Ham Radio Q and A Episode 2: Selecting Coax Cable
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- čas přidán 21. 07. 2024
- www.jpole-antenna.com/2015/07/...
What type of feed line cable should I buy for my antenna system. What connectors should be on the cable?
Links and Resources:
Feed Line Attenuation Chart
www.jpole-antenna.com/faq/coax...
Cable Experts
www.cablexperts.com/cfdocs/ind...
The Wire Man
www.thewireman.com/
I never hear anyone mention the cut-off frequency of coax and how it applies to it's diameter. You are very good with all the videos you do and I compliment you for that.
Sincere thanks from Appleton! Just passed both my Tech and Gen test in one shot and... which means I am totally new to most of this stuff. Yet am very anxious (read: impatient) to get started with my privileges on HF! Your j-poles and videos are helping me greatly. Thanks for being my CZcams Elmer!
Ah, this is quite helpful. I appreciate that you also discussed connectors. I was confused about SO239s and PL259s; now I understand that they are basically the female and male versions of the same thing, respectively.
Great video. I would mention again that cable length is SUPER important in VHF/UHF. Beyond 25 feet the losses become intolerable with something like RG58 or RG8x. Time to step up to some RG8, LMR400 or RG213.
Brilliant video again Michael👍
I think it is worth considering not just the frequency and length of cable but also the use it is being put to, many years ago I was active on 2m packet radio. The radio was more than powerful enough and I was on top of a hill, there was no need for a "hot receiver" or maximum ERP, quite the opposite, of course for 2m SSB the requirements are different...
Thanks, Michael. I appreciate your comments.
Thanks. I'm trying to plan my VHF/UHF setup. Got my tech a couple weeks ago and want to do it right the first time.
Thank You for this information. I'm getting ready to buy my first length of cable and your video was very helpful.
Very informative video thanks - I'm planning a new station and and am considering a high quality cable run to a junction box that I could then connect forward from to the various aerials I am planning. Do you think the junction box would cause any loss / problems if I used the best components and cable connecting from it to the aerials to follow?
Great explanation Michael
Great video. I am using 75 feet of rg213u on my 2m/70cm colinear. Dose the U imply UHF?
Question please... I will be putting up an Eantenna lfa5. The gain is 11.1 and the coax run is 75 feet. Using the chart in your excellent video, if I use RG-8X, the loss would be 4.7 X .75 = 3.5Db. I realize something like LMR400 would be the ideal, but am I totally wrong to call the trade off acceptable?
Can I use a short piece of a different type of cable say after a lightning protector near the end of the antenna?
Ham Radio Q & A Episode 2: What type of feed line should I buy for my antenna system. czcams.com/video/FOtbpdh0D-E/video.html
I’ve installed a silver rod antenna on a 10ft mast with 65ft coax. My problem is what ever I do with my antenna I still have got a high SWR everything is brand new. I just got no idea what is wrong
Great Video! Very usefull understandable information. As you pointed out early in this video, A persons Ham Radio Station is really as good as the Cheapest link in the system. I will try to get the most low loss coaxial cable I can for sure!
How about BNC connectors ? Thank you
Excellent video! Thanks.
Very informative! Thanks!
i have 75 feet of to run to the antenna to my SWR and power meter but i only have rg58 or rg 8x to run to my lener and radio . how well would this affect the swrs . or sould find some other cable for the meter and lener
The best cable I have found is Andrew Heliax LDF4-50A 1/2" can be found cheap on eBay the connectors are cheap also easy to install. I use a dremel to do the cutting or you can get the cutting tool off eBay for about $20. I found LD4f-50 for about 125 feet for $143.00. There is a guy on eBay selling UHF connectors that work on LD4F this coax is amazing 100 feet at 100 MHz loss is 0.815 lower then 1 DB at 1 MHz its 0.205 loss. IT's not the most flexible but for a base station its fine I had no problem bending it.
Great channel I've now subscribed 🤘
Will RG8 MINI be okay for jumpers (3 to 6 feet) for 2m,70cm and 1.25m?
