Posted: 11/17/2015 6:41:39 AM EDT
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..what are you guys using/recommend? Trying to order some stuff to get my FT 857 Set up to use... still waiting on call sign... I want some good quality cable that won't break the bank... I am looking at some MPD Digital RG-213 but at $89 for 75 feet is kinda putting a kink in my budget.... What say you guys? WP 73 |
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Only 75'? RG-8X isn't bad at all.
Here are two loss calculators. When using them remember that 1 db is the smallest difference, louder or softer, that the human ear can hear in lab conditions. That's headphones in a quiet studio, playing pure tones, which one is louder? http://www.arrg.us/pages/Loss-Calc.htm http://www.qsl.net/co8tw/Coax_Calculator.htm 3 db is more of what most people can hear in average conditions. Does your stereo have a volume knob with clicks? One click is about 3-4 db. And 3 db is what is heard with a doubling or halving of power. 6 db is the accepted figure for 1 S-unit, and is what is heard with a quadupling or 1/4 of power. Let's plug in some real numbers, using the first calculator (but it won't matter which one). Using 75' of RG-213 (82678) and a 2:1 SWR at 14.200 mhz, 100 w input, you get -.56 db from match loss and -.122 db from SWR, total -.681 db, for 85.5 watts out. That's less than one db, and no one will hear that tiny bit of loss. That's about as good as can be done. Now let's try again, but change to RG-8X (9258), making that change only, click Calculate. Now you get -.821 db match loss, -.168 db from SWR, total -.989 db. And 79.6 w out. 5 watts output difference. As compared to the RG-213, total difference .989 - .681 = .308 db. No one would hear the difference. Hint: The higher the frequency, the greater the loss for a particular coax type. It's not until you get up to VHF and UHF frequencies that coax makes a lot of difference. Order 100', save the other 25' for making jumpers. About 35 - 39 cents per foot. I get mine from Universal Radio. |
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What type of antenna do you plan on putting up?
If you have a wide range antenna tuner, a dipole fed with open wire or ladder line gives good bang for the buck. The SWR gets really high on some bands, but the loss is so low with open wire feeders that it's not a problem. Other options are Off-Center-fed Dipoles, Fan Dipoles, and trap dipoles. A 43' vertical works sell, but requires ground radials. For these, you'll need 50 Ohm coax. The Wireman is one good source of coax, antenna wire, and accessories. |
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Ok... wow.. I am going to be running a FT-857D with a LDG z-100 tuner. Starting out I will probably be on some sort of a DIPOLE antenna and I am looking into building a NVIS Antenna that replicates an AS-2259. I plan on setting up to be a portable field rig... Will be running on battery power most of the time. 75 feet is what I estimate it will take to get me to the side yard.... I plan on running HF and some V/U stuff but that is not what the intended purpose of this radio is... mainly HF... WP |
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Quoted:
-snip- I plan on setting up to be a portable field rig... Will be running on battery power most of the time. 75 feet is what I estimate it will take to get me to the side yard.... I plan on running HF and some V/U stuff but that is not what the intended purpose of this radio is... mainly HF... WP ahh, definitely go with the good quality rg-8x then. rg-8 'size' coax (flex or not) would be a trade off for the bulk/hassle/weight to db gain ratio on a portable setup :) 'monkey |
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ahh, definitely go with the good quality rg-8x then. rg-8 'size' coax (flex or not) would be a trade off for the bulk/hassle/weight to db gain ratio on a portable setup :) 'monkey Quoted:
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-snip- I plan on setting up to be a portable field rig... Will be running on battery power most of the time. 75 feet is what I estimate it will take to get me to the side yard.... I plan on running HF and some V/U stuff but that is not what the intended purpose of this radio is... mainly HF... WP ahh, definitely go with the good quality rg-8x then. rg-8 'size' coax (flex or not) would be a trade off for the bulk/hassle/weight to db gain ratio on a portable setup :) 'monkey I'll second this for portable use. |
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Yeah some flexible (stranded center) RG-8X type would be a good choice for that application. The Wireman #118 is a pretty good option, but almost anything will work fine on the lower freq HF bands.
Quoted:
I am looking into building a NVIS Antenna that replicates an AS-2259. I plan on setting up to be a portable field rig... If you're going to do a replica of the AS-2259, change the element lengths to be resonant on the amateur bands instead of duplicating the military lengths/bands. |
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Quoted: Yeah some flexible (stranded center) RG-8X type would be a good choice for that application. The Wireman #118 is a pretty good option, but almost anything will work fine on the lower freq HF bands. If you're going to do a replica of the AS-2259, change the element lengths to be resonant on the amateur bands instead of duplicating the military lengths/bands. Quoted: Yeah some flexible (stranded center) RG-8X type would be a good choice for that application. The Wireman #118 is a pretty good option, but almost anything will work fine on the lower freq HF bands. Quoted: I am looking into building a NVIS Antenna that replicates an AS-2259. I plan on setting up to be a portable field rig... If you're going to do a replica of the AS-2259, change the element lengths to be resonant on the amateur bands instead of duplicating the military lengths/bands. |
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61 to 65 feet for 80 meters depending on where in the band you want to be.
