S9V 31ft antenna questions

[bluestallion]

Hello everyone. Im thinking of purchasing the s9v 31 ft antenna. Had a few questions. What size wire should i use for the radials? and when you guys strech them out about your yard, when you go to mow, do you leave them down and hope you dont mow them or do you roll them up, then unroll again? thanks to anyone that can help

 

[acyddrop]

What I suggest you do, with regards to ground wires is this...

Make the ground wires as long as you can in each given direction you are able to, and run as many as you can. Do not bend them into any shape other than a straight line radiating out from your grounding point. If you don't want to bury them (and you don't have to just for the record), get yourself some of those biodegradable spikes from DXEngineering. Before you start running your ground wires however, set your lawn mower deck to it's lowest setting and mow the entire yard in that fashion. After you're finished mowing return your lawn mower deck to it's previous height.

Now this time of year isn't ideal as your grass will probably stay short until next spring/summer, you'll just have to wait for your grass to grow again to cover up the wires properly. After you finish mowing, run your wires out, spiking them down with those biodegradable staple things. What will happen is they will disappear and the grass will hold down your wires and they will be essentially invisible for you when your grass resume growing. And by cutting the grass as short as possible initially you'll ensure you're wires will be below the mower blades when it comes time for regular grass cutting (just remember to return the mowing deck to your previous height).

Also don't worry if you can't cover the area 360 degrees, you don't have to. Just cover as much as you can and it should be fine. I highly recommend 20-30 radials if possible, but you'll notice marked improvement with as few as 8-10. Good luck.

PS: If you're handy with a drill, you can make your own 43 foot vertical for around $100, and less if you build the UnUn yourself. I have no idea why anyone would charge $70+ for an UnUn, you can make one with an FT240-61 ferrite core, some stranded 14ga speaker wire (enough for 12 bifilar turns), and a length of RG58A/U (or RG8X) coax, and a small handful of other parts from Home Depot. This UnUn would handle 1kw RMS easy and 2kw PEP. If you wanted to be fancy you could use two FT240-61 cores and the same number of turns. The soldiering skills for this are fairly minimal to be honest, I'd be happy to advise if you felt like you wanted to try this. The radiating element is made up of aluminum tubing from DXEngineering.

Hello everyone. Im thinking of purchasing the s9v 31 ft antenna. Had a few questions. What size wire should i use for the radials? and when you guys strech them out about your yard, when you go to mow, do you leave them down and hope you dont mow them or do you roll them up, then unroll again? thanks to anyone that can help

 

[bluestallion]

does it matter what size wire i use for the radials? or just whatever wire i can get ahold of?

 

[acyddrop]

18awg wire works fine, you can also use the grounding wire from DXEngineering it works really well, but any wire 16-18ga should work fine, use stranded wire though because you need it to be flexible. If you decide to bury your ground wire, you only have to go down 1-2 inches.

does it matter what size wire i use for the radials? or just whatever wire i can get ahold of?

 

[kb2vxa]

Here's a trick from the broadcast industry, never let a building get in your way. Ring it with copper, solder the radials to the ring and continue each one on the other side. The radial field will never know it's there if you make it invisible to RF.

A tip from experience, stranded wire will give you trouble and it's no more flexible (except for a tight turning radius you'll never encounter with radials) than solid soft drawn of the same diameter. If broadcast stations use it you should too BTW. Here's the horrible experience, NEVER use hard drawn because it hates to lay down and you'll have copper springs all over your yard.

While radials on the surface are best they're usually buried a couple of inches to keep them out of the way, the slight loss of efficiency is negligible. If digging a whole lot of slit trenches isn't your cup of tea a Ditch Witch will make short work of it.

Oh do I have to tell you to to keep it on the QT or you just might wake up to what's left after a thief in the night harvested your lawn? It happened to a ham I know, just sayin'.

 

[acyddrop]

Actually KB2XVA is correct, you'll want solid core wire described not stranded. I've been too stuck on my unun project lately, I highly recommend the stuff at DXE for ground radials along with the lawn spike things they sell.

Here's a trick from the broadcast industry, never let a building get in your way. Ring it with copper, solder the radials to the ring and continue each one on the other side. The radial field will never know it's there if you make it invisible to RF.

A tip from experience, stranded wire will give you trouble and it's no more flexible (except for a tight turning radius you'll never encounter with radials) than solid soft drawn of the same diameter. If broadcast stations use it you should too BTW. Here's the horrible experience, NEVER use hard drawn because it hates to lay down and you'll have copper springs all over your yard.

While radials on the surface are best they're usually buried a couple of inches to keep them out of the way, the slight loss of efficiency is negligible. If digging a whole lot of slit trenches isn't your cup of tea a Ditch Witch will make short work of it.

Oh do I have to tell you to to keep it on the QT or you just might wake up to what's left after a thief in the night harvested your lawn? It happened to a ham I know, just sayin'.

 

[prcguy]

Speaker wire or house wire insulation is not a good choice for RF applications like windings on a balun. The FT-240 size core is adequate for legal limit under a matched input/output condition but probably not when used with a non resonant vertical.

I made a 1:1 balun using the FT-240-61 core and used it at on a G5RV at the transition of the ladder line and coax. At 1300w it heated up, arched and almost caught my roof on fire.

