Hi, has anybody had trouble building the ELENCO 108 AM/FM RADIO KIT

[michael1978]

Hello, i build the radio like they say in the book, and i did everything with VOM(testing with only multimeter),
everything was like in book , but when i finish, i switch to am or fm, i just hear high noise

 

[berkeman]

When I built it, I accidentally got the battery and the speaker swapped. It took me a while to figure out my mistake.

But seriously, how are we supposed to help you with so little information? Post the schematic and label it with the DC voltages you measure in your circuit -- that will give us a starting point to try to help you...

 

[michael1978]

When I built it, I accidentally got the battery and the speaker swapped. It took me a while to figure out my mistake.

But seriously, how are we supposed to help you with so little information? Post the schematic and label it with the DC voltages you measure in your circuit -- that will give us a starting point to try to help you...

You had the same, i can tell you the value, you mean the TEST POINT(TP)? i don't know, which value you are interessed? just tell me and i will do it

 

[berkeman]

You had the same, i can tell you the value, you mean the TEST POINT(TP)? i don't know, which value you are interessed? just tell me and i will do it

I was kidding in my first paragraph, making fun of the fact that you posted with so little information and wanted help. Sorry if my humor wasn't obvious.

In my second paragraph, I asked you to Upload a copy of the schematic (as a PDF or JPEG file), and be sure to mark the DC voltages you measure at each node of the circuit on the schematic. That will help us to look for obvious problems (like if you measure a zero voltage at a place in the circuit where the voltage should be non-zero). Mark up the voltage you measure on the schematic that you have, and use the UPLOAD button to Upload a PDF or JPEG copy of that marked-up schematic. Here is an example without the measured voltages marked on it yet...

http://electroschematics.com/wp-content/uploads/2010/07/fm-radio-receiver.gif

 

[berkeman]

You had the same, i can tell you the value, you mean the TEST POINT(TP)? i don't know, which value you are interessed? just tell me and i will do it

I was kidding in my first paragraph, making fun of the fact that you posted with so little information and wanted help. Sorry if my humor wasn't obvious.

In my second paragraph, I asked you to Upload a copy of the schematic (as a PDF or JPEG file), and be sure to mark the DC voltages you measure at each node of the circuit on the schematic. That will help us to look for obvious problems (like if you measure a zero voltage at a place in the circuit where the voltage should be non-zero). Mark up the voltage you measure on the schematic that you have, and use the UPLOAD button to Upload a PDF or JPEG copy of that marked-up schematic. Here is an example without the measured voltages marked on it yet...

http://electroschematics.com/wp-content/uploads/2010/07/fm-radio-receiver.gif

 

[michael1978]

When I built it, I accidentally got the battery and the speaker swapped. It took me a while to figure out my mistake.

But seriously, how are we supposed to help you with so little information? Post the schematic and label it with the DC voltages you measure in your circuit -- that will give us a starting point to try to help you...

I Measure, Test Point, without connection a speaker(because i thought the speaker was bad, so i desoldeer, and i connect with wire other speaker 8ohm but the same problem stays),
so
i switch to FM
tp15 and tp2=2.74V
tp15 and tp13=1.4V
tp15 and tp11=6.59V
tp15 and tp10=1.20V
tp15 and tp9=7.08V
tp15 and tp8=6.43V
tp15 and tp12=6.74V
i switch to am
tp15 and tp2=0.02V
tp15 and tp3=7.77V
tp15 and tp1=4.21V
tp15 and tp4=8.13V
tp15 and tp5=1.34V
tp15 and tp6=0V
tp15 and tp14'=0.02V
TP15=GND

 

[berkeman]

I Measure, Test Point, without connection a speaker(because i thought the speaker was bad, so i desoldeer, and i connect with wire other speaker 8ohm but the same problem stays),
so
i switch to FM
tp15 and tp2=2.74V
tp15 and tp13=1.4V
tp15 and tp11=6.59V
tp15 and tp10=1.20V
tp15 and tp9=7.08V
tp15 and tp8=6.43V
tp15 and tp12=6.74V
i switch to am
tp15 and tp2=0.02V
tp15 and tp3=7.77V
tp15 and tp1=4.21V
tp15 and tp4=8.13V
tp15 and tp5=1.34V
tp15 and tp6=0V
tp15 and tp14'=0.02V
TP15=GND

Please upload the schematic or link to a copy of it on the Internet. Thank you.

 

[michael1978]

Please upload the schematic or link to a copy of it on the Internet. Thank you.

 

[michael1978]

I was kidding in my first paragraph, making fun of the fact that you posted with so little information and wanted help. Sorry if my humor wasn't obvious.

