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Post by ytradio on May 7, 2020 19:28:49 GMT -5
I have run across this recently talking to some guys in my general area, and I thought it was interesting. I have a ground mounted receiving antenna located 350 feet from my shack that I have connected with RG-6. I had thought one day of trying to transmit on it but I did not have an F connector to UHF adapter, so it never happened. Talking recently to some fellows, I found out that several of them have been using RG-6 for incredibly long runs and that they were happy with the results. None of them had any idea as to how much loss there was on the feed lines, just that they were able to receive quit well and talk to anyone that they could hear. The lengths are from 800 to 1300 feet of RG-6 and one fellow is running 900 watts on an 1100 foot run.( That's 900 watts into the feed line, watts on the far end, ? much lower for sure.) I personally have not verified any of this but know others who I trust that claim it is in fact true. Talking to one of them 3 nights ago that was giving me an excellent signal for the range, had 900 ft and was running 400 watts. He says that as far as he knows none of these fellows are using a tuner, they have been adjusting the match with length alone. If all this is in fact true, I find it to be a very interesting and cost effective alternative for long runs. Also, later that same night another regular on the frequency that I have not been able to hear before, came in loud and clear with an S-5 on his newly extended RG-6 mountaintop line. I know that the loss will have to be incredible, but locating the antenna in an otherwise un accessible area cost effectively may be worth it. I live in the very bottom of the Ohio River valley, and run 500 watts into a beam. I can drive to the top of the hill 1 mile away with a 40 watt mobile and talk to and hear people that I can not at the base. Antennas like Real Estate are location, location, location. Has anyone else tried transmitting through RG-6?
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Post by ytradio on May 7, 2020 19:56:22 GMT -5
Not sure if this would be correct, but for DX Engineering RG-6 attenuation is 1.1 per 100 ft. But I am not sure if that applies to transmit or just receive. I don't think RG-6 was meant for transmitting, so would that be correct? I am not sure. But that would be 11 db loss on 1000ft. 500 watts in would be about 41 watts out. A lot of loss, but at least it may be 41 watts from a much better location.
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Sandbagger
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Post by Sandbagger on May 8, 2020 20:02:31 GMT -5
Not sure if this would be correct, but for DX Engineering RG-6 attenuation is 1.1 per 100 ft. But I am not sure if that applies to transmit or just receive. I don't think RG-6 was meant for transmitting, so would that be correct? I am not sure. But that would be 11 db loss on 1000ft. 500 watts in would be about 41 watts out. A lot of loss, but at least it may be 41 watts from a much better location. One thing to keep in mind, RG6 is 75 ohm cable. Most 2 way radio systems use 50 ohm cable. Using 75 ohm cable on a 50 ohm system will result in a mismatch, which will introduce additional SWR into the antenna system. I've known people who had access to 1/2" CATV hardline and used it for their radio setups because the very low loss made up for the 50 ohm - 75 ohm mismatch. RG6 isn't all that special though. It is probably comparable to RG8 in loss. I'm curious what the antenna was for, that had the RG6 attached to it (along with a CATV style "F" connector). |
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Post by ytradio on May 9, 2020 20:29:43 GMT -5
The mis match was adjusted by the final coax length according to those who were using it. I personally have never used any 75 ohm for Xmit but did think of trying with the recieve ant once, but did not have the proper adapter. Was sceptical of all this, but did not know since I never tried it.
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Post by ytradio on May 12, 2020 8:24:41 GMT -5
Ok, I guess I have been behind the times. I have been looking at some info on the internet, and the use of RG-6 for amateur and CB radio use is something some folks have been doing for awhile. Something that I did not know. 73 Whitey
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Post by SIX-SHOOTER on May 12, 2020 16:35:19 GMT -5
RG-6 has very Low losses & don't let the fact that it's 75ohms throw you off.You may either use a antenna tuner or make your own matching network & it works great.A G5RV & may other wire antennas use 450 ohm ladder line & it works great as well.
SIX-SHOOTER
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Post by cbrown on May 13, 2020 12:23:10 GMT -5
Any time we'd co-phase antennas we'd use 75 ohm coax feeding the antennas that was fed by a 50 ohm coax coming from the transmitter going into a T connector. And if I remember correctly, RG-6 shielding isn't good for frequencies below 50 MHz.
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Post by ytradio on May 13, 2020 16:22:56 GMT -5
Well that was just it, I had not heard of anyone before this using this low cost coax to transmit with. Receive yes, I use it for that. But thinking about it, back in the old days I remember a lot of us staring out using RG-59 because that was all we had access to. It worked pretty good most of the time but the runs were almost always pretty short (50 feet or less).
