I got a few hundred feet of RG6 from the end of a roll used on a large commercial cable TV installation. Most importantly, I got it for free. I made up several low-loss 50 Ohm to 75 Ohm matching transformers to put on the antenna end of my rig with the antenna tuner, and for wherever applications I might need them for, although I also found I could simply tune a couple of my antennas to have a 75 Ohm feedpoint, so I seldom have use for the matching transformers. I'm not the sort who is particularly concerned about losing 7 or 8 Watts out of 100, but I do like to keep everything running cool and happy, and I find that my feedline matching losses are extremely minimal to nonexistent. You just have to stop thinking of 50 Ohms as being somehow magical and essential, and learn to match to whatever impedance you have to work with.
Good video. I use a lot of RG-6. I buy it by the 1000 foot roll and it’s cheap. I also use the compression type connectors with the PL-259 adaptors. Regarding 75 ohm vs 50 ohm cable, it makes insignificant difference on a dipole. The feed point impedance of a dipole varies widely with the height above ground. As the height is varied from very low up to several wavelengths high the impedance varies from very low up through a 50 ohm value and rise to a peak around 90 or more ohms then back down to maybe 60 when it rises again. It oscillates around 75 ohms until at several wavelengths it is essentially damped out to near 72 or 73 ohms. It can be fed with any 50 or 75 ohm coax. To get the minimum SWR with either coax you can usually adjust the length of the dipole above or below resonance changing the reactance ( making it either inductive or capacitive) this changes the impedance such that it can become either 50 or 75 ohms. The impedance is a combination of R and X. So length of the dipole is adjusted until you get a minimum SWR with either 50 or 75 ohm cable. In other words an impedance of 50 ohms with no reactance can become a 75 ohm impedance by simply adjusting the antenna until there is a 55 ohm reactance. The feed point is changed from 50 +j0 ( 50 ohms impedance) to 50 + j 55 and that is 75 ohms of impedance. This would give a perfect 1:1 with 75 ohm cable. This is a case of the minimum SWR not being at the same frequency as the resonant frequency. This is done all the time with 50 ohm cable. We put up a dipole at some convenient height and feed it with 50 ohm cable. The SWR is not what we expected. We trim or lengthen the antenna until the SWR is as low as we can get it, frequently 1:1 but anything less that 1.5 is very good. What we don’t realize is that we are actually adjusting the reactance and varying the complex impedance until it matches the coax. You are doing pretty much the same thing when adjusting your delta loop differently with 75 ohms coax that with 50 ohm coax. I do want to mention that regardless of the coax type if there is an SWR on the coax, the impedance at the antenna will be transformed to some different impedance at the transmitter end depending on the length of the coax. If the electrical length of the coax is a half wave or multiple of a halfwave then the impedance will be the same as that at the antenna end. On a Smith chart we draw what is called an SWR circle and all the points on the circle have the same impedance but each point had a different R and X value. One revolution around the circle is one half wavelength and brings you back to the point you started with. That’s why the antenna impedance repeats itself every half wavelength of feedline. I as well as many of my friends have used very large 75 ohm hardline for long runs to our towers for low loss. We start with RG- 8 transition to the 75 ohm hardline underground and at the tower transition back to RG-8 up to the antenna. At one time the cable company near me gave away many leftover reels with only 100 to 300 feet left on them!
@@kd2wtu72I always recommend the ON4UN Low Band DXing book (Especially the Fifth Edition). Although it is primarily for 160 through 40 meters the info applies to all the HF bands. I have had most of the 5 editions. Excellent books and each edition got better. Some early editions had not so good information in places but the last two editions are really excellent. 73, N4DJ
many friends used RG6 to wire the Mcmansion in 2000. I get a lot free and might as well use it. I do use RG8X - used. For RG6 I used stnd F connectors and i have a crimper from my coax days in 1990's RG8X I use 239 ends. I am only using 100 watts max. Cheap and functional. You covered it all. thx 73.
My only reason to not have used RG6 for transcieve is its solid copper over steel center conductor with softer foam dielectric separating it from the Shield is in areas of continual flexing (especially like feeding a rotatible dipole, beam...) where failure is more apt to happen, along with its power limitation. And I usually had extra lengths of 8, 8X... at hand. BUT for 100-200 watt SSB and lower power usage into a more fixed Antenna you pretty well covered its benefits at low cost. I have used it several time with RX Antennas with good results, yes with water tight O-Ring'd F connectors and the F to PL adapters. Thanks for the Video! 🍺🍻 73 mike N4ONL
Great video! As you indicated, not a huge amount of mismatch and as some others have said, plenty of easy ways match things at a particular frequency. I really like the cost cutting approach for home stuff - the challenge of keeping costs down while still getting decent performance is what makes it fun.
