I purchased the ST2 from Antenna Craft http://www.antennacraft-tdp.com/ST2.htm to replace my Scantenna which I brought from Radio Shack (same antenna, different Mfg) It works very well. I paid about $30 from http://www.radiooutfitter.com
A Decent Antenna !
- Thread starter fireman_dude
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Nice , how's reception ?
Can you pull in Philly or Trenton ?
Can you pull in Philly or Trenton ?
From Ocean County I can actually pull in the five boro's of NYC. I can receive Camden County Dispatch, but I have a hard time getting Trenton City. Philly seems to be hit or miss. I have received Philly South District in the past but North I have never received.
Starion
Member
Thanks for sharing the information. The ST2 even comes with a BNC adapter.
Does anyone know if there is a difference between the Antennacraft ST2 and this antenna:
http://www.antennawarehouse.com/Scanner/Scantenna.htm
The reason that I'm asking is because the ST2 is about 1/2 the price.
Is the ST2 about 8' long?
Does it have to be mounted vertically? I have to mount it in my attic crawl space and it will only fit horizontally.
Thanks in advance,
Rich C
http://www.antennawarehouse.com/Scanner/Scantenna.htm
The reason that I'm asking is because the ST2 is about 1/2 the price.
Is the ST2 about 8' long?
Does it have to be mounted vertically? I have to mount it in my attic crawl space and it will only fit horizontally.
Thanks in advance,
Rich C
Starion
Member
The scantenna is about 8 and a half feet long. The ST2 and scantenna look similar. I don't know what the differences are. Perhaps someone else can answer the question.
Most communications in the public service bands use antennas that are mounted vertically. The antenna may not perform as well in a horizontal position than in a vertical position.
However, you should be able to recieve very strong and some weak signals if you mount the antenna horizontally. You can try mounting the antenna horizontally. If you can't hear many stations, then you must mount the antenna vertically.
Good luck!
Most communications in the public service bands use antennas that are mounted vertically. The antenna may not perform as well in a horizontal position than in a vertical position.
However, you should be able to recieve very strong and some weak signals if you mount the antenna horizontally. You can try mounting the antenna horizontally. If you can't hear many stations, then you must mount the antenna vertically.
Good luck!
As far as I'm concerned, they look the same to me. As far as mounting, I don't think it will make a difference if you mount it vertically or horizontally. Do expect some loss in performance if you mount it in the attic. Not much but some loss will be experienced.
I should have mentioned that my primary listening is as follows:
800 MHz - 30% 5-10 miles away
500 MHz - 50% Local to me
150 MHz - 15%
46 MHz - 5%
I also currently use a RS Discone with RG6 and F connectors with a BNC adapter at the scanner. Should the ST2 improve the reception over my current setup? even if mounted horizontally?
Thanks again.
800 MHz - 30% 5-10 miles away
500 MHz - 50% Local to me
150 MHz - 15%
46 MHz - 5%
I also currently use a RS Discone with RG6 and F connectors with a BNC adapter at the scanner. Should the ST2 improve the reception over my current setup? even if mounted horizontally?
Thanks again.
Al42
Member
Yes. It should get you about twice the signal, since the discone is pretty much a vertically polarized isotropic antenna (yes, for the purists I know that "vertical iso" is an oxymoron), so a plain dipole, which is what this antenna is, has 3db (twice the signal) gain.rgchristy said:
No. Cross-polarization - the antenna on one end of the path vertical (non-directional public service is all done with vertical polarization) and the antenna on the other end horizontal - your setup - gives you a 10db (90%) loss. Your net over the discone would be about 45% less signal.
