Date   

Re: How to make a cardioid loop with a Loop Antenna Amplifier +

Tom Crosbie G6PZZ
 

Can you get heatshrink in camo? :-)

-----Original Message-----
From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of Simon
Sent: 09 February 2021 23:02
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] How to make a cardioid loop with a Loop Antenna Amplifier +

No i use 1/4 w ..but am changing to 2w carbon just to make a more sturdy connection that can be encased in heatshrink tubing..

Simon


Re: How to make a cardioid loop with a Loop Antenna Amplifier +

Simon
 

No i use 1/4 w ..but am changing to 2w carbon just to make a more sturdy connection that can be encased in heatshrink tubing..

Simon


Re: How to make a cardioid loop with a Loop Antenna Amplifier +

Kev Haworth
 

Reading your reply, Simon, you mention NOT to use wirewound resistors on a cardioid loop,  I understand this is due to their self inductance and capacitance issues.

Open question, is there any merit in using a higher power rating (10 Watts upwards) for the resistors?

ATB

Kev


Re: VLF/LF/HF Active Vertical Antenna...5 kHz to 30 MHz Discontinued!

Chris Moulding
 

Hi Robert,

Thanks for your kind comments on the antenna. I think you probably got one from the last few batches where we used 2 mm thick tube for the elements.

Due to the Covid-19 situation we are limiting the time in the workshop so  some products that took a lot of workshop assembly were put on hold until things hopefully get back to normal.

I've checked and we still have some amplifier boards, the boxes are the standard polycarbonate ones we use for our other products so we would only need to order some tubing to make another batch.

When we have another batch ready I'll post details on the forum.

Regards,

Chris


VLF/LF/HF Active Vertical Antenna...5 kHz to 30 MHz Discontinued!

Robert, VA3ROM
 

Just had a look at the CCW website to buy another VLF/LF/HF active vertical antenna and much to my shock and dismay it was in the discontinued list!!

Sales drives survival so I'm guessing that it wasn't worthwhile cost wise to keep this outstanding performing antenna viable.

Any antenna that can survive in Canada's brutal winters, snow and ice storms and perform well especially on the VLF and LF bands is a keeper. It's been the only way for me to receive the basement beacons.

Is there any backstory to it and any hope of the antenna coming back in another shape or form that can perform down low.

73,
Robert, VA3ROM


Re: Ground rod on a loop

Simon
 

Didnt we in uk just get told to hide under a table if all hell between usa and ex ussr took place?

Good to know that my solid pine table is radiation proof..lol

Steve..pirate radio?? One needs to pm me..


Re: Ground rod on a loop

Oene Spoelstra <spoelstraoene@...>
 

I saw that in a movie down here in the Netherlands with the Flying Dutchman. They made an airstrip with lights to make it possible for the plane to land in bad weather.

Op zo 7 feb. 2021 14:13 schreef Kenny Witt via groups.io <kennywtn=yahoo.com@groups.io>:

Nice article.......add to that the AM signal was used by aviation for navigation for many years with the ADF radio, which could be tuned to any AM station.  Then after verifying the “ident” via the transmitting station’s callsign, the pilot could plot the position, direction and speed of the aircraft, and subsequently determine the distance to their destination.  Of note, many a trans-Atlantic flights used this technique using this technique.


Kenny, KC4OJS 



On Feb 7, 2021, at 12:58 AM, WA8LMF via groups.io <wa8lmf=aol.com@groups.io> wrote:


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>








Email problems?

scanmil
 

Hi Chris,

Hope this finds you well.

I'm just wondering if you are having problems receiving my emails again?

I have sent several since the 4th January (to both of your emails) and not received anything back as yet or any notifications they have been read, and there's nothing from you in my junk or spam folders either, I know and appreciate your very very busy but just a confirmation if you have got them or not would be good. :)

Cheers,

Adam.


Re: Ground rod on a loop

Kev Haworth
 

Stephen, 

Thank you for taking the trouble to post this. 

Very much appreciated.

Kev


Re: Ground rod on a loop

Chris Moulding
 

Very interesting. My first transistor radio back in the 1960s had the triangle in circle marks on the dial.

