Re: Topband: NORD antenna for top band.....

[James Rodenkirch]

Thank you, Frankhearing similar analysis here so it's sounding like the 
NORD style of antenna isn't for me. Appreciate the "advice."


72 de Jim nR. K9JWV



From: donov...@starpower.net 
Sent: Tuesday, February 2, 2016 11:14 PM
To: Top Band Contesting
Cc: James Rodenkirch
Subject: Re: Topband: NORD antenna for top band.

Hi Jim,

The NORD antenna is a relatively inexpensive low frequency
antenna (typically used at 50-100 kHz) where its impossible to
achieve vertically polarized antennas with close to 1/4 wavelength
vertical height.

The NORD antenna typically consists of an electrically short folded
unipole (typically less than 0.05 wavelength tall) with at three
(or more) umbrella wires attached to the top of the vertical spaced
evenly spaced at 120 degree intervals

Unlike umbrella antennas used on topband (such as in my W8JI/W5ZN
8-circle receiving arrays), the NORD antenna also uses a capacitor
at the end of each umbrella wire.   The three capacitors are used to
tune the antenna, avoiding the need for a lossy loading coil at the
feedpoint of the antenna,

The NORD antenna is a poor choice for Topband where many of us
can use much more efficient quarter wavelength inverted-L antennas
or in some cases full size quarter wavelength verticals.

To learn about the NORD antenna simply Google: "NORD Antenna"

73
Frank
W3LPL




From: "James Rodenkirch" 
To: "Top Band Contesting" 
Sent: Tuesday, February 2, 2016 4:12:27 PM
Subject: Topband: NORD antenna for top band.

.anyone experimented with a NORD-configured vertical antenna?


I have the Navy antenna publication - 
http://www.hamuniverse.com/US%20NAVY%20Antennas%20and%20Wave%20Propagation.pdf 
- but, other than a brief description, not much to go byany assistance, 
e.g., steerage to a web site or empirical data/analysis results appreciated.

Antennas and Wave Propagation - HAM 
RADIO
www.hamuniverse.com
NONRESIDENT TRAINING COURSE . Antennas and Wave Propagation. DISTRIBUTION 
STATEMENT A: Approved for public release; distribution is unlimited.




72 de Jim Rodenkirch K9JWV
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Re: Topband: CQ160

[Tim Shoppa]

I found it very effective to "spread up". When conditions to EU were really
top-notch Saturday night (your Sunday morning) I worked a lot of EU's above
1860 without the high QRM conditions found lower in the band.

There were some phone guys above 1850. Because they never stopped talking,
it was pretty to avoid them.

I think the really strong EU stations could hold a run frequency lower in
the band but not the majority could do that.

Overall, I felt this years running to have less QRM than some past years.
Yes, several times I would be CQ'ing, then an EU would come up underneath
me CQ'ing. I'd generally go S to work the guy and go even higher in the
band! But that happens every year. I'm happy for the 10-pointer no matter
how I got it.

Tim N3QE

On Sat, Jan 30, 2016 at 1:03 PM, Carl Jonsson 
wrote:

> Cq160 is not very interesting for a dx-er anymore. A handfull of european
> big guns are covering the band with CQ over and over again but they don't
> seem to hear very well. During the morning hours I can hear a layer of NA
> and SA stations behind the usual european contest stations who keep CQ-ing
> test continuously. And it seems to be the same problem in the US. Hope to
> meet you after the contest!
> 73 Carl SM6CPY
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Re: Topband: Placement of RX feedline chokes

[Herbert Schoenbohm]

Interesting information Jim because my quietest Beverage is fed with 
some double shielded double foil (braid foil braid foil) with robust 
braid RG-6 type cable but in order to get it to fit a connector both 
braids are tied together.


