Date   

Re: Ground rod on a loop

Oene Spoelstra <spoelstraoene@...>
 

Nice info ! One exception on 590 khz. VOCM callsign is mentioned about every 3 minutes 😄

Op zo 7 feb. 2021 06:58 schreef WA8LMF via groups.io <wa8lmf=aol.com@groups.io>:

On 2/6/2021 9:14 PM, Simon wrote:
Yep

No yanks on 160m

But mw lively..

1010 interesting..atleast 2 other usa stations competing against WINS..
Shame they don’t announce who they are often..
No make that 3 other stations competing against Wins.. 
all taking it in turns..

God they like adverts!!

 

Some general info on AM medium-wave radio in the US:


1)   There are approximately 5000 AM stations in the US on about 100 channels.  This means an average of 50 stations on every channel across the US.

2)    Legal station IDs are required at the top and bottom of each hour, although most stations mention their call far more frequently.  The legal IDs are plain voice, while the others each hour may be dressed up with music, sound effects or not even mention the legal callsign.    The real problem for DXing is that all the stations on a given channel are giving their legal plain-language IDs at the same time at :00 and :30 .

3)   US (and Canadian) stations are spaced on 10 KHz steps rather than the 9 KHz steps used in most of the rest of the world. This results in really nasty heterodynes when trying to DX US stations from the UK and Europe.  Euro carriers land in the middle of American sidebands and vice versa.

4)   US stations range from 500 watt locals in small towns to 50,000 watt long-range monsters. 

5)   The great majority of US stations go off the air at sundown local time, to avoid the massive interference from numerous co-channel stations propagating via long-range sky wave at night.  Or they sharply reduce power at night such as from 10KW day vs 500 w night.  The day vs night changes are based on local solar time and are calculated for the exact location (lat/long) of the station; they change each month of the year. These are actually part of the license document.  As a result, the "daytimers" as they are known have a much longer broadcast day in the summer than in the winter.


6)   With some exceptions, the low-power 500-watt - 1KW - 5 KW local stations mainly populate the upper part of the AM band, while the high-power 10 KW - 25 KW - 50KW regional stations occupy the lower part of the band. (Long haul daytime ground wave is better as lower.freqs.)


7)    In the early 1930s, before there were stations in thousands of small towns, the federal communications authorities created the "clear channel concept". For a lucky two dozen or so stations, all but one station on the channel was ordered off the air at night to produce interference-free long-range reception of a single high-power station over huge distances in rural areas at night.  Most of these 50,000 watt clear-channel stations were the early founders of AM broadcasting in the early-to-mid 1920s.

Most of them are distinguished by having 3 letter callsigns rather than the 4-letter calls that later stations have.  I.e. the "grand old calls" such as WWL (New Orleans), WGN & WLS (Chicago), WJR & WWJ (Detroit), WSM (Nashville), WLW (Cincinati), KSL (Salt Lake City), KOA (Denver), KFI (Los Angeles), etc.   With a few exceptions, calls beginning with "W" are east of the Mississippi River (which roughly divides the continental US in half), while calls west of the Mississippi begin with "K".  


8)    Most of the stations that started broadcasting in the 1920s and 1930s (i.e. the early entrants) have non-directional antenna patterns from a single 1/4-wave stick.  Later arrivals to the ever-more-crowded AM band have been obligated to protect the coverage of existing stations on each channel. This usually has meant multi-tower directional antenna patterns for the new-comers.   The most common directional array is three phased towers in a straight line.  (Broadcast antenna arrays almost always drive all elements, rather than have passive elements like HF yagis.)   Some arrays can get very complex. For example, there is one station in Detroit, Michigan that has 11 towers in two rows that create a weird amoeba-like pattern with multiple lobes and nulls in various directions to protect stations in Ohio, Indiana and Ontario, Canada.  

A lot of stations run higher power with a non-directional antenna in the daytime, and then switch to lower power and a directional pattern at night.   

For you DXers from the other side of the Atlantic, this is significant.   When the grey line reaches a given location (i.e. sunset), the signal from a particular station can actually instantly disappear or appear, depending on the day vs night pattern and power level changes.


