LongRangeLocators Forums  

Go Back   LongRangeLocators Forums > Main Forums > All-Electronic LRLs

Reply
 
Thread Tools Display Modes
  #1  
Old 12-26-2022, 05:37 PM
Mike(Mont) Mike(Mont) is offline
Guru
 
Join Date: May 2007
Posts: 2,103
Default Harmonics vs fundamental frequency

I have been using fundamental frequencies for a while but I used to use harmonics. Anyway I went back to harmonics of fundamental freq x 100. I have a list of frequencies that supposedly came from Bob Fitzgerald and some of his frequencies were the fundamental frequency set at a mag reading of 50000. So I decided to bump up the fundamentalfreq for gold 39.769 Hz and converted it to 3976.9 Hz -- this is how Fitzgerald has it on his frequency chart. I've heard different things about higher frequencies like they don't penetrate as deeplp, and they hit small targets better, and pinpointing is easier at least on my receiver. I know Dell Winders and some others use the lower frequencies said it locks-on faster. Oh yeah, I also heard the higher frequencies are more temperature sensitive. Feel free to add any comments.
Reply With Quote
  #2  
Old 12-27-2022, 02:40 AM
Mike(Mont) Mike(Mont) is offline
Guru
 
Join Date: May 2007
Posts: 2,103
Default

Most people have herd of 8.6 or 8.7 KHz for silver. At an earth filed mag reading of 50000 the fundamental frequency for silver is 86.163 so multiply by 100. But note that your mag reading is going to be different. Tim Williams lrlman.com used to sell a phone app to calculate the various element frequencies depending on the mag readout. It's handy but you cn do your own calculations. SOmewhere on this forum I explain how to calculate. Sorry my typing is bad, got a keyboard and I'm not adjusted to it yet. It won't allow me to go back and edit. You might ask why he multiplies the fundamental frequency by 100 instead of say 10. Well, mulitply by ten and you can end up with other element frequency. So by 100 there are no other fundamental freq's in that zone.
Reply With Quote
  #3  
Old 12-27-2022, 03:19 PM
Mike(Mont) Mike(Mont) is offline
Guru
 
Join Date: May 2007
Posts: 2,103
Default

There is also the possibility that a higher frequency can penetrate through a pile of metal junk better. I saw an article a while back about degaussing. They used a different frequency depending on the metal thickness and hardness. I have the article somewhere in a big stack of papers. I'll try to find it.
Reply With Quote
  #4  
Old 12-28-2022, 02:59 PM
Mike(Mont) Mike(Mont) is offline
Guru
 
Join Date: May 2007
Posts: 2,103
Default

LOL I spent too long looking through my stuff. Looked on the internet, too. I recall the ompany name of the website Vallon but I counld not find the graph. I'll find it.
Reply With Quote
  #5  
Old 12-31-2022, 05:14 PM
Geo's Avatar
Geo Geo is offline
Guru
 
Join Date: Mar 2005
Location: Greece
Posts: 3,919
Default

Quote:
Originally Posted by Mike(Mont) View Post
I have been using fundamental frequencies for a while but I used to use harmonics. Anyway I went back to harmonics of fundamental freq x 100. I have a list of frequencies that supposedly came from Bob Fitzgerald and some of his frequencies were the fundamental frequency set at a mag reading of 50000. So I decided to bump up the fundamentalfreq for gold 39.769 Hz and converted it to 3976.9 Hz -- this is how Fitzgerald has it on his frequency chart. I've heard different things about higher frequencies like they don't penetrate as deeplp, and they hit small targets better, and pinpointing is easier at least on my receiver. I know Dell Winders and some others use the lower frequencies said it locks-on faster. Oh yeah, I also heard the higher frequencies are more temperature sensitive. Feel free to add any comments.
Hi Mike.
Years ago.. i tried harmonics. I used a big generator (up to 1 Ghz) and did experiments at harmonics.... as i remember the last harmonic was near to 500Mhz.
Anyway.... what i saw ....
1.The higher frequency ... the smaller distance
2. when i was working at higher frequency the center of target was going many cms forward.
3. At high frequency i had not good discrimination, i was catching every rust iron...

Thats all i remember....

Attached Images
 
__________________
Geo
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 05:17 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.