Antenna Location Options

[KF5YBZ]

First off, I live on the west side of a hill. It is called Brown's Mountain but it is really just a hill. This gives me a great elevation advantage to the west, north and south but no signals are coming through from the east. I live near a large metro area but can't pick up ANY television stations. My house is a 2 story with an attic on top so I can get even more elevation. I have an Antennacraft ST4 Outdoor Scanner/Ham Discone TV Antenna (ST4) or something similar. The antenna is clamped to the metal railing on my second floor balcony. I am considering moving it to the attic. I am curious what the trade offs might be. Does the metal railing enhance the signal? Would the attic block the signal or would the extra 10' in height help? Do I just need to play around with it? Is this antenna self-grounding or do I need to run a ground?
Thanks, Ron

 

[KF5YBZ]

Basically would like to know if an antenna being clamped metal on metal to a balcony railing has any effect on signal strength be it good or bad.

 

[popnokick]

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Height nearly always helps. Move it on up.

 

[Rt169Radio]

How would the antenna be mounted in the attic? Usually metal to metal works good, but it wouldn't hurt to move it and see what happens.

 

[KF5YBZ]

In attic would just clamp to rafter as high as I could go but wouldn't be easy. Just trying to figure if worth the effort before I start crawling and drilling and puling wires.

 

[KF5YBZ]

I was wrong about the antenna being a Antennacraft ST4. I have had this thing maybe 10 years and can't remember where I bought it and can't find an exact match. Anyone ID this thing so I can re-research why I got it in the first place? hah

 

[mmckenna]

So, that looks like a basic discone type antenna. It doesn't need a ground plane, so mounting it to the metal railing isn't necessary. From the way you have it mounted, it's likely having it's performance degraded by the close proximity to the railing. Getting it up above the railing would probably help a bit.

Mounting it in the attic might help the altitude, but you need to consider your roof construction. If you have a metal roof, it will essentially block the signal and you'll likely get worse performance. If the roof is wood shingles or composite, you'll probably be OK.

Best place would be to get it above the roof, as high as you can.

So, two options I see:
1. Move it above the railing in its current location. A short piece of pipe, even PVC pipe would work, and you'd likely see a slight improvement in performance.
2. If you roof is not metal, try it in the attic. The additional height should help.

If you put it in the attic, make sure it's away from any wiring, plumbing or ventilation ducts. Metal close to the antenna will affect its performance.
Also, that looks like RG-58 coax? Stepping up to a better cable will get more signal from your antenna to the radio. If you can get your hands on RG-6, it'll work a bit better. LMR-400 is better yet. Much above that and it gets hard to route.
Keep your coax run as short as possible, use the best cable you can, and get the antenna up as high as you can get it.

 

[mancow]

That thing tangled up the metal railing is not good at all. That has to be causing numerous issues.

 

[KF5YBZ]

Thanks again for the tips and advice. My attic has a radiant barrier, which is pretty much metal foil adhered to the underside of the plywood on the roof, so I guess better to not try place any antennas in there. I nestled the antenna in the railing like that about a year ago to try and be incognito. The only part touching metal is the clamp. I had no idea that the coiled cable could degrade signal either. I am going to move it to the top of the railing for now and run the cable as straight as possible. Would mounting the antenna upside down cause any performance issues? Considering ceiling mounting above the railing. I really like that location as it is close to my radio. If I decide to put in the effort of going to a roof mount, I think I would like to get a better antenna and cable first.
Thanks again, Ron

 

[Rt169Radio]

I don't think putting it upside down will cause any major problems, but putting a antenna to close to metal at the same height will cause issues though. So it might be a good idea to get a small pipe and attach that to the railing with the antenna on it until you get a base roof antenna.

 

[mmckenna]

I'd agree, the horizontal radiation pattern of a discone, depending on which website you look at, looks like it won't be affected too much being upside down. On the other hand, I don't think you'll gain anything. Since you don't need a conductive mast, anything will work, broomstick, PVC pipe, shower curtain rod, etc. You need to get it away from anything conductive.

Yep, the foil barrier in your roof would likely create some poor performance. Getting it above the roof is your best bet, if you can pull that off. Even clamping it to a vent pipe would help.

 

[mmckenna]

Anyone ID this thing so I can re-research why I got it in the first place? hah

I don't know the specific brand, but that is a discone design. Discone antennas work well at covering a lot of spectrum. They don't have any gain, so don't expect too much from them. If you are more into scanning specific bands, or even 2 bands, you can do better with a dedicated single band or dual band antenna. They'll have more gain and thus give you more signal.

But, since that is what you already have, best to make the most of it. Getting it up and away will help. Upgrading coaxial cable will help more signal make it to your radio. Even if you can get it out, away form the house/railing at it's current height will probably help. But, when it comes down to it, height is key. Getting the antenna up as high as you can helps it "see" more. Upgrading coax will get more of the signal the antenna "sees" to your radio. With the lower grade coax, you lose more of your signal to cable losses. This might result in weak signals not making it to the radio with enough strength to break squelch. With the combination of better cable and increase height, you should see a noticeable improvement.

 

[KF5YBZ]

Okay thanks again and all advice will be considered. So the new plan is to pole mount to the eve a few feet above the lowest part of the second story roof. I should be able to balance on a stool, lean out over the railing (with a water hose around my waist for safety of course) and get a mount attached to the eve for a short piece of pipe. Should be a decent improvement and the radiant barrier roof should only block signals from the east, where the mountain blocks them anyway. One day in the future I hope to borrow a loooong ladder and grow the cajones to hike up to the steeeep west peak of my taaaall roof and install a proper mount.

 

[kf5bti]

I know you already have a plan in place but I just wanted to echo what others have been saying. First, you need to elevate the antenna a minimum of a couple feet to get it away from the railing. Higher = better performance. Could you attach a 10' pipe to the railing and install the antenna on top of it? Secondly, upgrade the coax. I highly recommend you stay away from the cheap ebay vendors, radio shack, and truck stops when it comes to coax. The length and desired freq will determine the exact coax needs but I purchase my coax from thewireman.com

 

[KF5YBZ]

It will be about 5' above the railing but I guess I could always extend the pipe. Was planning on using some gray PVC I have laying around and running the coax down the pipe. The coax length will be 20-25' at current placement and I really want to pick up all frequencies but I guess 700Mhz and my local LTR would be my priority. Still not sure really. Hope to learn much more about RF and get new antenna/coax in the future when I know WHY I am buying what... And I thought all coax was the same. Guess it has to do with better shielding and conductivity? Ideas on where to shop welcomed.

 

[kf5bti]

Getting it 5' above that railing should improve things greatly. Since you only have 25' of coax the type of coax you use isn't as critical. However, I would look at replacing it with something like LMR400 when the funds are available. I do caution you though there are some really cheap and crappy coax manufactures out there which is why I highly recommend thewireman. RG58 from radioshack is among the worst.

 

[KF5YBZ]

Any way to minimize the influence of attracting lightning? The thought just crossed my mind but I am sure the issue has been well thought out before by many others...

 

[mmckenna]

Not really. You can keep it below other structures, but direct strikes are not the only thing you need to be worried about. Even a nearby strike can induce enough energy into the antenna and feed line to cause damage. You should ground the antenna itself and install some lightning protection on the feed line before it enters the house. There are some pretty good discussions about this on the page already.

 

[KF5YBZ]

I got the antenna relocated to the best place I could with what I had to wok with. Coax was just long enough to run through 4' of PVC and bolt to the eve of the second story. Everything, the coax, antenna, pvc and cruddy mount job are all temporary.

 

[mmckenna]

That looks pretty good. How does it work now?