Just put up a sirio NV4K

**222DBFL** · 11-04-2015, 07:06 AM

Hello all. Just wanted to give my opinion about this antenna and some of my experiences with it so far. 1st off, I got this antenna from my boss as a gift, it one I have wanted for a long time. I had an accident with my sirio tornado while working on it by myself and trying to move it a bit. Big mistake!!! Needless to say the tornado looked like it went through one! So I had to put the old A99 back up. This made radio kind of not fun for me as the A99 just isn't my cup of tea. Ground noise went up 2 S-units, rx and tx range cut in half at least. Anyway. Fast forward. Took down the A99 and put up another dipole headed E/W as I have one pointed N/S already and got both of the dipoles up to 35-40ft at feedpoint. They work great for dx, but again, no local range at all. 4-5 miles tops. So now comes the new sirio vector 4000 (NV4K). I put this antenna up at 26-27ft at the feedpoint. It tuned as follows.
R=50, X=0, vswr 1.0:1. Freq= 27.400.
Man talk about flat tune!! This antenna has some ears and tx is great as well. Can hear stations as far as 100+ miles at times now and can talk to all my locals out to 50+ miles. This is on SSB. About 20 watts of power. The antenna is 28'6" and is one heck of an antenna. Sirio beefed up the joints and I've had some decent winds here the last few days and antenna stays pretty straight. I am one happy camper. I have made quite a few contacts with it and all reports are great signal and clean clear audio. Using an Icom 746 for my base station. Have 4 antennas up total. 3 for 11m and one for 144mhz rx only. It's a home brew long wire. Works well and can hear quite a few airports locally along with a lot of other stuff. Both of my dipoles are cut for 27.385 freq and hold a pretty broad range for tx. The vector 4000 is a great antenna that is the best I've ever used. I'm no antenna expert, but this antenna if tuned properly even setup at 18-20ft will perform well. It doesn't need a bunch of height although height is might for locks talk. Dx wise, when the conditions pick up I'll post back some more results and also how the antenna is holding up. Noting also that I used HD heat shrink on every joint, including the bottom section and also used no-ox on the entire antenna, minus the coax connector. A very light coat over the entire antenna and also at every joint and screw. Don't know how much it helps, but the heat shrink and no-ox should keep the antenna clean and free of water hopefully. I weather proofed connector at bottom with self amalgamating tape. This can be bought at Home Depot or Lowes. I also isolated coax from entire mast and from touching any metal from antenna feedpoint to my room. This was done with 1/2" lmr400 grommets made for 1/2" snap ins for commercial tower stuff. So none of my coax ever touches the mast at any point from top to bottom. Also used some ferrite chokes at the feedpoint as well. Anyway, here are a few photos.

**222DBFL** · 11-04-2015, 07:08 AM

I also have the measurements that I will post as well if anyone needs them. Again, antenna is tuned for 27.400, and vswr from 1.0 to 2.0 is almost 2mhz of bandwidth.

**222DBFL** · 11-06-2015, 05:35 AM

Radio being used is an Icom 746. Coax is Andrew lmr400. Amphenol connectors. Not that it matters. But this is my base setup with the antenna being the one listed. Works well and if I can hear them I can usually talk to them now!!

**222DBFL** · 11-08-2015, 05:30 AM

I don't know if anyone has viewed this thread but I want to say, this antenna just plain rocks. Talked all the way across the state yesterday to the west coast of FL from the east coast. Good trip and great qso. Also talked 70 miles south now everyday since placing the antenna up. So my range has definitely gone up considerably. I hear guys now have conversations that I could barely and I mean just barely hear before. Now they come in crystal clear. One hell of an antenna for the money!! It knocks the socks off the A99 and the sirio tornado by far. More the A99 as the tornado was a good antenna. This one just plain has ears and if I can hear them I can talk to them usually!! Anyway, just some experience with the antenna now and getting some feedback from other locals and they all say I've gotten a much stronger signal out at 50+ miles than I did before. Antenna is 26ft to feedpoint. Tip is at approx. 54ft. I've come down a few feet from original position, but am planning on adding a 40ft push up mast soon. It's already bought, just gotta go pick it up. Other things going on at the moment, but at least I know I have it. And I only paid $35 for it!! No rust and all guyed wire holders are clean. Soon I'll have my station the way I want it!! Anyway, just some updates about the antenna and how it performs. Also here are my dimensions for tuning it for 27.400 if anyone wants to use them.

**222DBFL** · 11-08-2015, 05:31 AM

Here are the rest.

**222DBFL** · 11-08-2015, 05:33 AM

**JAF0** · 10-16-2016, 07:57 PM

Hello 222DBFL,
Do you know how many feet of mast is beneath the cone arm mounting HUB at the base of the radiator?