👍 Good video and some very useful info, thanks. I always thought it seemed odd that the impedance of a dipole is ~72 Ohms, yet hams use 50 Ohm co-ax and the standard output impedance of rigs is 50 Ohms. Though, I do appreciate there are reasons for using 50 Ohms. When I use that tape trick, I found it easier to wrap the tape on clockwise. This means, when I screw the connector on clockwise, it doesn't tend to unwrap the tape.
Thank you for the information on using RG6 for feed-line connections. I thought I was doing something politically incorrect in the Ham world. I am financially constrained so, cheap(and sometimes free) RG6 was my choice. And I had a terrible time trying to connect PL259 connectors to it. I tried soldering, not knowing the braid was made of aluminum. And also realized that my SWR wasn't so great - not skilled enough to use an antenna analyzer like nanoVNA wondered why my dips on the display kept going al over the place. I am an OM but a New Ham and I have tons to learn...73
I was not sure just how taboo using rg 6 was in the ham o sphere. It's one of the reasons why I made the video to show yes, it's ok lol. Thanks for watching!
Picked up some quad shield RG6 not to long ago. Going to use it from the shack to the tower. Got it for practically nothing, almost 500ft of it. Great video
First, love the video, doing things on the cheap is always good. I’ve worked around pay tv and internet for almost 20 years, I’d stay away from pre run cables because of the copper clad. I suppose it depends on which devil you want to face, more expensive coax of higher than normal SWR. Bet no one could tell the difference in an emergency.
Thanks for putting this out there, I was building a coax dipole and pretty much have the measurements to get the same results every time. Used an f connector and saw craziness with SWR. I swapped the connector for a pl259 and so239 and replicated the first two dipoles I built. Your video helped me understand why.
Let me assure you that using a quarter wave length section of 75 ohm RG6 to transform a delta loop into 50 ohm coax works for me every time. Just finished one for a crippled ham for a 6 meter Delta loop and it tuned up like a dream. I have a 40 meter Delta loop waiting for a ride to the top of the big tower. It was in use on a lower tower with a 4:1 ferrite transformer and RG400 and was changed to a quarter wave RG6 matching stub to reduce weight, windage, and bulk. The radio could not tell the difference in the two configurations - other than I will not be hitting the RG6 transformer with 1500 watts. K8DO
That was a good idea, swapping out the balun for a matching stub to reduce the wind load. I should use a matching stub if I ever build a portable loop. Thanks for watching!
I bought 2/3 of a 1000ft box from a home builder for $20.00 on marketplace. I’ve made several receive antennas for different projects. Time to try transmitting with it.
I bought a 100m roll of VERY HIGH Quality RG6 for $30AUD New Old Stock...to redo my TV antenna runs about 4 years ago. It's connected to 3 separate SDR's, two scanners and an AIRBAND receiver. The SECOND 100m roll I then bought to do my TV's is servicing a second set of 4 antenna's, for transmitting on various bands. I made two flowerpot antenna's for 10/11m portable use, both are 1.01:1 or less SWR on a 5m test feedline of RG58, I run one on a 40m length of RG-213 and I get a 1.05:1 reading on either 27Mhz or 28mhz. the second one on RG6 gives me 1.5:-1.6:1 at the same length. BOTH work perfectly well. For the cost saving, i can live with the 10w power loss i MIGHT suffer at 100m, at my limited 40m length, I get a return loss of under 2w on the RG6. When I run my IC7300 at home, it runs into a 40m length of LMR240 and into a EFHW with a 49:1 UnUn, it shows a return loss of around 1.5w, so not a lot of difference. During a field test, using 50w power and over a 15Klm distance on 27.305 AM, the signal on the RG213 was less than one S point above the signal on the RG6 at the receive end. Using the same radio, same antenna, just different cable. NOT a definitive test by any means, but a solid result to be sure. The RG6 cable is cheap, works great and is simple to get, you can even buy 30m lengths with connectors fitted for $25 in my local supermarket.....I see mental images of HAM's going in on any given day, buying toilet paper, a toothbrush, laundry detergent and 30m of coax...just a normal days shopping..... And YES, the TV's are still waiting their new cable runs....time to buy a third 100m roll......
Haha I love that your radios soaked up all that coax and the tv's didn't get any. Your proof is in the pudding, not much difference in feedlines at your station. Thanks for watching !