Hello I have a section of chain link fence rail (18' 4"). Can I use this for a J-pole mast? Also, I have 50 ft. of rg8x for feed line.
This is an old post, but that's exactly what I used for my Bilal antenna farm in when I lived in an apartment. When not in use the mast and antennas were laid on the deck, then socketed in a mount on the rail while operating. Worked great.
Question ?? I'm having to replace my coax cable on our marine/ais radio . My question is how do I measure the cable in feet with out screwing it up ? Every 3 feet or every 1.5 feet ? I'm going to drop in west marine and pick up a super good coax and do my own ends myself but unsure on my limits . I really don't need anymore than 6 feet and tired of picking up junk coax . This coax will be going on our small boat with a 3db antenna and a Standard Horizon 25 watt radio . Might not sound like a big deal but for some reason every time we are in this boat something always goes wrong near by and we are talking from Myrtle Beach SC to Charleston SC coast guard . It would be nice to know I'm doing every thing possible to send information.. Thanks !!
As I was taught. Your antenna is 90% of your system. That includes the feed line. Hardline is the best, next is LMR-400 and crimp connectors.
Would you buy a $ 800.00 Flat screen TV and connect it to a set of rabbit ears?
I have used LMR400 for microwave due to loss issues. Not cheap is right!!
You answer a few questions I have thanks
great video! What about rg-214 for 70cm repeater? I've heard that this is good also?? I will be using with a steel j-pole 25' run. Motorola m1225 repeater.
thanks
d
RG-214 has 5.5 db of loss per 100 feet at 400 Mhz. I think it would be plenty good for your 25 foot cable run. It has the advantage of being double shielded, which is a good thing for repeater use, especially if the repeater is located in a high RF environment. But there would be better choices for a 70cm repeater if low loss and long cable runs are your concern.
Thank you so much for this video. Is the LMR400 too stiff and thick? I am trying to set up an antenna in my attic or roof and run the cable thru the inside of my wall into my radio in the second floor. Would it bend enough or not?
LMR400 is about .400” or 10mm thick, and it’s quite stiff. There is a minimum bend radius, which I don’t recall, but it’s specified in the spec charts online. It’s not a super tight radius. It’s going to be some struggle to bend it 90 degrees within a typical wall, either in a conduit elbow or to fit a wall-mounted feedthrough connector. LMR has an expanded foam dielectric that’s fairly soft, so bends must be gentle to keep the center conductor actually centered within the shield. There is an LMR400 ultraflex that has a stranded center conductor. It’s more flexible.
@@PeopleAlreadyDidThis thank you! I posted this a while back. Since then I was able to pass it thru the wall of my house without much of a problem with the bends😊
Hi KB9VBR DE E23GNP from THAILAND. May i say something please. l would like to build 2 meter antenna on top my car and i have rg58 coaxial cable .and i wanna to know. How long cable to use ? Sorry about my poor language .Thankyou .73
i cant find a 50ohm cable so how to make a balun
On a wire dipole fed with coaxial cable, does the feed line have to hang straight down to earth, or can I bring it down a few feet, then turn at about 90 degrees and run it through the trees?
+Steve Tomlinson The feed line doesn't have to hang straight down, you can certainly pull it away from the antenna at an angle. The feed line doesn't radiate, so it's orientation won't have an effect on the antenna.
+Steve Tomlinson Thanks for the quick reply..
Ha ha I was gifted a 1000 ft of rgu 58 u . Verry good for good runs for 25-50 foot runs. Rgu 8 u is better. I get that however the military surplus claimed they have better is that right. If so what is the noumclatere.?
can i use rg59 to baofeng uv 82
WHAT IS THE MAXIMUM WATTAGE HANDLING FOR RG-213 AT 24 MHZ TO 29MHZ ?
Great video.
What would you recommend for an online retailer to buy LMR400?
I usually purchase my cable from MPD Digital: usacoax.com/
Great tip. Thank you.
New to radio, I'm going to be buying a house soon and plan on wiring the entire thing with CAT6 and RG-6 or RG-11 for tv and stuff.
Can you use RG-6 or RG-11 for radio stuff? I'm buying a 1000' spool so I know I'll have some extra that I was hoping re-purpose.
