The John Doty Reading List courtsey of Hard-Core-DX.Com
RHF
THE JPD READING LIST => http://tinyurl.com/3amvw6
Install Your Antenna Properly -by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/feed/coax2.html
The Purpose of a Balun -by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/feed/balun3.html
Matching Less Important for Reception -by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/feed/balun5.html
The Perfect FeedLine for Wire Antennas -by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/feed/feed1.html
To Get the Most from your Coax -by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/feed/coax1.html
Not Necessary to Balance Longwires -by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/feed/balun4.html
Magnetic Longwire Balun - Not Really a Balun -by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/feed/magbal2.html
ICE 180 a Reasonably Priced Professional Matching Unit
-by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/feed/ice180.html
http://groups.google.com/group/rec.radio.shortwave/msg/dcda787f87173280
Grounding is Key to Good Reception -by- John Doty
http://www.hard-core-dx.com/nordicdx/antenna/ground/ground2.html
http://groups.google.com/group/rec.radio.shortwave/msg/5fd8fe1179a5c6c8
.
.
MISSING IN ACTION - Are the OnLine Copies
of these Posts by John Doty
.
Low Noise Antenna Connection - by John Doty
X - http://www.anarc.org/naswa/badx/antennas/low-noise_antenna.html
FOUND IT
http://www.homediscussion.com/showpost.php?p=11014&postcount=6
http://www.diybanter.com/showpost.php?p=382890&postcount=4
.
Shortwave Listener (SWL) Longwire Antenna - by John Doty
? WHY Use a Fixed Matching Transformer ?
X - http://www.anarc.org/naswa/badx/antennas/SWL_longwire.html
.
Grounding is the Key to Good Reception - by John Doty
X - http://www.anarc.org/naswa/badx/antennas/grounding.html
FOUND IT
http://www.naswa.net/badx/grounding.htm
.
The ANARC and NASWA and BADX no longer Host these Posts.
.
Anyone know of other WebSites that still retain Copies of these
Posts ?
.
iane ~ RHF {pomkia}
.
Shortwave Listener (SWL) Antennas Group => http://tinyurl.com/ogvcf
GoTo => http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
The SWL Antenna Discussion Group => http://tinyurl.com/ogvcf
Shortwave Listener (SWL) Antenna HELP => http://tinyurl.com/ogvcf
Shortwave Listener (SWL) Antenna NEWS => http://tinyurl.com/ogvcf
Shortwave Listener (SWL) Antenna INFO => http://tinyurl.com/ogvcf
* * * All Are Welcome : Including ELMERS and 'Want-to-be-Elmers'
plus plain old "Mister-Know-It-Alls"; and even those Newbees with
"I Know This Is A Really Dumb Question - But _ _ _ _ _ _ _ _ "
.
Shortwave Radio Listener QSL Reports News & Info Group
http://groups.google.com/group/shortwave-listener-qsl-reports
Read & Post Your Shortwave Listener (SWL) Reception Reports
SWL-QSL-REPORTS => http://tinyurl.com/3awlyr
.
The Shortwave Listener's Blessing :
SWL BLESSING => http://tinyurl.com/s2bjm
May You Never Tire of Listening to the Radio and Always
have Strong Signals and Noise Free Reception ~ RHF {ibid}
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/message/9233
.
Tous Sont Bienvenus ! - - - Groupe par Radio
d'auditeur d'onde courte pour des Antennes de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Alle Sind Willkommen ! - - - Shortwave Radiozuhörer
Gruppe für SWL Antennen
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Tutti Sono Benvenuti ! - - - Gruppo Radiofonico
dell'ascoltatore di onda corta per le Antenne di SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Todos São Bem-vindos ! - - - Grupo de Rádio
do ouvinte do Shortwave para Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
¡Todos Son Agradables! - - - Grupo de Radio del oyente
de la onda corta para las Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
= = = = Plain Old American-English Translation = = = =
All are Welcome - - - To Join the Shortwave Listeners
(SWL) Antenna Group on YAHOO !
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
|
|
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/ \
.......!.......
JRCCr...@gmail.com
> The "John Doty" Reading List courtsey of Hard-Core-DX.Com
> THE JPD READING LIST =>http://tinyurl.com/3amvw6
>
> �.