I’ve been wanting to try this cable for HF. From my wholesaler, I can get 1000’ of generic quad core for $100-150 aussie. While I haven’t used it as transmission line, I have used it to make a series of magnetic loop antennas with varying amounts of success. The cable was from stuff I had left over from some older analog CCTV installs I did last decade. As far as matching it to an antenna, a simple balun with a 9 turn to 8 turn balun will do it for a 50 ohm feedpoint impedance. On your delta loop, you could use a similar strategy with a turns ratio of 1.6:1. Instead of 2:1
Give it a try I think you will be pleasantly surprised how well it works. I feed my delta loop bottom corner with a 4:1 balun. It works very well, resonant on 20m, and SWR is less than 3:1 on all the other bands so I run it multi band with a tuner. Thanks for watching !
@@kd2wtu72 thank you for taking time to respond I have a few theories that seem to fit the measurements I have taken of various antennae with the trusty NanoVNA who’s smith chart reveals so much more than SWR. I am currently working on higher power Magnetic Loop antenna designs, and have what I feel is a somewhat unique approach to a 20m through 40m mag loop that I can take portable and gives an end fed half wave an excellent run for its money. I’ll be making some more sensible videos on it with a friend VK2AOE who has his The Art of Engineering channel. There are some sneak previews of the loop antenna there. There is a roll of flooded RG11 that has been given to me that I need to test. But again, I am using it as a radiator and not as a transmission line. I do want to try RG6 with catenary wire as an antenna and see how the diameter affects the bandwidth for your regular dipole. The extra aluminium foil surface area should more than make up for any skin effect resistance, not that that is much of an issue with wire antennas as opposed to mag loops which can be little bundles of incendiary devices when placed under stress :-) I have a few entries in the _Hall of Flame_ to attest to that DE VK2NAP
I used to use 3/4 inch 75 ohm hard line that I got for free and it was fantastic for the 200 foot runs out to and up the tower.. You should check the price and specs of RG-11 as it will assemble into a regular PL-259 like RG-8.. I used the 75 ohm RG-11 coax cut to 1/4 wave sections on 6 meters to co-phase 2 antennas together with a coaxial T with great success and it was acquired for free as well from the cable TV companies dumpster.. For a time I also had a home made 160 bazooka antenna built with it which I built a home made baulin for..
Since the feed point impedance of a half wave dipole is close to 73 ohms, using 75 ohm feed line works very well ! I personally use RG - 6 Quad shield, and find that the antenna is significantly quieter !
Dipoles are not always 73 Ω due to height and location with nearby objects which is why sometimes a less that 1.5:1 SWR can be obtained as I found out. Mine are in the attic, 5 dipoles 20m to 10m, fairly close to each other and some ends close to the wall. The radio textbooks show how height makes a difference to the impedance. G4GHB.
@@kd2wtu72 Indeed ! And you'll pay hardly anything compared to all the high dollar Coax ! As I've said, I've had great luck with it running QRP thru 100 watts ! As to how quiet it is, it was just that , that drew my attention to it ! I thought that I was imagining things ! It got me to thinking just how much noise our coaxial cables may drag in ? I do also employ an ugly balun at the feed point , probably more from habit than necessity ? And this was something I was always curious about, and finally decided to use 75 ohm ! Too, unless you choose to do something different, you'll need the appropriate adapters, F type / RCA to PL 259 ! Good luck !
I gave 30 bucks for 500 foot of good stuff. When you make long runs for reception, it great. If you use it for 160 or 80 meter antennas, just mind you lengths and you’re good. Also need to check your connections more often. The aluminum sheath does not like to have the pull of the cable on connectors. You can also use it as the antenna on a reversible beverage.
Just 1 additional thing that may hurt you with RG6. The shield isn't made for the low requency ranges your'e talking about. Hence it may leak RF or take on QRM. Most of the times, this should be a problem because leaking in Ham bands while TX istn't problematic and you always want your station in a low QRM environment.... just be aware of that!
It's great getting a perfect match, but sometimes good enough is better than perfect. I use 9:1 random wires all the time when portable. The SWR for any given band is never perfect. Thanks for watching!
Nice picture of the old AN/FPS 35 tower and sail. Bet I can tell you from that where you were located. BTW, I spent most of my USAF career in Air Defense.
Thank you for your service! The background picture for the slides is my station set up in front of the old tower at Camp Hero state park in Montauk NY. Cool place to do a POTA.