No, unfortunately. Aside from loss, TV-friendly cables often have construction that makes mounting our connectors difficult or impossible as well.
@@RobMacKendrick I figured there would be something minor like that, I appreciate the reply though.
Is a 12 awg thhn insulated solid ground wire good to use on the antenna ?
Thanks again for your information video
CAREFUL, SOMETHING NOT QUITE RIGHT
Good explanation. I don't know where you got the specs (in the table) for Belden 9913, seems wrong, I went to the "Belden" web site and checked the specs for 9913 and they were totally different than the ones in your video. Much higher loss. The 9914 is correct and seems to be transposed to the 9913 spec's.
Anyway you helped me out in my quest for knowledge on this subject.
Can someone tell me what I should use for nice flexible coax for my test gear? Maybe grey? I have Spectrum Analyzers, Scopes, Power meters etc. Need to go from DC to 3G/5G at up to 10 feet. Connect to antenna's and probes. Fittings are N type but I can adapt up/down. Leads supplied with the equipment are too short. I am a bit of a "Newbie" , so any help is appreciated.
Thanks again,
David (from "Down Under")
David, thanks for bringing this to my attention. I did look around and recheck the coax attenuation values for 9913 and 9914. I did find a variety of numbers in the various charts online, but it appears that my referenced chart does track closely with the Belden 9913 & 9914 data sheets: www.belden.com/techdatas/english/9913.pdf www.belden.com/techdatas/English/9914.pdf.
As for the type of coax to use with your test equipment, I'm not sure what would be the best choice for you. Maybe the folks at MPD Digital could give you some guidance: mpddigital.us/
can you tell me if rg-316 water proof. thanks
I am using LMR 400 cable and I want to paint a foot or so so that it is less obvious to passers by. Is that a bad idea. I know I never painted 300 ribbon but that was in the Lead paint days. Thank you... john Randall
Painting the cable will have no affect on its performance.
My rule of thumb: 10Mhz and down, RG8 should be fine. 10-30 Mhz I would use nothing less than RG213. If you are going into VHF (6 meter, 2 meter, etc) I would never use anything other than LMR400. The only exception would be super short runs, but anything over 20ft you should be using decent coax.
That's pretty good advice.
Thank you for posting that.
What about pigtails at either end?
Good advice...thanks.
hi kb9vbr. im a new b, just passed foundation, several of the lads from local club hv said (recommended) me to use rg213 as it would be suitable for all acassions… due to where I live I cant hv antennas anywhere so all my radio work will be out in the fields. my rig is a yaesu 891 end fed wire n auto tuner. need 25 feet coax... are my new club buddies right??
For HF, 10-80 meter operation, RG-213 is an excellent choice.
Mike I need 100 Feet of Cable feed line for Yeasi 2900 Rt to my Tram Anteen which is better RG-8 or MLR 400
100 feet of LMR-400 at 150 Mhz has 1.5db of loss. The RG-8U has 2.8db of loss per 100 feet at that frequency. Each 3db of loss is equal to cutting your power output in half. If you transmitted 50 watts out of the radio, with RG-8U you'd have 25 watts by the time the signal reached the antenna. LMR-400 would be about 38 watts. So the LMR-400 would be the more efficient cable.
KB9VBR Antennas
What size farrier beads for lmr400 w/85' feed line via yeasu ft2900 on your j pole.
I'm looking to purchase, doing my homework
Hello. Because of the terrain around my shack, I need to install my 2 meter antennas on a hill adjacent to the house. Total run of approximately 200 feet. Cannot be buried due to rocky soil. I will be running 100 watts. What coax do you recommend on: A. Unlimited budget and B. under $300. Thank you
200 foot cable run will necessitate use of low loss coax. At the bare minimum I'd use LMR-400 or even something lower like LMR-600.
@@KB9VBRAntennas Thanks... that's what I was looking at.
I want to buy RG223 and RG213 cable for VHF and UHF band, the question is what is the maximum length is best. My requirement is 100 feet
I wouldn't got over 75 feet with RG-213 on VHF. Look into LMR-400, it really isn't that much more a foot, and it will make a world of difference
What cable should I use as a feed line for a 5 w handheld radio ?
😂😂
Great Video
I have built a 7 element yagi antenna taking centre frequency to 98MHz for fm dxing, Can I use 1/2 s.f feeder cable to connect the antenna?? Cable length will be 15 metre and antenna will be 50 feet above the ground. I want to listen very long distance FM stations up to 1000 km. I will also use a LNA which 50 ohm. Please suggest me which coax should I use??
For VHF at that length‚ I'd recommend LMR-400
@@KB9VBRAntennas thank you so much
Hi mike my name is jack i use just a piece of 148 ft 20 awg silicone flixeable hi temp wire one end in the tree and the other end to my LDG ic-100 ant. Tuner there is no balun in line and i have worked all bands 100% what do you think!. Jack kb2txr
Michael can your jpole antennas be cophased or would there be an issue because of the jpole design. Thanks Art. K2ADC
uncleart112 While I haven't tried co-phasing the J-Poles, I have done a bit of research on the subject. I see no reason why you can't phase two or more of the J-Pole antennas. The key to proper phasing is in the construction of the harness to feed the two antennas. There's plenty of plans online, but I can send you a couple of links if you are interested.
Thanks Michael for your response.
Hello sir, can you give me a suggestion what best coax cable should i use for my setup
Antenna = diamond X520M
Portabase = boufeng UV82
Ham base = TYT TH-9000D
and im planning to do a 25meters above the ground tower. Echo siera papa 73's and godbless.
oh and im also using frequency
140mhz
I'd go with a low loss cable like LMR-400 for a 25 meter cable run for VHF/UHF.
KB9VBR Antennas thank you so much sir i will do the lmr 400.
I’ve got 18 feet of mini 8 feeding an Antron 99. It’s too short. Can I safely use a coupler and another mini 8 and how much loss would I be looking at. Thanx
Loss will be minimal. on HF‚ couplers may only add about .125db to the entire feed line system
Awesome. Thanx for a speedy reply.
Thanks
I have rg8x in 100ft.. When i am using icom ic2300h in high power 65w how much power it can transmit in output of antenna
I believe RG-8X is rated for 250 watts on VHF, so you should be fine using it with the IC-2300
@@KB9VBRAntennas how much loss it will present in rg8x.
Ever heard of. RF10. Coax
?..... just seen video on it....
New coax out....military spec. Air craft. Coax...has like 3 or 4 shielding on it,,,...bbi. has video on it.......like 2 try to find some of that stuff..& make a 12 feet coax for my cb radio with my scb hustler antenna.for my company semi truck.... .
If u could help me out that would be great......Mike from Minnesota
Is the center conductor on LMR-400 solid copper?
The Andrews/Times Micowave LMR-400 does have a solid copper center conductor. The generic brand LMR cables sometimes do not and instead will be copper clad steel. This is often not a problem for VHF/UHF as the signal is traveling along the outside of the conductor due to the phenomenon of the skin effect. But it does make for a stiffer and less flexible cable.
@@KB9VBRAntennas thank you 73
Hi and thanks for the informative video. I have seen things about RG8U being obsolete and RG213U taking it's place. I am just getting into ham radio and will be working on 2 meters initially. I am looking to buy a used Kenwood TM-218 from my license instructor and he is throwing in a discone rooftop base antenna. I figure I will need around 40 to 50 feet of feed line. Which of these two would you recommend? Thanks!
RG-213 and RG-8U are very similar, but RG-213 has the advantage of a higher power rating and can be direct buried. HF operators prefer 213 as if you are planning to use an amplifier, you will want a cable rated for that power level. For VHF/UHF, it's less useful as there are better low loss cables out there. But a 50 foot run of RG-213 will work fine for VHF operation.
Dear radio-mate, I am a total beginner concerning amateur and CB radio ... I actually would like to get the best coaxial cable for 27 MHz CB applications. Please can you recommend me one -- the price is not important. Thanks a lot for help and kind regards from Zuerich ETH, Stephan
For 27Mhz, I'd recommend either RG-8U or RG-213. Both cables have decent loss characteristics for that frequency and aren't outrageously expensive. If your cable is going to be quite long, that is over 100 feet, only then would I consider something low loss like LMR-400.
