In article , "Robert11"
wrote:

Hello:

Will probably try a coax feed, and a Balun, to the random length wire
running around the four sides of my attic to reduce noise, hopefully.
Do listening only, up to 30 MHz.

a. For a receiving 9:1 Balun (coax to a random length wire in attic),
does the Balun have to be grounded ?

Or, is it grounded "adequately" via the coax - to the radio chassis - to
an earth ground from the radio chassis ?

[If the Balun Does require a ground (also), wouldn't this possibly
cause a ground loop in that it would be grounded at both ends ?]

b. Anyone have any experience with, or opinions on:

-the 9:1 Balun by RF Systems in the Netherlands
(termed a magnetic balun, how it's different from a normal toroidal
transformer coupling, I have no idea ?)

-or the unit by Win Radio (WiNRADiO WR-LWA-0130 Long Wire Antenna
Adapter
$39.95 ADP35)

c. Any significant difference in the type of coax used for listening
only, with a run of about 50 feet.
Used LMR 400 for my attic scanner, but would like to avoid the
hassle
of stringing the large diameter coax again, and possibly
just use a small diameter coax. Would one likely notice any
difference
up to 30 MHz ?

Thanks, Bob

Read the four articles at:

http://anarc.org/naswa/badx/antennas/

Your questions match their content remarkably well.

--
| John Doty "You can't confuse me, that's my job."
| Home:
| Work:

Balun Grounding Question ?
 

Hello:

Will probably try a coax feed, and a Balun, to the random length wire
running around the four sides of
my attic to reduce noise, hopefully. Do listening only, up to 30 MHz.

a. For a receiving 9:1 Balun (coax to a random length wire in attic),
does the Balun have to be grounded ?

Or, is it grounded "adequately" via the coax - to the radio chassis -
to an earth ground from the radio chassis ?

[If the Balun Does require a ground (also), wouldn't this possibly
cause a ground loop in that it would be grounded at both ends ?]

b. Anyone have any experience with, or opinions on:

-the 9:1 Balun by RF Systems in the Netherlands
(termed a magnetic balun, how it's different from a normal toroidal
transformer coupling, I have no idea ?)

-or the unit by Win Radio (WiNRADiO WR-LWA-0130 Long Wire Antenna Adapter
$39.95 ADP35)

c. Any significant difference in the type of coax used for listening only,
with a run of about 50 feet.
Used LMR 400 for my attic scanner, but would like to avoid the hassle
of stringing the large diameter coax again, and possibly
just use a small diameter coax. Would one likely notice any difference
up to 30 MHz ?

Thanks,
Bob

Bob,

So you are going to 'locate' your Random Wire Antenna in the Attic
and use a Magnetic Longwire 'type' Balun (MLB}.
- - - Here are My Thoughts:

#1. {First=Job #1} Make sure that you have a good outside Ground Rod
and a Heavy Duty Ground Wire routed/running up to your
radios/receivers.
+ TIP#1: Create a 'common' Ground Buss at this place in your "Shack"
to Tie-All Your [In House] Ground Together.

#2. Select your Long Wire Balun (actually a Matching Transformer) to
be used between the Random Wire Antenna Element and the Coax Cable.

#3. Select your Coax Cable (See the + TIP#2 below). Measure 'out'
distance (add an extra 5Ft to 10Ft) require for your Coax Cable. Fit
one-end of this Coax Cable with a Connector that 'matches-up-with'
your radio/receiver Coax Connector. Run/Route your Coax Cable to the
Attic. Then Fit the other-end of this Coax Cable with a Connector
that 'matches-up-with' your Balun's Coax Connector. If you follow the
+ TIP#2: Then also use the built-in Ground wire to Ground your Balun
in the Attic.
+ + + IMHO: For In-the-Attic Antennas this is the Best, Simplest,
Cost Effective and 'most' Practical Method of running/routing a
'common earth' Grounding Point to the Attic and ensuring that the
Balun is adequately Grounded.
= = = Sorry Everyone, but why create an overly reductant ground system
and bypass and duplicate the Grounding System that is being used for
the radios/receiver. [Ground to Radios to Attic Antenna is the
Shortest Route.] It is better for In-the-Attic Antennas; to first
improve upon the radios/receivers Grounding System: Then 'extend' it
up into the Attic to "Complete" the Entire Grounding System. {One For
All! -&- All For One!}
- - - Hey, What Works... WORKS !

#4. Select your Wire for your Antenna Element. I suggest using one
of these two high quality antenna wires: "Flex-Weave" Antenna Wire
-or- "QuietFlex" Antenna Wire.

Also look below for my additional comments marked with -RHF-.


iane ~ RHF
-o/m- http://groups.yahoo.com/group/SWL-AM-FM-Antenna/
..
..
= = = "Robert11"
= = = wrote in message ...
Hello:

Will probably try a coax feed, and a Balun, to the random
length wire running around the four sides of my attic to
reduce noise, hopefully. Do listening only, up to 30 MHz.

a. For a receiving 9:1 Balun (coax to a random length wire
in attic), does the Balun have to be grounded ?

-RHF- YES - Either via direct Ground Wire and good Ground Rod.
- - - Or, indirectly via a Coax Cable that is itself Grounded.


Or, is it grounded "adequately" via the coax - to the radio
chassis - to an earth ground from the radio chassis ?

