RELIC HAWK

[eclipse]

smart, spammer go away!

[Qiaozhi]

smart, spammer go away!

Please use the red triangle at the top right to report any posts, as sometimes spam posts do slip through. For your info - Smart will not be bothering us again.

[lonelyWOLF]

I will post some pictures next week (including opened coil).
[COLOR=black]
Regards,

Hi wam..
long time past, but
I'm interested with gc1020. maybe I get from Ebay please share photos..

regards..

[metaldetector107]

relic hawk for sale

http://www.djlaan.nl/index.html?product_id=3&view=947

[amtech2005]

http://www.djlaan.nl/index.html?product_id=3&view=947

Wow thanks for posting , looks like its in excellent condition !! This one will sell fast . Wonder what the price is in U.S. Dollars ?
I see one splice on one of the search coil cable's , make an offer !!

HH...........Eugene

[Qiaozhi]

Wonder what the price is in U.S. Dollars ?

$713.34

[amtech2005]

Hello Qiaozhi , Thank-you for the dollar conversion , plus add high over-seas shipping and we have a big over-priced Minelab !!

Will be a good deal for a local buyer .

Regards..........Eugene

[mikebg]

Eugene, I posted SPICE circuit for TX revision of Relic Hawk in a thread started by you:
http://www.thunting.com/smf/vlf_desi...1333#msg221333
Every familiar with SPICE can test and improve this incompetent designed TX.

[mikebg]

Exercises for Beginners

EXERCISES FOR BEGINNERS

Lately I can spend more time for the forum. I have time to explain for beginners how a hobbyist can design TXs, RXs and search heads for metal detectors.

What would happen if my future explanations and exercises in design are aimed at Minelab designers?
I don't know, but I know that it is unethical I to accuse of incompetence Minelab designers especially in a forum sponsored by Minelab. This may affect badly on the sponsorship of THUNTING.com forum. Guilty of this is Eugene, who started the above mentioned thread, knowing that the circuit digrams of Relic Hawk, Musketeer and Coinseeker Pro are bad designs.

To avoid adverse effects on that forum, I will continue here with several posts for ham designers called EXERCISES FOR BEGINNERS. Let we start to make revision and improvements of above mentioned circuit diagrams.
Here is the first exercise titled

ANALYSIS OF TX

SPICE analysis of TX was made in this thread several years ago, but not for beginners. For beginners, here is attached a compressed file ready for simulation. Every ham designer can download LTspice and open this file. The SPICE circuit of TX is made according posts of Max. His circuit is more convenient for simulation and design because LC tank is connected to SPICE ground.
Let we see how TX circuit works. Try to obtain the following picture.

[Davor]

I am quite interested where this thread will lead to

[amtech2005]

Guilty ?

EXERCISES FOR BEGINNERS

Lately I can spend more time for the forum. I have time to explain for beginners how a hobbyist can design TXs, RXs and search heads for metal detectors.

What would happen if my future explanations and exercises in design are aimed at Minelab designers?
I don't know, but I know that it is unethical I to accuse of incompetence Minelab designers especially in a forum sponsored by Minelab. This may affect badly on the sponsorship of THUNTING.com forum. Guilty of this is Eugene, who started the above mentioned thread, knowing that the circuit digrams of Relic Hawk, Musketeer and Coinseeker Pro are bad designs.

To avoid adverse effects on that forum, I will continue here with several posts for ham designers called EXERCISES FOR BEGINNERS. Let we start to make revision and improvements of above mentioned circuit diagrams.
Here is the first exercise titled

ANALYSIS OF TX

SPICE analysis of TX was made in this thread several years ago, but not for beginners. For beginners, here is attached a compressed file ready for simulation. Every ham designer can download LTspice and open this file. The SPICE circuit of TX is made according posts of Max. His circuit is more convenient for simulation and design because LC tank is connected to SPICE ground.
Let we see how TX circuit works. Try to obtain the following picture.

Hello MikeBG. Your work on the forums is impeccable and very appreciated .
A few years back on Thunting.com I posted some Minelab VLF topics way before the administrator starting advertising Minelab products . In the past I always tried to post any metal detector circuit that is discontinued and no longer in production . Its ok though , nothing to worry about , Minelab DOES NOT REPAIR ANY of its discontinued Metal Detector Models . If you read various forums around the world this gets many customers of Minelab upset because they do not back their older products anymore , they use to !! If you keep the customer coming back that brings more business of the new products and customers also tell their friends which brings even more business . I guess that is not important to some companies in this day and age . Mass production is NOT the only key !!

I am only guilty of not finishing my work on the forums , because I never have spare time anymore .

Best Regards always...............Eugene

[mikebg]

I am quite interested where this thread will lead to

I think that it will lead participants of this forum to more knowledge and gaining design experience if they ask questions and receive answers. So far I know the answers but don't know the questions.
However I will put a question:
How to calculate the resistance of these 4 resistors?

[WM6]

Excellent mikebg, don't stop to early.

Here you have ivconic's version of RH - proven as working:

[mikebg]

Excellent mikebg, don't stop to early.

Here you have ivconic's version of RH - proven as working:

WM6, I know that it works, but it is incompetent and incorrect designed. Its TX and RX sections will work better if we redesign them. I will post SPICE circuit of RX preamp to show that it also has drawbacs.

I use for simulation of TX a single supply opamp like LM358 and LM324, which operates better than 074 because have small value Vo_min (see post #927). If we remove transistor Q3 and all components forming voltage source V3, the TX starts to operate better until 10.2V battery discharge and with increased power. Please make the above SPICE analysis to see what happens when battery discharges from 12.2V with 0.1V only.

[WM6]

Please make the above SPICE analysis to see what happens when battery discharges from 12.2V with 0.1V only.

Working under Ubuntu and I can't import your LTSpice file in my Qucs simulator. Depend on your demo for now.