OT: possible ham operation in the region of 415-526.5 Khz

[Johnny Siu]

Hello Group,
 
This is off topic but I know there are experts in this group.
 
I am the amateur radio sector representative of Radio Spectrum Advisory
Committee (RSAC) of Telecommunication Authority of Hong Kong.  RSAC is an
official advisory committee under the Hong Kong Government.
 
http://www.ofta.gov.hk/en/ad-comm/rsac/main.html
 
The Asia Pacific Telecommunity is now having its meetings in Hong Kong. 
 
http://www.aptsec.org/
 
One of the discussion is related to WRC 2012 Agenda item 1.23 about the
allocation of a 15Khz segment within 415-526.5Khz for amateur services.
 
As a representative of RSAC, I am now attending the discussion group for the
Agenda item 1.23.
 
Propagation in this band is primarily by means of ground wave,so availability of
this band for the amateur service may provide a useful extension of the
capability of the amateur service to provide disaster notification and relief
communications on a wider area basis than is normally provided by the VHF or UHF
bands that form the main-stay of amateur disaster relief communications.

 
My questions are :
1.  practically speaking, apart from huge traditional wire antenna, are there
any other antennas of managable size (also reasonable efficiency) which can be
easily set up under distress situation?
2.    to make communciations of say within 200-300km, what ERP is required?
3.    for a segment of 15Khz, voice communciation seems quite restrictive.  How
efficent will it be under digital mode (not CW) such as Pactor?
 
I must admit that I am not a radio man by profession and have limited knowledge
on MF radio operation.  I am looking forward to your advice and apologise for
the band width in this mail reflector.
 73


Johnny VR2XMC


     
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[Matt Zilmer]

You might try a magnetic loop.  Here is a Wikipedia article with
references to others:
http://en.wikipedia.org/wiki/Magnetic_loop

73,
Matt W6NIA

On Tue, 14 Dec 2010 23:41:47 +0800 (HKT), you wrote:

>Hello Group,
> 
>This is off topic but I know there are experts in this group.
> 
>I am the amateur radio sector representative of Radio Spectrum Advisory
>Committee (RSAC) of Telecommunication Authority of Hong Kong.  RSAC is an
>official advisory committee under the Hong Kong Government.
> 
>http://www.ofta.gov.hk/en/ad-comm/rsac/main.html
> 
>The Asia Pacific Telecommunity is now having its meetings in Hong Kong. 
> 
>http://www.aptsec.org/
> 
>One of the discussion is related to WRC 2012 Agenda item 1.23 about the
>allocation of a 15Khz segment within 415-526.5Khz for amateur services.
> 
>As a representative of RSAC, I am now attending the discussion group for the
>Agenda item 1.23.
> 
>Propagation in this band is primarily by means of ground wave,so availability of
>this band for the amateur service may provide a useful extension of the
>capability of the amateur service to provide disaster notification and relief
>communications on a wider area basis than is normally provided by the VHF or UHF
>bands that form the main-stay of amateur disaster relief communications.
>
> 
>My questions are :
>1.  practically speaking, apart from huge traditional wire antenna, are there
>any other antennas of managable size (also reasonable efficiency) which can be
>easily set up under distress situation?
>2.    to make communciations of say within 200-300km, what ERP is required?
>3.    for a segment of 15Khz, voice communciation seems quite restrictive.  How
>efficent will it be under digital mode (not CW) such as Pactor?
> 
>I must admit that I am not a radio man by profession and have limited knowledge
>on MF radio operation.  I am looking forward to your advice and apologise for
>the band width in this mail reflector.
> 73
>
>
>Johnny VR2XMC
>
>
>      
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:[hidden email]
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html

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[Augie "Gus" Hansen]

On 12/14/2010 8:41 AM, Johnny Siu wrote:

> ...
> My questions are :
> 1.  practically speaking, apart from huge traditional wire antenna, are there
> any other antennas of managable size (also reasonable efficiency) which can be
> easily set up under distress situation?

I built a magnetic loop that covers the range of 160-80 meters. It
consists of three turns of 7/8" hard line as the loop conductor and
a remotely controlled vacuum variable capacitor for tuning. The
antenna is just a tad over six feet in diameter. It can be tuned
down to about 1.5 MHz with a 500 pF vacuum variable. With a longer
loop conductor (either more turns or larger antenna diameter) and a
1000 pF VVC, such an antenna could get down to the 600 meter band.
The instantaneous bandwidth is quite narrow (~2 kHz), suitable for
CW and data modes, but not SSB.

> 2.    to make communciations of say within 200-300km, what ERP is required?

I have worked all over North America from Colorado (~2000 mile
range) with this antenna running only 100 watts during several
contests, and daytime regional coverage is typically out to about
200 miles using 500 watts. The antenna hangs from a tree branch with
the bottom of the loop about 8 feet above ground.

> 3.    for a segment of 15Khz, voice communciation seems quite restrictive.  How
> efficent will it be under digital mode (not CW) such as Pactor?

The three-turn mag loop typically has a 10-15% transmitting
efficiency at the low end of its tuning range if it is built well,
and the nulls along the loop axis help in reducing at least one
noise source, providing acceptable S+N/N performance on receive.

---------------------
Johnny, I can send you a picture of my 160/80m version of this mag
loop if you want. Its from an article in preparation for the
antenneX on-line magazine.

73,
Gus Hansen
KB0YH

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[Augie "Gus" Hansen]

I initially responded only to Sam's request for the 160/80m mag loop
picture, but have had several direct requests also. So here is the
reply for anyone else who may be interested.

