Hi, I with a ferrite rod antenna please

[michael1978]

hello to everybody,
can some help to make a ferrit rod antenna and to explain me thnx

is for am radio, trf regenerative

i have a ferrit rod 90mm diameter, and i have 0.5mm wire magnetic.

this is the schematic , i make also the am receiver, but i don't know the ferrit rod(is problem i try to make but the radio don't work)(simpele i don't know how to make a ferrit rod antenna), i follow the steps but i try he does nt work

thnx

 

[anorlunda]

Perhaps English is not your first language. However, our rules say

SMS messaging shorthand ("text-message-speak"), such as using "u" for "you", "please" for "please", or "wanna" for "want to" is not acceptable.

 

[berkeman]

i follow the steps but i try he does nt work

Can you post the steps? Did this come as part of an AM Radio Kit? Or are you trying to do this mostly from scratch without a pre-made blank Printed Circuit Board (PCB)?

What test equipment do you have available? Do you have a Digital Voltmeter (DVM)? Do you have an Oscilloscope? Do you have a Signal Generator? Do you have any other test equipment?

And do you have anybody there where you live who has done this before? If you have any HAM radio operators near where you live, they can be a great resource for helping you to learn these kinds of circuits.

Is the AM radio band around 1MHz where you live?

 

[Averagesupernova]

I doubt the rod is supposed to 90 mm diameter. 9 sounds closer. This looks like the type of antenna that was used in the old radio shack kits. My bet is if you scored one of them it would work. https://www.google.com/search?clien.....0...0.0....mobile-gws-wiz-serp.eQ9otP4Mhm4=

 

[berkeman]

I doubt the rod is supposed to 90 mm diameter. 9 sounds closer.

Good point, or maybe he means 90mm long. But you're right, that's certainly not the diameter!

 

[michael1978]

Perhaps English is not your first language. However, our rules say

but i try my best...;-(

 

[michael1978]

Can you post the steps? Did this come as part of an AM Radio Kit? Or are you trying to do this mostly from scratch without a pre-made blank Printed Circuit Board (PCB)?

What test equipment do you have available? Do you have a Digital Voltmeter (DVM)? Do you have an Oscilloscope? Do you have a Signal Generator? Do you have any other test equipment?

And do you have anybody there where you live who has done this before? If you have any HAM radio operators near where you live, they can be a great resource for helping you to learn these kinds of circuits.

Is the AM radio band around 1MHz where you live?

this is the site where i make in breedeboard, is not my idea, but i want to learn, so i try also one am i hear one radio with noise, and i destroy, because ferrit rod problem, i don't go so much outside i work a little with my child a little with electronics. this the site where complete tell https://imgur.com/a/JpwJs, i have a normal standard multimete and one smath oscillscope, because i try when i put diode he demulate, i so in oscillscope, i know ferrite rod antenna i make bad i think

 

[michael1978]

I doubt the rod is supposed to 90 mm diameter. 9 sounds closer. This looks like the type of antenna that was used in the old radio shack kits. My bet is if you scored one of them it would work. https://www.google.com/search?client=ms-android-verizon&ei=GsnLWrjkD-OLjwTMx5PgCw&q=radio+shack+150+in+1+electronic+project+kit&oq=tadio+shavck+kits&gs_l=mobile-gws-serp.1.0.0i71l5.0.0..3952...0...0.0....mobile-gws-wiz-serp.eQ9otP4Mhm4=

i buy it long time one 300 experiments complets kit, but i finish is almost nothing to teach, but i take from internet this circuit and the other, i don't use that anymore

 

[berkeman]

this is the site where i make in breedeboard, is not my idea, but i want to learn, so i try also one am i hear one radio with noise, and i destroy, because ferrit rod problem, i don't go so much outside i work a little with my child a little with electronics. this the site where complete tell https://imgur.com/a/JpwJs, i have a normal standard multimete and one smath oscillscope, because i try when i put diode he demulate, i so in oscillscope, i know ferrite rod antenna i make bad i think

Fun project, especially to do it with your child.

So does your circuit look pretty much like the one in the link you posted? Where did you get the ferrite rod for the antenna? Can you verify its dimensions, and maybe post a picture of it and your circuit that you built based on the website?

Can you use your multimeter to measure the voltages at each point in the circuit and label a printout of the circuit diagram? That will help us to verify that it is build correctly. Can you also post a picture of the variable capacitor that you are using? Thanks.

 

[michael1978]

Fun project, especially to do it with your child.

So does your circuit look pretty much like the one in the link you posted? Where did you get the ferrite rod for the antenna? Can you verify its dimensions, and maybe post a picture of it and your circuit that you built based on the website?

