Active Antennas
Stephen Drummonds
antenna?? Thanks for any comments about this Steve
D Peter Maus
> Can anyone tell me about them?? Are they any better or worse than wire
> antenna?? Thanks for any comments about this Steve
>
>
An active antenna can be a wonder. Compact size. Excellent gain.
Offers a lot of mounting choices. Uniform impedance across the spectra.
An active antenna can also be a PITA. Subject to overload.
Increased noise floor. Fragile connections. Susceptible to damage by
static.
Two things will determine whether an active antenna will be right
for you: 1) the quality of the active antenna. 2) the RF levels in
your listening area.
If you're not in a high RF zone...that is to say, if you don't
have local MW transmitters...you can get away with a relatively
inexpensive active while still enjoying decent performance. A poorly
designed active in a high RF area, will overload. Producing cross
modulation artifacts, and some stations will appear multiple
locations up and down the dial. You may also experience hum when a
strong clear signal is zeroed in.
A nearby lightning strike can wipe out an active in a stroke.
A random wire is not subject to overload. Although the front end
of your receiver may be. A random wire can be cut to size and
conditions. And will often have a lower noise floor at the input to
your receiver than an active. If you do overload your receiver, you
can always reduce the length of the wire.
A good active can cost you between $400 and $600 without
cracking a sweat. A good active will often require careful placement
to avoid man made noises. But this can be true of any antenna.
Are they better or worse? Neither. Each has its applications.
Each is superiour under specific conditions. You have to determine
if an active is right for you based on your own unique
circumstances, expectations.
My personal recommendation...start with a random wire, and see
how it works. Then experiment to determine if modifying your random
wire will get you where you want to go. Along the way, if an active
is a better choice, you'll see the clues.
I have one active which I take on the road with me. At the home
base, I use only passives.
Telamon
"Stephen Drummonds" <step...@centurytel.net> wrote:
> Can anyone tell me about them?? Are they any better or worse than wire
> antenna?? Thanks for any comments about this Steve
That's a big topic. It depends on many factors like what kind of active
antenna you are looking at and comparing it to what kind of passive
antenna. A big factor is where you live. If you live in town with a lot
of local noise on a small lot an active antenna could be a good choice.
If you are far apart from your neighbors and have a good size lot a
passive wire antenna is probably a better choice.
You are going to have to give us more information.
--
Telamon
Ventura, California
none
> Can anyone tell me about them?? Are they any better or worse than wire
> antenna?? Thanks for any comments about this Steve
>
>
pli...@telkomsa.net
wrote:
> Can anyone tell me about them?? Are they any better or worse than wire
> antenna?? Thanks for any comments about this Steve
D Peter Maus and Telamon gave you good advice. Always try a passive
wire antenna first if you have enough yard space. See my thoughts on
that and my own experiments over the years at:
http://www.dxing.info/community/viewtopic.php?f=17&t=2347&sid=2c8b2dae1e521a93c32495db5c0f1183
If you can't get up a passive antenna then there is quite a wide
choice of active powered antenna's. The best reviews in one place of
all those can be found in Passport to World Band Radio: see
http://www.passband.com/
It's well worth buying because it has good advice and good reviews of
all sorts of radio gear. However, I don't always agree with them as I
have owned some of things that they rate quite highly and found them
absolute junk (mainly anything MFJ [Mighty Fine Junk]).
With active antenna's the general rule applies - the more you pay the
better it will be. The cheaper ones tend to pick up a lot of static
and suburban noise and can be subject to overloading if you have
powerful stations nearby. Also some of them are not very good on the
AM MW bands and may not work on the LF/LW band at all. The two best
actives in my opinion are the Wellbrook Ala1530 and the RF Systems DX1
Professional MkII. See:
http://www.wellbrook.uk.com/products.html#ALA1530
http://www.rf-systems.nl/DX-one.html
I have owned a DX1 Pro for eight years now and it gives me superb
reception. Here are my various thoughts on this great antenna:
http://www.dxing.info/equipment/dx1pro.dx
http://www.dxing.info/community/viewtopic.php?f=17&t=2343
http://www.dxing.info/community/viewtopic.php?f=17&t=2353
Please remember though that active antenna's must have the same care
and attention to their placing as a good passive wire antenna. The
higher up they are the better, erect it away from household noise
sources and ground it to earth well.
Universal also have a good range of antenna's. See:
http://www.universal-radio.com/catalog/sw_ant.html
Have fun and good luck.
John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
Icom IC-7700, Icom IC-756 PRO III with MW mods
ERGO software
Drake SW8. Sangean 803A
Sony 7600D, GE SRIII, Redsun RP2100
Antenna's RF Systems DX 1 Pro Mk II, Datong AD-270
Kiwa MW Loop.
http://www.dxing.info/about/dxers/plimmer.dx
Bob Miller
I have a Dymek DA100D active antenna I've used for years, indoors, on
an NRD-525 receiver. It pulls in stations, but not as well as a full
size outdoor wire antenna -- the Dymek is about 2 S-units down on a
given frequency, compared to an Alpha Delta 1/4 wave swl sloper.