In my second paragraph, I asked you to Upload a copy of the schematic (as a PDF or JPEG file), and be sure to mark the DC voltages you measure at each node of the circuit on the schematic. That will help us to look for obvious problems (like if you measure a zero voltage at a place in the circuit where the voltage should be non-zero). Mark up the voltage you measure on the schematic that you have, and use the UPLOAD button to Upload a PDF or JPEG copy of that marked-up schematic. Here is an example without the measured voltages marked on it yet...

http://electroschematics.com/wp-content/uploads/2010/07/fm-radio-receiver.gif

i post schematic

 

[berkeman]

i post schematic

Thank you, that helps a lot. I think I'll move this thread to the EE forum, to get more specialized help.

It looks like there are several adjustable components in the schematic. Was there an "alignment procedure" included in the instructions? Also, did you assemble this from a kit with a PC board included?

 

[berkeman]

I Measure, Test Point, without connection a speaker(because i thought the speaker was bad, so i desoldeer, and i connect with wire other speaker 8ohm but the same problem stays),
so
i switch to FM
tp15 and tp2=2.74V
tp15 and tp13=1.4V
tp15 and tp11=6.59V
tp15 and tp10=1.20V
tp15 and tp9=7.08V
tp15 and tp8=6.43V
tp15 and tp12=6.74V
i switch to am
tp15 and tp2=0.02V
tp15 and tp3=7.77V
tp15 and tp1=4.21V
tp15 and tp4=8.13V
tp15 and tp5=1.34V
tp15 and tp6=0V
tp15 and tp14'=0.02V
TP15=GND

It looks like TP17 (lower right of the schematic) is Ground. Can you please measure the voltages of the other test points with respect to TP17 Ground? That would be helpful. Just keep you meter's negative test lead on TP17, and measure the voltages of the other test points with your meter's positive lead. Thank you.

 

[michael1978]

It looks like TP17 (lower right of the schematic) is Ground. Can you please measure the voltages of the other test points with respect to TP17 Ground? That would be helpful. Just keep you meter's negative test lead on TP17, and measure the voltages of the other test points with your meter's positive lead. Thank you.

It looks like TP17 (lower right of the schematic) is Ground. Can you please measure the voltages of the other test points with respect to TP17 Ground? That would be helpful. Just keep you meter's negative test lead on TP17, and measure the voltages of the other test points with your meter's positive lead. Thank you.

I don't use transistor amplifier, but i use lm386,

 

[berkeman]

I don't use transistor amplifier, but i use lm386,

Please post the schematic for what you have built, and post the test point voltages. Thank you.

 

[michael1978]

Please post the schematic for what you have built, and post the test point voltages. Thank you.

I show you tomorow maybe, because i go to sleep, here is 24:10 goodnight berkeman

 

[Tom.G]

It looks like TP17 (lower right of the schematic) is Ground.

TP15 is also GND; that's below Q5 in the FM section.

@michael1978
I have only looked at the AM section because that part is easier. Let's get that and the earphone working first.
Page 34 of the manual says the battery should measure 8.5V or more with the power switch turned on. Your measurements show around 7.8V to 8.1V. Please replace the battery.

This test can be done with the old battery. It will give you something to do until you get a new one.
There is a problem at TP6, it reads 0V but should be about 8V or higher (about the same voltage as at TP4).
Check the wiring at the primary (left) side of T6, around L5 and around Q7. There is probably a bad or missing connection to T6.

Let us know what you find.

Cheers,
Tom

 

[michael1978]

TP15 is also GND; that's below Q5 in the FM section.

@michael1978
I have only looked at the AM section because that part is easier. Let's get that and the earphone working first.
Page 34 of the manual says the battery should measure 8.5V or more with the power switch turned on. Your measurements show around 7.8V to 8.1V. Please replace the battery.

This test can be done with the old battery. It will give you something to do until you get a new one.
There is a problem at TP6, it reads 0V but should be about 8V or higher (about the same voltage as at TP4).
Check the wiring at the primary (left) side of T6, around L5 and around Q7. There is probably a bad or missing connection to T6.

Let us know what you find.

Cheers,
Tom

GoodMorning, i was wrong, because now between T6 is 8.7V, now is not anymore so high noise, but low noise, and when i rotate the VARcapacitor
i don't hear nothing changes, i can't pickup any fm or am radio station?
what do you think where is problem?
have a nice day

 

[michael1978]

Thank you, that helps a lot. I think I'll move this thread to the EE forum, to get more specialized help.

It looks like there are several adjustable components in the schematic. Was there an "alignment procedure" included in the instructions? Also, did you assemble this from a kit with a PC board included?

yes

 

[michael1978]

TP15 is also GND; that's below Q5 in the FM section.

