More Discone Antenna questions

[Wahoos4Life]

So has I noted earlier Ive ben looking at buying a new rooftop antenna for my pro 106

I live out in a county area, wanting to increase my range further

when I am outside my house, i currently get more things then I do while I am inside my house, do to some kind of interfearnce in the room.


My big question is, Is getting a Quality Discone Antenna up on the roof, mounted on the chimney

1.Well it really make a Big enough noticable differnce when using the scanner inside, attached to the discone, apposed from the stock anntena?

2. What do I need to Mount the antenna to the chimney? it said it came with some kind of pole, but how do I mount that to the chimney?

3. Is a $100 discone a quality antenna?

 

[khoelldobler]

these are my personal experiences, and suggestions to you... judging from what you have told us here. Chimney mounting will be fine, Radioshack sells a chimney mount kit by itself... it has stainless steel bands which wrap around the standard size residential square or rectangle shaped chimney, and has a bracket racheting system that tightens up on the bands to adhere it safely and securely. It usually has an upper stainless steel band and a lower stainless steel band... 2 stainless steel bands total come in the kit. This kit mounts to the chimney in approx 25 to 30 minutes, once your on the roof with all of your tools required, using standard hand tools. THE POLE, or mast would be a seperate purchase... also from Radioshack. I suggest a ten foot steel mast from Radioshack. 10 feet above your chimney, outdoors WILL surely show imediate reception improvement, compared to what you are using now. I also suggest a discone antenna... but not from Radioshack if you can avoid it. I have compared RS discones to other discones, and the RS discones are near the bottom of my list. My preference is Diamond D-130 Discone Antennas as they are cost effective and durable. Depending on how far you want to take the hobby, and depending on what you want to monitor, and haw far away the signals are, a D-130 Discone will bring you great success... just my personal experience of course. My D-130 brings in signals from appro 60 miles away, in Florida (which is relatively all flat terrain) Your results will very. Click on my name, go to my profile on RR and read what I wrote on my albums page concerning MY PREFERED DISCONES AND COAX. Take care.

 

[hoser147]

Be sure to check the Chimney structure itself. Rat shack mounts are ok but on the narrow flimsy side. Check out the mounts by Ronard http://www.ronard.com/ychim.html

 

[khoelldobler]

hoser, thanks for the added support to this thread, I almost forgot that RS chimney kits are not rated as the best... but they are in-expensive, and easy to install. To be honest with you guys, I had extremely good luck with the RS chimney kit several years ago. I pushed it to the limit too. You might get a kick out of this, around 16 or 17 years ago, when I lived in NY, I installed a RadioShack chimney mount kit on a 3 story residential roof. I was renting at that time from a relitive. I installed the kit securely, then installed 2 ten foot masts and a 5 foot mast together... hoisting a 25 ft total mast, with discone atop, thick coax, guy wire clamps, and a small CB antenna to the Rat Shack chimney mount kit. This thing was top heavy, and a ***** to lift and hold into place with my shoulder as a brace while racheting the bands. I secured 6 total guy wires to various points on the roof. It looked professional, and weathered out many NY storms. From the ground the discone was approx 50 feet up in the air. I even had a small red clearance marker light on the mast, 12 volts dc around 3/4 of the way up the mast, with a wall-wart inside the house. It looked like it belonged at an airport... I would plug-in the light when friends were coming over... I told them the light keeps the planes and helicopters from hitting the antenna. The Chimney kit gave me sturdy results. I don't know if they still mfr todays chimney kits in the same manner as they did back then.

 

[hoser147]

Kevin, good write. My current one is Radio Shack about 4yrs old. Its just one of those deals after you install it, that leaves a ? mark in the back of your mind. So much I found what its going to be replaced with. The band is thin and narrow and the turnbuckles aren't made strong enuff either. IMHO

 

[Wahoos4Life]

this is the antenna i was going to get

http://www.scannermaster.com/ProductDetails.asp?ProductCode=13-540456&CartID=1


also thanks for the link to the mount. and info

there are trees around the house, but above the single story house where the chimney is, and where the antenna would go, is a perfect view of the sky

 

[Wahoos4Life]

Also, Could I get up to 60 miles with it in the attic? or should it be on the roof for that distanc


also, I have a wirless 2.4ghz router in my room, and cuases some really bad noise on far away stations on the pro 106, What exactly is picking up the interfearnce, the scanner, or the antenna on the scanner?

 

[hoser147]

Also, Could I get up to 60 miles with it in the attic? or should it be on the roof for that distanc


also, I have a wirless 2.4ghz router in my room, and cuases some really bad noise on far away stations on the pro 106, What exactly is picking up the interfearnce, the scanner, or the antenna on the scanner?