On the other hand, the Dymek is a heck of a lot smaller than a big
outdoor wire; it has about a 5-foot whip on it.
I do like the Dymek indoors, as it allows safe listening when there
are thunderstorms about. But a simple wire, thrown out the window, may
receive as well or better, and be a lot cheaper.
Also, in reference to another post, I'm about a mile from a 50,000
watt AM station at 550 khz and it does not seem to cause a problem
with the Dymek active antenna.
bob
k5qwg
Stephen Drummonds
research thankgs again Steve
"Bob Miller" <NOS...@neosoft.com> wrote in message
news:pgsia4lhdt3k4mdq5...@4ax.com...
Dave
> Thanks to all who gave me some very good answers I will do some more
> research thankgs again Steve
Don't forget the MFJ-1024. Pretty much the same as the Dymek, except for
the flimsy mechanicals on the MFJ.
cuh...@webtv.net
need to tightnen up a few nuts, bolts, or screws.I think they have a few
brews while they (Mighty Fine Junk) are working.
www.MFJEnterprises.com
I have never used an active antenna before (or have I? that Tiny Tenna
which was dead on arrival) so I really don't know.
cuhulin
cuh...@webtv.net
Union Pacific Railroad.
Wayyyyyy back in those years while the Railroads were building, some of
them had a Railroad Car that had prostitutes in those Cars.
cuhulin
cuh...@webtv.net
antennas introduce ''noise'' into the signal.
Now, the Red Light District got it's name many years ago when some
Railroad people would set their red lantern down in front of a window
outside of whichever of their galfriends they were visiting.That
Railroad lantern meant, Keep Out!
Dave
MFJ is a love-hate kind of thing. Once I "hardened" my 1024 outside unit
it has performed flawlessly.
Dave
They might be called "Stoner" nowadays.
harvey
> Now, wait a minute! True, if you buy any Mighty Fine Junk, you might
> need to tightnen up a few nuts, bolts, or screws.I think they have a few
> brews while they (Mighty Fine Junk) are working.www.MFJEnterprises.com
MFJ Pre selectors always did a pretty fine job for me!
>
> I have never used an active antenna before (or have I? that Tiny Tenna
> which was dead on arrival) so I really don't know.
> cuhulin
Had a tiny tenna hoked up in between the Pre selector and the set;
Zouds !! Pu;;ed in Lotta stuff !
But without the pre selector it was just overload heaven;
Air planes, Tai Cabs; heck didn't really need a scanner
Signals was all piled on top of one another..
Currently have a Son AN-LP-1;
Pretty good little rig, has a pre selector built right in.
RHF
The "DYMEKS" -aka- McKay Dymek DA-100E Active Antenna
are readly available everyday via Universal-Radio.Com
http://www.universal-radio.com/catalog/sw_ant/0328.html
Coverage is 500 kHz to 30 MHz
56 Inch Whip Antenna with 50 Foot of Coax Cable
MFJ-1024 Outdoor Active Antenna
http://www.universal-radio.com/catalog/sw_ant/1132.html
Coverage is 50 kHz to 30 MHz
54 Inch Whip Antenna with 50 Foot of Coax Cable
LF Engineering H-800 "SkyMatch" Active Antenna
is readly available everyday via Grove Enterprises
http://www.grove-ent.com/ANT15.html
and via the LF Engineering.Com website
http://www.lfengineering.com/products.htm
Coverage is 10 kHz to 50 MHz
26 Inch Antenna Probe with 50 Foot of Coax Cable
iane ~ RHF
.
RHF
- They might be called "Stoner" nowadays.
They are presently called "McKay-Dymek"
-aka- McKay Dymek DA-100E Active Antenna is
RHF
wrote:
- Can anyone tell me about them??
- Are they any better or worse than wire antenna??
- Thanks for any comments about this
- Steve
.
Three 'Tips' For Most Active Antennas : Location + Grounding +
Mounting
http://groups.google.com/group/rec.radio.shortwave/msg/fe4b0674c12e9f59
.
Indoor Antennas and Active Antennas
http://groups.google.com/group/rec.radio.shortwave/msg/02a05ebb94d76b0b
http://groups.google.com/group/rec.radio.shortwave/msg/8e7b7cb20e7d643f
.
Shortwave Listening (SWL) : Active Antenna ? -or- Wire Antenna ?
http://groups.google.com/group/rec.radio.shortwave/msg/04ae30c852c6cb3c
http://groups.google.com/group/rec.radio.shortwave/msg/258fc6cb0d502452
.