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Sandbagger
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Post by Sandbagger on May 14, 2020 16:46:47 GMT -5
Any time we'd co-phase antennas we'd use 75 ohm coax feeding the antennas that was fed by a 50 ohm coax coming from the transmitter going into a T connector. And if I remember correctly, RG-6 shielding isn't good for frequencies below 50 MHz. That's a whole different animal. You need 75 ohm cables in a co-phase harness, which actually works out to be close to 50 ohms at the feedpoint at the "T" connector. |
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Sandbagger
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Post by Sandbagger on May 14, 2020 17:04:50 GMT -5
RG-6 has very Low losses & don't let the fact that it's 75ohms throw you off.You may either use a antenna tuner or make your own matching network & it works great.A G5RV & may other wire antennas use 450 ohm ladder line & it works great as well. SIX-SHOOTER RG6 has a loss of 1.4db per 100' at 50 Mhz. RG213 has 1.3db loss per 100' at 50 Mhz. So unless someone gives you a roll of RG6 and you're on a low budget, it's not worth the additional mismatch (which translates into additional loss) to run 75 ohm cable when decent 50 ohm cable is available. And RG213 is not even at the top of the pile in best loss. LMR-400 has .9db loss per 100' at 50 Mhz. Non-resonant multi-band ham antennas often use 450 and 600 ohm ladder line, because those feedlines closer match the impedance of the antenna. You have to typically run a balun and an antenna tuner to properly match a 50 ohm radio into that antenna system. That's a whole different ballgame. |
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Post by ytradio on May 17, 2020 10:30:19 GMT -5
RG-6 has very Low losses & don't let the fact that it's 75ohms throw you off.You may either use a antenna tuner or make your own matching network & it works great.A G5RV & may other wire antennas use 450 ohm ladder line & it works great as well. SIX-SHOOTER RG6 has a loss of 1.4db per 100' at 50 Mhz. RG213 has 1.3db loss per 100' at 50 Mhz. So unless someone gives you a roll of RG6 and you're on a low budget, it's not worth the additional mismatch (which translates into additional loss) to run 75 ohm cable when decent 50 ohm cable is available. And RG213 is not even at the top of the pile in best loss. LMR-400 has .9db loss per 100' at 50 Mhz. Non-resonant multi-band ham antennas often use 450 and 600 ohm ladder line, because those feedlines closer match the impedance of the antenna. You have to typically run a balun and an antenna tuner to properly match a 50 ohm radio into that antenna system. That's a whole different ballgame. I totally agree Sandbagger, and that is just the point that the fellows using this were giving me for using it, cost. 800 to 1300 ft of low loss 50 ohm would definitely be better, but that would also have been cost prohibitive. This they could afford, and it does seem to be working for them. Even with all of that loss. |
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Post by peacemaker656 on Oct 30, 2020 1:01:09 GMT -5
Im curious as to what band or frequency you guys are using. Im going to assume for now given one guys running 900watts that its an HF frequency. I can't see modern transistorized hf ham rigs or export radios or cb's or transistor amplifiers lasting very long on that set-up without a tuner. Tube amps might and I stress might be able to tune to work there but it would be hard on them. You can still buy rg58 cheap which I think would be a much better option. Yes its lossy but its going to keep you in tune. A F connector isnt rated for 900 watts either but I will assume they are probably using PL-259's to hook up the transmitters? An F connector would fail quick with that amount of power. Common mode currents would be out of sight. Id sure like more info.
73's
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Post by ytradio on Nov 5, 2020 20:52:41 GMT -5
Im curious as to what band or frequency you guys are using. Im going to assume for now given one guys running 900watts that its an HF frequency. I can't see modern transistorized hf ham rigs or export radios or cb's or transistor amplifiers lasting very long on that set-up without a tuner. Tube amps might and I stress might be able to tune to work there but it would be hard on them. You can still buy rg58 cheap which I think would be a much better option. Yes its lossy but its going to keep you in tune. A F connector isnt rated for 900 watts either but I will assume they are probably using PL-259's to hook up the transmitters? An F connector would fail quick with that amount of power. Common mode currents would be out of sight. Id sure like more info. 73's Well, the fellows that were telling me about it were talking to me on 27.395. And they were giving me a great signal for the distance. The connectors were Belden compression F connectors screwed into F to PL259 adapters. Since the original post I have tried this on my ground mounted receiving antenna, which is an 8ft stainless whip, using the same connectors. It is a 350 ft run, and I was amazed that I was seeing almost a 1 to1 swr on 11 meters. Signal coming out left a little bit to be desired but it was a good match. Then one night I connected a 60 ft wire to the base of the whip, and the other end to the gutter on my garage, and talked all over the eastern US on 80 meters. It did a better job than my ladder line fed 80 meter inverted L, because of the NVIS I am sure but still did better. And it also handled 500 watts in. I know that LMR400 and Andrew Helliax 50 ohm would be FAR superior to RG-6, but the guys who made these incredibly long runs were not about to put out that kind of money, and this did seem to work for them. And I have now seen it work for myself. Am I going to replace my good coax with RG6? Hell no, but I also am not having to buy several hundred feet to get my antenna to a workable location. As far as the power rating for an F connector goes, I don't know that F connectors are even rated for transmit power at all. But like ALL connectors, I am sure that they will handle the amount of power that it takes them to breakdown and fail. |
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