[Lowfer] Lowfer JH Loop Experiment

Tue Nov 30 19:54:06 EST 2021

John and the list;

I put a high res image of the simple LED RF Detector on my qsl page.
The components are one LED, and 1 or 2 diodes. I think the ones in the 
picture are schottky diodes. In the loop tuner that I used on the three 
LF bands, I used only 1 diode.

The pictured unit lights brightly a number of feet away from my 2m handheld.

http://qsl.net/n8oou/ledrfdetector.jpg

73   de   N8OOU - Mike Meek

On 11/30/21 2:38 PM, John Hamer wrote:
> Mike,
> 
> My mica's should be in this week and I think that will solve the tuning
> issue. I bought some old 4ls style ones and some standard through hole
> ones. They range from 500V to 5KV.
> 
> I will try the led trick tonight. That will be really cool if it works for
> me. I have never heard of that. I think I have some pretty high turn CT's
> somewhere, so I will build a current meter when I come across them. I need
> one for this type of stuff anyways.
> 
> Yes, Your capture does seem to match up. I used the same frequency counter
> to tune it, so it should be at the same place.
> 
> John Hamer
> 
> On Tue, Nov 30, 2021 at 3:04 PM N8OOU <n8oou at meekfarm.us> wrote:
> 
>> John,
>>
>> I have used Mylar and polystyrene caps for determining the values needed
>> to tune the loops. They seem to do ok, but after getting pfff's needed I
>> have always put Mica HV caps and Air variables on the air.
>>
>> I use a simple LED - Diode as an rf detector with one lead connected to
>> a loop end. The other hanging in free air. Tune for max brightness.
>>
>> I also put up this 2020 capture of JH. I was comparing the frequency
>> from it to last night. Last night the noise level was a lot higher.
>>
>> qsl.net/n8oou/JHbeaconJan152020.jpg
>>
>> 73   de   N8OOU - Mike Meek
>>
>> On 11/30/21 9:11 AM, John Hamer wrote:
>>> Mike,
>>>
>>> Thanks for looking last night. There is definitely something there. It's
>>> hard to tell if there is a JH in there, but it definitely looks like it
>>> could be.
>>>
>>> I am using some met poly capacitors I had right now for tuning the loop,
>>> but I have some mica's on order. I also have a 900pF tuning cap for fine
>>> tuning. Do you have any experience with Met Poly caps with something like
>>> this? They claim to be pretty stable. Something is changing after the
>>> transmitter cuts on. I am tuning the antenna using a nanoVNA. The current
>>> on my final looks exactly correct for the 50Ohm load every time the
>>> transmission starts, but over the next 30 seconds to 1 min the current
>>> slowly drops. I'm not sure if the capacitors are warming and changing
>> value
>>> or if there is just a connection issue with them in a breadboard. I will
>>> remove one of those possibilities when I solder everything together, but
>> it
>>> kinda looks like it's just coming out of tune. I also need to build
>>> something to measure antenna current. I should have it all next week
>>> sometime.
>>>
>>> Finals are staying cool and frequency is stable.
>>>
>>> The link below has some pictures.
>>> http://jwhamer.me/lowferJH/Loop2021/
>>>
>>> John Hamer
>>>
>>> On Tue, Nov 30, 2021 at 7:55 AM N8OOU <n8oou at meekfarm.us> wrote:
>>>
>>>> John,
>>>>
>>>> Thanks for the info, I can relate your results to the tests I made using
>>>> Quad Shield RG6 and RG8.
>>>>
>>>> I shut down WM to listen overnight. Nothing seen until Gray Line this
>>>> morning. See the first capture at;
>>>> http://qsl.net/n8oou/nov29210006.jpg
>>>>
>>>> I have a second screen comming, it looks like you went qrt at 06:30 CST.
>>>> The filename will be nov29210007.jpg when it's ready.
>>>>
>>>> 73   de   N8OOU - Mike Meek
>>>>
>>>> On 11/29/21 8:58 PM, John Hamer wrote:
>>>>> Mike,
>>>>>
>>>>> I actually have some pretty good size litz wire. It looks to be around
>> 3
>>>> or
>>>>> 4mm diameter.  Ill see if there is a label on spool with more
>>>> information.
>>>>> I'm not sure if the spool came with the wire.  I got it from my last
>> job
>>>>> years ago when they were trashing it.
>>>>>
>>>>> I still have everything breadboarded, so I'm not sure if that is
>> causing
>>>>> any issues,  but I will solder it all together in the next few days
>>>>>
>>>>> John
>>>>>
>>>>>
>>>>> On Mon, Nov 29, 2021, 9:52 PM N8OOU <n8oou at meekfarm.us> wrote:
>>>>>
>>>>>> John,
>>>>>>
>>>>>> Good to have another loop experimenter. I am curious about what you
>> are
>>>>>> using for the loop conductor. My experiments have shown the larger the
>>>>>> conductor, the better.
>>>>>>
>>>>>> Good Luck
>>>>>>
>>>>>> 73   de   N8OOU - Mike Meek
>>>>>>
>>>>>> On 11/29/21 5:17 PM, John Hamer wrote:
>>>>>>> I have a 12'x12' square loop setup. I am transmitting my usual mode
>> of
>>>>>>> qrss60 and a graphic on 181.818KHz. I just got it going tonight and
>>>> still
>>>>>>> have some work to do, but if you are looking for a challenge, give
>> it a
>>>>>>> shot! It is aimed in the N/S direction.
>>>>>>> ______________________________________________________________
>>>>>>> Lowfer mailing list
>>>>>>> Home: http://mailman.qth.net/mailman/listinfo/lowfer
>>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>>> Post: mailto:Lowfer at mailman.qth.net
>>>>>>> Post must be less than 50KB total for message plus attachment!
>>>>>>>
>>>>>>> This list hosted by: http://www.qsl.net
>>>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>>>
>>>>>> ______________________________________________________________
>>>>>> Lowfer mailing list
>>>>>> Home: http://mailman.qth.net/mailman/listinfo/lowfer
>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>> Post: mailto:Lowfer at mailman.qth.net
>>>>>> Post must be less than 50KB total for message plus attachment!
>>>>>>
>>>>>> This list hosted by: http://www.qsl.net
>>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>>
>>>>> ______________________________________________________________
>>>>> Lowfer mailing list
>>>>> Home: http://mailman.qth.net/mailman/listinfo/lowfer
>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>> Post: mailto:Lowfer at mailman.qth.net
>>>>> Post must be less than 50KB total for message plus attachment!
>>>>>
>>>>> This list hosted by: http://www.qsl.net
>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>
>>>> ______________________________________________________________
>>>> Lowfer mailing list
>>>> Home: http://mailman.qth.net/mailman/listinfo/lowfer
>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>> Post: mailto:Lowfer at mailman.qth.net
>>>> Post must be less than 50KB total for message plus attachment!
>>>>
>>>> This list hosted by: http://www.qsl.net
>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>
>>> ______________________________________________________________
>>> Lowfer mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/lowfer
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Lowfer at mailman.qth.net
>>> Post must be less than 50KB total for message plus attachment!
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>> ______________________________________________________________
>> Lowfer mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/lowfer
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Lowfer at mailman.qth.net
>> Post must be less than 50KB total for message plus attachment!
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
> Post must be less than 50KB total for message plus attachment!
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> 