Herb, KV4FZ


On 2/3/2016 6:59 PM, Jim Brown wrote:

On Wed,2/3/2016 10:10 AM, Herbert Schoenbohm wrote:
It has come to my attention by a seasoned topbander that I have this 
all wrong and the decoupling coil should be close as possible to the 
Beverage transformer.  He reasoned that the long RG6 cable (some 500 
feet long)  couple random pickup right back into the Beverage 
transformer and could also reduce the side lobe rejection from the 
Beverage itself. So where is the best placement for for a feed-line 
choke? 


He's right -- if you're using only one feedline choke, it should be as 
close as practical to the feedpoint (that is, out by the transformer, 
or up in the air for a TX antenna). There is also benefit to one or 
more additional chokes on a feedline. Two benefits. First, it 
minimizes interaction between that feedline and other antennas, 
fulfilling the same function as egg insulators breaking up guy wires.


Second, it minimizes feedline current, which, due to imperfections in 
the coax shield, can convert noise picked up in the shield to a 
differential signal on the coax. The metric for this conversion is 
called the transfer impedance of the cable, and is defined as the 
differential voltage divided by the shield current. EMC guru Henry Ott 
notes that the lower limit for transfer impedance is the resistance of 
the shield at the frequency of interest. The uniformity and the 
"coverage" of the shield also contributes.


Coax made for CATV is optimized for its performance at VHF-UHF. 
Shields are typically thin Al braid plus one or more layers of Al 
foil. These are pretty good shields at VHF/UHF, but their relatively 
high resistance can seriously degrade shielding at MF and HF.


73, Jim K9YC

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Re: Topband: Placement of RX feedline chokes

[Jim Brown]

On Wed,2/3/2016 10:10 AM, Herbert Schoenbohm wrote:
It has come to my attention by a seasoned topbander that I have this 
all wrong and the decoupling coil should be close as possible to the 
Beverage transformer.  He reasoned that the long RG6 cable (some 500 
feet long)  couple random pickup right back into the Beverage 
transformer and could also reduce the side lobe rejection from the 
Beverage itself. So where is the best placement for for a feed-line 
choke? 


He's right -- if you're using only one feedline choke, it should be as 
close as practical to the feedpoint (that is, out by the transformer, or 
up in the air for a TX antenna). There is also benefit to one or more 
additional chokes on a feedline. Two benefits. First, it minimizes 
interaction between that feedline and other antennas, fulfilling the 
same function as egg insulators breaking up guy wires.


Second, it minimizes feedline current, which, due to imperfections in 
the coax shield, can convert noise picked up in the shield to a 
differential signal on the coax. The metric for this conversion is 
called the transfer impedance of the cable, and is defined as the 
differential voltage divided by the shield current. EMC guru Henry Ott 
notes that the lower limit for transfer impedance is the resistance of 
the shield at the frequency of interest. The uniformity and the 
"coverage" of the shield also contributes.


Coax made for CATV is optimized for its performance at VHF-UHF. Shields 
are typically thin Al braid plus one or more layers of Al foil. These 
are pretty good shields at VHF/UHF, but their relatively high resistance 
can seriously degrade shielding at MF and HF.


73, Jim K9YC

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Topband: on behalf of 4V1TL for TB reflector

[Sam Harner]

 

 

It was an honor to participate in a special event station commemorating the
founder of Haiti, General Toussaint Louverture who led the first successful
slave rebellion. Haiti has a proud history and provided important assistance
to their neighbors, including important assistance to the USA in the
Revolutionary War. The 4V1TL callsign is a special club callsign assigned by
CONATEL to the Radio Club of Haiti (RCH) to commemorate Toussaint Louverture
who led the only successful slave rebellion in history and helped to
establish the first black-led democracy in the world .  The 4V1TL operation
will continue throughout 2016 by operators of the RCH.  The callsign include
the letters "TL" as a memory to General Toussaint Louverture

 

The QSL manager for 4V1TL and other RCH callsigns has always been W3HNK.
Joe is an outstanding and wellknown QSL manager. To my knowledge W3HNK does
not participate in LOTW.  QSL  directions for our portable calls are at the
discretion of the operator.  HH2/N3BNA via KA2AEV and 100% on LOTW.
HH2/WS6X via WS6X.  Not sure about LOTW at this time, I have only returned a
few hours ago.

