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Please help to buy those components

michael1978

Mar 17, 2012
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please can somebody help, how to find in electronics shop online
those components and to buy, is here juse one to make for all, i need juse one, wich i can use for all projetcs
L1 antenna coil: 470uH with 1 turn wrapped = 2
L2 antenna coil: 470uH primary, 23uH secondary = 2
L3 antenna coil: 600uH to 680uH primary, to to 20 turn secondary = 2
L4 antenna coil: 330uH primary 10 to 20 turns for secondary = 2
L5 antenna coil: 600uH to 680uH with tap or secondary winding = 2

i dont know how to find self and to buy, can somebody teach me how to select

because i am reading on book, make your own radio transistor
i was in one shop here, i whait 3 months he cant find me, because he say is very difficult to find and, they dont use anymore, but book is from 2013 is not old thnx
 

BobK

Jan 5, 2010
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These are not off-the-shelf components. Does not the book not tell you how to make them yourself?

Bob
 

kellys_eye

Jun 25, 2010
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Does the book not advise on how to MAKE those coils? They do sound like INSTRUCTIONS rather than a list of bits to be purchased.
 

kellys_eye

Jun 25, 2010
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All I can recommend is that you obtain some ferrite/dust iron toroids and wind coils to those values yourself. The Micrometals range are popular and fairly easy to obtain.

There are various sites that offer help in doing this - tools for calculating the required number of turns etc, such as this:

http://www.micrometals.com/downloads/Toroid.zip
 

73's de Edd

Aug 21, 2015
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Can you copy relevant pages from the book, so that we can evaluate its content here ?
Or the name of the book and its author, as we might also find it .
73's de Edd
 

michael1978

Mar 17, 2012
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Can you copy relevant pages from the book, so that we can evaluate its content here ?
Or the name of the book and its author, as we might also find it .
73's de Edd
here the name of book Build Your Own Transistor Radios 2013
you can find it on the internet
 

kellys_eye

Jun 25, 2010
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Can you copy relevant pages from the book, so that we can evaluate its content here ?
Can you scan a copy of the pages you're referring to into here?

I don't think we're about to purchase a book just to help you resolve some construction issues but if you posted the pages we could tell you how to proceed.

I don't know of ANY construction book of that level that simply states the inductance of the coils required without giving some indication of either how to make them or where to purchase them.
 

michael1978

Mar 17, 2012
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Can you scan a copy of the pages you're referring to into here?

I don't think we're about to purchase a book just to help you resolve some construction issues but if you posted the pages we could tell you how to proceed.

I don't know of ANY construction book of that level that simply states the inductance of the coils required without giving some indication of either how to make them or where to purchase them.
ah ok no problem
for example this Naamloos.jpg
 

kellys_eye

Jun 25, 2010
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Those inductors symbols are typical of the way they indicate the toroidal construction types.

You can get tables of the various toroids and their parameters where the tables show how many turns of wire are needed to get a specific inductance.

In your schematic, L1 is shown with two dots...... these indicate the START of the winding on the toroid core and that there are two such windings on the same core material.

L2 and L3 are standard 'chokes' and available as axial devices from many component suppliers (they look like small fat resistors).

L1 antenna coil: 470uH with 1 turn wrapped = 2

In this example you would wind magnet wire around an appropriate core to get the 470μH value THEN wind another SINGLE turn around the same core. You then have the coil labelled as L1 in your schematic but you MUST take care to note the START point of your winding so they can be connected in the right phase.

Here's a document that will help - it's 'Toroids for the terrified' and tells you how to chose and use the right one.
 

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BobK

Jan 5, 2010
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In that schematic, the two coils on the left are almost certainly to be wound on a ferrite rod and make up the antenna for the radio. If the book does not tell you how to wind them, then it is useless. I don't believe they can be wound on a toroid because that would not make an effective antenna.

Edited to add: The other two inductors are standard parts that you can buy.

Bob
 
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michael1978

Mar 17, 2012
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Those inductors symbols are typical of the way they indicate the toroidal construction types.