It sounds like you may have hit a very lucky combination of factors, judging by how superior it sounds like your NV4K is performing.

Perhaps you've stumbled on an excellent combination of the number of feet of mast verses how high above ground, depending on the path the coax takes from the base of your mast.

And if you don't mind me asking, what is the path of the coax after it leaves the bottom of the mast, and how many total feet of coax, which appears to be coiled (acting like a choke?) at the base of the mast?

**222DBFL** · 10-16-2016, 09:10 PM

I did have to take my antenna down due to the Hurricane we had. But will be placing it back up.
At any rate, my antenna was 27ft to the actual bottom of the base. This would have placed the cone hub arm at about 28ft or so.
My coax was routed down the mast and completely isolated from the mast with 1/2" snap in's and 1/2" grommets made for LMR400 from my previous job as a cell site tech. The coax then was coiled up at the base of the mast and then again isolated from anything using more snap in pieces and 1/2" rubber grommets as seen in the pic below. I did this all the way to my radio room. Then I placed a surge arrester in line. The first length of coax was 60ft and the 2nd piece was approx 30ft. Here are the parts I used to keep the coax isolated from the mast and also from touching my roof or any other part of the house.

I tuned the antenna with the 60ft piece of coax using an MFJ269C antenna analyzer which is pretty close to being a multiple of an electrically tuned 1/2 wave coax jumper. I ended up with the results of
R=50
X=0
VSWR= 1.0:1.
If I could have gone higher with the antenna I would have and when I remount the antenna I plan on getting it up to at least 30ft or more. I have a 40ft push up pole that I just need to pick up from a local pals house. Last I checked which was a couple months ago, the antenna still was at the same readings as I listed above. And boy did it work well for me at the height at which it was at. For only being 27ft to the base of the antenna it did an excellent job for me both locally and DX'ing. If I left anything out I will post more info. I can't see what you wrote at the moment so I am going off what I saw from reading your post.

**222DBFL** · 10-16-2016, 09:20 PM

The coax came down the mast to the roof and you see the coiled up coax. From there it's isolated again from the roof with the above parts and this was done all the way to my radio room.
Also I ran a solid #2awg ground wire to the base of the antenna and all the way to the ground where I had approx. 10 or more ground rods. The entire back half of my house had ground rods and #2awg was used to connect them all together as well as my radio equipment. I used an Icom 746 for a radio and with 100 watts or less, in which case I tried to keep the power down to about 20-50 watts most of the time unless the band was really crowded. I spent lots of time setting this antenna system up and will do the same when I place the antenna back up again. Until then I have the antenna sitting in my garage and it's being cleaned up slowly and I am making sure all bolts and such are tight and that all screws are cleaned. I will then recoat the antenna with NO-OX again again and make sure I weather proof all jointing sleeves as I did last time. As I said I was a cell site tech for 17 years so I accumulated many parts and a lot of coax. Was planning on using some LDF4-50A but my Andrew LMR400 is just fine. I am no antenna expert and went on the advice of someone when I got the Sirio vector 4000 and I am darn happy I did. I was amazed at the distance at which I could talk to others on SSB. And the antenna tuned perfectly!! It took me some time to get it right but I was rewarded with many contacts and if I could hear then I could make contact with them.
Hope some of this info helps. And thanks for asking about the setup. Like I said, I spent many hours trying to make sure I had the antenna setup correctly as well as the entire antenna system.

**222DBFL** · 10-17-2016, 06:20 AM

I also want to add that I didn't side mount this to my mast pipe but rather used a 1 5/8" fence rail post and slid the base of the antenna down into the pipe. This I believe helped with the stress placed on the base of the antenna and made it more or less balanced than mounting it on the side of the mast like most do. If you look at the pic below you'll see that there is no visible base section of my antenna. Like I said it slid into the mast pipe and then 3 self tapping metal screws were used to keep it in place. Do I think I had some magic going on. Certainly not IMO. I just took a lot of time and effort getting the antenna the way i wanted it. I also used HD heat shrink on all joining sleeves of the antenna where they screw together. This kept all moisture out and also kept my screws looking almost new when I removed the heat shrink. I will be placing the antenna back up again and it will be higher than previously placed. I also planned on using LDF4-50A coax but was told not to at the moment as there were no issues with the Andrew LMR400 I used originally to setup the antenna. Here are a couple of pics of the antenna before it came down for Hurricane Mathew. And I am glad o did this as my local plan lost his 85ft ROHN 18" tower to a very large tree that fell on a guyed wire. He lost his 3 element beam and also a repeater antenna and most of his Commscope 1/2" superflex coax. Not a good deal as the tower was twisted about 120 degrees and then snapped at the base legs.
Anyhow here are a couple pics of my antenna and note the mounting area. No base is noticeable due to it being inside the top mast pipe.