> MISSING IN ACTION - Are the OnLine Copies
> of these Posts by John Doty
> �.
> �.
> Shortwave Listener (SWL) �Longwire Antenna - by John Doty
> ? WHY Use a Fixed Matching Transformer ?
> X -http://www.anarc.org/naswa/badx/antennas/SWL_longwire.html
> SNIP
> �.
> The ANARC and NASWA and BADX no longer Host these Posts.
> �.
> Anyone know of other WebSites that still retain Copies of these
> Posts ?
> �.
> iane ~ RHF {pomkia}
You will find the one above at
www.webarchive.org
specifically:
http://web.archive.org/web/20031204024006/http://anarc.org/naswa/badx/antennas/SWL_longwire.html
I had to try a couple of different dates until I found an archive copy
with the graphs included.
The original article was posted to rec.radio.shortwave on Dec 23,
1996.
Given the original web addresses, you should be able to find all of
the articles at the archive
HTH and 73
John KC0G
sw...@live.com
> The "John Doty" Reading List courtsey of Hard-Core-DX.Com
> THE JPD READING LIST =>http://tinyurl.com/3amvw6
The only major problem I have with any of John Doty's ideas
is he fails to understand that in the USA >ALL< grounds
must be bonded in common. I know that many hams and
SLWs fail to do this and most never suffer any unpleasantness.
But the NEC is very specific about this and years of personal
experience have shown the NEC rules to to be valid. By bonding
all the grounds with a suitable conductor, 6AWG solid copper
minimum, the entire home and antenna all rise to the same
potential and there are minimum voltage gradients between
devices nominally at the same reference.
As I pointed out before a NEC compliant ground only needs to
be 25 ohms, or less, and 25 ohms isn't sufficiently low enough to
trip even a 15A breaker on a 120V circuit in the event of a
ground fault. 125v//25 = 5 amps. I cheated and went with 125
instead of 120 because the math came out even.
The only way to avoid this is to use an RF isolation transformer
between the antenna and entry ground point.
On way to do this is shown at:
"Another Look at Noise-Reducing Antenna Systems"
By Mark Connelly - WA1ION - 06 JUL 1992
<http://members.aol.com/WA1ION/nrants.pdf>
I built several of these and found his matching network made no
detectable difference.
In the event of a lightning strike with such a 1:1 isolation
transformer,
I suspect the vaporized copper and iron would form a fairly effect
conductive path.
A minor point I have is John's failure to understand that a single
point ground like a NEC 8' ground rod is a very ineffective RF
ground.
The loss of efficiency is not too important but the electrical
imbalance
that results can and often does allow electrical noise from within the
house to creep into the antenna via common mode. John's suggestion
of burying the feed line coax to suppress common mode currents is
an excellent idea. Be sure to us cable rated for direct burial. I
favor
th 75 Ohm Belden used for satellite dishes.
Terry
RHF
- A minor point I have is John's failure to understand that
- a single point ground like a NEC 8' ground rod is a very
- ineffective RF ground.
I think that I read around 100 of his posts in the
last two days trying to find the three that were
most often cited.
JD does address the fact that the 8 Foot Ground Rod
"ain't" the best ground; and does recommend using one
or more 20 Foot or longer ground radials attached to
it as a means of improving the effectiveness and the
efficiency of your Ground.
An 8 Foot Ground Rod does get you into the ground and
ideally deep enough into the Ground where you do have
moist soil 24/365 and better ground conductivity.
-BUT- It is still a Single-Point-Ground : Meaning you
do have a Ground {Earth Potential}
-But Again- It is not a very effective or efficient
Electical and RF Ground.
- The loss of efficiency is not too important but the
- electrical imbalance that results can and often does
- allow electrical noise from within the house to creep
- into the antenna via common mode.
He suggest at least using a Ground Rod at each end of
the Coax Cable : One Ground Rod at the base of the
Antenna and a Second Ground Rod at the point on the
Ground where the Coax Cable enters the House.
-Note- This does 'tie' these two Grounds "Together"
-via- the Outer-Shield of the Coax Cable.
-and- Burying the Coax Cable between them does 'unify'
the Area-of-the-Ground between them to some extent.