I've looked at RG6 and wondered about using it. With 50 Ω coax there's a mismatch anyway at a dipole which is 73 Ω depending on height, location etc. RG6 puts a mismatch at the transmitter but then the coax matches the aerial. Does it matter? I think some tests using an r.f. pickup meter at the aerial and one length of RG6 and one of mini 8 both the same length to see if there is a difference in r.f. output is needed. When I first started on h.f. I did use about two feet of t.v. coax to a tuner for a long wire. I have attic dipoles each with about 25 feet of mini 8 coax, 20m to 10m bands and an outdoor inverted vee with about 45 feet of coax on the 60m band so no great losses anywhere. G4GHB.
I'm in no way a RF engineer, but I don't believe it matters whether your mismatch is at the radio or the antenna, I think you will have the same losses. But that sounds like a good idea for a future video. Thanks for watching!
Having made my own tcvr and copied a p.a. circuit for 50 Ω, it seems to me I could just as easily use 75 Ω. I used the accepted standard of 50 Ω. Is a tx output really 50 Ω? Or only thereabout? I don't see how it can be guaranteed to be 50 Ω. If I use 75 Ω coax and as long as I change the resistors in my Wheatstone Bridge type SWR meter then everything will be 75 Ω, coax, SWR meter, and my dipoles supposedly the 73 Ω textbook value. I'm going to try this. My FT817 would show a mismatch but I guess that would be because the 817 SWR meter circuit is set for 50 Ω. Could that be altered for 75 Ω? Are manufactured tx SWR meters set for 50 Ω and nothing else? But dipoles can't be guaranteed to be 73 Ω either, due to height and nearby objects which is why an SWR of less that 1.5:1 can be obtained. A 75 Ω dummy load on a 50 Ω tx SWR meter shows 1.5:1. G4GHB.
I'm not sure about altering your equipment but you could definitely "tune" your dipole by connecting a nanovna or antenna analyzer and adjusting the antenna height until you get 75 ohms. Interesting idea, making everything 75 ohms. Give it a try!
I have not built a flower pot antenna myself, but yes it should be fine to use rg6 to build it. And yes it will be safe for your radio. Good luck with the antenna!
I have added links to the connectors in the description of the video, I should have had them in there from the start. The PL 259 to type F adaptors on amazon: a.co/d/atdRGcx The PL 259 screw on connectors on amazon: a.co/d/4JPMqGc Good luck have fun!
I have said this in the past, as how many antenna are fifty ohms anyway? Scanners users this is a cheep way to get your antennas away from the noise Also poor CB ops this is also good. How many have a feed line of 100 feet so if your scanner or CB antenna is say fifty feet the loss will be even less
I got a few hundred feet of RG6 from the end of a roll used on a large commercial cable TV installation. Most importantly, I got it for free. I made up several low-loss 50 Ohm to 75 Ohm matching transformers to put on the antenna end of my rig with the antenna tuner, and for wherever applications I might need them for, although I also found I could simply tune a couple of my antennas to have a 75 Ohm feedpoint, so I seldom have use for the matching transformers. I'm not the sort who is particularly concerned about losing 7 or 8 Watts out of 100, but I do like to keep everything running cool and happy, and I find that my feedline matching losses are extremely minimal to nonexistent. You just have to stop thinking of 50 Ohms as being somehow magical and essential, and learn to match to whatever impedance you have to work with.
Well said!
Good video. I use a lot of RG-6. I buy it by the 1000 foot roll and it’s cheap. I also use the compression type connectors with the PL-259 adaptors. Regarding 75 ohm vs 50 ohm cable, it makes insignificant difference on a dipole. The feed point impedance of a dipole varies widely with the height above ground. As the height is varied from very low up to several wavelengths high the impedance varies from very low up through a 50 ohm value and rise to a peak around 90 or more ohms then back down to maybe 60 when it rises again. It oscillates around 75 ohms until at several wavelengths it is essentially damped out to near 72 or 73 ohms. It can be fed with any 50 or 75 ohm coax. To get the minimum SWR with either coax you can usually adjust the length of the dipole above or below resonance changing the reactance ( making it either inductive or capacitive) this changes the impedance such that it can become either 50 or 75 ohms. The impedance is a combination of R and X. So length of the dipole is adjusted until you get a minimum SWR with either 50 or 75 ohm cable. In other words an impedance of 50 ohms with no reactance can become a 75 ohm impedance by simply adjusting the antenna until there is a 55 ohm reactance. The feed point is changed from 50 +j0 ( 50 ohms impedance) to 50 + j 55 and that is 75 ohms of impedance. This would give a perfect 1:1 with 75 ohm cable. This is a case of the minimum SWR not being at the same frequency as the resonant frequency. This is done all the time with 50 ohm cable. We put up a dipole at some convenient height and feed it with 50 ohm cable. The SWR is not what we expected. We trim or lengthen the antenna until the SWR is as low as we can get it, frequently 1:1 but anything less that 1.5 is very good. What we don’t realize is that we are actually adjusting the reactance and varying the complex impedance until it matches the coax.