--------------------------

On 12/14/2010 1:00 PM, Sam Morgan wrote:
> I would like a pic please
> and even a copy of the article if possible
> I find the antennx experience just to distressing to try to find it
>

Hi Sam,

Most of my articles are behind the "pay wall" on antenneX, so I
cannot distribute them. But I uploaded a picture of the three-turn
160/80 meter mag loop to the following antenneX page, which is
freely viewable:

http://download.antennex.com/listarch/files/3t6d_8_2.jpg

The VVC is in the box at the top along with the motor and limit
switches. The control voltage is obtained from the small  box just
above the bottom of the structural PVC frame. That box separates the
DC motor-control voltage from the RF, passing the RF through a
capacitor to the small driver loop. The DC goes up a twisted pair
cable inside the vertical PVC support tube. The VVC handles up to 15
KV at up to 65 amps.

I hope this helps,
Gus, KB0YH
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[Johnny Siu]

Thanks to all the replies here and also off-the-list replies.
 73


Johnny VR2XMC


     
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[AC7AC]

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[Leigh L. Klotz Jr WA5ZNU]

Johnny,

It would be great if you could take a look at this:

http://www.500kc.com/

The FCC gave some hams and the ARRL an experimental license for the 500 KHz band a couple of years ago.

There's a tremendous amount of info on antennas, propagation, equipment, modulation, ERP, etc. from the knowledge this group gained.  I'm sure any of them would be happy to coordinate with you, as getting a ham allocation there is their goal as well.

Leigh/WA5ZNU

[ANTNEE N3ANT]

I can't get the link to work ! ! ! Is It correct ?

Anthony N3ANT

[Jeff Cochrane - VK4XA]

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[ANTNEE N3ANT]

I'm having trouble with the link to AnteenaX...not working ! ! !

Anthony N3ANT

[Augie "Gus" Hansen]

On 12/15/2010 3:13 PM, ANTNEE N3ANT wrote:
> I'm having trouble with the link to AnteenaX...not working ! ! !
>
> Anthony N3ANT

It might work better if you spell it correctly:

     http://www.antennex.com/

Cheers,
Gus Hansen
KB0YH

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[Johnny Siu]

Thanks, Leigh.  It is very useful website indeed.

 

Seasons greetings to you and others who replied to my mail on this topic.

 

cheers,

Johnny VR2XMC

---

寄件人﹕ Leigh L. Klotz Jr WA5ZNU [via Elecraft] <[hidden email]>
收件人﹕ Johnny Siu <[hidden email]>
傳送日期﹕ 2010/12/16 (四) 5:04:05 AM
主題： Re: OT: possible ham operation in the region of 415-526.5 Khz

Johnny,

It would be great if you could take a look at this:

http://www.500kc.com/

The FCC gave some hams and the ARRL an experimental license for the 500 KHz band a couple of years ago.

There's a tremendous amount of info on antennas, propagation, equipment, modulation, ERP, etc. from the knowledge this group gained.  I'm sure any of them would be happy to coordinate with you, as getting a ham allocation there is their goal as well.

Leigh/WA5ZNU

 

[Jim Cox]

Unless my grammar fails me, Antenna  is the correct spelling..

Jim K4JAF


----- Original Message -----
From: "ANTNEE N3ANT" <[hidden email]>
To: <[hidden email]>
Sent: Wednesday, December 15, 2010 4:13 PM
Subject: Re: [Elecraft] OT: possible ham operation in the region of415-526.5
Khz

>
> I'm having trouble with the link to AnteenaX...not working ! ! !
>
> Anthony N3ANT
> --
> View this message in context:
> http://elecraft.365791.n2.nabble.com/OT-possible-ham-operation-in-the-region-of-415-526-5-Khz-tp5835891p5838503.html
> Sent from the [HAM] mailing list archive at Nabble.com.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html 

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[Don Wilhelm-4]

  Jim,

Nothing wrong with your grammar, but the site calls itself "Antennex",
so you have to put in their spelling whether right or wrong.

73,
Don W3FPR

On 12/15/2010 7:50 PM, Jim Cox wrote:
> Unless my grammar fails me, Antenna  is the correct spelling..
>
> Jim K4JAF
>
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[k5oai]

/soapbox on

I think they are referring to the Antennex website
http://www.antennex.com/Stones/st0906/antennex.html

you know the one that took the free L.B. Cebik's website
and commercialized all Cebik's content after he died

this rape of Cebik's material it is denied here:
http://www.antennex.com/Stones/st0509/lb_and_me.htm

all I know is, what was one freely given,
now must be paid for,
but whither or not that was Cebik's wishes for his legacy
well I guess we will each just have to decide for our selves

hint:
who's name is on the check you must write

/soapbox off

GB & 73
K5OAI
Sam Morgan

On 12/15/2010 6:50 PM, Jim Cox wrote:

> Unless my grammar fails me, Antenna  is the correct spelling..
>
> Jim K4JAF
>
>
> ----- Original Message -----
> From: "ANTNEE N3ANT"<[hidden email]>
> To:<[hidden email]>
> Sent: Wednesday, December 15, 2010 4:13 PM
> Subject: Re: [Elecraft] OT: possible ham operation in the region of415-526.5
> Khz
>
>
>>
>> I'm having trouble with the link to AnteenaX...not working ! ! !
>>
>> Anthony N3ANT

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[AC7AC]

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