If you forget about making the antenna work on 46 MHz (local fire? they'll be strong enough to pick up on a 150 MHz antenna), you need a ground plane with 3 vertical elements - 150, 500 and 800. The longest one, 150, will be around 16". (You could actually take off the bottom half of the Scantenna and replace it with a sheet around 5 feet in diameter.)
http://www.eham.net/articles/7005 You'll want a 3rd rod sticking up, about 3" long, for 800. The longer one should be about 16" for the bottom of the 150 MHz band. Figure on about $10-$15 if you have to buy everything - drill bit, welding rod, silicone caulk, piece of pipe to mount it, and it should perform just about as well as a Scantenna. (If you don't have a soldering iron or gun, get someone to do the soldering for you. It's easy to melt the insulator on a SO-239.)
Next problem - attic mounting. Do you have foil-faced insulation on the inside of your roof? If you do, no antenna mounted up there will be worth anything. If the insulation is in the beams under the floor of the attic (whether there's actually a floor there or not), it won't hurt and the anternna should work pretty well.
Hi guys,
Both of those antennas look the same but not quite. That "Star Trek communicator badge" thingamajig is a device for broadening the bandwidth, a trick used on UHF TV antennas. Aside from that minor difference both are fan dipoles mounted vertically.
Now this is VERY important, on VHF Hi Band cross polarization loss is >20dB and it gets worse as the frequency goes up. On UHF I would be surprised if you hear anything but the transmitter down the street if you mount an antenna horizontally. I can vouch for that personally, since at least for now I'm limited to a vertical I can barely communicate with a 2M ham in Barnegat using SSB which is horizontal. Point Pleasant isn't all that far from Barnegat, but I have no trouble with a guy in Pennsylvania when he switches to vertical.
Hmmm, Fireman Dude is getting to know me. (;->)
"Yes. It should get you about twice the signal, since the discone is pretty much a vertically polarized isotropic antenna (yes, for the purists I know that "vertical iso" is an oxymoron), so a plain dipole, which is what this antenna is, has 3db (twice the signal) gain."
Oxymoron and the wrong dB calculation aside, whatever gave you that idea? A discone, dipole and groundplane ALL have unity gain. I really wish this mathematical model, that misleading "standard" called isotropic would bite the dust, it's sole purpose is to confuse people and sell antennas. Before this snake oil salesman came along dBd was the standard reference, this dBi has got to go and the confusion stop.
The only real difference between those antennas is SWR bandwidth. The dipole is fairly narrow, (large diameter conductors broaden it somewhat) the groundplane a bit broader and the discone broader still. The discone has been used at airports in particular for many years because in many applications the radios are frequency agile.
Of course we're talking transmitting here, for receive the SWR bandwidth matters not. Still that broad band charicteristic is very helpful although the antenna is completely nonresonant out of band. You'll notice in the adverts that one may be used for transmitting only where it's resonant AND provides a 50 ohm load to the transmitter. I'm about to go all techie on you with odd multiples of a quarter wave? No, just take my word for it, the discone is just about the best scanner antenna around overall provided you're not looking for a high gain specialized antenna.
Oh let's not forget the second runner-up, the fan dipole that opened this discussion. Being a group of resonant dipoles connected together at the centers it makes a very good multi-band transmitting antenna. Hams have been using them for years and so have SWLs who like to concentrate their efforts on selected bands. Like the discone it has unity gain across the board and again being nonresonant out of band matters not for receive. I'll bet if you put them side by side in a wide open test range and took accurate measurements it would be a close race.
Both of those antennas look the same but not quite. That "Star Trek communicator badge" thingamajig is a device for broadening the bandwidth, a trick used on UHF TV antennas. Aside from that minor difference both are fan dipoles mounted vertically.
Now this is VERY important, on VHF Hi Band cross polarization loss is >20dB and it gets worse as the frequency goes up. On UHF I would be surprised if you hear anything but the transmitter down the street if you mount an antenna horizontally. I can vouch for that personally, since at least for now I'm limited to a vertical I can barely communicate with a 2M ham in Barnegat using SSB which is horizontal. Point Pleasant isn't all that far from Barnegat, but I have no trouble with a guy in Pennsylvania when he switches to vertical.