9)    The most powerful AM stations in the US run 50,000 watts.  In the mid 1930s one station (WLW north of Cincinnati, OH) was allowed to experiment with 500,000 watts for a few years. This was the most powerful AM station that has ever existed in the United States.   [There were several 500KW  "border blasters" operating from Mexico, but directed to audiences in the US about the same time.]

A few years later, the US government tapped the engineering expertise of Crosley Broadcasting (owners of WLW) to build multiple 500 KW shortwave transmitters with monster rhombic antennas to beam news into Germany during WWII.  This site, about a mile west of WLW's site, consumed so much electricity that it was connected to both the City of Cincinnati power grid to the south, and to the City of Dayton grid to the north at the same time!   In the post-war era, this facility became one of only three Voice of America transmitters actually on American soil.   

The Bethany, Ohio VOA site was decommissioned about 20 years ago, and converted into a museum. If you ever visit the Dayton Hamvention, don't miss this museum which is about a 45-minute drive south down I-75 from the Hamvention site.  They keep the museum open for special extended hours during the Hamvention. The museum ham club has re-created some of the rhombics from the VOA era and has a commanding signal on the HF bands.  


Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
EchoLink:  Node #  14400  [Think bottom of the 2-meter band]
Home Page:          http://wa8lmf.net

-- APRS over FLdigi Modes  --
   <http://wa8lmf.net//FLdigiAPRS/index.htm>

60-Meter APRS!   HF NVIS APRS Igate Now Operating
   <http://wa8lmf.ddns.net:14447/>

Flying Digipeater!
   <http://WA8LMF.net/FlyingDigi>

11 Copies of UIview in Action on One Computer!  
Live Off-The-Air APRS Activity Maps
   <http://wa8lmf.net/map>








Re: Ground rod on a loop

WA8LMF
 

On 2/6/2021 9:14 PM, Simon wrote:
Yep

No yanks on 160m

But mw lively..

1010 interesting..atleast 2 other usa stations competing against WINS..
Shame they don’t announce who they are often..
No make that 3 other stations competing against Wins.. 
all taking it in turns..

God they like adverts!!

 

Some general info on AM medium-wave radio in the US:


1)   There are approximately 5000 AM stations in the US on about 100 channels.  This means an average of 50 stations on every channel across the US.

2)    Legal station IDs are required at the top and bottom of each hour, although most stations mention their call far more frequently.  The legal IDs are plain voice, while the others each hour may be dressed up with music, sound effects or not even mention the legal callsign.    The real problem for DXing is that all the stations on a given channel are giving their legal plain-language IDs at the same time at :00 and :30 .

3)   US (and Canadian) stations are spaced on 10 KHz steps rather than the 9 KHz steps used in most of the rest of the world. This results in really nasty heterodynes when trying to DX US stations from the UK and Europe.  Euro carriers land in the middle of American sidebands and vice versa.

4)   US stations range from 500 watt locals in small towns to 50,000 watt long-range monsters. 

5)   The great majority of US stations go off the air at sundown local time, to avoid the massive interference from numerous co-channel stations propagating via long-range sky wave at night.  Or they sharply reduce power at night such as from 10KW day vs 500 w night.  The day vs night changes are based on local solar time and are calculated for the exact location (lat/long) of the station; they change each month of the year. These are actually part of the license document.  As a result, the "daytimers" as they are known have a much longer broadcast day in the summer than in the winter.


6)   With some exceptions, the low-power 500-watt - 1KW - 5 KW local stations mainly populate the upper part of the AM band, while the high-power 10 KW - 25 KW - 50KW regional stations occupy the lower part of the band. (Long haul daytime ground wave is better as lower.freqs.)


7)    In the early 1930s, before there were stations in thousands of small towns, the federal communications authorities created the "clear channel concept". For a lucky two dozen or so stations, all but one station on the channel was ordered off the air at night to produce interference-free long-range reception of a single high-power station over huge distances in rural areas at night.  Most of these 50,000 watt clear-channel stations were the early founders of AM broadcasting in the early-to-mid 1920s.

