[Lowfer] Radio Morocco LW-AM on 171 kHz

Fri Apr 7 21:48:49 EDT 2023

Hi there Zack. Tried to send this shortly after you posted....not sure 
why the first one did not make it. Here it is again.

Anyway, so neat to see you here and up on 10 GHz.

I have WOWO (a 50kW AM station) less than 15 miles away from me. I could 
LPF things but wanted to try a purely passive resonant antenna which 
this loop is. I have since seen many others using this type of antenna 
but when I started designing it and building it I was doing so as my own 
creation and purely as an experiment.

This is a 36T square loop on a PVC frame, 47" on a side resting 12" off 
the ground. I tune the loop with a variable "C" box I put together. I 
then use a single turn P/U loop inside the main 36T loop which get 
connected to a CMC then 150' of LMR-240. I use another CMC where the 
coax enters the house.

It is a _very_ high Q antenna. So high that a typical AM signal and it's 
sidebands will not fit in the bandpass of the antenna. I would say the 
bandpass is about 2 kHz. This is actually a good thing for me as it 
knocks the snot out of any out of band signals and naturally amplifies 
the freq of interest.

Last night I was comparing the loop against my various HF wire antennas 
which do a great job hearing VLF signals (75m Inv-V at 70', 33' elevated 
vertical, 40m rotatable dipole at 70', etc and the small loop always has 
at least 15-20 dB more S/N than the wire antennas and a stronger overall 
RF level.

I was like you were I was hearing the carriers of all the AM stations 
fine ! They were always 20 dB above my NF but I was baffled why I never 
heard anything. Since then I have found (for me) that the carriers need 
to be about 30 dB or more out of the noise before I can start hearing 
modulation well. The best I could ever do with the wires were very 
faint, ghostly whispers now and then. Hope this helped. I had replied 
over an hour ago but my post did not make it. I suspect the picture was 
not permitted. I provided a link to that image. It was very strong but 
the severe lightning crashes from down south made recording it not 
interesting. 73

https://drive.google.com/file/d/1aY8_i5KXvuH6t7etlgOaC15Hj15r5qVA/view?usp=share_link 

Gedas, W8BYA EN70JT

Gallery at http://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.

On 4/7/2023 10:59 AM, Zack Widup wrote:
> I have been trying to hear the EU broadcast stations for years and still
> have not heard one. People posted on this list earlier that this is one of
> the worst years for LF in recent history. I haven't even bothered lately.
>
> Gedas, what antenna are you using? Preamp?
>
> Zack W9SZ
>
> On Fri, Apr 7, 2023 at 9:00 AM Gedas <w8bya at mchsi.com> wrote:
>
>> GM John. Thank you. Last night I was trying to get a nice recording of
>> the BBC-4 before they go QRT for good and they had a wonderful signal
>> but the QRN from all the lightning down south made it impossible.
>>
>> BTW, are you, or were you active on 630m? Your call seems very familiar
>> to me as I used to get many dozens of WSPR decodes from maybe you when I
>> was active on the band several years back.  73
>>
>> Gedas, W8BYA EN70JT
>>
>> Gallery at http://w8bya.com
>> Light travels faster than sound....
>> This is why some people appear bright until you hear them speak.
>>
>> On 4/7/2023 12:44 AM, John VE7BDQ wrote:
>>> Great to hear you nice reception, thanks for posting.
>>>
>>> 73  John  /  VE7BDQ
>>>
>>> On Thu, Apr 6, 2023 at 1:30 PM Gedas <w8bya at mchsi.com> wrote:
>>>
>>>> Please forgive me if this is OT within the group. I have been trying for
>>>> over a year to listen to the few remaining LW-AM radio stations which
>>>> from here in the Midwestern part of the states can be a challenge.
>>>>
>>>> After finally making an experimental loop antenna and a good night w/o
>>>> too much lightning crashes and static several days ago I was able to get
>>>> some nice reception. 73
>>>>
>>>> https://www.youtube.com/watch?v=g3C83ggWBVg
>>>>
>>>> Gedas, W8BYA EN70JT
>>>>
>>>> Gallery at http://w8bya.com
>>>> Light travels faster than sound....
>>>> This is why some people appear bright until you hear them speak.
>>>>
>>>>
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