+KB9VBR Antennas Thanks a lot !
@Stephan Strauss: KB0VBR recommendations are fine. If you want better I also recomment you look at 'Aircell' or 'Pope H100' cable. The only drawback with these are that they are not as flexible as RG-8U or RG-213. 73, PD0PSX
Do you know Bolton 400 coax is good or not Amazon sells it as LmR 400 or is it a scam thanks
I have no experience with the Bolton 400 coax, but generally inexpensive LMR-400 knock-offs will use a copper clad aluminum center conductor. That in itself isn't necessarily a bad thing as due to the skin effect, RF energy will travel along the copper skin of the conductor. But it creates two significant deficiencies. First, the coax will be very stiff. It will be harder to work with and bend. Second, it will be more fragile. Aluminum core LMR-400 is prone to breaking if you flex it too much. The coax will be fine if you install it once and leave it in place without moving it. But repeated moves and flexes could compromise its long term usability.
@@KB9VBRAntennas Thank you so much for your insight. I’ve decided to send it back I found some RG8 steren that I’m going to trust before I do this other stuff. I tried to search them out they claim their a US company but you try to search it out it becomes a dead end. Anyways thanks so much I sure enjoy your videos I’m working on my ham license thanks again for your response
Thank you
Can you run an lmr-400 in a vehicle 18 ft long on a 40 channel 10 m radio?
You can, but really would offer no advantage. At that length and frequency, RG-58 would be just as capable and be easier to work with.
@@KB9VBRAntennas I had no problem working with mine I got a102-in stainless steel whip with a one to one match on my mobile. and I talk skip when skip condition is good no problems there, my dx86v Galaxy 120 pep upgrade!
@@KB9VBRAntennas
I could agree with you on that but the LMR 400 at 18 ft there is no loss of power and I got a one-to-one match. It's working fine in my vehicle I have a Galaxy DX 86 v 10 m amateur radio upgrade swings to
120 pep Either way they both work. but I think I get a little better output to my antenna with the LMR 400 coax I run 102-in stainless steel whip with ball mount and spring and it gets out.
Hyperflex 13 or 10 is the best!
But its pricey $$$$$$$$$
I like LMR600, but it's more brittle than a 90 year old hip that's why I recommend M&P pure copper coax.
I use a custom dipole antenna w/ traps tuned to 11m or a small rooftop tower antron99 on top of a 2 story house.
alpha Zulu 983 click click 73s
excellent coax, quality product.. from my research. iam about to buy 1ooft of hyperflex Messi&Paloni..MFJ is NA distributor they dont make it just sell it 7 3
I was told the foil on cable such as lmr400 is no go for hf should I run rg58 instead thanks for any help
I haven't had any issues using foil shielded cables on like LMR-400 or Belden 9913 on the HF bands. but if that is a concern for you, I'd probably choose RG-213. RG-58 is ok for HF, but it still has limitations: it is still lossy at HF freqs and has low power handling capability. RG-213 has excellent loss characteristics on the HF bands and has a UV resistant direct burial jacket, so it will stand up better long-term outdoors.
KB9VBR Antennas I meant 213 Thanks for the info It was the maker of the ultimax extreme who had mentioned the foil style cable I’m very limited on space so I’m looking for a compromise for my hf antenna 73
RG-213 is a great choice for HF, it should serve you well.
I can't afford to buy good coax but i have a 5kw amp. Bang for buck there is no expensive coax and the performance gains / $ are great. If your coax vf is not 87% you haven't done your homework. You can go better. The best cable shown on this list is still not as good as other coax available and it's far more expensive. Even better try not to use coax when possible.
If solid transciever costs 1000-2000$, I don't see the issue of 200$ cable
Lmr 400 the best way to go
Why does everyone have a different name for best coax
I want less Loss everyone say this one or that one for less loss .
I’m more confused
Thanks