Most of them are distinguished by having 3 letter callsigns rather than the 4-letter calls that later stations have.  I.e. the "grand old calls" such as WWL (New Orleans), WGN & WLS (Chicago), WJR & WWJ (Detroit), WSM (Nashville), WLW (Cincinati), KSL (Salt Lake City), KOA (Denver), KFI (Los Angeles), etc.   With a few exceptions, calls beginning with "W" are east of the Mississippi River (which roughly divides the continental US in half), while calls west of the Mississippi begin with "K".  


8)    Most of the stations that started broadcasting in the 1920s and 1930s (i.e. the early entrants) have non-directional antenna patterns from a single 1/4-wave stick.  Later arrivals to the ever-more-crowded AM band have been obligated to protect the coverage of existing stations on each channel. This usually has meant multi-tower directional antenna patterns for the new-comers.   The most common directional array is three phased towers in a straight line.  (Broadcast antenna arrays almost always drive all elements, rather than have passive elements like HF yagis.)   Some arrays can get very complex. For example, there is one station in Detroit, Michigan that has 11 towers in two rows that create a weird amoeba-like pattern with multiple lobes and nulls in various directions to protect stations in Ohio, Indiana and Ontario, Canada.  

A lot of stations run higher power with a non-directional antenna in the daytime, and then switch to lower power and a directional pattern at night.   

For you DXers from the other side of the Atlantic, this is significant.   When the grey line reaches a given location (i.e. sunset), the signal from a particular station can actually instantly disappear or appear, depending on the day vs night pattern and power level changes.


9)    The most powerful AM stations in the US run 50,000 watts.  In the mid 1930s one station (WLW north of Cincinnati, OH) was allowed to experiment with 500,000 watts for a few years. This was the most powerful AM station that has ever existed in the United States.   [There were several 500KW  "border blasters" operating from Mexico, but directed to audiences in the US about the same time.]

A few years later, the US government tapped the engineering expertise of Crosley Broadcasting (owners of WLW) to build multiple 500 KW shortwave transmitters with monster rhombic antennas to beam news into Germany during WWII.  This site, about a mile west of WLW's site, consumed so much electricity that it was connected to both the City of Cincinnati power grid to the south, and to the City of Dayton grid to the north at the same time!   In the post-war era, this facility became one of only three Voice of America transmitters actually on American soil.   

The Bethany, Ohio VOA site was decommissioned about 20 years ago, and converted into a museum. If you ever visit the Dayton Hamvention, don't miss this museum which is about a 45-minute drive south down I-75 from the Hamvention site.  They keep the museum open for special extended hours during the Hamvention. The museum ham club has re-created some of the rhombics from the VOA era and has a commanding signal on the HF bands.  


Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
EchoLink:  Node #  14400  [Think bottom of the 2-meter band]
Home Page:          http://wa8lmf.net

-- APRS over FLdigi Modes  --
   <http://wa8lmf.net//FLdigiAPRS/index.htm>

60-Meter APRS!   HF NVIS APRS Igate Now Operating
   <http://wa8lmf.ddns.net:14447/>

Flying Digipeater!
   <http://WA8LMF.net/FlyingDigi>

11 Copies of UIview in Action on One Computer!  
Live Off-The-Air APRS Activity Maps
   <http://wa8lmf.net/map>








Re: Ground rod on a loop

Simon
 

Yep

No yanks on 160m

But mw lively..

1010 interesting..atleast 2 other usa stations competing against WINS..
Shame they don’t announce who they are often..
No make that 3 other stations competing against Wins..
all taking it in turns..

God they like adverts!!


Re: Ground rod on a loop

Kev Haworth
 

Simon, Greyline just over Newfoundland now and 590 under splatter from 585 RNE Spain, holding its own though. 750 quite loud, good capture tonight with 1440 kHz Radio 208 out of Copenhagen, 500 Watts only.. Great music they play too... As I type this, VOCM coming up against RNE. Set the passband high and it has helped considerably, think a Cardioid now has to be tried when the resistors land up...


Re: Ground rod on a loop

Simon
 

Opps..i think we also have answered at similar times ..so me not seeing your ( Chris) reply..

Any way Kev..make a cardioid loop..very interesting loop..but it DOES lose its 90 degree null..so if you are using to null out noise then one will need to get creative..