@michael1978
I have only looked at the AM section because that part is easier. Let's get that and the earphone working first.
Page 34 of the manual says the battery should measure 8.5V or more with the power switch turned on. Your measurements show around 7.8V to 8.1V. Please replace the battery.

This test can be done with the old battery. It will give you something to do until you get a new one.
There is a problem at TP6, it reads 0V but should be about 8V or higher (about the same voltage as at TP4).
Check the wiring at the primary (left) side of T6, around L5 and around Q7. There is probably a bad or missing connection to T6.

Let us know what you find.

Cheers,
Tom

I see one video, all collector of fm have the same value, he show in the video and i tested my the same they have,
but like in am and fm sometimes is high noise, sometime little bit noise, but i can't catch any signal,

 

[michael1978]

now is low NOISE like in am or fm but i can get any signal, what do you think , where is problem

 

[Tom.G]

Does anything you do make a change in the high noise or low noise?
If yes, tell use what you do to make that change.

 

[michael1978]

Does anything you do make a change in the high noise or low noise?
If yes, tell use what you do to make that change.

I think maybe, i soldeer it one more lm386 WITH bypass capacitor at pin 2 and 6, and also i change the battery little bit old,
and also i can hear nothing from earphony, totaly nothing,

 

[Tom.G]

WITH bypass capacitor at pin 2 and 6

That should be pin 4 and 6.

Do you have any test equipment besides the voltmeter?

 

[michael1978]

That should be pin 4 and 6.

Do you have any test equipment besides the voltmeter?

how not, how i measure til now?, but in the book is between pin 2 and 6 capacitor, how come now pin 4 and 6(are you sure)?

 

[michael1978]

how not, how i measure til now?, but in the book is between pin 2 and 6 capacitor, how come now pin 4 and 6(are you sure)?

i have dvm

 

[Tom.G]

how not, how i measure til now?, but in the book is pin 2 and 6, how come now pin 4 and 6(are you sure)?

The image below is from the datasheet for the LM386 made by National Semiconductor. As you can see, the supply voltage is on pin 6, Ground is pin 4, and -Input is pin 2. Your circuit has pin 2 connected to Ground, probably as a short circuit trace between pins 2 and 4. I said pin 4 for the bypass capacitor just to be very safe (conservative). If there is a bad connection on the board between pins 2 and 4, the bypass might not connect to Ground if soldered to pin 2.

If the connection between pins 2 and 4 are good, for your circuit it probably will not make much difference. For other circuits it can make a difference, so we all get in the habit of connecting bypass capacitors to the power and Ground pins just to avoid problems.

OK, you have DVM. What make and model is it?

 

[michael1978]

The image below is from the datasheet for the LM386 made by National Semiconductor. As you can see, the supply voltage is on pin 6, Ground is pin 4, and -Input is pin 2. Your circuit has pin 2 connected to Ground, probably as a short circuit trace between pins 2 and 4. I said pin 4 for the bypass capacitor just to be very safe (conservative). If there is a bad connection on the board between pins 2 and 4, the bypass might not connect to Ground if soldered to pin 2.

If the connection between pins 2 and 4 are good, for your circuit it probably will not make much difference. For other circuits it can make a difference, so we all get in the habit of connecting bypass capacitors to the power and Ground pins just to avoid problems.

OK, you have DVM. What make and model is it?

View attachment 228076

Thnx man i go to change, and i will let you know, i will let you know direct

 

[michael1978]

Thnx man i go to change, and i will let you know, i will let you know direct

I have DVM9915, i soldeer it, now the earphone is working i hear noise but i don't get SIGNAL

 

[Tom.G]

Does anything you do make a change in the high noise or low noise?
If yes, tell use what you do to make it change.
Does it just get louder and softer or does it sound different?

 

[michael1978]

Does anything you do make a change in the high noise or low noise?
If yes, tell use what you do to make it change.
Does it just get louder and softer or does it sound different?

the earphone is working, and i have a little bit louder, but not like in begin

 

[Tom.G]

Does the sound change when you turn down the volume control?
How does it change?

 

[michael1978]

Does the sound change when you turn down the volume control?
How does it change?

Does the sound change when you turn down the volume control?
How does it change?

Yes it go faster and faster, or i hear low noise

 

[Tom.G]

What is the battery voltage when you can hear the noise?
Is the noise the same for both AM and FM?
Does the noise change when you connect TP2 to TP15? If yes, how does it change?
With the switch set for AM.
Does the noise change when you connect the Cathode (K) of D4 to TP15? If yes, how does it change?