You are doing pretty much the same thing when adjusting your delta loop differently with 75 ohms coax that with 50 ohm coax. I do want to mention that regardless of the coax type if there is an SWR on the coax, the impedance at the antenna will be transformed to some different impedance at the transmitter end depending on the length of the coax. If the electrical length of the coax is a half wave or multiple of a halfwave then the impedance will be the same as that at the antenna end. On a Smith chart we draw what is called an SWR circle and all the points on the circle have the same impedance but each point had a different R and X value. One revolution around the circle is one half wavelength and brings you back to the point you started with. That’s why the antenna impedance repeats itself every half wavelength of feedline.
I as well as many of my friends have used very large 75 ohm hardline for long runs to our towers for low loss. We start with RG- 8 transition to the 75 ohm hardline underground and at the tower transition back to RG-8 up to the antenna. At one time the cable company near me gave away many leftover reels with only 100 to 300 feet left on them!
That makes a lot of sense. Thanks for the info!
@@kd2wtu72I always recommend the ON4UN Low Band DXing book (Especially the Fifth Edition). Although it is primarily for 160 through 40 meters the info applies to all the HF bands. I have had most of the 5 editions. Excellent books and each edition got better. Some early editions had not so good information in places but the last two editions are really excellent.
73,
N4DJ
excellent presentation. I like that I can use 75 ohn RG6 on a dipole and the match is starting off at 1:1
Thank you!
I have used RG6for my scanners for years. Works great!
Excellent!
many friends used RG6 to wire the Mcmansion in 2000. I get a lot free and might as well use it. I do use RG8X - used. For RG6 I used stnd F connectors and i have a crimper from my coax days in 1990's RG8X I use 239 ends. I am only using 100 watts max. Cheap and functional. You covered it all. thx 73.
Thank you!
My only reason to not have used RG6 for transcieve is its solid copper over steel center conductor with softer foam dielectric separating it from the Shield is in areas of continual flexing (especially like feeding a rotatible dipole, beam...) where failure is more apt to happen, along with its power limitation. And I usually had extra lengths of 8, 8X... at hand. BUT for 100-200 watt SSB and lower power usage into a more fixed Antenna you pretty well covered its benefits at low cost. I have used it several time with RX Antennas with good results, yes with water tight O-Ring'd F connectors and the F to PL adapters.
Thanks for the Video! 🍺🍻
73 mike N4ONL
Thank you!
Great video! As you indicated, not a huge amount of mismatch and as some others have said, plenty of easy ways match things at a particular frequency. I really like the cost cutting approach for home stuff - the challenge of keeping costs down while still getting decent performance is what makes it fun.
Thank you! I agree, I try to keep costs down so I can try out lots of antennas
👍 Good video and some very useful info, thanks. I always thought it seemed odd that the impedance of a dipole is ~72 Ohms, yet hams use 50 Ohm co-ax and the standard output impedance of rigs is 50 Ohms. Though, I do appreciate there are reasons for using 50 Ohms.
When I use that tape trick, I found it easier to wrap the tape on clockwise. This means, when I screw the connector on clockwise, it doesn't tend to unwrap the tape.
I'll try a clockwise wrap the next time I fit a connector. Thanks!
Thank you for the information on using RG6 for feed-line connections. I thought I was doing something politically incorrect in the Ham world. I am financially constrained so, cheap(and sometimes free) RG6 was my choice. And I had a terrible time trying to connect PL259 connectors to it. I tried soldering, not knowing the braid was made of aluminum. And also realized that my SWR wasn't so great - not skilled enough to use an antenna analyzer like nanoVNA wondered why my dips on the display kept going al over the place. I am an OM but a New Ham and I have tons to learn...73
I was not sure just how taboo using rg 6 was in the ham o sphere. It's one of the reasons why I made the video to show yes, it's ok lol. Thanks for watching!
I been experimenting with this and got the same results nice job I'll b back
Awesome I'm glad it worked out for you. Have fun experimenting!
