Using cheap Cable TV Coax for Ham Radio
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- Опубліковано 25 січ 2025
- In this video I detail how I use regular ol' 75 ohm, RG 6 Cable tv coax for my amateur radio station, and the pros and cons of doing so.
Link for PL 259 to Type F adaptors on amazon:
a.co/d/fKAFRQv
Link for PL 259 screw on connectors on amazon:
a.co/d/bAgmEZV
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
Why aren't you teaching this on UA-cam or elsewhere? That has to be one of the easiest to understand descriptions I've heard yet.
@@kd2wtu72Okay. Good enough for the girls I go out with... But... impedance is always a 'combination' of resistance and reactance...even if the reactive part is zero... and has units of ohms. If the reactive part of an 'impedance' is zero... you are talking about pure resistance. For a dipole antenna...at resonance...of the at the frequency it was designed for, the dipole antenna's feedpoint..is purely resistive... 73 ohms... and that is known as the 'radiation resistance;. Saying "50 ohms with no reactance can become a 75 ohm impedance by simply adjusting the antenna until there is a 55 ohm reactance' does not make sense. It confuses resistance, and impedance... which are not the same things. You can change the radiation resistance of a dipole antenna... bringing it off resonance... by adding, or subtracting... to or from, the length But this also changes the impedance, and make the feedpoint reactive. You can cancel the reactance introduced when a dipole antenna is off-resonance by using external tuning methods, such as a tuner or a stub. The characteristic impedance, not just impedance, of an ideal coaxial cable is purely resistive and depends only on its geometry and dielectric properties.
Real-world cables introduce slight reactance due to imperfections, but these are typically negligible for most practical applications at RF and microwave frequencies. The longer the cable, the more those 'imperfections' matter.
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!
I have been using a bunch of RG-11 (also 75 ohms) for years. This is the larger cable which looks something like RG-8. I got three free reel tailings from a residential construction job. Great stuff!!! No major performance difference between RG-11 and the 50-ohm stuff. The best part: A PL-259 will spin right on to RG-11. No adapters or tape needed. Just make sure you fold the 'drain' wires back over the jacket before installing the connector because the wires are steel and you cannot solder to them. Solder to the center and you are done!
By the way, hams were using 75-ohm coax long before 50-ohm coax was available. I have an old SWR meter which has a switch to select between 50 and 75 ohms.
P.S. I still use 'real' copper braid RG-59 too. You can still buy it. But you need an adapter to solder it to a PL properly. 73!
Very cool, I want to test some RG 11 next. Thanks for watching!
On your technique of screwing the PL-259 over the braided-end, many half-baked keyboard-warriors will chastise for using this technique, claiming that the connection will corrode, deteriorate and fail--even causing you house to slide off its foundation!
Well, I have been doing this for nearly 60 years and every time I take one of these apart, the connection is just fine with shiny copper braid-strands; this means that there had to be a 'gas-tight' connection!. This includes all the connections I made up on my tower back in 1988 without a single failure! So, this is just fine, but there are a few tips:
First off, you do have to have a tight-fit without cutting the strands, but this is usually never a problem. Next, I use Coax-Seal (and we also have the same people complaining about this excellent material!), that I hand-mould over the finished connector and coax as an additional seal (however for many years I never had Coax-Seal or even used electrical tape!). I like Coax-Seal because if you will clean the outer surface before you open the connection, you can actually re-use then Coax-Seal. I have some of it that is 40+ years old and it is still pliable--just keep it clean! Finally do fill the center-conductor with enough solder to 'plug' it to keep ny moisture out of the center conductor.
Cable-TV coax is great stuff and will work in most all situations unless you are going full QRO! In fact, Doug DeMaw made a matching transformer (radio---50-ohm coax---75-ohm matching-xfmr--antenna) for a Delta-Loop that we build, which had excellent SWR across the whole 40-meter band without using a tuner! This antenna survived for 30+ years before a large tree came down and obliterated it--all of the connections were still just fine, even laying on the forest-floor the whole time!
Great video and community!
73...
Thank you !
Excellent example of using the best you can afford and is available too. Examples such as this are useful for expanding the hobby to people on a tight budget. It's also could be useful in emergency situations when the "good stuff" isn't readily available. 73
Thank you!
Great tutorial. I've used inexpensive RG-6 coax to feed my monoband dipole for years. Never a problem. One could also get a better match by making a RG-58 (or RG-8X) and RG-6 impendance transformer...easy project.
Thanks for watching!
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!
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!
I have read 5hat RG6 is great for receiving antenna. You mentioned loop on the ground. Scanner fans can use it to connect to an outside antenna.
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!
While a simple dipole in free space is around 70 ohms , the impedance will vary a lot when near the earth ( say less than 1 or 2 wavelengths. Often lower than the 70 ohm impedance so you get a low swr with 50 ohm cable. In reality if a dipole is 70 ohms and fed with 70 ohm cable the SWR will be 1:1 instead of 1.5:1. However if measured with a 50 ohm bridge like most hams have it will not show that 1: 1 but another SWR.