ABOUT - "Omni" {Non} Directional Vertical Active Antennas
http://groups.google.com/group/rec.radio.shortwave/msg/57df7f47f701f5f4
.
SWLers - Two Important Things To Do With Any Active Antennas
are . . .
http://groups.google.com/group/rec.radio.shortwave/msg/b6c057920e20ac0c
They Work Well for Small Low Noise Passive Antennas Too !
.
Alternatives to the 'old' Sony AN-1 Active Whip LW/MW/SW Antenna . . .
http://groups.google.com/group/rec.radio.shortwave/msg/729ddff9340a4743
.
One Yard or One Metre Diameter Hula-Hoop
Signal Turn (1T) Coax Cable {Shielded} Loop
Antenna for Shortwave Radio Listening (SWL)
http://groups.google.com/group/rec.radio.shortwave/msg/b22753cba485235d
.
SWL -Newbies- Beyond the "Tiny-Tenna"
-DIY- Active Antenna Kits and a lot more . . .
http://groups.google.com/group/rec.radio.shortwave/msg/b5d90a539eb30f90
http://groups.google.com/group/rec.radio.shortwave/msg/5821a5fed2d7de20
.
The Added Task of Tuning the Active Antenna
-versus- Simply Tuning the Radio and Being
Focused on Listening-to-the-Radio
http://groups.google.com/group/rec.radio.shortwave/msg/230ba7572f444a03
.
Simplifying the Dallas Lankford "Relay Tuned"
Fifteen Foot (15') Noise Reducing Vertical Antenna
for Shortwave Listening (SWL) Only
http://groups.google.com/group/rec.radio.shortwave/msg/9d68f0da6c38d25a
.
PA0RDT 'Micro' Active Antenna - What Is It ?
-and- How To Install It Better !
http://groups.google.com/group/rec.radio.shortwave/msg/14b1c17886a44d60
.
The In-Door Shortwave Listener (SWL) Antenna
-with- An Out-Side Antenna Element
http://groups.google.com/group/rec.radio.shortwave/msg/80a916f4cc134e1d
http://groups.google.com/group/rec.radio.shortwave/msg/3eb0d610a70a61f2
.
Two Ready-Made Alternatives to the C.Crane
Twin Coil Ferrite Rod AM/MW Antenna . . .
http://groups.google.com/group/rec.radio.shortwave/msg/71f7d19e4f3054ce
.
Building as Torus Tuner {Equivalent} AM/MW Loop Antenna
http://groups.google.com/group/rec.radio.shortwave/msg/dfd433c33551bd61
.
.
shortwave radio listening -swl- keeping it simple and practical
-kisap- it is about listening to the radio - iane ~ RHF {pomkia}
.
Are You Interested in building a better Shortwave Listening*
(SWL) Antenna ? {SWL Group} => http://tinyurl.com/ogvcf
GoTo => http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
RHF's Standard "Shortwave Radio Listener (SWL) Antennas Group"
Reference Message Signature-Line => http://tinyurl.com/25zbrg
http://groups.google.com/group/rec.radio.shortwave/msg/411dac3b4a1798e0
.
* Remember 55.5% of Shortwave Radio Listening (SWL)
is the Shortwave Antenna =>http://tinyurl.com/ogvcf
.
RHF's Radio Shack in Twain Harte, California -USA-
SHACK INFO =>http://tinyurl.com/2skmxm
Shortwave Radio / Receiver and SWL Antenna Info
.
-=2SKMXM=-
-=25ZBRG=-
SWR3:SWL:INFO
.
Bob Miller
<rhf-new...@pacbell.net> wrote:
>On Aug 19, 9:12 am, Dave <j...@somewhere.com> wrote:
>> On Tue, 19 Aug 2008 10:27:28 -0500, cuhulin wrote:
>> > Dymeks are as rare as hens teeth nowadays, aren't they? I think active
>> > antennas introduce ''noise'' into the signal.
>>
>> > Now, the Red Light District got it's name many years ago when some
>> > Railroad people would set their red lantern down in front of a window
>> > outside of whichever of their galfriends they were visiting.That
>> > Railroad lantern meant, Keep Out!
>>
>> >www.mfjenterprises.com/about_mfj.php
>> > cuhulin
>
>- They might be called "Stoner" nowadays.
>
>They are presently called "McKay-Dymek"
>-aka- McKay Dymek DA-100E Active Antenna is
>readly available everyday via Universal-Radio.Com
>http://www.universal-radio.com/catalog/sw_ant/0328.html
>Coverage is 500 kHz to 30 MHz
>56 Inch Whip Antenna with 50 Foot of Coax Cable
The "E" looks identical to my DA-100D, and the price has gone up only
$20 since 1988. Not a bad buy.
bob
k5qwg