Nice to see the swr ratio since everyone says that a certain type is best but never show testing results.
Thank you!
I used the shield as a long wire from a left in drop after disconnecting cable service. You can make capacitors with lengths of cable TV coax.
Interesting. Yea I've seen people cut coax to length for capacitance. Thanks for watching!
Picked up some quad shield RG6 not to long ago. Going to use it from the shack to the tower. Got it for practically nothing, almost 500ft of it. Great video
Thank you!
Thanks so much for precious information . I'm gonna have one for sure ❤.
Thank you!
Thanks for posting this. 500ft rolls of rg6 at homedepot here in canada is $67 cnd. :)
That's lots of good cheap feedline for lots of antennas. Have fun!
Done this before and plan on doing it again. Never had an issue with HF/VHF/UHF.
It works great. Thanks for watching!
First, love the video, doing things on the cheap is always good. I’ve worked around pay tv and internet for almost 20 years, I’d stay away from pre run cables because of the copper clad. I suppose it depends on which devil you want to face, more expensive coax of higher than normal SWR. Bet no one could tell the difference in an emergency.
Thank you!
Thanks for putting this out there, I was building a coax dipole and pretty much have the measurements to get the same results every time. Used an f connector and saw craziness with SWR. I swapped the connector for a pl259 and so239 and replicated the first two dipoles I built. Your video helped me understand why.
Glad I could help! @texican8441
Let me assure you that using a quarter wave length section of 75 ohm RG6 to transform a delta loop into 50 ohm coax works for me every time. Just finished one for a crippled ham for a 6 meter Delta loop and it tuned up like a dream.
I have a 40 meter Delta loop waiting for a ride to the top of the big tower. It was in use on a lower tower with a 4:1 ferrite transformer and RG400 and was changed to a quarter wave RG6 matching stub to reduce weight, windage, and bulk. The radio could not tell the difference in the two configurations - other than I will not be hitting the RG6 transformer with 1500 watts.
K8DO
That was a good idea, swapping out the balun for a matching stub to reduce the wind load. I should use a matching stub if I ever build a portable loop. Thanks for watching!
I bought 2/3 of a 1000ft box from a home builder for $20.00 on marketplace. I’ve made several receive antennas for different projects. Time to try transmitting with it.
Go for it, it should work just fine!
I bought a 100m roll of VERY HIGH Quality RG6 for $30AUD New Old Stock...to redo my TV antenna runs about 4 years ago. It's connected to 3 separate SDR's, two scanners and an AIRBAND receiver. The SECOND 100m roll I then bought to do my TV's is servicing a second set of 4 antenna's, for transmitting on various bands. I made two flowerpot antenna's for 10/11m portable use, both are 1.01:1 or less SWR on a 5m test feedline of RG58, I run one on a 40m length of RG-213 and I get a 1.05:1 reading on either 27Mhz or 28mhz. the second one on RG6 gives me 1.5:-1.6:1 at the same length. BOTH work perfectly well. For the cost saving, i can live with the 10w power loss i MIGHT suffer at 100m, at my limited 40m length, I get a return loss of under 2w on the RG6. When I run my IC7300 at home, it runs into a 40m length of LMR240 and into a EFHW with a 49:1 UnUn, it shows a return loss of around 1.5w, so not a lot of difference.
During a field test, using 50w power and over a 15Klm distance on 27.305 AM, the signal on the RG213 was less than one S point above the signal on the RG6 at the receive end. Using the same radio, same antenna, just different cable. NOT a definitive test by any means, but a solid result to be sure. The RG6 cable is cheap, works great and is simple to get, you can even buy 30m lengths with connectors fitted for $25 in my local supermarket.....I see mental images of HAM's going in on any given day, buying toilet paper, a toothbrush, laundry detergent and 30m of coax...just a normal days shopping.....
And YES, the TV's are still waiting their new cable runs....time to buy a third 100m roll......
Haha I love that your radios soaked up all that coax and the tv's didn't get any. Your proof is in the pudding, not much difference in feedlines at your station. Thanks for watching !
I’ve been wanting to try this cable for HF.
From my wholesaler, I can get 1000’ of generic quad core for $100-150 aussie.
While I haven’t used it as transmission line, I have used it to make a series of magnetic loop antennas with varying amounts of success.
The cable was from stuff I had left over from some older analog CCTV installs I did last decade.