The 50 ohm cable mostly comes from an old standard in that it handles the most power for coax with reasonable loss. The 70 ohm cable has lesser loss for the same outside diameter cable so works well for receiving or transmitting at lower power levels.
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!
Very well done sir. Clear, concise and encouraging! Keep up the good work. 73 OM
Thank you!
I have used RG6for my scanners for years. Works great!
Excellent!
Great video, note that a dipole has an impedance of 72Ω making RG6 a better choice than 50Ω cable. I use RG6 for a 20 meter vertical dipole that is hung from a tall tree, it provides great DX, N2SN.
While in free space the dipole may be 72 ohms most dipoles for frequencies below 30 MHz are near the earth and the impedance may not be near 72 ohms, often lower and may be closer to 50 ohms. Your 20 meter vertical may be close to 72 ohms but if you measure the SWR with the common ham swr meter the swr will not be accurate for what is really on the coax.
@@ralphmowery2898 Thanks for the very good advise. My vertical dipole seems to match very well with a 1.4:1 ratio. I don't use low dipoles due to limiting one's only working non DX stations. I do however have an end fed cut for 80 meters that allows me to run on 80 through 10 with a usable but far from perfect SWR. It runs about 90 feet vertically to the top of a pine tree and the rest of it goes horizontal to another pine tree. I have worked three UK stations from here in NE Florida on 75 phone very late at night - early morning on SSB with 100 Watts. I have also worked VK, ZL, ZS and many other countries on other bands with my IC - 7300 running just 100W. Thanks again for your advice, I am always trying to learn something, Dave, N2SN.
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!
I've used RG6 for receive antennas for years. I just recently got a length of RG-11 and may try it with a 2:1 or 4:1 balun.
I have been a cb operator for years and I make my own wire antennas and I use RG6 coax works great my swr is 1.1 to 1.3
When I was first starting in ham radio ages ago, my dad had some partial rolls of RG-59 (75 ohm) given to him by the local cable TV company. We used this stuff to feed a dipole antenna that served as my one and only HF antenna for many years. I ran 100w CW from an ancient 6146-based tube transmitter and a homebrew antenna tuner. I never had any issues with power handling, and given that RG-58 is markedly inferior to RG-6 in all key performance metrics, I wouldn't hesitate to run that same amount of power (or even a bit more) on RG-6.
If the cost or availability of coax is standing between you and getting on the air, RG-6 is a perfectly acceptable approach to get past that hurdle.
My feelings exactly. Thanks for watching!
I think that rg59 has slightly lower loss than rg58 but not enough to make any difference.
Thank you !!
I have a basement filled with RG-6-Quad Shielded cable and RG-11 direct burial cable.
About 10k feet of the RG-6 & 4k feet of the RG-11.
My only dilemma = Most of my work is in the VHF / UHF ranges.
I’ve used RG-6 for receive antennas only for decades and it works well.
Wow that is an absurd amount of coax!
@@kd2wtu72 I was “hired” at a rate of FREE to pre-wire all of my siblings homes. That’s just the leftovers after 6 homes.
LOL
Thanks for your channel + videos Sir!
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 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!
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 !
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!
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!
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
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!
Have you just cut 75ohm coax to a 1/4 wave and solder it in or do you trim for velocity factor?
Interesting. I have been licenced since 1978 and have never tried 75 ohm. I will some day because I like home brew wire antennas so length isn't a problem. THANKS from Niagara on the lake Canada
Thanks for watching!
Excellent video Steve.
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!
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
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.
It appears to me that rg6 is a low loss cable able to maximize signal strength over long distances.
The only question that remains is to whether there is a BNC connector to fit rg6 directly, or to use the F connectors and use adapters. I've used 75 ohm BNC connectors for work before but I don't recall what cable I used.
Most antennas, both commercial and homemade, can be adjusted (trimmed) to match up with 75Ω coax just fine. I have been using RG6 for many years, as it is MUCH lower loss than RG8X, usable even on 440 on moderate (50') runs. However, don't use any solid center conductor coax on sections that move, such as around rotors.
I generally use BNC compression fittings (specific to the cable), as they are weatherproof and can easily handle 100W.
Good stuff, thanks!
Problem is that most hams will not have a SWR bridge that is calibrated for 72 ohms. The 72 ohm cable is fine if you do not really care about the SWR on the line and use something to tune out the mismatch at the transmitter if needed. I have no problem with using the 72 ohm cable.
@@ralphmowery2898 If you use a standard 50 ohm SWR meter, connected to the rig with a 50 ohm jumper, you'll be fine.
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 !
At one time radios transmitted on 75 ohm coax. If so, wht the change to 50?
There are many types of feedlines that hams should consider, but are too narrow-minded to consider it. I use the little-known SMR-240 which uses SMA on one end (to get through the hole I drilled in my window casing) and PL-259 on the other. I've run up to 1KW with it. I have zero issues.
