T-bone wrote:

GeorgeF wrote in
ink.net:


redrum wrote:

Which is better?

is scantenna really omnidirectional? is it built for a better reception
on the most used frequencies or is really multiband?

who sells the better implementation of discone?


I have three scantennas and they work much much better than any discone
I've yet to own. In the last 5 years I have thrown away 2 discones
(even the Diamond $100+) because they didn't come close to what the
AntennaWarehouse ScanTennas could do.

Most of my listening is 225-400 MHz however have compaired them on many
other freqs as well.

I got my ScanTennas from
http://www.antennawarehouse.com/Scanner/Scantenna.htm
(AntennaWarehouse). Free shipping and speedy delivery.

George - Daytona Beach, FL
http://www.MilAirComms.com


I got one of those and am not overly impressed with it.
My discone consistantly pulls in stronger signals than the scantenna in
just about every range. The only variables are
1) Discone is about 5 ft higher up
2) Discone uses a better feed belden 9913
3) Discone uses an N connecter vs. BNC for scantenna.


You are compairing apples and oranges here. First your 5' higher on
the discone is going to be a little improvement.

But the HUGH HUGH HUGH difference is the coax! 9913 is much better than
the RG6 which comes with the ScanTenna. I don't use the RG6 that comes,
I replace it with either 9913 or LMR-400. But that alone your going to
see a major improvement on your ScanTenna in the UHF range.

N .vs. BNC, not much there.....

George - Daytona Beach, FL
http://www.MilAirComms.com

"GeorgeF" wrote in message
nk.net...


You are compairing apples and oranges here. First your 5' higher on
the discone is going to be a little improvement.

But the HUGH HUGH HUGH difference is the coax! 9913 is much better than
the RG6 which comes with the ScanTenna. I don't use the RG6 that comes,
I replace it with either 9913 or LMR-400. But that alone your going to
see a major improvement on your ScanTenna in the UHF range.

----------------------------------------------------------------------------------------

I dont think he's comparing apples to oranges at all. First off when it
comes to VHF or UHF, 5' more height is nothing. Second of all there is no
HUGE,, HUGE difference in db's of attenuation between RG 6 and 9913.
The "average" db of attenuation for 9913 per 100' from 1mhz to 1ghz is 2.17
db. The "average" atenuation for RG 6 per 100' from 1mhz. to 1ghz is 3.2 db.
The average difference between the 2 is 1.03 db, wouldnt even be noticeable.
And those specs. are for a 100' run. I believe he said his run was more like
30'. I use quad shielded RG 6 all the time and it works great, not to mention
its much easier to work with than the thick, stiff 9913, or LMR 400.


Jeff

GeorgeF wrote in
nk.net:

T-bone wrote:

GeorgeF wrote in
ink.net:


redrum wrote:

Which is better?

is scantenna really omnidirectional? is it built for a better reception
on the most used frequencies or is really multiband?

who sells the better implementation of discone?


I have three scantennas and they work much much better than any discone
I've yet to own. In the last 5 years I have thrown away 2 discones
(even the Diamond $100+) because they didn't come close to what the
AntennaWarehouse ScanTennas could do.

Most of my listening is 225-400 MHz however have compaired them on many
other freqs as well.

I got my ScanTennas from
http://www.antennawarehouse.com/Scanner/Scantenna.htm
(AntennaWarehouse). Free shipping and speedy delivery.

George - Daytona Beach, FL
http://www.MilAirComms.com


I got one of those and am not overly impressed with it.
My discone consistantly pulls in stronger signals than the scantenna in
just about every range. The only variables are
1) Discone is about 5 ft higher up
2) Discone uses a better feed belden 9913
3) Discone uses an N connecter vs. BNC for scantenna.


You are compairing apples and oranges here. First your 5' higher on
the discone is going to be a little improvement.

Very little, granted.
I've already pointed out that fact twice already.


But the HUGH HUGH HUGH difference is the coax! 9913 is much better than
the RG6 which comes with the ScanTenna. I don't use the RG6 that comes,
I replace it with either 9913 or LMR-400. But that alone your going to
see a major improvement on your ScanTenna in the UHF range.

Never said I used RG6.
RG8x is what I use for the scantenna feed.
I have no problem deferring to your judgement, more or less.
You are obviously more up to date than me on both equipment and methods.
I think its generally accepted that the discone is a great all around
monitoring antenna, but is really a jack of all trades, and master of none.
Ideally, one would want to have a discone, along with one or more other
antennas optimized for specific bands.
Thats what I had in mind with my setup, and so far it hasn't worked out,
but I must admit I haven't put a whole lot of effort into examining this
apparent problem.
I just don't think that discones should be dismissed as pure junk.
Within their limits, I've found them to be fine general all around signal
recievers, which is what their purpose is.

T-bone wrote:

I just don't think that discones should be dismissed as pure junk.
Within their limits, I've found them to be fine general all around signal
recievers, which is what their purpose is.