As far as matching it to an antenna, a simple balun with a 9 turn to 8 turn balun will do it for a 50 ohm feedpoint impedance. On your delta loop, you could use a similar strategy with a turns ratio of 1.6:1. Instead of 2:1
Give it a try I think you will be pleasantly surprised how well it works. I feed my delta loop bottom corner with a 4:1 balun. It works very well, resonant on 20m, and SWR is less than 3:1 on all the other bands so I run it multi band with a tuner. Thanks for watching !
@@kd2wtu72 thank you for taking time to respond
I have a few theories that seem to fit the measurements I have taken of various antennae with the trusty NanoVNA who’s smith chart reveals so much more than SWR.
I am currently working on higher power Magnetic Loop antenna designs, and have what I feel is a somewhat unique approach to a 20m through 40m mag loop that I can take portable and gives an end fed half wave an excellent run for its money. I’ll be making some more sensible videos on it with a friend VK2AOE who has his The Art of Engineering channel. There are some sneak previews of the loop antenna there.
There is a roll of flooded RG11 that has been given to me that I need to test. But again, I am using it as a radiator and not as a transmission line.
I do want to try RG6 with catenary wire as an antenna and see how the diameter affects the bandwidth for your regular dipole. The extra aluminium foil surface area should more than make up for any skin effect resistance, not that that is much of an issue with wire antennas as opposed to mag loops which can be little bundles of incendiary devices when placed under stress :-) I have a few entries in the _Hall of Flame_ to attest to that
DE VK2NAP
Yea man I have been using rg6 for years now, and long ass runs no problem
Yessir! Thanks for watching
I used to use 3/4 inch 75 ohm hard line that I got for free and it was fantastic for the 200 foot runs out to and up the tower.. You should check the price and specs of RG-11 as it will assemble into a regular PL-259 like RG-8.. I used the 75 ohm RG-11 coax cut to 1/4 wave sections on 6 meters to co-phase 2 antennas together with a coaxial T with great success and it was acquired for free as well from the cable TV companies dumpster.. For a time I also had a home made 160 bazooka antenna built with it which I built a home made baulin for..
Rg 11 might be a future video. Thanks for watching!
Since the feed point impedance of a half wave dipole is close to 73 ohms, using 75 ohm feed line works very well !
I personally use RG - 6 Quad shield, and find that the antenna is significantly quieter !
Dipoles are not always 73 Ω due to height and location with nearby objects which is why sometimes a less that 1.5:1 SWR can be obtained as I found out. Mine are in the attic, 5 dipoles 20m to 10m, fairly close to each other and some ends close to the wall.
The radio textbooks show how height makes a difference to the impedance.
G4GHB.
Nice! I should get my hands on some quad shield.
@@kd2wtu72
Indeed !
And you'll pay hardly anything compared to all the high dollar Coax !
As I've said, I've had great luck with it running QRP thru 100 watts !
As to how quiet it is, it was just that , that drew my attention to it !
I thought that I was imagining things !
It got me to thinking just how much noise our coaxial cables may drag in ?
I do also employ an ugly balun at the feed point , probably more from habit than necessity ?
And this was something I was always curious about, and finally decided to use 75 ohm !
Too, unless you choose to do something different, you'll need the appropriate adapters, F type / RCA to PL 259 !
Good luck !
Excellent video Steve.
Thank you!
I gave 30 bucks for 500 foot of good stuff. When you make long runs for reception, it great. If you use it for 160 or 80 meter antennas, just mind you lengths and you’re good.
Also need to check your connections more often. The aluminum sheath does not like to have the pull of the cable on connectors.
You can also use it as the antenna on a reversible beverage.
Good point, I should check my connectors as I've had my run of RG6 up for over a year now. Thanks for watching !
absolutely for wire antennas. RG6 is sexy
Cheap coax for cheap wire antennas. The only thing I run at my station are wire antennas. Thanks for watching !
Well, I have been using RG-6 and RG-11 for years, making Double Boozaha Antennas for 40 meters, and have successfully run the full legal limit.
Thanks this is the info we need to hear: I've tested RG 6 up to 100 W but you have gone beyond.
@kd2wtu72, you can hear me on 7285 TTN and 7935 Gulf Coast, Terex running 1200 watts.
Just 1 additional thing that may hurt you with RG6. The shield isn't made for the low requency ranges your'e talking about. Hence it may leak RF or take on QRM. Most of the times, this should be a problem because leaking in Ham bands while TX istn't problematic and you always want your station in a low QRM environment.... just be aware of that!
I was not aware of that! Thanks for the info
Too many hams are SWR obsesive. In my years I found 2:1 or less works fine. This obsession is a bleed over from 11 meter electronic engineers.