1. Outside and up would be your best bet. Lots of varibles come into play when attempting to pull in a signal at that distance. ( terrain, atmosphere just a couple.)

2. There is really know way to tell other than messing around to see how you are getting the RF. If you have a piece of metal window screen try laying it over the router(kind of a shield).

 

[khoelldobler]

outside would be your best bet, with optimim performance at what this antenna will give, you should mount it outdoors at a minimum of 20 feet above ground. A 10 foot mast on a chimney would show good results, at a one story home, would be approx 20 to 25 feet above ground. This should show positive results. I prefer outdoor mounting, over attic locations... for obvious reasons. Results vary, but I think you will be quite pleased. There are big performance gains by mounting outdoors. No-one will argue that point .

Tin foil wrapped around a router will shield well. make sure it allows any heat build up to escape properly. Some people line the inside case of the router with tin foil, or manafactured RF shield foil to elliminate cross interuption. But since the Router operates on a different wave of RF I wouldnt worry about any shielding at all. I had a router sitting right next to a Pro-2006 and my Pro-106 scanners, and there was absolutely no problem at all between the devices... virtually inches away from each other, no problem at all. It should not be an issue.

 

[Wahoos4Life]

outside would be your best bet, with optimim performance at what this antenna will give, you should mount it outdoors at a minimum of 20 feet above ground. A 10 foot mast on a chimney would show good results, at a one story home, would be approx 20 to 25 feet above ground. This should show positive results. I prefer outdoor mounting, over attic locations... for obvious reasons. Results vary, but I think you will be quite pleased. There are big performance gains by mounting outdoors. No-one will argue that point .

Tin foil wrapped around a router will shield well. make sure it allows any heat build up to escape properly. Some people line the inside case of the router with tin foil, or manafactured RF shield foil to elliminate cross interuption. But since the Router operates on a different wave of RF I wouldnt worry about any shielding at all. I had a router sitting right next to a Pro-2006 and my Pro-106 scanners, and there was absolutely no problem at all between the devices... virtually inches away from each other, no problem at all. It should not be an issue.

Interesting, I am able to pick up Richmond NOAA from outside my home, and inside most of the house, But I take it into my bedroom, where the router is located, and I get this anoying feedback sound in the background

So lastnight I experimented

Turned off/unplugged computer
Turned off/Unplugged LCD tv
Turned off/unplugged 360/ps3
Turned off/unplugged Sirius radio
Turned off/unplugged Digital cable box/audio reciever

anoying background interferance went away and station came in clear like it did outside

Proceded to plug back in and turn back on devices, and all was still good untill I got to the router, once that was plugged back in and booted back up, anoying noticible background noise came back into the station, Now this noise only occours on faraway Freq's and not local strong signaled freq's

It is a Linksys wirless G 2.4ghrz router

But yea Im going to Mount that Discone on the chimney outside anyway, I just got to go up on the roof and do some measuring so I know how long of a cable to get.Im hoping 100ft would be plunty.

Becuase unfortuantly, The room the cable would be going to is on the oppisite side of the house from the chimney

 

[Wahoos4Life]

Also, on a side note

Has anyone with a 106 used this anntena?

http://www.scannermaster.com/ProductDetails.asp?ProductCode=28-541173&CartID=1

Im looking for a good replacement for portable use, wondering what the range gain would be with that

 

[Wahoos4Life]

P.s.

Sorry for all the questions

this stuff is all new to me, and I want to make sure I get the proper stuff

Thanks again for all the help

 

[ridgescan]

Like I said in another thread about discones and above-the Diamond DJ-130 kicks overall ass in the discone realm. Tough to weather, and I have recieved up to 45 miles from here on this thing.

 

[KT4HX]

I agree, as the others have said, go with a quality discone. I checked Kevin's profile and concur with his recommendation of using LMR-400 cable. Since a discone is a unity gain antenna, and as we all know, there is some loss involved with coax, then you want the lowest loss cable you can afford, and keep your run as short as you can. The higher in frequency you go, the more loss cable exhibits, and as the length increases so does loss. Therefore, as important as your antenna is, the cable is even more important when trying to bring that signal into your house.

One thing of concern when using an external antenna with a GRE produced scanner, is that they have very hot front ends. Therefore, they are more prone to overload than Uniden products (at least from my experience and from what I see in the forums). Therefore, you might find your scanner is overloaded at times with strong signals. You might have to utilize the scanner's attenuator more with your outside antenna.

 

[Wahoos4Life]

yea i was going to get a 100 ft 400lmr Nmale Bnc male pre made coax cable, Im really hoping 100ft is enough, I almost think it is going to be extra, when the weather clears up, Im going to have to head up to the roof, and do some measuring, and thats not going to be easy becuase it is not a flat roof

 

[mancow]

Absolutely!!! If you you use good cable, even RG-6 75 ohm... if you put that thing up there the difference will be incredible. Just be prepared that once you do it you will keep doing it until the roof looks like metal porcupine.