Cardioid loop aimed at usa ..listening on mw..lets say 1010 WINS.. s9 nw . gone se.( ie rotating 180 degrees.)

Simon

On 6 Feb 2021, at 21:21, Simon via groups.io <ohhellnotagain=gmail.com@groups.io> wrote:

Ok

Maybe i think we are are different pages..

I though kev was asking if grounding one side of normal loop will make it into cardioid loop..which it will not ..( as I understand.)

Yes i totally agree about gnding coax at bnc/ so239 outer to gnd if you can..( coax side of common mode choke.) and even making common mode choke for cat5 if using..

By the way, null phaser almost done for broadside loops..abit of metal bashing still to do for box..
Making the post null steerer amp seperate so can try out different amps..

Simon ..







Re: Ground rod on a loop

Simon
 

Ok

Maybe i think we are are different pages..

I though kev was asking if grounding one side of normal loop will make it into cardioid loop..which it will not ..( as I understand.)

Yes i totally agree about gnding coax at bnc/ so239 outer to gnd if you can..( coax side of common mode choke.) and even making common mode choke for cat5 if using..

By the way, null phaser almost done for broadside loops..abit of metal bashing still to do for box..
Making the post null steerer amp seperate so can try out different amps..

Simon ..


Re: Ground rod on a loop

Kev Haworth
 

Thanks for the replies, Gents.

I’m toying with the idea of a cardioid and have ordered the resistors just in case I decide to go ahead with it.

I did wonder if it was feasible, thanks for the info about the common mode currents, Chris. 


Re: Ground rod on a loop

Chris Moulding
 

That's why I suggest adding the ground after the common mode choke built into the Loop Antenna Amplifier + so that the ground connection doesn't affect the conventional loop due to the common mode RF isolation in the choke.

With the cardioid loop the ground is part of the antenna system so one side of the loop needs to be connected to ground.  The resistor in the top of the cardioid loop then makes the antenna a combined loop and vertical sense antenna to give the cardioid pattern.

Regards,

Chris


Re: Ground rod on a loop

Simon
 

But this will not give cardioid pattern???

No added r or l in top..

Or am I completely wrong?
Simon


Re: Antenna amplifier for Beverage and large cardioid loop antennas

Simon
 

Sounds like you need a van!! Lol

Or ex mil signals vehicle??


Re: Thanks to Chris #chat

Simon
 

Interesting..will listen wife allowing later too..
Simon


Re: Ready for Stage 2

Simon
 

Use the coax..join inner and outer together..


Re: Ground rod on a loop

Chris Moulding
 

With a conventional loop using the Loop Antenna Amplifier + I would ground it at the loop with a connection between ground rod and the BNC connector screen.

This will ground any common mode RF noise coming down the coax from the station before the common mode choke in the amplifier.

It will also drain  any electrostatic charges to ground.

Regards,

Chris


Re: Antenna amplifier for Beverage and large cardioid loop antennas

Kev Haworth
 

Simon, oh yes, my favourite antenna is a vertical over salt. 

We used them on the GB0HI and GB2HI activations and to hear JA/VK coming over the top of local stations on 40M in the morning was something I won't forget in a hurry. I've used kite antennas for 160 too over salt, probably at the wrong time of year though as we were working stateside/EU stations only. When I buy my next transceiver, I will be portable from a local beach and will be out in the wintertime with the kites.

Just sorting some ideas out now as how to power / feed from the car to test the beverages over the same beaches,  will take a loop with me as well to switch to and from.


Ground rod on a loop

Kev Haworth
 

Reading the cardioid loop posts with interest, is it worth earthing a conventional loop (With LAA+)? If so, would it be better at point where coax enters the house or at the base of the loop?

Thanks


Re: Thanks to Chris #chat

Kev Haworth
 

Simon.. 

Where to start!
 590 VOCM, Sister Station CBGY on 750 were the first two. 1130 Bolomberg and of course WINS. I was picking lots up in the 1400 and higher, but the idents weren't forthcoming, tonight may well see me listening to 700 / 800 for Caribbean stuff, I just wish I could find a reasonably priced rotator now...


Re: Ready for Stage 2

Kev Haworth
 

Tom..