 

[michael1978]

What is the battery voltage when you can hear the noise?
Is the noise the same for both AM and FM?
Does the noise change when you connect TP2 to TP15? If yes, how does it change?
With the switch set for AM.
Does the noise change when you connect the Cathode (K) of D4 to TP15? If yes, how does it change?

Sir can i tell you tomorow, i am sorry because is 2 hours nights, i am tired, i want to sleep, thnx for time and help, goodnight…..

 

[michael1978]

What is the battery voltage when you can hear the noise?
Is the noise the same for both AM and FM?
Does the noise change when you connect TP2 to TP15? If yes, how does it change?
With the switch set for AM.
Does the noise change when you connect the Cathode (K) of D4 to TP15? If yes, how does it change?

Googmorning Tom, i did now the test, yes the noise is the same,
FM voltage is 8.6V at the battery, the TP2 AND TP15 stay at 2.6V, and the
AM cathode does not change but the value at cathode is 0V, and TP2 and TP15, are 0 volt at AM

 

[michael1978]

Googmorning Tom, i did now the test, yes the noise is the same,
FM voltage is 8.6V at the battery, the TP2 AND TP15 stay at 2.6V, and the
AM cathode does not change but the value at cathode is 0V, and TP2 and TP15, are 0 volt at AM

Sir can i tell you tomorow, i am sorry because is 2 hours nights, i am tired, i want to sleep, thnx for time and help, goodnight…..

Goodmorning Tom are you here somewhere….

 

[Tom.G]

Goodmorning Tom are you here somewhere….

Yes. It is ten minutes before midnight here and I was looking at your latest results.

FM voltage is 8.6V at the battery, the TP2 AND TP15 stay at 2.6V,

Something is not right. TP15 should be Ground, 0V. Where was the other voltmeter lead when you measured 2.6V at TP15?

The following was typed before I noticed the TP15 voltage. I will leave it here in case the TP15 voltage was just a measurement error. (That way I will not have to type it again.) Please check the TP15 voltage, and correct any errors, before doing the below tests.

There seems to be a problem with either the power supply (battery and C39) or something around the LM386.

Please check that C39 is the correct value (470uF) and installed in the right direction. If it is wired backwards that would be a problem. Also make sure the solder connections are good.

Check all the parts around the LM386. Make sure they are the correct value and in the right spot.
C42 = 10uF, C43 = 470uF, C44 = 0.047uF. C42 and C43 must be installed the correct direction.
R44 = 47 Ohm (Yellow Violet Black), R45 = 10 Ohm (Brown Black Black)
Check jumpers J2 and J3 that they are in the right location and soldered.
Check soldering of the socket for LM386.

Sometimes when an IC (LM386) is put in a socket, a pin will bend and not plug into the socket. Check that all the LM386 pins are in the socket. You may have to unplug the LM386 to see if a pin is bent.

(The time here is now 30 minutes after midnite.)

Cheers,
Tom

 

[michael1978]

Yes. It is ten minutes before midnight here and I was looking at your latest results.Something is not right. TP15 should be Ground, 0V. Where was the other voltmeter lead when you measured 2.6V at TP15?

The following was typed before I noticed the TP15 voltage. I will leave it here in case the TP15 voltage was just a measurement error. (That way I will not have to type it again.) Please check the TP15 voltage, and correct any errors, before doing the below tests.

There seems to be a problem with either the power supply (battery and C39) or something around the LM386.

Please check that C39 is the correct value (470uF) and installed in the right direction. If it is wired backwards that would be a problem. Also make sure the solder connections are good.

Check all the parts around the LM386. Make sure they are the correct value and in the right spot.
C42 = 10uF, C43 = 470uF, C44 = 0.047uF. C42 and C43 must be installed the correct direction.
R44 = 47 Ohm (Yellow Violet Black), R45 = 10 Ohm (Brown Black Black)
Check jumpers J2 and J3 that they are in the right location and soldered.
Check soldering of the socket for LM386.

Sometimes when an IC (LM386) is put in a socket, a pin will bend and not plug into the socket. Check that all the LM386 pins are in the socket. You may have to unplug the LM386 to see if a pin is bent.

(The time here is now 30 minutes after midnite.)

Cheers,
Tom

Thank you very much Tom, i will check it and i will let you know, Have a nice sleep

 

[berkeman]

Something is not right. TP15 should be Ground, 0V. Where was the other voltmeter lead when you measured 2.6V at TP15?

@michael1978 -- Apologies if I missed it, but could you please attach the negative lead of your voltmeter to TP15 (ground), and post the voltages that you measure at all of the other test points when you attach your positive lead to them? Thanks.