You can get tables of the various toroids and their parameters where the tables show how many turns of wire are needed to get a specific inductance.

In your schematic, L1 is shown with two dots...... these indicate the START of the winding on the toroid core and that there are two such windings on the same core material.

L2 and L3 are standard 'chokes' and available as axial devices from many component suppliers (they look like small fat resistors).



In this example you would wind magnet wire around an appropriate core to get the 470μH value THEN wind another SINGLE turn around the same core. You then have the coil labelled as L1 in your schematic but you MUST take care to note the START point of your winding so they can be connected in the right phase.

Here's a document that will help - it's 'Toroids for the terrified' and tells you how to chose and use the right one.
no they use for antenna this sort
look
Naamloos.jpg

i dont know how to make
 

BobK

Jan 5, 2010
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It is not a radio circuit, instead it is a very simple tuner that receives strong local AM broadcast band signals.
Does anybody use an awful sounding AM radio anymore?
Is not a radio circuit?

I build a TRF radio using MK484 which is pretty much the same thing but 3 stages all in a TO92 package to tune the local station that broadcasts the Red Sox games. It can separate the signal from a very strong station nearby, though I have to turn the antenna to null the strong station.

Bob
 

michael1978

Mar 17, 2012
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So, now are you telling us the book DOES tell you how to construct the antenna coils?

And, by the way, that is what I meant by a ferrite rod.

Bob
No he just show this kind of antenna, but for more details NO, so please can you help me to make own. what i need?
 

michael1978

Mar 17, 2012
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It is not a radio circuit, instead it is a very simple tuner that receives strong local AM broadcast band signals.
Does anybody use an awful sounding AM radio anymore?
this book teach you step by step up to fm tuner, but the problem was antenna, i told al ready i whait 3 months for those antenna, in the end he say i cant help you.
 

michael1978

Mar 17, 2012
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You recently attached the schematic of an old TRF AM tuner, not an FM tuner.
People do not make old AM radios anymore so nobody sells parts for them.
Take an old AM radio that somebody threw away and use its parts.
iam not agree, i dont know how to make tht antenna, because this book is 2013, and the author with not speak about old time, but he want to teach you......why you ont help how to make an antenna and you speak something else
 

michael1978

Mar 17, 2012
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I have never made an awful sounding AM radio that is too simple to be a real radio. A real radio has a super heterodyne circuit with a tuned RF stage with AGC, an oscillator and mixer and an IF stage with a few transformers. Then it has the usual diode detector and audio amplifier.

If you want to make the antenna coil then where will you find the ferrite bar for its core? Maybe you should look for a TRF AM radio circuit that uses a normal little RF transformer and a long wire antenna.
i have but i dont know how to make antenna rf, i have a wire + the other stuck where you wind wire
 

duke37

Jan 9, 2011
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Ferrite rods are available from many hobby stores but cost a considerable amount. Get a long one for maximum sensitivity. As has been suggested, get one from a scrap AM radio which will have the coil already fitted.

To wind your own coil, you ideally should use Litz wire with cotton (or other) insulation. To do the winding, place the rod in a hand driven drill and carefully wind the turns side by side. Count the turns, it is easy to do it when winding but much more difficult to count when they are in place.

A coil of a few turns one end connected to earth and the other end connected to a long wire will give more sensitivity. This winding is often available on old portable radios intended for use in a car.
 

michael1978

Mar 17, 2012
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Ferrite rods are available from many hobby stores but cost a considerable amount. Get a long one for maximum sensitivity. As has been suggested, get one from a scrap AM radio which will have the coil already fitted.

To wind your own coil, you ideally should use Litz wire with cotton (or other) insulation. To do the winding, place the rod in a hand driven drill and carefully wind the turns side by side. Count the turns, it is easy to do it when winding but much more difficult to count when they are in place.

A coil of a few turns one end connected to earth and the other end connected to a long wire will give more sensitivity. This winding is often available on old portable radios intended for use in a car.
thank you, ,
but those antenna have 4 wire to connect, do you see, how can i make one like here Naamloos.jpg
 
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