Now I know what they were for.

Regards,

Chris


Re: Ground rod on a loop

WA8LMF
 

On 2/7/2021 7:03 AM, Kenny Witt via groups.io wrote:
Nice article.......add to that the AM signal was used by aviation for navigation for many years with the ADF radio, which could be tuned to any AM station.  Then after verifying the “ident” via the transmitting station’s callsign, the pilot could plot the position, direction and speed of the aircraft, and subsequently determine the distance to their destination.  Of note, many a trans-Atlantic flights used this technique using this technique.


 

This use of AM broadcast signals for air navigation has another interesting  historic footnote. 

During the cold  war era of the 1950s and 1960s, it was feared that Soviet bombers might use AM signals to navigate to American cities.   The Dept of Defense and the civil  federal  communications regulators (the FCC - Federal Communications Commission) implemented the plan called "CONELRAD" which stood for "CONtrol of Electromagnetic RADiation".  

Under this plan, in case of a Soviet attack, the majority of AM stations would go off the air, while ALL remaining stations (mainly the high-power regional stations) would instantly switch to either 640 or 1240 KHz.. The idea was to put so many strong signals on these two frequencies that it would be impossible to home in on just one -- while keeping stations on the air to inform the public.   All stations were obligated to continuously monitor a major station in their region for CONELRAD alerts, and be ready to go off the air at a moment's notice. 

Nearly all AM radios of the day had the  triangle-in-circle  civil-defense logo on their AM dials (this was decades before digital displays!) marking the 640 and 1240 frequencies that would remain on the air.  

Hams were also obligated to monitor an AM station and be ready to go off the air if CONELRAD was activated.   A standard ham shack accessory "back-in-the-day" was a "CONELRAD monitor".  This was an ordinary AM radio tuned to a local AM station, with a carrier-activated relay that would sound an alarm if the carrier left the air.   You monitored with the volume turned down - you only needed to know if the carrier disappeared.     


In the late 60's early '70s when the Soviet threat moved from manned bombers to ICBMs (that didn't navigate using radio stations on the ground), CONELRAD was phased out. It was replaced by EBS, (Emergency Broadcast System).  EBS's  purpose was not to get stations off the air, but to alert the public with official information in case of a natural disaster or a presidential address.  EBS originated with tone sequences sent from designated higher-power regional stations that would un-mute monitor receivers at all lesser local stations in the area, and in numerous other public and private institutions such as schools, hospitals, police stations, etc. 

For decades, stations have been obligated to conduct and log weekly tests of the EBS alerting system.   Local programming would be randomly interrupted with this script:

"For the next 60 seconds this station will conduct a test of the Emergency Broadcast System . THIS IS ONLY A TEST!    <30 seconds of an obnoxiously loud single tone>  This concludes this test of the Emergency Broadcast System. The broadcasters of your area  in cooperation with the FCC and local authorities have developed this system to keep you informed in an emergency..  Had this been an actual emergency, you would have received official information.  This concludes this test of the Emergency Broadcast System."

Many of us who ran pirate radio stations on college campuses in the '70s and '80s would parody the EBS test by changing the final lines of the test message to:

" HAD THIS BEEN AN ACTUAL EMERGENCY, YOU WOULD HAVE BEEN DEAD BY NOW!  This concludes this test of the Emergency Broadcast System."



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

Kenny Witt
 

Nice article.......add to that the AM signal was used by aviation for navigation for many years with the ADF radio, which could be tuned to any AM station.  Then after verifying the “ident” via the transmitting station’s callsign, the pilot could plot the position, direction and speed of the aircraft, and subsequently determine the distance to their destination.  Of note, many a trans-Atlantic flights used this technique using this technique.


Kenny, KC4OJS 



On Feb 7, 2021, at 12:58 AM, WA8LMF via groups.io <wa8lmf@...> wrote:


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
 

Hi Steven

Indeed very interesting..thank you, that took some time to write!

Mag loop Simon


Re: Ground rod on a loop

Chris Moulding
 

Thanks, Stephen!

That's very useful information for the medium wave DXers ove here.

Regards,

Chris G4HYG


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 ..

241 - 260 of 7862