Agreed! You are absolutely right. George has been shilling Scantennas
for Antenna Warehouse for several years now. He belittles whatever else
anyone my recommend and refuses to acknowledge that another product may
suffice for another's purposes. His shamelessly partisan promotion gets
old after awhile.


--
Milepost 11.7 - UPRR Jeff City Sub - N 38°34'53", W 90°22'32", 680'
"We sleep safe in our beds because rough men stand ready in the night to
visit violence on those who would do us harm"

"Dan Morisseau" wrote in message
...
T-bone wrote:

I just don't think that discones should be dismissed as pure junk.
Within their limits, I've found them to be fine general all around signal
recievers, which is what their purpose is.

Agreed! You are absolutely right. George has been shilling Scantennas for
Antenna Warehouse for several years now. He belittles whatever else anyone
my recommend and refuses to acknowledge that another product may suffice
for another's purposes. His shamelessly partisan promotion gets old after
awhile.

A discone is going to exhibit no gain, in fact probably less than unity
gain, when compared to an isotropic, but you can essentially call a discone
a 0 dB gain antenna across its entire bandwidth of operation. Using an
oversimplification, the lower frequency of the discone will be largely
determined by cone and disc element lengths (about 0.25 and 0.17
respectively), the upper frequency by the gap between the two. Although a
discone will probably only exhibit an ideal response across about a 3 to 1
range (well short of this gap limitation). A dipole will exhibit a slight
gain over the same source (isotropic), about 2.7 dB in the real world,
across its bandwidth. However, the dipole will be much more narrow banded.
The dipole has a single resonant frequency, determined mostly by physical
size. It is easy to use transmit bandwidth to define 'peak' operation.
Transmit bandwidth is defined as the band between the two frequencies at
which the SWR on the feedline has risen to stated values, it being assumed
the SWR at the band center has previously been adjusted by some means to be
1:1. However, receive bandwidth can also be defined. Receiving bandwidth
is defined as the band between the two frequencies at which receiver input
power has fallen to 1/2 the level at the band center. It is described as the
3dB bandwidth. For a Zo-matched receiver, 3dB bandwidth is 2*Fc/Q where Fc
is the center frequency and Q is the intrinsic Q of the antenna. Remember
this Q and look at where it is in the formula. For receive antenna purposes
a lower Q will mean a broader bandwidth.

The Scantenna is a modified multiple dipole antenna, on the quoted website
it calls it a '15 element clustered dipole design'. The elements that splay
out from the main element are there to broaden the bandwidth. The short
elements on the mounting boom are to cover the higher frequencies. Without
having tried the antenna myself, but having more than a little bit of
professional experience with RF, I can make a pretty good stab at what I
would expect the antenna to do in use. The longest length is about 101
inches. This is going to put the lowest usable frequency around 50 MHz.
Guestimating the length of the other elements from this 101 number it looks
like they have selected lengths that fall near certain bands, probably the
'major' scanner bands. So that the antenna will probably function quite
well in those frequency areas. If you stay in those bands you will probably
get better performance with the scantenna than you will with the discone.
However, outside those narrow bands the discone will probably perform
better.

One thing to note. At the higher frequencies the Scantenna seems to use
short boom mounted dipoles. These WILL display a directionality based on
the relationship of the received signal directions to the main set of
elements. In other words, it will look 'down' the boom better than to the
side. At those higher bands the Scantenna will probably display a better
performance ONLY when the transmitting station is along this direction.
Other than that the discone will probably appear to perform better on
average.

So, depending on your primary scan activities, the discone will probably be
the less limited choice. But, if the Scantenna fits your specific
application it may exhibit a slight performance edge, within its band
limitations.

All just a guess on my part, but defendable. For most things I would opt
for a well designed and built discone myself.

C

"Colic" wrote in message
news:lZxDd.79015$k25.9878@attbi_s53...
All just a guess on my part, but defendable. For most things I would opt
for a well designed and built discone myself.

If your receiver had a front end with good dynamic range the discone might
be ok. Most scanners do not have particularly good dynamic range. The
discone will be fairly efficient in the FM broadcast band and also on some
TV channels. That may overload the scanner and result in poor performance
all around. It depends on how close the broadcast transmitters are to your
receiving antenna.

A five foot height difference can be significant if it allows the antenna to
clear nearby obstructions.

For most purposes a good grade of RG/6 like Belden 9116 performs well enough
that changing to 9113 will not result in a significant improvement. Quad
shield RG/6 has the same loss as ordinary RG/6 according to the Belden
catalog.

Has anyone had experience with both of these antennas.The 20-014 is the big
ground plane that was discontinued 5-6 years ago, it has several verticals
(three I think) and I think the radials are 14 or 15 ft wide, looks more
like a CB ground plane than a scanner antenna.
I'm trying to decide which one I want to go up with. If memory serves me
right MT gave the 20-014 a great write up. Rob Mills

Colic wrote:
For most things I would opt
for a well designed and built discone myself.

Something to consider. Anyone with basic hand tools can build their own
discone that will work just fine - and build it inexpensively, easily, and
quickly.
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