Try a search for 8mm Kunifer pipe, it's Cupro Nickel, self supporting and works well,

Kev


Re: Ready for Stage 2

Tom Crosbie G6PZZ
 

Thanks for all the replies guys, much appreciated. I get the properties of Pex, but for a number of reasons, I don’t want to introduce new materials at this time.

I’ve got to build this with materials I have to hand. This is a Scrapheap Antenna Challenge.

My main query was about what wire would give me the best upgrade in signal pickup

  • 2.5mm2  stranded earth wire.
  • UR43M Coax (like RG58) 5mm OD.

The hose was just to be a former to hold multiple cores together but that’s probably going to be too heavy for my support. I guess that’s going to need work!

 

Tom G6PZZ

 

From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of Paul Sayer
Sent: 06 February 2021 11:34
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] Ready for Stage 2

 

I was lucky and got hold of free 25m roll of the stuff. Great for a loop. Very light and self supporting. 

 

Paul G0VKT 

 

On Sat, 6 Feb 2021, 09:12 leslie norton, <gm4jnw@...> wrote:

The material is called pex-al-pex its commonly used for under floor heating systems, ive used it and it works well, easily formed to whatever size you want.

Its got a thin aluminium lining, its a bit tricky to get a good joining for the coax but there is a link below to show you how one person joined it.

I have also used it with RG213 threaded inside it as a former and that works well too.

 

 

Look at Big fat loop down the page.

I bought mine as a coil from a local DIY plumbers, very cheap.

 

Les



On 6 Feb 2021, at 08:10, Facility 406 <facility_406@...> wrote:

 

"that would work well..someone will say its name..peta??"

PEX.

https://www.homedepot.com/p/The-Plumber-s-Choice-3-4-in-x-100-ft-PEX-Tubing-Potable-Water-Pipe-Combo-1-Red-1-Blue-PPWRB34100/303337387

Excellent material, but, NOT for unsterilized water, as mold grows wildly in it.

VERY rugged, I use it to pass 12AWG power cable through vehicles.

Kurt




 


Re: Ready for Stage 2

Paul Sayer
 

I was lucky and got hold of free 25m roll of the stuff. Great for a loop. Very light and self supporting. 

Paul G0VKT 

On Sat, 6 Feb 2021, 09:12 leslie norton, <gm4jnw@...> wrote:
The material is called pex-al-pex its commonly used for under floor heating systems, ive used it and it works well, easily formed to whatever size you want.
Its got a thin aluminium lining, its a bit tricky to get a good joining for the coax but there is a link below to show you how one person joined it.
I have also used it with RG213 threaded inside it as a former and that works well too.


Look at Big fat loop down the page.
I bought mine as a coil from a local DIY plumbers, very cheap.

Les

On 6 Feb 2021, at 08:10, Facility 406 <facility_406@...> wrote:

"that would work well..someone will say its name..peta??"

PEX.

https://www.homedepot.com/p/The-Plumber-s-Choice-3-4-in-x-100-ft-PEX-Tubing-Potable-Water-Pipe-Combo-1-Red-1-Blue-PPWRB34100/303337387

Excellent material, but, NOT for unsterilized water, as mold grows wildly in it.

VERY rugged, I use it to pass 12AWG power cable through vehicles.

Kurt







Re: Ready for Stage 2

leslie norton
 

The material is called pex-al-pex its commonly used for under floor heating systems, ive used it and it works well, easily formed to whatever size you want.
Its got a thin aluminium lining, its a bit tricky to get a good joining for the coax but there is a link below to show you how one person joined it.
I have also used it with RG213 threaded inside it as a former and that works well too.


Look at Big fat loop down the page.
I bought mine as a coil from a local DIY plumbers, very cheap.

Les

On 6 Feb 2021, at 08:10, Facility 406 <facility_406@...> wrote:

"that would work well..someone will say its name..peta??"

PEX.

https://www.homedepot.com/p/The-Plumber-s-Choice-3-4-in-x-100-ft-PEX-Tubing-Potable-Water-Pipe-Combo-1-Red-1-Blue-PPWRB34100/303337387

Excellent material, but, NOT for unsterilized water, as mold grows wildly in it.

VERY rugged, I use it to pass 12AWG power cable through vehicles.

Kurt






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