Many years ago there was a ham who came to the Dayton Hamvention who made and sold Baluns ( or were they .ununs? ) that allowed operators to use the 1 inch aluminum trunking cable for CATV systems. This cable was available very cheap ( sometimes free ) from your cable TV supplier. Short leftover runs from a trunk instal were useless to the CATV systems operators.
These devices were used to match the 75 ohm cable at both ends to the 50 ohm output of the radio to the 50 ohm input to the antenna. I do believe these were frequency dependent to the HF bands and I am not sure if they were custom made to work with specific portions of the HF bands. Anyone have any info on these items?
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.
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 !
Thanks so much for precious information . I'm gonna have one for sure ❤.
Thank you!
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
Yea man I have been using rg6 for years now, and long ass runs no problem
Yessir! Thanks for watching
I look at it like this. If it is something as easy as better transmission line that will give me a better signal, that is very cheap gains! All these losses add up in the end. I guess if you are mainly running sub audible modes, then it's probably no big deal. If you need to get a good signal out to be heard than maybe not. If you were in my area, I would give you some better coax! haha
I will absolutely accept coax donations lol. I'll make a comparison video. As far as usable signal, I make it down to Brazil and across the Atlantic SSB phone regularly. If the losses are adding up, its not adding up to much. Thanks for watching!
Provided the role of the feedline as an impedance transformer is understood, then use what you like.
Thanks for watching!
It’s always better to match the impeadance of source to load, if saving a couple bucks is extremely important I guess… personally I think I’ll stick to best practice engineering and be out a few more bucks and know it’s built correctly… Appreciate the info 73…
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!
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.
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 :-)
Good enough info and presentation to sub after watching this one video of yours....
Thank you I appreciate that! Thanks for watching
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!
I'm a 1.7,1.8 guy myself but splitting hairs I suppose. I like to keep the reflected power down without paying that much attention to the actual swr. Those $400
finals in a 706 will make you that way. Probably non existent now.
Great video! 🤝
Thank you!
RG6 specs vary wildly by manufacturer.
That's true
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!
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!
My Brotha!
Eyoooo my man!
What's up homie @@kd2wtu72
i used for CB station and wold talk over most ruining a small amp. thy used r8x vs me rg6! i used 1/2 wave multipls to see the right impedance at radio.
We know that receive antenna coax preforms best at around 73 ohms. Transmission antenna coax performs best at around 37 ohms. 50 ohms is a compromise. So, why is that? It boils down to power handling and Ohm's law. At 37 ohms, there is half the impedance so you can transmit twice the current at the same voltage, hence twice the power. At the receiver, twice the voltage helps, so 73 ohms is better. However, for transmitting, high voltage is not a good thing, it stresses the dielectric in the coax and brings us closer to arcing. Increasing the dielectric adds nothing but cost and weight to our setup. If you are running a kilowatt rig, you want the bigger, low loss coax. Power costs money and a kilowatt spins the utility meter. Is there a disadvantage to RG6 for QRP? Remember, high voltage is not a concern. The in between power ranges are a judgement call.
Interesting video but I’ll stick with RG213.
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!
Thanx!
Thanks for watching!
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
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!
Glue lined double walled heat-shrink ;-)
Radio is dead because you need thousands to millions to get into the hobby
Find a local radio club I'm sure they will get you on the air for free!
You obviously didn't listen to the HF bands this weekend if you think radio is dead. Oh, and I've worked the world with a radio from the 80s that i paid $100 for, made all of my antennas from scrap materials, and the only other expenditure was coax (another cost you could avoid by watching this video). This hobby is only expensive if you think you need brand new equipment, manufactured antennas, and an amplifier. You've given up before you've explored all the options.
wow he hasnt a clue.. dang... no clue at all
That's a lot of power to lose. 100 watts in a 200 foot run of RG8X gets me 90 watts out the other end at 14.250 MHz. Your looses are extreme to say the last. Will your class work, ya, but not very well.
100 watts is 20 db over 1 w or 20dbw ,80w is 19 db over 1w or 19dbw , 90 watts is somewhere between 19 and 20 db . The human ear needs 1db minium to hear a difference.
I suggest the difference between 100w and 80 watts is marginal at best ?
Yes, under certain circumstances but in others you may want every watt you can eek out. Thanks for watching!
Ouch. I thought this show had a solid way to convert impedances, that we could copy. I learned nothing here.
Thanks for watching
I've used rg6 for years. safely used with 1kw on HF with no heating, but that will vary from manufacturer to manufacturer.
6 is best in a noisy environment, it is 100% shielding as opposed to the 95-98% of RG8 series.
Use a crimp connector for RG8x on these, same dimensional specs. *OR* rg6 with copper braid and aluminum shield can be found. As well as you can use UG-176 reducers
Dipoles are naturally 73 ohm, so a better match than rg8 series of coaxes,
Don't use transformer for the 75 to 50 ohm mismatch, you lose more power in the transformer than the mismatch. besides, worrying around a 1.5:1 swr is only paranoia.
Sounds like some good advice, thanks!