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THE AM BULLETIN BOARD => Technical Forum => Topic started by: N9NEO on October 27, 2019, 03:29:05 AM



Title: 428kHz propagation from POH to N9NEO.
Post by: N9NEO on October 27, 2019, 03:29:05 AM
Greetings.

I am interested to copy a 428kHz / 25W  airport beacon (POH) in Iowa.  I am in Warner, NH.  What would be best time of day and season to copy call?   I am thinking best season may be directly ahead when it is a little colder. Best time dusk or dawn perhaps.   I am on a very quiet hilltop with closest electric wires about 1/4 mile away.

Receiver is a TRF tuned to 428kHz.   It has 4 stages and is about -110dBm sensitivity.  I have a 3' tuned loop that I will try out.  If I need to build a 6' or 10' then that is easy.  I have high ceiling in my workshop.

thanks,
Bob
N9NEO.


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: KK7UV on October 27, 2019, 08:36:08 AM
If interested in NDB listening consider joining the "NDB List" group on groups.io (https://groups.io/)

Best listening is autumn through spring, during darkness, subject to all the daily and hourly propagation variations caused by solar conditions.


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: WA1LGQ on October 28, 2019, 02:18:13 PM
I did  some tuning around early this morning down there. I think  I heard about a dozen NDB stations. The conditions are getting better as winter approaches. You might consider recording all night on that freq. A SDR should do that job  nicely. Have fun.
Larry


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: DMOD on October 29, 2019, 12:13:17 AM
You are probably hearing KPOH (POH) in Pocahontas Iowa on 428 khz.

--  ---  ....

I am currently in the process of designing a 130 to 480 KHz LF dedicated receiver to this range just for listening only.

Pochahontas is about 3 hours from my QTH.


Phil - AC0OB

 


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: N9NEO on October 31, 2019, 05:13:49 AM
I am going to attempt to work POH with a tracking receiver.  I will try to keep this tome as short as possible.

We make tracking devices for old people in nursing homes and babies in maternity ward in hospitals.  (We've actually stopped few kidnappings with our baby trackers.)  When tracking device gets near door, the door will lock.  Trackers work at 430kHz.  We have been looking at maximizing the range of trackers  better transistors and so forth.  I have asked boss for a couple receivers to soup up on my own. 

So you probably have figured out that I will modify a 430kHz receiver to 428kHz and go after the NDB in Pocahontas, IA.  I have a nice Amrad antenna, but leaning towards using a loop ante.

Thanks for your response.
Bob
N9NEO


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: WU2D on November 03, 2019, 06:01:02 PM
I remember hearing my home NDB in Potsdam NY PTD for the first time. My Grandfathers farm was on what is now that airport. I picked it up on my BC 348 on 400 kHz. I am in Manchester NH.

It is a 14 Watt 1970 system.

Mike WU2D


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: R. Fry SWL on November 06, 2019, 07:40:44 AM
I am interested to copy a 428kHz / 25W  airport beacon (POH) in Iowa.  I am in Warner, NH....

Using FCC methods, below are the nighttime skywave fields expected for a similar path length from a 50W ERP transmit system on 530 kHz.

Probably even those fields would be well below the ambient r-f noise level at the receive site, unfortunately.

(https://i.postimg.cc/k5W7Mdt1/530-k-Hz-TIS-Station-Skywave-to-NH.jpg)


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: WA2SQQ on November 06, 2019, 11:25:15 AM
Last night's N-S propagation was quite good, best catch ~850 miles, many NDB's from up in Northern central Canada. Tonight I'm going to twist the loop for favor East / West. NE weather this weekend says temps down in the high 20's so the noise should start diminishing. Than again, cold also causes many HV insulators to start getting noisy!


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: W1DAN on November 06, 2019, 01:47:02 PM
Hi Bob!

Great to see you here....

73,
Dan
W1DAN


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: N1BCG on November 10, 2019, 06:06:45 AM
This site features a comprehensive directory of LF beacons:

http://www.dxinfocentre.com/ndb.htm


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: WA1LGQ on November 10, 2019, 01:20:40 PM
CBC on 415 from Cayman is coming in pretty good now here in CT. Thats a long haul. Over water mostly.
Larry


Title: Re: 428kHz propagation from POH to N9NEO.
Post by: N9NEO on February 28, 2020, 06:31:31 AM
Thank you for responses.  I have hope.   I am out in woods off grid so no QRM to deal with.  Nearest neighbor is over 1/2 mile.  I think I will be able to copy with my existing 3' loop for AM broadcast.

Bob
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands