[x] Welcome at THunting.com!

A fun place to talk about Metal Detecting, Treasure Hunting & Prospecting. Here you can share finds and experience with thousands of members from all over the world

Join us and Register Now - Its FREE & EASY

THunting.com
Treasure Hunting & Metal Detecting Community
   
Advanced Search
*
Welcome, Guest! Please login or register HERE - It is FREE and easy.
Only registered users can post and view images on our message boards.
Did you miss your activation email?

Login with email, password and session length
Or Login Using Social Network Account
2
News:
Pages: 1    Go Down
Print
Share this topic on FacebookShare this topic on Del.icio.usShare this topic on DiggShare this topic on RedditShare this topic on Twitter
Tags:
0 Members and 1 Guest are viewing this topic.
Offline whitkenight38Topic starter
Foil
*

Join Date: Jan, 2009
Thank you0

Activity
0%

Canada
Posts: 1
Referrals: 0

10.00 Gold
View Inventory

Awards
« on: January 04, 2009, 12:28:14 pm »
Go Up Go Down
Hi all.
I'm looking for an old-school BFO detector for a project.
No luck on ebay so far.
Prefer vintage but will settle for a newer model with BFO technology.
I've heard about about Chinese/Asian market BFOs, maybe designed for kids? Any on got a line on something like that?




Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,2823.msg21136.html#msg21136

Logged
Offline Christian
Administrator
Platin Member
*****

Wuf! Wuf!
Join Date: Sep, 2006
Thank you56

Activity
0%
Male
Independent Rouge States
Posts: 5261
Referrals: 0

2305.00 Gold
View Inventory

WWW Awards
« Reply #1 on: January 04, 2009, 01:30:20 pm »
Go Up Go Down
Hello,

I think the Chinese MD Series if VLF. If not not they could be picked up real cheap.

There is also a Russian manufacturer who sells very good qualiyt BFO kits. What's your budget?

Regards,

Christian

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,2823.msg21149.html#msg21149

Logged
THunting.com - Your Friendly One Stop Treasure Resource
Offline Eugene52
M.D. Electronic Builders Club
Moderator
Gold Member
*****

Mood:Happy
Happy

M.D. Electronic Builders Club
Join Date: Dec, 2008
Thank you398

Activity
0%
Male
United States
Posts: 2630
Referrals: 0

17957.00 Gold
View Inventory

Awards

Teknetics , Fisher , Discovery3300 and TIANXUN 19 kHz VLF Metal Detector
« Reply #2 on: January 04, 2009, 05:42:45 pm »
Go Up Go Down
Hello Whitkenight38 , as Christian said , very few "NEW" BFO "BEAT FREQUENCY OSCILLATORS" are on the Market.  Hays Electronics rings a bell with a 100 khz model  Idea , But let me  research today for you , I will post some answers today or tommorrow , if you can wait . Also check craigslist.org , I think they are world-wide  !!!! Thank-You and welcome to the Thunting forum !!!!.....................Regards.....Eugene
Posted on: January 04, 2009, 01:53:14 PM
I found a Perfect "BFO-PROJECT" for you . A pretty good , easy to build BFO in a nice clear PDF File !!!.....I will post more later...........Regards.......Eugene52

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,2823.msg21172.html#msg21172


There are 1 attachment(s) in this post which you can not view or download

Please register for viewing them.

eti561_150.pdf

Logged
Let's Talk Treasure right here on Thunting.com
Offline Eugene52
M.D. Electronic Builders Club
Moderator
Gold Member
*****

Mood:Happy
Happy

M.D. Electronic Builders Club
Join Date: Dec, 2008
Thank you398

Activity
0%
Male
United States
Posts: 2630
Referrals: 0

17957.00 Gold
View Inventory

Awards

Teknetics , Fisher , Discovery3300 and TIANXUN 19 kHz VLF Metal Detector
« Reply #3 on: January 04, 2009, 06:35:35 pm »
Go Up Go Down
Hello Again !! Remember the "BFO" Type detectors Do not go deep !!! And will NOT work good in bad mineralized soil or bad soil conditions . Craigslist has old Garrett BFO detectors for $20.00 to $25.00 dollars . Garrett last manufactured a BFO in 1982 , called the Master Hunter "BFO" !!! After you build this project then I am sure you will build a VLF I.B. Metal Detector , and there are many Great older Tesoro projects on several internet sites........Also you can buy a good "VLF" discovery 1000 or 1100 for $50.00 or less on craigslist.org..............Bye for now...............Eugene52