- John's suggestion of burying the feed line coax to
- suppress common mode currents is an excellent idea.
Yes -If- Possible Burying the Coax Cable from a few
Inches and up to a Foot under the Ground; between the
Antenna and the House has a couple of Advantages over
having it laying on the ground or hanging in the Air
over Head.
- Be sure to us cable rated for direct burial.
- I favor th 75 Ohm Belden used for satellite dishes.
Most RG6 Quad-Shield Coax Cable will work OK for Direct
Burial. Using Half-Inch (1/2") Black PVC Water Tubing
is an added layer of protection for Buried Coax Cable;
especially when the Coax Cable is within a few inches
of the surface of the ground and lays across pathways
and walkways.
- Terry
~ RHF
.
RHF
wrote:
> I had to try a couple of different dates until I found an archive copy
> with the graphs included.
> The original article was posted to rec.radio.shortwave on Dec 23,
> 1996.
>
> Given the original web addresses, you should be able to find all of
> the articles at the archive
>
> HTH and 73
>
>
> - Show quoted text -
John [KC0G],
TYVM - All Three Are There In The Web Archive.
+ Plus I was able to locate the Original Postings
here on the Rec.Radio.Shortwave Newsgroup. ~ RHF
SWL Longwire -by- John Doty
[ Shortwave Listener (SWL) Longwire Antenna ]
http://www.google.com/group/rec.radio.shortwave/msg/9e3dd73e36381d46
http://groups.google.com/group/rec.radio.shortwave/msg/9e3dd73e36381d46
http://web.archive.org/web/20031204024006/http://anarc.org/naswa/badx/antennas/SWL_longwire.html
* Actually, a fixed matching transformer can dramatically
reduce the wild swings in antenna efficiency that a coax
fed wire antenna exhibits.
Low Noise Antenna Connection -by- John Doty
http://www.google.com/group/rec.radio.shortwave/msg/1cde8bb62764b23a
http://groups.google.com/group/rec.radio.shortwave/msg/1cde8bb62764b23a
http://web.archive.org/web/20030701222251/anarc.org/naswa/badx/antennas/low-noise_antenna.html
* The difference between a mediocre antenna system and
a great antenna system isn't the antenna itself: it's
the way you feed signals from the antenna to the receiver.
* The real trick with a shortwave receiving antenna system
is to keep your receiver from picking up noise from all
the electrical and electronic gadgets you and your
neighbors have.
Grounding Is Key To Good Reception -by- John Doty
http://www.google.com/group/rec.radio.shortwave/msg/5fd8fe1179a5c6c8
http://groups.google.com/group/rec.radio.shortwave/msg/5fd8fe1179a5c6c8
http://web.archive.org/web/20030605064509/anarc.org/naswa/badx/antennas/grounding.html
* With grounds the most common experience is
"the more the merrier".
* The method I use is to ground the cable shield at
two ground stakes and bury the cable in between.
.
sw...@live.com
> * Actually, a fixed matching transformer can dramatically
> reduce the wild swings in antenna efficiency that a coax
> fed wire antenna exhibits.
>
> * The difference between a mediocre antenna system and
> a great antenna system isn't the antenna itself: it's
> the way you feed signals from the antenna to the receiver.
> * The real trick with a shortwave receiving antenna system
> is to keep your receiver from picking up noise from all
> the electrical and electronic gadgets you and your
> neighbors have.
>
> * With grounds the most common experience is
> "the more the merrier".
> * The method I use is to ground the cable shield at
> two ground stakes and bury the cable in between.
> .
This quote leads me to believe he has his RF ground isolated from his
house hold or utility ground:
"Yes, you have a "ground loop". It's harmless. In case of a nearby
lightning strike it may actually save
your receiver. My R8 isn't grounded like that, so I had to take steps
to prevent the coax ground potential
from getting wildly out of kilter with the line potential and arcing
through the power supply. I'm using a
surge supressor designed to protect video equipment: it has both AC
outlets and feedthroughs with
varistor or gas tube clamps to keep the various relative voltages in
check. Of course the best lightning
protection is to disconnect the receiver, but I'm a bit absent minded
so I need a backup."