 

A word about our 160m operation.  It has been my dream to put in a serious
effort on 160m from Haiti using a tall broadcast tower.  Except for the east
coast of USA, Haiti is rare on TB.  Other bands are less needed by the
deserving.  The reason for the need on TB is that all existing Haitian
stations are using compromised antennas. My idea was to fill some of the
need in EU and west coast with an effective antenna.

 

Our results have exceeded my expectations. We worked over 100 EU stations
and more than 250 western USA stations. FOr most of these and many others we
were a new one on 160. Our hearing was less than perfect and we were
suffering from quick QSB that left many partial callsigns out of the log.
But with 885 QSOs, we were hearing at least some of the callers.

 

We could not have been successful without the efforts of Jim WS6X. Jim built
the huge 160m delta loop that gave us the big signal, did most of the
operating on TB, and was a wealth of technical expertise.  We did not have a
big amp.  We only had a solid state ALS1306 with no mods. The good signal
was due to the antenna, perhaps aided by the 180 foot tower that supported
it.  We needed every inch of that 180 foot tower to put up the delta loop.
The tower is located in a saltwater marsh and happens to be resonant on 80m
and near 40m.  We look forward to using the tower in future contests along
with a WRTC yagi and a SteppIR vertical.

 

If anyone is interested in joining us in a future contest, please let me
know.

 

Thanks for all the contacts on topband.

 

73,

 

Dale - N3BNA  (just an operator for the special event station of 4V1TL)



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Re: Topband: Placement of RX feedline chokes

[Greg Zenger]

"More shields in parallel reduces...shield coverage"?

This seems counter intuitive, or did you mistype?


Greg N2GZ

On Wed, Feb 3, 2016 at 6:48 PM, Jim Brown  wrote:

> On Wed,2/3/2016 3:36 PM, Herbert Schoenbohm wrote:
>
>> Interesting information Jim because my quietest Beverage is fed with some
>> double shielded double foil (braid foil braid foil) with robust braid RG-6
>> type cable but in order to get it to fit a connector both braids are tied
>> together.
>>
>
> Double shields in CATV cable are not handled like those in broadcast to
> separate signal return from "ground." In CATV, it's simply the "more is
> better" approach -- more shields in parallel reduces shield resistance and
> shield coverage.
>
>
> 73, Jim K9YC
>
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Topband: Placement of RX feedline chokes

[Herbert Schoenbohm]

I have always used a 3 inch ferrite (TDK 9930) choke with  for each 
Beverage RG6 feedline (13 turns) near the shack entrance.  There is a 
common ground and on the remaining RG6  going to the radio (20 feet or 
less) I have another 3 inch ferrite with another 13 turns of RG6.  To 
better describe they are for the RG6 a coil, a common ground, and 
another coil.It has come to my attention by a seasoned topbander 
that I have this all wrong and the decoupling coil should be close as 
possible to the Beverage transformer.  He reasoned that the long RG6 
cable (some 500 feet long)  couple random pickup right back into the 
Beverage transformer and could also reduce the side lobe rejection from 
the Beverage itself. So where is the best placement for for a feed-line 
choke?


Please share with me your thoughts on this.  Thanks

Herb Schoenbohm, KV4FZ


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Re: Topband: CQ160

[Henk PA5KT]

During contest when the band is full with CQ machines I used to listen 
below 1810 to check out conditions. There are always stations active and 
as that part is always clear it is very useful to check if I can hear NA.


It would be very effective to work split around 1810.

73 Henk PA5KT

Op 2/3/2016 om 7:43 PM schreef Petr Ourednik:

Herb

for lot of EUs is prohibited to operate below 1810!
For that reason we missed several stations which did not tuned up over
the test...

73 - Petr, OK1RP

BTW: definitely agree with Carl. I heard several US stations calling own
CQ test under EU big guns...