Can you use your multimeter to measure the voltages at each point in the circuit and label a printout of the circuit diagram? That will help us to verify that it is build correctly. Can you also post a picture of the variable capacitor that you are using? Thanks.

yes i can show you my circuit, but the antenna i destroy so i have only ferrit rod and is 9m and for long i don't know i will put my tomorow.

 

[berkeman]

yes i can show you my circuit, but the antenna i destroy so i have only ferrit rod and is 9m and for long i don't know i will put my tomorow.

So you are saying that you have a ferrite rod that is 90millimeters in diameter and 9 meters long? What the heck did you get that giant thing out of?

 

[michael1978]

So you are saying that you have a ferrite rod that is 90millimeters in diameter and 9 meters long? What the heck did you get that giant thing out of?

sorry i make 0 zero morei is 9 of 9.2 mm round, and yesterday in the night was 1 clock night, and now is 7 clock morning, but today i goona send you my circuit and ferrit rod with wire, which i put out all the wire... and for the rest, have a nice day.

 

[michael1978]

Fun project, especially to do it with your child.

So does your circuit look pretty much like the one in the link you posted? Where did you get the ferrite rod for the antenna? Can you verify its dimensions, and maybe post a picture of it and your circuit that you built based on the website?

Can you use your multimeter to measure the voltages at each point in the circuit and label a printout of the circuit diagram? That will help us to verify that it is build correctly. Can you also post a picture of the variable capacitor that you are using? Thanks.

here is my photo, i did not take a proper photo sorry, but is enough to see

 

[michael1978]

Fun project, especially to do it with your child.

So does your circuit look pretty much like the one in the link you posted? Where did you get the ferrite rod for the antenna? Can you verify its dimensions, and maybe post a picture of it and your circuit that you built based on the website?

Can you use your multimeter to measure the voltages at each point in the circuit and label a printout of the circuit diagram? That will help us to verify that it is build correctly. Can you also post a picture of the variable capacitor that you are using? Thanks.

hi man i solved ferrit rod antenna, somebody told me how to make it, so i make it, but, you say is very easy, can you help me with amplifier is not working i get no signals...do you know how to fix it, i use lm386

 

[berkeman]

can you help me with amplifier is not working i get no signals...do you know how to fix it, i use lm386

Glad your antenna is okay now (how can you tell it is okay now?).

To help you fix your circuit, please use your meter to measure the voltages at the connection points in the circuit and write those voltages on the schematic so you can post a picture of that. Put the negative wire of your meter on "ground", and measure the voltages at the other connection points in the circuit. Thanks.

 

[michael1978]

Glad your antenna is okay now (how can you tell it is okay now?).

To help you fix your circuit, please use your meter to measure the voltages at the connection points in the circuit and write those voltages on the schematic so you can post a picture of that. Put the negative wire of your meter on "ground", and measure the voltages at the other connection points in the circuit. Thanks.

I will do it

 

[michael1978]

Glad your antenna is okay now (how can you tell it is okay now?).

To help you fix your circuit, please use your meter to measure the voltages at the connection points in the circuit and write those voltages on the schematic so you can post a picture of that. Put the negative wire of your meter on "ground", and measure the voltages at the other connection points in the circuit. Thanks.

I measure transistor 1 and 2 = 1.77V
lm386
pin1 = 2,96V
pin 2 = 1.88
pin 3 = 4.20
pin 4 = 4.60
pin 5= 2.60
pin 6 = 0.84
pin 7 = 0
pin 8 = 2.84
BATTERY SUPPLY 5V AND SOMETHING

i don't know what to measure else?

 

[berkeman]

I measure transistor 1 and 2 = 1.77V
lm386
pin1 = 2,96V
pin 2 = 1.88
pin 3 = 4.20
pin 4 = 4.60
pin 5= 2.60
pin 6 = 0.84
pin 7 = 0
pin 8 = 2.84
BATTERY SUPPLY 5V AND SOMETHING

i don't know what to measure else?

The schematic shows a TL081 opamp, not a LM386 audio amp. Can you show us exactly your schematic, with pin numbers on the parts?

Also, the original schematic uses a 9V battery. How come your battery is only about 5V?

And the original schematic with the TL081 opamp appears to have a problem with biasing the inputs to the opamp -- the TL081 is not designed to run with its inputs near ground when it is operated on a single supply (like 9V). An opamp like an LM324 is a better choice for single-supply operation.

Also, can you show us what you are using now for the variable capacitor that is used to help tune the antenna?

 

[michael1978]

The schematic shows a TL081 opamp, not a LM386 audio amp. Can you show us exactly your schematic, with pin numbers on the parts?

Also, the original schematic uses a 9V battery. How come your battery is only about 5V?