about 33'6" for 40 meters. In a multi-dipole aka fan dipole, the higher frequency elements end up longer than normal. These lengths are somewhat longer than the traditional design but should give you improved performance. You could shorten them with some loading at the cost of bandwidth and efficiency. Instead of arraying the elements 90 degrees apart, try 60/120 degrees. This will give you a better impedance on frequencies higher than the resonant dipoles as the antenna will start to function as a sort of biconical antenna, if you would need higher frequencies. |
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Thanks for the heads up... I got a design for one that is made by a ham but I will make sure my info is correct... Quoted:
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I am looking into building a NVIS Antenna that replicates an AS-2259. If you're going to do a replica of the AS-2259, change the element lengths to be resonant on the amateur bands instead of duplicating the military lengths/bands. Gamma speaks the truth: if you see element lengths of 25' and 38' without loading coils, it's a direct copy of a military antenna for military frequencies. This is dead wrong, avoid these. Some examples: Wrong: http://www.marc.on.ca/marc/ares/documents/NVIS_2040-80_20antenna.pdf Wrong: http://www.fracassi.net/iw2ntf/manuali/Homebrew%20AS-2259GR%20NVIS%20Antenna.pdf Wrong, but fixed with loading coils. Includes coil construction details: http://arrl-ohio.org/SEC/nvis/Modified%20AS-2259%20NVIS%20Antenna.pdf If you have the room, use the lengths Gamma gave you and profit. As an added benefit, you can tune the antenna to be resonant: no tuner required, which can save your butt if your tuner takes a dump in the field. If you don't have the room for a full 80m leg, make the 40m legs resonant and use the Coil+38' legs from that third link. Edit: forgot to address OP's first question. RG-8X is fine for this application. A pre-assembled LMR-240 Ultraflex cable from MPD would be even nicer and easier to work with, but would more than blow the budget. No sense using the -213 size cables in this application, save that for VHF/UHF work. |
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Quoted:
Only 75'? RG-8X isn't bad at all. Here are two loss calculators. When using them remember that 1 db is the smallest difference, louder or softer, that the human ear can hear in lab conditions. That's headphones in a quiet studio, playing pure tones, which one is louder? http://www.arrg.us/pages/Loss-Calc.htm http://www.qsl.net/co8tw/Coax_Calculator.htm 3 db is more of what most people can hear in average conditions. Does your stereo have a volume knob with clicks? One click is about 3-4 db. And 3 db is what is heard with a doubling or halving of power. 6 db is the accepted figure for 1 S-unit, and is what is heard with a quadupling or 1/4 of power. Let's plug in some real numbers, using the first calculator (but it won't matter which one). Using 75' of RG-213 (82678) and a 2:1 SWR at 14.200 mhz, 100 w input, you get -.56 db from match loss and -.122 db from SWR, total -.681 db, for 85.5 watts out. That's less than one db, and no one will hear that tiny bit of loss. That's about as good as can be done. Now let's try again, but change to RG-8X (9258), making that change only, click Calculate. Now you get -.821 db match loss, -.168 db from SWR, total -.989 db. And 79.6 w out. 5 watts output difference. As compared to the RG-213, total difference .989 - .681 = .308 db. No one would hear the difference. Hint: The higher the frequency, the greater the loss for a particular coax type. It's not until you get up to VHF and UHF frequencies that coax makes a lot of difference. Order 100', save the other 25' for making jumpers. About 35 - 39 cents per foot. I get mine from Universal Radio. what a year ago when I ask about coax. RG8X was shit"" if you wrent running lmr400 for jumpers and 5/8 hardline your shack was shit???? |
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A pre-assembled LMR-240 Ultraflex cable from MPD would be even nicer and easier to work with, but would more than blow the budget. I'm avoiding LMR-240UF anymore. The jacket is so rubbery that it doesn't support the braid at all, and the braid breaks at connectors. I've seen failed cables from this. The center conductor on the Wireman 118 is a much finer strand for more flexibility, and the jacket is better IMO. |
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what a year ago when I ask about coax. RG8X was shit"" if you wrent running lmr400 for jumpers and 5/8 hardline your shack was shit???? Last year the coax lobby was paying out in HRO credit or ammo. This year the SDR lobby is kicking their butts with free kittens and bourbon. |
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Thanks guys for all the info... I am probably going to order 100' of RG8X cable and some connectors then cut it how i need it then put it together and use the extra for jumpers and the sort like suggested.... Thanks again for all the help... WP 73 Still waiting on that damn call sign... and working on power... I have ordered 2 12ah AGM batteries... some Anderson powerpols... some 10ga wire... I plan on putting it all in a box. I still need to figure out what charger I need.. Soon I will get a Solar Charge controller and some 100W panels... Its a process getting started getting the license is the easy part... WP |
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Last year the coax lobby was paying out in HRO credit or ammo. This year the SDR lobby is kicking their butts with free kittens and bourbon. Quoted:
Quoted:
what a year ago when I ask about coax. RG8X was shit"" if you wrent running lmr400 for jumpers and 5/8 hardline your shack was shit???? Last year the coax lobby was paying out in HRO credit or ammo. This year the SDR lobby is kicking their butts with free kittens and bourbon. QSL lol 
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Quoted:
what a year ago when I ask about coax. RG8X was shit"" if you wrent running lmr400 for jumpers and 5/8 hardline your shack was shit???? Quoted:
what a year ago when I ask about coax. RG8X was shit"" if you wrent running lmr400 for jumpers and 5/8 hardline your shack was shit???? That's always been the arfcom way, gotta save 0.5dB in line loss on the cable run to a negative 5dB gain antenna. Quoted:
I'm a big fan of LMR-400. You can find some really good deals on it if your search around. LMR400 is a great product when used within its limitations. It should never been used for portable use or any application where it's subject to be flexed around. |