R) pointed it at Goser and grunted "Let's show this pre-historic bitch how we do things downtown." Ray and Egon and I joined in, crossing our antennas and directing the crossed radio streams right at our nemesis. Luckily, the plan worked perfectly. There was a tremendous explosion and we were all thrown back about 20 feet and severely burned. Goser vanished and the world was safe from the trouble we caused. Other than that, the only other consequences for the recklessness of coiling coaxial cable and then transmitting radio signals through it, was the fact that the FCC jailed all of us for 8 years for transmitting on GMRS frequencies through a Boefang UV5R. I have to tell you, every day of those 8 years in Leavenworth all I could think about was how stupid we were to violate the FCC rules about the Baofeng UV5R, how incredibly stupid we were for coiling our coaxial cables and how lucky we all were that the outcome wasn't any worse.
Wait.. So Goser was female? Was she hot?
The creativity for something like this. Just amazing. Good read
@@TheNotaRubicon Would anybody goose her if she wasn't hot?
@@TheNotaRubicon superhot like those demons that stick out really farz
There's just one little flaw with this story. There weren't any Baofeng UV-5Rs back in the mid 80s. You almost had us all fooled.
huh.. sometimes they tell us to coil it on purpose to make an rf choke to keep rf off the sheid.
True, but that only affects RF electricities on the OUTSIDE of the shield where none is supposed to be. RF signals on the inside of the coax shield is mostly uneffected. Coiling coax does help a little but you are hiding a problem with either the cable or the antenna because there is not supposed to be any electric currents traveling down the outside of the shield in the first place. The more 'non resonant' your antenna is - the higher swr will be on the inside of the coax and that means the energy tries to travel down the outside of the shield instead.
Many radio books do suggest doing that because a balanced aerial such as a dipole when fed with unbalanced coax can induce r.f. on the outer of coax.
G4GHB
Proof that Coiled Coax isn't as bad as Moist Coax. Moist.
Back in the day (probably 25 years ago...) I coiled up coax a LOT for my CB rig. Not going to cut a perfectly fine cable, just because it would mean I wouldn't have to coil it up when using that antenna in that specific car. And I never had any difference in SWR. Never even had to re-tune the antenna is I switched cars, and just had an SWR of 1,05.
I’ve heard this debate for 25 years
I don’t see and difference . I’ve never did a test but I personally operate mostly on 10/11 meter SSB . I’d be interested to look at the differences between straight and coiled excess coax on a Bird setup for a reflect comparison just out of curiosity
Anyway ,, good video man 👍
Love your videos, as a tech person I have to agree that winding and unwinding cables continually is not good for the cable. With network and power cables we extended the life of our cables by not twisting the cable as it was coiled them up.
As for avoiding winding up cable by cutting it and terminating the cable has the potential to introduce other issues if not done correctly
Asked my wife to help me coil my cable and she just rolled her eyes! 🤷
Because of an aged and broken SO239, I stopped using my coax and now I have lost it 🚫🍆💦
🤣🤣
Funny, she rushed over and helped me out when i asked her. Guess your lil inch worm doesnt excite her
I read that and walked straight in from the garage to use it.
Also got an eye roll.
Experiment proven
it used as a choke or lightning chock also
Solid test.
Real data is better than hearsay.
I am so glad you made this video because I am dealing with this right now I installed a cb in my jeep and bought a antenna with a long coax cable so I needed to watch this 😀 thank you
I was tuning my buddies antenna that he ran through his old satellite TV cable in his walls. He had a coil of about 4ft and it actually made it worse if he uncoiled it lol. Oh BTW thank you very much for the step by step on how to get your GMRS license, that website is horrendous.
Great content, man! The SWR dropped because the coil made a load, a small load but a load non the less. I would be curious if it affected the forward power, and if so, by how much?
The FWD power is visible on the meter. (lwr left of the screen)
Before doing these tests could you state your null hypothesis? Some people need to know. My null hypothesis is that more fars is better especially when transmitting without an antenna.
It’s fairly common practice to deliberately coil coax to form a choke whenever connecting to a balanced antenna, or to create a drip loop to stop water coming indoors.
New to the channel. Liked and subbed! Love the cut of your jib Sir! Keep 'em coming! Need more channels like this.
Can you answer this. I have my Tram 1177 tuned to 1.2-1 for the car mount AND magnet mount . I installed it on the tram ground plane adapter with a short section of cable and it goes up .3. When I used lmr400, it jumped to 2.2 to one. The coax test good,. All coax lengths are about the same.????