There is a good reason why people who have bought various brands of 43ft verticals are buying the DX Engineering balun since it seems to be giving some noticeable improvement over their stock balun and they are really bullet proof.
prcguy

PS: If you're handy with a drill, you can make your own 43 foot vertical for around $100, and less if you build the UnUn yourself. I have no idea why anyone would charge $70+ for an UnUn, you can make one with an FT240-61 ferrite core, some stranded 14ga speaker wire (enough for 12 bifilar turns), and a length of RG58A/U (or RG8X) coax, and a small handful of other parts from Home Depot. This UnUn would handle 1kw RMS easy and 2kw PEP. If you wanted to be fancy you could use two FT240-61 cores and the same number of turns. The soldiering skills for this are fairly minimal to be honest, I'd be happy to advise if you felt like you wanted to try this. The radiating element is made up of aluminum tubing from DXEngineering.

 

[bluestallion]

could solid core be used? I found a good deal on a 500ft roll. or does it need to be stranded? thanks

 

[acyddrop]

As kb2vxa was correct when he said that solid core, soft drawn wire is the way to go. If as he pointed out it's the hard drawn variety you will have hours and hours of misery laying the ground wires properly (on top of the misery of crawling around on your lawn and the back and knee pain already associated with this wonderful activity).

could solid core be used? I found a good deal on a 500ft roll. or does it need to be stranded? thanks

 

[bluestallion]

getting ready to put up my vertical. Would it be ok to run around 90 feet of coax (RG213) to it and be fine with an external tuner at the radio?

 

[acyddrop]

I would assume so.

Sent from my HTC Rezound using Tapatalk 2

 

[bluestallion]

got the antenna all set up. I have around 36 radials put a choke in the coax, when i went to try it out last night there are stations that are seem to be booming in, but when i try to call for them no answers.
Would this be from having around 120ft of coax? can have around 95 if take choke out. Should i get a remote tuner and put at the base, i would if it would help with my signal. any help is appricated
73s kc9oza

 

[acyddrop]

There are lots of reasons you may not be able to make contact. Some, or all of those stations could be running 1.5Kw and if you're running barefoot (whatever the max your rig can put out) you may not be able to return the contact. That's one reason I can think of straight away anyway... Although with that said, there are plenty of people (not me) that have made many many DX contacts with QRP (5-20 watts).

With regards to a remote tuner.. A remote tuner is *always* going to be better than using a lossy matching transformer. So putting a remote tuner at the base of the antenna will most likely help your overall power output from the antenna, it doesn't necessarily mean you'll be able to contact booming stations any better than you can now. You could have problems with your install as well. Have you looked at your output with a field strength meter? Do your radials all run out in straight lines from the base of your antenna (Intersecting, bent, zig zag patterns, etc are all no-no's).

I'm assuming you're getting a 1:1 (or at least close to that) with your tuner up at the transmitter, and you're using an external tuner and not the one built into your rig. Is your external tuner an automatic or a roller inductor tuner, both of those help you get a better match to your load than the A..B..C.....Z type rotary switch tuners due to a wider range of options.

Lastly, while RG-213 (which I'm assuming your using) is good stuff along with LMR-400... It probably represents the largest loss in your system. In most vertical designs (that I've seen) the losses in said coax are part of the design of the overall design and are counted on. Plus or minus 20-30 feet is probably not a very big deal, maybe even plus or minus 50 feet, I would worry overly much about the length of your coax though. I've made short (to Cuba) DX contacts with a tangled up bundle (read: mess) of LMR-400 with a dipole 2 feet off the ground with BPSK-31 -and- phone with ~100 watts.

Just remember propagation is fickle and some of the people you hear (in fact perhaps quite a few, especially from 40 meters down) are running full legal limit (I'm assuming you're not of course).

 

[bluestallion]

I have one of the z100 auto tuners and on 40 20 15 and 6 i get around 1.2/1.3:1. on 10 meters its around 2.3:1. The radials are pretty much straight, maybe few tiny curves in the fence wire, but pretty straight. On some of the wire fence I have them 2 coming off one lug i have one wire twisted around the other and soldered to it. i can take them off and see. With the propagations thing, i did take my 706 with me in my jeep and trimmed my cb antenna down and reached puerto rico on 20 watts. That made my day

 

[acyddrop]

I use the LDG AT series, I like them better than the MFJ stuff. Though I like the MFJ remote tuners, mainly because I have yet to find a reasonable alternative.

Sounds like your radial system is good too.... It's possible something could be messed up elsewhere, perhaps a bad soldier joint or some such.

I want to play around with QRP more, it's a whole different world. I also enjoy mobile HF immensely.

Sent from my HTC Rezound using Tapatalk 2

 

[bluestallion]

i'm also using the free 4:1 ldg unun. i took the plate off the back when i got it, and everything seemed to be fine. maybe one of the solders on it gave. will check and see. Yes when i had my buick with my 706 and ah-4tuner and 102 whip i made many 20meter contacts. loved the hf mobile scene, hope to get back into it sometime

 

[acyddrop]

I've listed pretty much everything I can imagine could go wrong, but I'm certainly no expert either. I hope you can get the problems worked out as I've enjoyed using my vert and have found it to be a fun antenna to use.

On the mobile front, I just finished bonding my Range Rover all together and am looking to upgrade to a Scorpion antenna (SA-680S or SA-680 model) from a Little Tarheel II. Kind of excited about that one. I'd also like to look into a modest linear for mobile use, nothing super powerful maybe in the 300-600 watt range or something along those lines.