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,2823.msg21178.html#msg21178

Logged
Let's Talk Treasure right here on Thunting.com
Offline treasuremomo
micmomo
Bronze Member
*

micmomo
Join Date: Oct, 2009
Thank you0

Activity
0%
Male
United States
Posts: 418
Referrals: 0

1990.00 Gold
View Inventory

Awards

I'VE USED MANY BRANDS AND MODELS-TESORO, WHITES,GARRETT,FISHER,NAUTILUS,D-TEX,WILSON NEUMAN,ETC.
« Reply #4 on: January 09, 2010, 05:08:53 pm »
Go Up Go Down
The Beat Frequency Oscillator(BFO) detectors were a few years ahead of my beginning detector hobby...I started back about 1986 and the unit I started with was a Transmitter Receiver (TR) type detector. I have held an old and simple BFO unit , but never have searched with one. From what I've read in older and newer detector mags, the BFO units are really good at ore sampling and hunting in ground with little mineralization but they don't operate too well in mineralized ground. Back in the early days of detecting, many good finds were made by folks using BFO units. When TR units were created and placed on the market, the BFO units became obsolete in a few years. Very Low Frequency(VLF) detectors were an improvement over the TR units and continue to be the most popular detector type today. Wise
BFO OUGHT TO STAND FOR  BEST FORGOTTEN OLD...DETECTOR CIRCUITRY!!!  LOL

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,2823.msg67133.html#msg67133

« Last Edit: January 09, 2010, 05:11:32 pm by treasuremomo » 		Logged
Offline GoldDigger1950
The Old Man and the Soil
Global Moderator
Platin Member
*****

Just call me GD.
The Old Man and the Soil
Join Date: Jun, 2009
Thank you225

Activity
0%
Male
United States
Posts: 11219
Referrals: 12

47848.00 Gold
View Inventory

Awards

Garrett Groundhog ADS, Garrett Sea Hunter, Bounty Hunter Tracker IV, Bounty Hunter Pioneer 505,Minelab Eldorado Mk II, Tesoro Compadre, Tesoro Tiger Shark & A Few Home Brew Detectors
« Reply #5 on: January 09, 2010, 05:19:15 pm »
Go Up Go Down
Quote:Posted by whitkenight38
Hi all.
I'm looking for an old-school BFO detector for a project.
No luck on ebay so far.
Prefer vintage but will settle for a newer model with BFO technology.
I've heard about about Chinese/Asian market BFOs, maybe designed for kids? Any on got a line on something like that?


If you are skilled with electronics you can make or design one yourself. What you need are two oscillators both very close in frequency. One should be built using a small inductor and the other with a large one that will be your detecting coil. Both should be in proximity to each other and "beat" against one another with a difference frequency that is in the middle of the human audio range (50-20,000hz) so that you can hear the beat frequency. When a metal object comes close to the larger coil, it offsets that oscillator and causes a variation in the beating frequency which then varies the buzz you hear. Simple as that.

For the stable oscillator, use a 555. For the one that is to detect the metal, use discrete components. You want an oscillator that can be drifted by an impedance mismatch which is what happens when the large coil comes near metal objects.

The Geotech Forums offer several designs for you to use.

You are not allowed to view links.
Please Register or Login

http://www.geotech1.com/cgi-bin/pages/common/index.pl?page=main&file=main.dat


Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,2823.msg67136.html#msg67136

« Last Edit: January 09, 2010, 05:20:51 pm by GoldDigger1950 » 		Logged
It's all about that moment when metal that hasn't seen the light of day for generations frees itself from the soil and presents itself to me.
Let's Talk Treasure!
Offline aparjona
Pull Tab
*

Join Date: Jan, 2010
Thank you0

Activity
0%

Brazil
Posts: 8
Referrals: 0

40.00 Gold
View Inventory

Awards
« Reply #6 on: January 22, 2010, 12:27:19 pm »
Go Up Go Down
dear friend
I would be sending you some information later
Arjona

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,2823.msg68421.html#msg68421

Logged
Print
Pages: 1    Go Up
Jump to:  

Powered by SMF 1.1.19 | SMF © 2005, Simple Machines | Sitemap
Copyright THunting.com