This line:"coax ground potential from getting wildly out of kilter
with the line potential and arcing through
the power supply." suggests he either has serious NEC grounding issues
or is using separate grounds.
I am assuming the R8 is like the R8B and the So259 is connected to the
case and the IEC power
cord has a ground that is also connected to the case.
See <http://en.wikipedia.org/wiki/IEC_connector> for an overview of
IEC power connectors.
See <http://en.wikipedia.org/wiki/NEMA_connector> for an overview of
NEMA power connectors.
I know my Kenwood R2000 came with a 'illegal' power cord. The R2000
has a standard IEC C14 but
the power cord ended in a ungrounded NEMA 1–15P 2 blade connector. I
say 'illegal' because the NEC
frowns on such cords. I know that Sony and Panasonic also used C14 on
some mid 1980 video equipment
and NEMA 1-15P for the wall plug. The fire marshal/electrical
inspector had a "hissy fit" and required us
to cut the cables into pieces and throw them away.
My R8B lived most of it's life in the original box, and I was assured
that all of the cables, bags etc where
OEM as delivered from Universal Radio. The power cord that I received
with my R8B is a standard
IEC C13 to NEMA 5-15, standard 3 conductor grounding plug.
If John was experiencing voltage differentials high enough to damage
power supplies, it strongly suggests
that the case was not connected/bonded to both the coax ground and
mains ground. I have seen several
installations where a separate ground rod that was not bonded to the
utility ground could have as much as
150V AC between the two points. Enough voltage and current blow a 100W
120V incandescent bulb. All
three cases had serious wiring errors by the power utility. I much
prefer excess current to be shorted by
a suitable conductor then to test my receiver power supply's 'punch
through' or break down voltage.
I do not want to rely on the case mounted SO259 and the IEC/NEMA
ground for my ground bonding.
I guess I harp on ground issues because I have seen the effect that
lightning can have on non NEC compliant
installations. In a direct hit your receiver is toast. But your house
shouldn't burn down. NEC compliant
grounding systems also increase your receivers chances of survival
from nearby or weak secondary strikes.
And when all of the grounding systems are bonded with buried 6AWG
solid copper wire, the effectiveness
for RF gets much better.
Terry
RHF
- He suggest at least using a Ground Rod at each end of
- the Coax Cable : One Ground Rod at the base of the
- Antenna and a Second Ground Rod at the point on the
- Ground where the Coax Cable enters the House.
- -Note- This does 'tie' these two Grounds "Together"
- -via- the Outer-Shield of the Coax Cable.
- -and- Burying the Coax Cable between them does 'unify'
- the Area-of-the-Ground between them to some extent.
-
THE NEXT STEP - "BONDING" {{UNIFYING} THE GROUNDS :
I guess that during the process of Burying the Coax Cable
between the two Ground Rods : A Solid Bare Copper Wire
at least # 10 AWG or Bigger could be buried in the Trench
along with the Coax Cable and 'connected' to both Ground
Rods.
This would at least solidly 'connect' these two Grounds
and Thus "Bond" {Unify} these two Ground Rods.
Plus this # 10 AWG Wire would also function as an
In-the-Ground 'Radial' for the Antenna.
Then Adding at least # 10 AWG or Bigger Ground Wire
between the House's AC Service {Mains} Ground and the
Coax Cable's near House Ground Rod would then 'Bond"
all these Ground 'together'.
iane ~ RHF
.
>
> - John's suggestion of burying the feed line coax to
> - suppress common mode currents is an excellent idea.
>
> Yes -If- Possible Burying the Coax Cable from a few
> Inches and up to a Foot under the Ground; between the
> Antenna and the House has a couple of Advantages over
> having it laying on the ground or hanging in the Air
> over Head.
>
> - Be sure to us cable rated for direct burial.
> - I favor th 75 Ohm Belden used for satellite dishes.
>
> Most RG6 Quad-Shield Coax Cable will work OK for Direct
> Burial. Using Half-Inch (1/2") Black PVC Water Tubing
> is an added layer of protection for Buried Coax Cable;
> especially when the Coax Cable is within a few inches
> of the surface of the ground and lays across pathways
> and walkways.
>
> - Terry
>
> ~ RHF
> .- Hide quoted text -