...portions deleted...My big question is, Is getting a Quality Discone Antenna up on the roof, mounted on the chimney...


...1.Well it really make a Big enough noticable differnce when using the scanner inside, attached to the discone, apposed from the stock anntena?

 

[KT4HX]

I certainly hope so too, because as good as LMR-400 is, it still has loss, and the longer it is, combined with the higher in freq you go, the loss can be enough to degrade reception of distant signals significantly. As nice as discones are for wide frequency coverage, since they don't have any appreciable gain to combat coax loss, then, depending on your target frequency range, you might not see as much improvement as you would hope. Keeping the cable to the minimum length you can is the right way go to. For example, by using a coax cable loss calculator, the following illustrates losses using 100 ft of LMR-400:

at 160 MHz you would experience 1.569 db of loss
at 470 MHz you would experience 2.75 db of loss
at 850 MHz you would experience 3.766 db of loss

And remember that for every 3 db of loss you have, your signal level is cut in half. If you had a 50 ft run then the losses above would be cut in half. Just food for thought. Those figures are with LMR-400, so you can just imagine what would happen if you tried to use something like RG-58.

I'm only passing this along to get across how important keeping your cable length to a minimum is, even with good quality cable like LMR-400. The cable type coupled with quality installed connectors are critical at anytime, but take on added importance as your cable run increases.

yea i was going to get a 100 ft 400lmr Nmale Bnc male pre made coax cable, Im really hoping 100ft is enough, I almost think it is going to be extra, when the weather clears up, Im going to have to head up to the roof, and do some measuring, and thats not going to be easy becuase it is not a flat roof

 

[Wahoos4Life]

I certainly hope so too, because as good as LMR-400 is, it still has loss, and the longer it is, combined with the higher in freq you go, the loss can be enough to degrade reception of distant signals significantly. As nice as discones are for wide frequency coverage, since they don't have any appreciable gain to combat coax loss, then, depending on your target frequency range, you might not see as much improvement as you would hope. Keeping the cable to the minimum length you can is the right way go to. For example, by using a coax cable loss calculator, the following illustrates losses using 100 ft of LMR-400:

at 160 MHz you would experience 1.569 db of loss
at 470 MHz you would experience 2.75 db of loss
at 850 MHz you would experience 3.766 db of loss

And remember that for every 3 db of loss you have, your signal level is cut in half. If you had a 50 ft run then the losses above would be cut in half. Just food for thought. Those figures are with LMR-400, so you can just imagine what would happen if you tried to use something like RG-58.

I'm only passing this along to get across how important keeping your cable length to a minimum is, even with good quality cable like LMR-400. The cable type coupled with quality installed connectors are critical at anytime, but take on added importance as your cable run increases.

would that other antenna link I posted serve me better then sense I have a somewhat distance to cover with cabling?. The discrption of that portable antenna, made it seem like it was quite well

This one: http://www.scannermaster.com/ProductDetails.asp?ProductCode=28-541173&CartID=1

 

[KT4HX]

Don't get me wrong, I'm not trying to shy you away from installing a discone in the least. Just more to make you aware of the importance of coax in the installation. The antenna you linked to is a good antenna I'm sure, but it still will be used indoors or out in your yard, versus installing an antenna up on the chimney. True, you wouldn't have the loss associated with it that you will incur with a long cable run, but based on your previous postings, you still have to deal with some interference in your house. A base station, outdoor mounted antenna will still be what you want to install if you can, as elevation above ground is a very good thing to have.

Perhaps you mentioned, but I don't recall seeing it, but what and where specifically are you trying to receive? What frequency ranges? Is it that you're trying to pick up your neighboring county's police and fire/ems? Or are your targets broader and more distant than that? Just curious.

If you want to use that antenna for portable use, then thats ok. For portable I can highly recommend the Diamond RH77CA. It is a dual band ham antenna VHF/UHF, and does very well indeed. Many members here use them.

would that other antenna link I posted serve me better then sense I have a somewhat distance to cover with cabling?. The discrption of that portable antenna, made it seem like it was quite well

This one: http://www.scannermaster.com/ProductDetails.asp?ProductCode=28-541173&CartID=1

 

[Wahoos4Life]

I scan whatever, Nothing to inperticular, there are just some far away freqs (mostly ham) that i would like to try and get improvement on aswell

basicly, Improvement alltogether

Somewhere between 40-60 miles

is that portable replacement i linked you two worth my wild too, as in alot better than the stock for the 106, or just a slight improvement?