Antennas are very sensitive to their surroundings and how the cable is attached to the feed point so we would need to see some pictures of your installation to know anything for sure. But, remember, there is no need to worry about anything below 2.0 swr.
Will tying excess cable into a Hangman's Noose increase SWR? What about a standard Bowline Knot or the mighty Sheepshank? I smell a playlist!
Awesome video debunking the straight coax purists out there. You are doing the Lord's work, even if it's Lord Xenu.
I do have a question ' on my Ford pickup, since I'm mounting a gmrs antenna on the roof, I was told that I could shorten my coax by 3ft and the extra coax I would wind up and hide somewhere, can this be done???? Please advise me
you can wind up the extra coax and throw it under the seat or wherever you want, just coil it loosely and dont bend/kink it.
I'm curious if the swr would change if you were pushing more watts out?
SWR is a ratio, so no matter how much power you push, the ratio should not [significantly] change.
How about you do a test where you shorten the cable. I would be interested as to what the results would be. It would be nice to cleanup a Jeep install. Thanks for all you information!
Like the shirt!! The “loading” symbol looks like a ferrite toriod with coax wrapped around. 😂
How about running coax alongside your power cable... is this ok?
Depends on the coax, the power, and the cable.
You should never ever roll up your coax cable. Having the electrons go around in a circle slows them down. That is why top fuel dragsters are much faster than NASCAR cars. Top fuel dragsters go in a straight line, whereas NASCAR go around in circles, slowing them down. Not only does it slow them down, but the electrons going in circles might get them dizzy and disorientated and they may lose their way. So always run your coax in a straight line, even if it means you have to put your antenna in your neighbors yard.
I bet you are a old time ham operator.
@hogcat858 I guess your sarcasm meter indicator light is malfunctioned or you got mixed up with the idiot light
I love sarcastical learning, hats off
I never was worried about swr.
does it affect the noise floor?
No.
You mentioned that LMR 400 isn't the best coax, what do you suggest for a base antenna installation with a length of approx 60 ft for VHF use GMRS and/or 2 Meters?
I suggest LMR400, because its plenty good enough for normal people that arent rich.
I only say "its not the best" because if i dont say that, 100 sad-hams will leave comments saying that I dont know what I'm doing because LMR400 is not "the best".
My radio has plenty of FaRs and my coax is in a big pile up out side the shack because it is about 25ft too long. My SWR is >1.5:1 across 10-30MHz. What is the big deal?
Would this effect power at the other end ?
Randy, you forgot to add that “if you try this at home, your fars may vary” 😂🤣😂.
Awesome!! Nice putting the old argument to rest. I have mine coiled and been that way for awhile at my small “base station.”
I understand your frustration with people. Some days, I feel like Luke Wilsons character in the movie Idiocracy!
I appreciate this..
Since I coil my extra CB antenna coax under the seat, I will sleep better knowing the radio doesn't give a F!
OTOH... there are a few (ham radio) antenna experts on here on YT that could give you a one-word answer...
with a 20-minute explanation! 😁😆
Have you done a test of different cables? Also which meter did you use?
Great test Randy
For sure, standing waves occur when you have an impedance mismatch (varies from 50 ohms at your alternating current frequency, when your line to load have a reflection from a "discontinuity," kink in the line or other factors that change the distance from the center conductor to the other conductor, moisture/vapor/water/dust/bugs... or other stuff in-between), loose or otherwise nasty connections, extraneous electromagnetic waves penetrating through the shielded connector, or worst of all - EMPs and/or direct hit by a nuclear detonation!
Newly subscribed here and I got to say, I'm loving your videos, I've been personally interested and currently am studying to get my license and finally get into HAM radios, ect. Used to be a CATV Technician for a while and have been curious about experimenting and trying out and see how different coaxial types can affect attenuation, signal loss, signal gain, ect. Keep rolling out great content!😀
i read the title and i thought NO. isn't the wire inside a shield, hence the name COAXial?... you could have imperfect shielding and stuff like that, but not thaaat bad...
Thank you for these videos. Some practical tests teaches us a lot, if not more than theoreticals.
I have been running 10kw on cb radio for years with 150ft 7/8 in coax no problem here. It’s about common mode after that.
if you run power consider the heat. am i right?
