Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.
Thanks...Bob

BobS wrote:
Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.


Bob, a friend of mine has the ham radio transmitting version. It's half
a trap dipole with a proprietary matching coil. We have some theories of
exactly what the coil is, but they are speculation, so I'll leave it
out.

As a dipole, you need two sides. PAR accomplishes this with the ground side
of the dipole being ground. Since it connects to a coax cable, the feed
is unbalanced, and so is the antenna.

In short it needs a ground to operate. Otherwise it is just a wire (with
a loading coil) stuck at the end of a coax.

If I were you, I would make a ground at the receiver end of your wire.
The best would be a tuned counterpoise, such as 50 feet of wire connected to
a cheap antenna tuner. Second best (but maybe not very different in actual
performance) would be a multi conductor wire, such as a rotor cable, cut
at various wavelengths.

From what I have read, the best length for a counterpoise wire that is not
on the ground is 28% of a wavelength. Since you are receiving and not
transmitting, length is not all that critical, nor is insulation.

The wire can be run around the floor of your room, even looped around if it
is a smaller room.
The far end of the wire is a voltage node if you are transmitting and
therefore needs good insulation. For reception, enough to prevent it from
causing a short if it ends up in the wrong hole is good enough.

Since it will be "cold", it can be under a rug, etc.

For electrical saftey, I recommend that some sort of grounding (a wall
outlet near the window is fine) is used when not receiving to prevent
static build up or a nearby lightening strike damaging anything.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.

BobS wrote:
Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.
Thanks...Bob

What kind of receiver? Does it have an ANT IN receptacle? I'd say
OTTOMH a 50' wire to a tree should work as well as anything in that
location.

Thanks Geoffrey and Dave,

R8B

On 4/4/2010 10:25 AM, dave wrote:
BobS wrote:
Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.
Thanks...Bob

What kind of receiver? Does it have an ANT IN receptacle? I'd say OTTOMH
a 50' wire to a tree should work as well as anything in that location.

On Apr 4, 5:45*am, BobS wrote:
Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.
Thanks...Bob

Dale at PAR will tell you that a ground helps but is not essential.
If the connecting end is high up in a tree, for example, it would be
difficult (and perhaps not terribly helpful) to even attach a ground
wire of adequate size to make it to a real earth ground.

I use one as a portable antenna, and I never use a ground. Most of the
time it works pretty well, but it does pick up a lot of noise.

On 4/4/2010 8:45 AM, BobS wrote:
Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.
Thanks...Bob

On Apr 4, 8:45*am, BobS wrote:
Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.
Thanks...Bob

From PAR's website:

The Par End-Fedz are a full length half wave dipoles, but with an
important difference. The coax connector is at one end of the dipole,
where it is most needed. These antennas can be mounted horizontally,
vertically or as a sloper. No ground plane or counterpoise is needed.
Portable operation could not be easier. Simply hang the far end from a
tree limb–the coax is at the bottom. Hang it up in a hotel window or
string it up in the attic. End insulators are supplied making
suspension easy.

On 4 abr, 14:45, BobS wrote:
Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.
Thanks...Bob

Hello Bob,

Using a ground provision may reduce interference from domestic
equipment inside the building. Without the ground the cable braid will
"receive" interference from inside your home and transports this to
the antenna.

Are you able to connect the coaxial braid directly to a large metallic
fence on the balcony? If so, this will serve as a large local ground.
You may connect other large metallic structures to each other to
enhance the local ground (and reduce interference). This will be
better then using the safety conductor of the mains.

You may use a snap-on ferrite or other large ferrite core on the
coaxial cable that runs from outside to your receiver.

I don't know the price of the PAR antenna, but you may experiment with
just 40..50" of wire directly connected to the center conductor of the
coaxial cable. When the noise exceeds the receiver's noise, the
additional transformer will very likely not result in better signal/
noise ratio.

Depending on the lowest frequency of use, you may add an inductor
between center and braid to reduce the stress on your receiver caused
by nearby lightning strokes. Off course it is best to disconnect the
antenna in case of nearby lightning.

Best regards,

Wim
PA3DJS
www.tetech.nl
remove abc first in case of PM.

On 4 abr, 14:45, BobS wrote:
Anyone using the PAR Electronics EF-SWL Antenna please advise if a
ground is necessary. Will using the PAR without a ground be any better
than a 50' random wire? I live on the second floor of a condo and only
can use a very thin hidden wire from my receiver to a nearby tree. No
ground available. I read all of the glowing reviews of the PAR but all
of them are using a ground. Unfortunately I don't have that luxury. Any
other recommendations appreciated.
Thanks...Bob

Hello Bob,

Universal Radio mentions USD 66.95 for the antenna. It is probably
worth the price, but it doesn't mean it is better then a home brew
construction or give better reception with respect to your current
setup.

Spring has arrived and noise (from new electronic devices) increased
(on a very fat strip dipole in the top of the attic. I decided to try
a similar setup as you are considering.

As floating ground I used the metal frame (about 8' * 3.5') that holds
the windows. The antenna is 25' of wire with d=3mm and leaves the
house at a height of 14'. It runs partly horizontally and party
vertically.

The transformer/common mode choke has same functionality as the PAR
antenna. In addition I can disable the 1:9 impedance transformer
(while the common mode filter remains). I use a narrow band tunable
preselector to avoid "noise" from intermodulation products.

Especially on the low HF, reception (S/N ratio) is better then with
the dipole under the roof. Signal output is significantly higher.
Bypassing the 1:9 impedance transformer does reduce the signal output,
but doesn't change the S/N ratio. So the improvement in S/N doesn't
come from the 1:9 transformer, but just from the outside wire with
respect to the indoor strip type dipole. Note that the dipole also has
a 1:9 transformer with separate common mode filter.

The dipole, in some cases, is better then the outdoor wire with 1:9
transformer and common mode choke (less signal output, but better S/N
ratio).

Maybe this info can be helpful to you with regards to the purchase of
the PAR SW antenna.

Best regards,


Wim
PA3DJS
www.tetech.nl
in case of PM, don't forget to remove abc from the address.

Wimpie wrote:

Universal Radio mentions USD 66.95 for the antenna. It is probably
worth the price, but it doesn't mean it is better then a home brew
construction or give better reception with respect to your current
setup.



As I said before, a friend of mine has their ham version, which is what I
base the following comment on. The quality of construction and materials
used is very high. It is not an antenna that your average guy is going to
duplicate for a lot less money.

Assuming I could figure out the wiring for the loading coil and the traps
(his has traps, I don't know if this one does), I could duplicate it,
but it would look like something someone with knowledge, but little skill
had built (becuase it would be built that way).

If I were in the US, I would buy one. Since ordering things like this is
difficult, and delivery services cost a small fortune (an order sent via
UPS or FEDEX would cost at least $50 and probably $20 in taxes), I would make
one an live with what I had. :-)


The transformer/common mode choke has same functionality as the PAR
antenna. In addition I can disable the 1:9 impedance transformer
(while the common mode filter remains). I use a narrow band tunable
preselector to avoid "noise" from intermodulation products.

Can you describe it better? a 1:9 balun as it were is easy to make, and 1:4
VHF TV/FM radio ones are getting harder to find, but are still out there.

Thanks, and 73,

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge or
understanding, as in he has a sub-wikipedia understanding of the situation.
i.e possessing less facts or information than can be found in the Wikipedia.