70kHZ transmitter

[WM6]

If one need a 70kHz transmitter with exact frequency, I suggest this solution:

1.
Use this module from eBay ($38 + free shipping):

0.01- 5MHz DDS Function Signal Generator Module




http://www.ebay.com/itm/0-01-5MHz-DD...-/270864768941


2.

Signal generator has enough amplitude to act as transmitter you need, but if you insist that you need more power, then connect signal generator to this module from eBay:

Mono 25W Audio Amplifier Module Board, Based on LM1875



http://www.ebay.com/itm/Mono-25W-Aud...item5d30720799

Do not drive it with full power - 1/10 of max power, no more.

Inductance of antenna (ferrite core or air core - the last one is better) have to be about 50mH. Exact value depend of antenna windings stray capacitance. You need to connect antenna instead of loudspeaker.

Of course this transmitter can generate any other arbitrary frequency too (for some very different antenna inductance need to be recalculated).

Use sine wave.

[mustefa ubram]

tank you very much freind
I have a problem in calculating the period number and size of the ferrite coil.Get tips on how to calculate the winding.If there is a formula to give.
If I have a signal generator, and can help to strengthen the ferrite Can I send a wave?
How?
tanks
ubram

[WM6]

Originally Posted by mustefa ubram

tank you very much freind
I have a problem in calculating the period number and size of the ferrite coil.Get tips on how to calculate the winding.If there is a formula to give.
If I have a signal generator, and can help to strengthen the ferrite Can I send a wave?
How?
tanks
ubram

It is simple, if you have L-meter (inductance meter).

You need to wind 10 (or better 20 or 30) testing turns of wire (diameter about 0.3 or so) on ferrite rod antenna you have.

Then measure inductance.

Par example:

If you wound 30 testing turns and then measured inductance is 15mH, then you calculate total turns this way:

30 / 15 = 2

This mean that you need 2 of turns to get 1mH.

To get 50mH you need 50x2(turns)=100 (turns).

So you need 100 turns in total on your ferrite rod to get 50mH ferrite cored antenna.


Ferrite cored transmitter antenna is not the best solution for TX, air cored antenna is better. Of course it depend of what you need and what you try to build. If you need "shielded" (i.e. mounted in a tin can) antenna (to radiate in one direction) ferrite core antenna can be better solution than air core.

[mustefa ubram]

Originally Posted by WM6

It is simple, if you have L-meter (inductance meter).

You need to wind 10 (or better 20 or 30) testing turns of wire (diameter about 0.3 or so) on ferrite rod antenna you have.

Then measure inductance.

Par example:

If you wound 30 testing turns and then measured inductance is 15mH, then you calculate total turns this way:

30 / 15 = 2

This mean that you need 2 of turns to get 1mH.

To get 50mH you need 50x2(turns)=100 (turns).

So you need 100 turns in total on your ferrite rod to get 50mH ferrite cored antenna.


Ferrite cored transmitter antenna is not the best solution for TX, air cored antenna is better. Of course it depend of what you need and what you try to build. If you need "shielded" (i.e. mounted in a tin can) antenna (to radiate in one direction) ferrite core antenna can be better solution than air core.

tank you very much dear freind

[WM6]

Here proposed TX configuration can be used till to 150kHz, even more. Of course not with same antenna specifications given here.

For frequencies 70kHz +-10kHz antenna even do not need to be recalculated.

[mustefa ubram]

Originally Posted by WM6

.
Ferrite cored transmitter antenna is not the best solution for TX, air cored antenna is better. Of course it depend of what you need and what you try to build. If you need "shielded" (i.e. mounted in a tin can) antenna (to radiate in one direction) ferrite core antenna can be better solution than air core.

dear wm6
Is the ferrite core and reflector antennas can be directly sent 70kh frequency?
Frequency of 70 kHz with a transmitter power is enhanced to within 50 meters sent?
Changes in the frequency or electromagnetic radius of 50 meters on the ground with metal?in coil ANTENNA and ferrite core?

[WM6]

Originally Posted by mustefa ubram

dear wm6
Is the ferrite core and reflector antennas can be directly sent 70kh frequency?
Frequency of 70 kHz with a transmitter power is enhanced to within 50 meters sent?
Changes in the frequency or electromagnetic radius of 50 meters on the ground with metal?in coil ANTENNA and ferrite core?

Sorry mustefa, my English is very bad. I do not understand your questions.

[WM6]

Hello Barbarossa, this can be your solution. First use signal generator to check your GG receiver exact frequency, then use the same to build TX stage working at the same frequency. Use round or square antenna so you can play with TX wave propagation (polarization) combined with proper TX distance.

[mohandes]

Originally Posted by WM6

If one need a 70kHz transmitter with exact frequency, I suggest this solution:

1.
Use this module from eBay ($38 + free shipping):

0.01- 5MHz DDS Function Signal Generator Module




http://www.ebay.com/itm/0-01-5MHz-DD...-/270864768941


2.

Signal generator has enough amplitude to act as transmitter you need, but if you insist that you need more power, then connect signal generator to this module from eBay:

Mono 25W Audio Amplifier Module Board, Based on LM1875



http://www.ebay.com/itm/Mono-25W-Aud...item5d30720799

Do not drive it with full power - 1/10 of max power, no more.

Inductance of antenna (ferrite core or air core - the last one is better) have to be about 50mH. Exact value depend of antenna windings stray capacitance. You need to connect antenna instead of loudspeaker.

Of course this transmitter can generate any other arbitrary frequency too (for some very different antenna inductance need to be recalculated).

Use sine wave.

thanks
i just need for Amplifier circuit to add signal generator.
if you have Golden king circuit please send here
regards

[Mike(Mont)]

That amp uses AC power. Don't get electrocuted.