-RHF- YES - If you use the Larger Better Quality Coax Cable.
+TIP+ For "Receive ONLY" SWL Antennas:
- - - Buy the DSS Coax Cable that has a separate Ground Wire
'molded' along side the Coax Cable. Were ever your Coax goes
your separate dedicated Ground Wire goes.


[If the Balun Does require a ground (also), wouldn't this
possibly cause a ground loop in that it would be grounded
at both ends ?]

-RHF- Unless you are Transmitting do not concern yourself
with ground loops. However, do not mix your Household's
A/C Electrical Ground and your Antenna's Grounding System.


b. Anyone have any experience with, or opinions on:

-the 9:1 Balun by RF Systems in the Netherlands
(termed a magnetic balun, how it's different from a normal
toroidal transformer coupling, I have no idea ?)

-RHF- Here is a webpage with a write-up on the MLB
http://www.universal-radio.com/catalog/sw_ant/1465.html
http://www.hard-core-dx.com/nordicdx...d/magbal1.html


-or the unit by Win Radio (WiNRADiO WR-LWA-0130
Long Wire Antenna Adapter $39.95 ADP35)

-RHF- http://www.winradio.com/home/lwa.htm


c. Any significant difference in the type of coax used for
listening only, with a run of about 50 feet.

-RHF- Not Really


Used LMR 400 for my attic scanner, but would like to avoid the
hassle of stringing the large diameter coax again, and possibly
just use a small diameter coax. Would one likely notice any
difference up to 30 MHz ?

-RHF- Not Really

Thanks,
Bob

..

MK,

E V E R Y T H I N G . . . That You Have Said Is TRUE:
- - - For a HAM and Transmitting Antenna Systems.

But, BOB is simply a SWL that envisions a "Random Wire"
(Receive ONLY) Antenna in his Attic.
* Using a MLB: Really a Matching Transformer designed to use
with a Single Wire Antenna.
* Plus a Coax Cable Lead-In from the Antenna Element to the Radio.
* All this to get a better signal with lower noise; and thus
improve his ablity to hear more and better.

My 'reply' was taylored to answer BOB's stated circumstances and
questions.

"KW" Here Is A Thought: Maybe BOB should consider some form of
balanced antenna in his attic. Perhaps you have some suggestions
on a good broad banded 'low noise' SWL Antenna designed for 500kHz
to 30MHz that can be place in an Attic.
- - - You are Welcome To -&- Please Feel Free To 'post' your
Suggestions and Ideas on the "SWL Antennas and AM/FM Antennas"
eGroup on YAHOO !

Alas, once again I sign-off "iane" = I Ain't No Elmer !
- - - As 'state' on the "SWL Antennas and AM/FM Antennas"
eGroup on YAHOO!
GoTo= http://groups.yahoo.com/group/SWL-AM-FM-Antenna/


iane ~ RHF
..
..
= = = (Mark Keith)
= = = wrote in message . com...
(RHF) wrote in message
+ + + IMHO: For In-the-Attic Antennas this is the Best, Simplest,
Cost Effective and 'most' Practical Method of running/routing a
'common earth' Grounding Point to the Attic and ensuring that the
Balun is adequately Grounded.
= = = Sorry Everyone, but why create an overly reductant ground system
and bypass and duplicate the Grounding System that is being used for
the radios/receiver. [Ground to Radios to Attic Antenna is the
Shortest Route.] It is better for In-the-Attic Antennas; to first
improve upon the radios/receivers Grounding System: Then 'extend' it
up into the Attic to "Complete" the Entire Grounding System. {One For
All! -&- All For One!}
- - - Hey, What Works... WORKS !

Maybe so, but it's even better to use an antenna that is complete in
itself. That way you don't have to worry about a ground at all.
Nothing personal, but to me, running a ground to an attic in order to
ground a balun is the silliest thing I've ever heard of. I don't use a
grounding system for my radios at all unless I want to attach it as an
option. I rarely do. Ground is a noise source, not a noise sponge.
Only in some cases on MW or LW will using a ground help a balanced
antenna. And even then , it usually doesn't change the s/n ratio. Just
pumps up the S meter a tad.



-RHF- Unless you are Transmitting do not concern yourself
with ground loops. However, do not mix your Household's
A/C Electrical Ground and your Antenna's Grounding System.

ALL grounds should be tied together at a common point. If your antenna
or tower ground is not connected with your electrical ground, it's a
violation of NEC. It also puts you at risk of lightning damage due to
the differences in ground potentials. Also, if all grounds are tied to
a common point, and all gear uses it's own ground lead to that single
point, you'll never have to worry about ground loops. I'm sitting here
at my table now, 3 radios going, a 21 inch monitor on the same table,
three inches from my IC-706g. My puter is next to the display. Wires
running o-plenty. None are grounded in any way, except for any safety
grounding from the line cords. I might get a few spurs from place to
place in the spectrum, but adding a ground to my radio will have no
effect on those. Making sure my feedlines are well decoupled is the
best time spent. I never use antennas that are not complete in
themselves. IE: if I run a random wire, or vertical, I'll always
provide it's RF ground AT the antenna, not at the radio. The antenna
is then complete. But this is different than just providing a ground
wire to a balun in an attic. If I can't provide a proper rf ground, or
radials, etc, at that antenna, I use a balanced antenna. MK