It's great getting a perfect match, but sometimes good enough is better than perfect. I use 9:1 random wires all the time when portable. The SWR for any given band is never perfect. Thanks for watching!
Great video! 🤝
Thank you!
Good enough info and presentation to sub after watching this one video of yours....
Thank you I appreciate that! Thanks for watching
Nice picture of the old AN/FPS 35 tower and sail. Bet I can tell you from that where you were located. BTW, I spent most of my USAF career in Air Defense.
Thank you for your service! The background picture for the slides is my station set up in front of the old tower at Camp Hero state park in Montauk NY. Cool place to do a POTA.
My Brotha!
Eyoooo my man!
I've looked at RG6 and wondered about using it. With 50 Ω coax there's a mismatch anyway at a dipole which is 73 Ω depending on height, location etc.
RG6 puts a mismatch at the transmitter but then the coax matches the aerial. Does it matter?
I think some tests using an r.f. pickup meter at the aerial and one length of RG6 and one of mini 8 both the same length to see if there is a difference in r.f. output is needed.
When I first started on h.f. I did use about two feet of t.v. coax to a tuner for a long wire.
I have attic dipoles each with about 25 feet of mini 8 coax, 20m to 10m bands and an outdoor inverted vee with about 45 feet of coax on the 60m band so no great losses anywhere.
G4GHB.
I'm in no way a RF engineer, but I don't believe it matters whether your mismatch is at the radio or the antenna, I think you will have the same losses. But that sounds like a good idea for a future video. Thanks for watching!
@@kd2wtu72 Thanks for the reply.
73. G4GHB.
Having made my own tcvr and copied a p.a. circuit for 50 Ω, it seems to me I could just as easily use 75 Ω. I used the accepted standard of 50 Ω.
Is a tx output really 50 Ω? Or only thereabout? I don't see how it can be guaranteed to be 50 Ω.
If I use 75 Ω coax and as long as I change the resistors in my Wheatstone Bridge type SWR meter then everything will be 75 Ω, coax, SWR meter, and my dipoles supposedly the 73 Ω textbook value. I'm going to try this.
My FT817 would show a mismatch but I guess that would be because the 817 SWR meter circuit is set for 50 Ω. Could that be altered for 75 Ω?
Are manufactured tx SWR meters set for 50 Ω and nothing else?
But dipoles can't be guaranteed to be 73 Ω either, due to height and nearby objects which is why an SWR of less that 1.5:1 can be obtained. A 75 Ω dummy load on a 50 Ω tx SWR meter shows 1.5:1.
G4GHB.
I'm not sure about altering your equipment but you could definitely "tune" your dipole by connecting a nanovna or antenna analyzer and adjusting the antenna height until you get 75 ohms. Interesting idea, making everything 75 ohms. Give it a try!
Great video simple and very well explain, question for you , where did you buy the Soldering Gun? i love to have one of does, thank you.
Thank you! I bought the butane soldering iron from Amazon. a.co/d/ede9MdO
hello sir, i want to build flower pot antenna for vhf, can you recomend rg6 coaxial cable? is it safe to my 8watts porble radio?
I have not built a flower pot antenna myself, but yes it should be fine to use rg6 to build it. And yes it will be safe for your radio. Good luck with the antenna!
@@kd2wtu72 big tango for your reply, by the way im your new subscriber from phipillipines, keep safe sir extending, 73!
So, I should expect the same out of RG11, which is 75 ohm also. It's a heavier cable and direct bury.
RG 11 might actually have less loss, better performance than RG 6 but I have not messed around with any RG 11 myself. Give it a try !
RG11 is the LMR400 of 75 ohm….kind of :-)
Thanx!
Thanks for watching!
What connecter is that and where did you buy it from? I would like to get some.
I have added links to the connectors in the description of the video, I should have had them in there from the start. The PL 259 to type F adaptors on amazon: a.co/d/atdRGcx The PL 259 screw on connectors on amazon: a.co/d/4JPMqGc Good luck have fun!
@@kd2wtu72 Thank you Sir!
You are welcome!
I have said this in the past, as how many antenna are fifty ohms anyway? Scanners users this is a cheep way to get your antennas away from the noise Also poor CB ops this is also good. How many have a feed line of 100 feet so if your scanner or CB antenna is say fifty feet the loss will be even less
Thanks for watching!
Speaking from experience those twist on connectors are junk, add a little moisture and the connection will degrade over time.
Good idea for a future video I have a few of these connectors out in the elements, maybe a 2 year update. Thanks for watching!