My extra LMR 400 UltraFlex is coiled up under the passenger seat in my Chevy Tahoe and my radio works just fine.
same thing here on cb, tried it both ways and no difference with swr, i still got 1.01 on channel 1 and 40. have you checked out the GT-5R radio
Could you possibly compare your current setup on your jeeps SWR to what it would be with a ground plane mount? Looking at your setup (mounted in front of the windshield) I’m confused as to how it gets a good ground plane. Keep in mind that I’m an idiot that is just starting into GMRS, and so far your videos BY FAR have the most useful information
The antenna location on my Jeep doesn't have a "good" ground plane.. But it is "good enough". Dont let the "experts" fool you into thinking that you must have a perfect groundplane.. Perfect is better, but anything below 3:1 is just fine for normal people.
@@TheNotaRubicon I’m still thinking about the mount for my side by side. I worry that a magnet mount on a plate on the roof will get knocked off continuously, but I’m concerned that a roll cage mount won’t have enough ground plane. I’m trying to avoid buying an SWR meter if I can help it but I don’t want to damage a brand new radio
Can you explain why some antenna manufacturees suggest coiling 8 to 10 turns in a 8" coil to act as a choke?
To reduce noise
The choke will stop r.f. on the outer of the cable and may therefore reduce the s.w.r. For example a dipole is a balanced aerial but coax is unbalanced so to stop r.f. a choke is used, a ferrite ring is more effective.
Do a Google search for "the Ugly Balun" & report back to us.
Hmmm🤔I'm quite surprised...somehow, someway, just not really sure why, but this video was somewhat interesting😲
The length would be important, and longer would probably be better (although, the cable loss/return-loss in the smaller cable would certainly make the indicated SWR actually better).
Also, in order to perform a valid test, a load with a known poor SWR would be needed... i.e., a "badly" matched antenna, or an intentionally un-matched dummy-load (e.g. a 75-ohm resistor of sufficient wattage). This would then present a higher VSWR along the line, and may show a more noticeable change in any "choking effect" and SWR change of a coiled cable (in similar fashion to an "ugly" balun) vs. an uncoiled cable.
Otherwise, somewhat interesting but really meaningless.
A similar test at higher-power HF would be interesting...
73 from west Texas!
I can communicate far FAR away with my cableatures. I use the figure 8 hoopty loopty configuration Incase your wondering.
The figure 8 method always works. You don't have to remember if it should be clockwise or counterclockwise.
Thank you for testing these configurations! Great vid! Keep’m coming!
Thanks for the test!👍
I have Ben Into Radio's for almost 40 Years & I Remember Hearing That Saying To When I Started back then & Of Coarse I believed It until i got older & Tested it my self & i Found Out That it Did not Really make any Difference on 10 ,11Or 12 Meter Either ! But i know from First Hand Experience That Buying Good Coax Online Is Very Hard to Do Now Days so take that with a Grain of Salt
So to clarify, low swirls equates more bars pushed out whether or not you choose to coil.
OMG I love your videos! Best on the inter webs! But, more importantly, I need that T-shirt. LOL. Please share where you got it. And thank you for the great content.
Look in the info section where it says "like my shirt? Click here to get one"
I replaced a 3 year old Cobra 29lx on my Kenworth rig that had a display issue with a brand new 29lx ..now I cannot get my SWR to calibrate ..old one was fine ..new one will not calibrate ..it’s especially high on the low channels ..I’m running a dual setup using Wilson 2000 model antennas ..anyone have any thoughts? ..thanks in advance for any help
Great video but lacking Chris who, is the REAL star of the channel!
All kidding aside, informative video Randy. Thank you!
it would be funny if Randy's myth busting ended up changing the ham test that one has to take to become a ham enthusiast. :-D
Right!🤣🤣🤣🤣
I have about 25' of rg8 coiled up for my cb and have great swr
Not trying to be a sad ham. but real question. do you guys think if you pushed the power to the 50 watt limit it would make any difference?
SWR is a ratio of reflected power, so no matter how much you push in (to a point), it should not make any [significant] difference as that ratio would stay [mostly] the same.
@@TheNotaRubicon hey, awesome to know! thanks for the awesome videos.
I read that 1 FaRs = 10^5 Smidges witch is equal to 10^11 c-bomb hairs.
I'm really liking that KG-S88G!
Thanks for your confidence!
Best vid I've seen in a long time.
Nice video and test. How's your GMRS reoeater doing? Any updates?
Htl1 coax cable antennea for cb use avoided coax for a choke . Not sure of the science but they work.
I would be curious to see how it affects other bands, and I wonder if it does make a difference there and that's where the advice came from.
I know you're just gmrs, so that's not your thing, but now I'm curious.
It may not affect SWR, but if you use digital modes you should not coil your cable. High radius bends can cause the 1's to get stuck in the corners while the 0's slide on through, causing massive confuckulation.