Hmmm, Fireman Dude is getting to know me. (;->)
"Yes. It should get you about twice the signal, since the discone is pretty much a vertically polarized isotropic antenna (yes, for the purists I know that "vertical iso" is an oxymoron), so a plain dipole, which is what this antenna is, has 3db (twice the signal) gain."
Oxymoron and the wrong dB calculation aside, whatever gave you that idea? A discone, dipole and groundplane ALL have unity gain. I really wish this mathematical model, that misleading "standard" called isotropic would bite the dust, it's sole purpose is to confuse people and sell antennas. Before this snake oil salesman came along dBd was the standard reference, this dBi has got to go and the confusion stop.
The only real difference between those antennas is SWR bandwidth. The dipole is fairly narrow, (large diameter conductors broaden it somewhat) the groundplane a bit broader and the discone broader still. The discone has been used at airports in particular for many years because in many applications the radios are frequency agile.
Of course we're talking transmitting here, for receive the SWR bandwidth matters not. Still that broad band charicteristic is very helpful although the antenna is completely nonresonant out of band. You'll notice in the adverts that one may be used for transmitting only where it's resonant AND provides a 50 ohm load to the transmitter. I'm about to go all techie on you with odd multiples of a quarter wave? No, just take my word for it, the discone is just about the best scanner antenna around overall provided you're not looking for a high gain specialized antenna.
Oh let's not forget the second runner-up, the fan dipole that opened this discussion. Being a group of resonant dipoles connected together at the centers it makes a very good multi-band transmitting antenna. Hams have been using them for years and so have SWLs who like to concentrate their efforts on selected bands. Like the discone it has unity gain across the board and again being nonresonant out of band matters not for receive. I'll bet if you put them side by side in a wide open test range and took accurate measurements it would be a close race.
Al42
Member
BTDT - which is why I say that the discone is a less-than-unity-gain antenna, referenced to 0dbd. Its main feature is a good match over a very wide frequency range, not 0dbd gain.kb2vxa said:
Thanks to everyone so far. My antenna is mounted above the insulation in a peak area below the roof. I have about 5' in height and about 12' in length to work with.
Since becoming disabled, I don't have the ability to make the antenna suggested, so I'm limited to a purchase only and have my nephew install it.
Does anyone know if there is anything better within those limitations that would be better than my current RS discone?
Again, thanks in advance,
Rich C
Since becoming disabled, I don't have the ability to make the antenna suggested, so I'm limited to a purchase only and have my nephew install it.
Does anyone know if there is anything better within those limitations that would be better than my current RS discone?
Again, thanks in advance,
Rich C
I would just suggest you use a thicker gauge cable (low loss) maybe a quad shield or something like that. Just be carefull of aluminum duct work in your attic crawl which can also have a effect on signal.
Al42
Member
It's the insulation between the center conductor and the shield that determines loss, not the gauge of the wire or the thickness of the cable (within reason).fireman_dude said:
Why? Unless he has some noise source in his attic, that'll just increase the cost. LMR-400 is just fine. So is Belden 9913 if the run isn't too long.
If it's within the antenna's field. It won't affect the cable.
Sorry to dredge up an old topic...
I am awaiting delivery of a scantenna from grove. At the present time, I will not be able to get it mounted on the roof vertically, so it will be temporarily placed inside my attic horizontally. Is anyone using this type of set-up that can provide some performance info? I know I do not have 7 feet to work with in the attic for a vertical set-up...and I know it is not optimal, but will it be worth the effort to get it in the attic?
I am awaiting delivery of a scantenna from grove. At the present time, I will not be able to get it mounted on the roof vertically, so it will be temporarily placed inside my attic horizontally. Is anyone using this type of set-up that can provide some performance info? I know I do not have 7 feet to work with in the attic for a vertical set-up...and I know it is not optimal, but will it be worth the effort to get it in the attic?
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