And the original schematic with the TL081 opamp appears to have a problem with biasing the inputs to the opamp -- the TL081 is not designed to run with its inputs near ground when it is operated on a single supply (like 9V). An opamp like an LM324 is a better choice for single-supply operation.

Also, can you show us what you are using now for the variable capacitor that is used to help tune the antenna?

man, this not normal the battery very fast up, because i buy just for test, he stays onlys 5v, 4V up, so in that site they say you can use lm386, that i had in my home, after variable i make one 500 to 600 pico farad, i found in the internet how to make variable capacitor,

now i put new battery from 9V, i hear noise like motor brbrbrbrbr fast and slow when i make with regen pot, but i have to put in my ear to hold it, because is only little bit volume in my 8ohm speaker,,
of maybe capacitor from china which i connected to 8ohm speakerwhat do you think what is not working, is working ferrit rod antenna
what do you think is not normal?
those are the pins number of lm386 SO lm386 have 8 pins

 

[berkeman]

in that site they say you can use lm386

But the LM386 is connected very differently from an opamp. There is no external feedback, for example. This is a more typical LM386 circuit:

https://www.theengineeringprojects.com/wp-content/uploads/2017/06/Introduction-to-LM386_5.png

 

[Averagesupernova]

Once you get the op-amp issue straightened out, you may be able to use another AM receiver to generate a carrier. You would do this by tuning into the local oscillator of your second receiver. By using several receivers you should be able to hear the beat between the two local oscillators (the difference in frequency between the two). But cross that bridge when you get there. Listen to @berkeman concerning the 386. He knows what he is saying.

 

[michael1978]

But the LM386 is connected very differently from an opamp. There is no external feedback, for example. This is a more typical LM386 circuit:

https://www.theengineeringprojects.com/wp-content/uploads/2017/06/Introduction-to-LM386_5.png
View attachment 223754

do you have any idea how to make easy to change that opamp with lm386,
and what do you think he going to work of not if we change opamp

 

[berkeman]

do you have any idea how to make easy to change that opamp with lm386,

For a start, I would get rid of the TL086 circuit shown and use the LM386 circuit instead. Take your point "A", keep the diode and capacitor out of it, and change the resistor to the potentiometer shown on the LM386 circuit. So point "A" feeds the LM386 input through the diode and cap and potentiometer. That should get you started.

 

[michael1978]

For a start, I would get rid of the TL086 circuit shown and use the LM386 circuit instead. Take your point "A", keep the diode and capacitor out of it, and change the resistor to the potentiometer shown on the LM386 circuit. So point "A" feeds the LM386 input through the diode and cap and potentiometer. That should get you started.

i make it, now what to do? so draw black line of pot where i connected

 

[michael1978]

For a start, I would get rid of the TL086 circuit shown and use the LM386 circuit instead. Take your point "A", keep the diode and capacitor out of it, and change the resistor to the potentiometer shown on the LM386 circuit. So point "A" feeds the LM386 input through the diode and cap and potentiometer. That should get you started.

HELLO, i change yesterday like i show you, but today i make separate the lm386, i hear nothing, what is this in gods name?

 

[Averagesupernova]

Do you know what the voltages around various parts of the circuit are and do you know what they are supposed to be?

 

[michael1978]

Do you know what the voltages around various parts of the circuit are and do you know what they are supposed to be?

somebodu told to solder lm386, now i am going to solder and after to connect

 

[berkeman]

somebodu told to solder lm386, now i am going to solder and after to connect

Solder it to what?

 

[michael1978]

Solder it to what?

to pcb

 

[berkeman]

What PCB? I must have missed something...

 

[michael1978]

What PCB? I must have missed something...

Is not working...man, like he don't exsit LM386, i hear with my earphone like i told you yesterday, but, i put 10u between pin 1 and 8 nothing change, because the signal is the same with or without LM386, is in MILIVOLT

 

[michael1978]

What PCB? I must have missed something...

hello
but you know what i did i destroy all,
i make new radio TRF, can you please tell what is the problem, i can hear in 8ohm speaker, i hear in crystalearphone i find the stations, i hear, after i try to to make low 0 volume, you hear nothing, after i start volume up i hear , when start more volume you hear noise not normal,
here is the circuit

 

[Averagesupernova]

How can you expect help when you just change to a different project? Folks here put some effort into this and with no notice you simply abandon it and start on something else and expect help with the problems it has. So, again, I will ask you if you have some DC voltage measurements and know what they are supposed to be? In this case, you have the advantage of being able to take measurements while it is working correctly if I understand you right. Compare those measurements against measurements you take when it is not working correctly. No one can simply know what is wrong just because.

 

[berkeman]

but you know what i did i destroy all,
i make new radio TRF, can you please tell what is the problem,

Thread is closed for now. This is too strange.