On Wed, Feb 3, 2016, at 07:20 PM, Herbert Schoenbohm wrote:

You nail it CarlIf there could only be by gentleman's agreement in
Europe a 5 Khz window anywhere on the band for NA stations to be at
least heard and worked...sort of a EU "CQ Test"  machine free zone.
Would that be of any help? I have thought of using 1809 and QSX up on
1811 but understand there are commercial data transmitters below 1810
there in EU.


Herb Schoenbohm, KV4FZ

On 1/30/2016 2:03 PM, Carl Jonsson wrote:

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Cq160 is not very interesting for a dx-er anymore. A handfull of european
big guns are covering the band with CQ over and over again but they don't
seem to hear very well. During the morning hours I can hear a layer of NA
and SA stations behind the usual european contest stations who keep CQ-ing
test continuously. And it seems to be the same problem in the US. Hope to
meet you after the contest!
73 Carl SM6CPY
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Re: Topband: Placement of RX feedline chokes

[shristov]

Herbert Schoenbohm  wrote:

> where is the best placement for for a feed-line choke?


At each point where the common to differential mode conversion is likely to 
happen.
In other words, where the current on the outside of coax shield is likely to 
get inside coax.

Primary target points are those where the coax [potentially] opens to the outer 
world:
antenna end, station end, coax extension joints, and similar.

In addition, placing several chokes at lambda/4 distance from each other
will make it difficult to develop large coax shield currents in the first place.


73,

Sinisa  YT1NT, VE3EA

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Re: Topband: CQ160

[Herbert Schoenbohm]

You nail it CarlIf there could only be by gentleman's agreement in 
Europe a 5 Khz window anywhere on the band for NA stations to be at 
least heard and worked...sort of a EU "CQ Test"  machine free zone.  
Would that be of any help? I have thought of using 1809 and QSX up on 
1811 but understand there are commercial data transmitters below 1810 
there in EU.



Herb Schoenbohm, KV4FZ

On 1/30/2016 2:03 PM, Carl Jonsson wrote:
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Cq160 is not very interesting for a dx-er anymore. A handfull of european
big guns are covering the band with CQ over and over again but they don't
seem to hear very well. During the morning hours I can hear a layer of NA
and SA stations behind the usual european contest stations who keep CQ-ing
test continuously. And it seems to be the same problem in the US. Hope to
meet you after the contest!
73 Carl SM6CPY
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Re: Topband: CQ160

[Petr Ourednik]

Herb

for lot of EUs is prohibited to operate below 1810!
For that reason we missed several stations which did not tuned up over
the test...

73 - Petr, OK1RP

BTW: definitely agree with Carl. I heard several US stations calling own
CQ test under EU big guns...

On Wed, Feb 3, 2016, at 07:20 PM, Herbert Schoenbohm wrote:
> You nail it CarlIf there could only be by gentleman's agreement in 
> Europe a 5 Khz window anywhere on the band for NA stations to be at 
> least heard and worked...sort of a EU "CQ Test"  machine free zone.  
> Would that be of any help? I have thought of using 1809 and QSX up on 
> 1811 but understand there are commercial data transmitters below 1810 
> there in EU.
> 
> 
> Herb Schoenbohm, KV4FZ
> 
> On 1/30/2016 2:03 PM, Carl Jonsson wrote:
> > Boxbe  This message is eligible for 
> > Automatic Cleanup! (carl.jonss...@gmail.com) Add cleanup rule 
> > 
> >  
> > | More info 
> > 
> >  
> >
> >
> >
> > Cq160 is not very interesting for a dx-er anymore. A handfull of european
> > big guns are covering the band with CQ over and over again but they don't
> > seem to hear very well. During the morning hours I can hear a layer of NA
> > and SA stations behind the usual european contest stations who keep CQ-ing
> > test continuously. And it seems to be the same problem in the US. Hope to
> > meet you after the contest!
> > 73 Carl SM6CPY
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