 

[michael1978]

@michael1978 -- Apologies if I missed it, but could you please attach the negative lead of your voltmeter to TP15 (ground), and post the voltages that you measure at all of the other test points when you attach your positive lead to them? Thanks.

But i desoldeer now, and i soldeer again, the volume is more high, where i rotate is for low to high but not so much high, and i have no signal, only the part of AM, but no problem i going to measure again, because i change all capacitor lytics

 

[michael1978]

Thank you very much Tom, i will check it and i will let you know, Have a nice sleep

Hi Tom, i desoldeer all the party of AM and i soldeer it, and i change all capacitor lytics, and i buy new LM386 and i change it, but now the voice is working beter and i hear when i rotate its goes down and love noise but no so much and no signal, i going to send you now the test

 

[michael1978]

Yes. It is ten minutes before midnight here and I was looking at your latest results.Something is not right. TP15 should be Ground, 0V. Where was the other voltmeter lead when you measured 2.6V at TP15?

The following was typed before I noticed the TP15 voltage. I will leave it here in case the TP15 voltage was just a measurement error. (That way I will not have to type it again.) Please check the TP15 voltage, and correct any errors, before doing the below tests.

There seems to be a problem with either the power supply (battery and C39) or something around the LM386.

Please check that C39 is the correct value (470uF) and installed in the right direction. If it is wired backwards that would be a problem. Also make sure the solder connections are good.

Check all the parts around the LM386. Make sure they are the correct value and in the right spot.
C42 = 10uF, C43 = 470uF, C44 = 0.047uF. C42 and C43 must be installed the correct direction.
R44 = 47 Ohm (Yellow Violet Black), R45 = 10 Ohm (Brown Black Black)
Check jumpers J2 and J3 that they are in the right location and soldered.
Check soldering of the socket for LM386.

Sometimes when an IC (LM386) is put in a socket, a pin will bend and not plug into the socket. Check that all the LM386 pins are in the socket. You may have to unplug the LM386 to see if a pin is bent.

(The time here is now 30 minutes after midnite.)

Cheers,
Tom

T15:TP1=4.11V
T15:TP2=0.54V
T15:TP3=7.33V
T15:TP4=7.33V
T15:TP5=1.32V
T15:TP6=7.92V
T15:TP7=1.32V
the coil red green black white are not like in show in book, they have other resistance(maybe here is problem)
greetings.

 

[michael1978]

T15:TP1=4.11V
T15:TP2=0.54V
T15:TP3=7.33V
T15:TP4=7.33V
T15:TP5=1.32V
T15:TP6=7.92V
T15:TP7=1.32V
the coil red green black white are not like in show in book, they have other resistance(maybe here is problem)
greetings.

Goodmorning, i contact elenco, they say maybe problem with tuning? i don't know, they say send me the picture of kit

 

[michael1978]

Thank you very much Tom, i will check it and i will let you know, Have a nice sleep

Tom i did my best, but still the problem i check it , all what you say, i don't know anymore what to do

 

[Tom.G]

You did a lot of work! Resoldering everything, replacing the electrolytics, replacing the LM386 and contacting Elenco.
The voltages at the TP look a little bit low. Maybe the battery is low. Did you use that battery a long time?

but now the voice is working beter and i hear when i rotate its goes down and love noise but no so much

When you say "its goes down" do you mean the noise is quieter or does it go slower?
Does the noise sound like 'ssssss' or does it sound like 'tap tap tap tap'?

 

[michael1978]

You did a lot of work! Resoldering everything, replacing the electrolytics, replacing the LM386 and contacting Elenco.
The voltages at the TP look a little bit low. Maybe the battery is low. Did you use that battery a long time?

When you say "its goes down" do you mean the noise is quieter or does it go slower?
Does the noise sound like 'ssssss' or does it sound like 'tap tap tap tap'?

no no like normal not nymore tap tap tap or ssssss, i think norma volume down and high, i desoldeer also the fm, and i solder i pick up just one station and i don't hear anymore, but there is no sound at speaker i hear with earphone, in am with speaker, i was so happy when i catch one station i thougt is working, what do you think what's the problem?what to do

 

[Tom.G]

VERY GOOD! YOU GOT IT TO WORK.

If radio stations are far away they are hard to hear. Are you in or near a city with many stations?

The instruction book for the radio tells how to adjust (tune) it on pages 34, 35, 36. Did you do that?

 

[michael1978]

VERY GOOD! YOU GOT IT TO WORK.

If radio stations are far away they are hard to hear. Are you in or near a city with many stations?

The instruction book for the radio tells how to adjust (tune) it on pages 34, 35, 36. Did you do that?

VERY GOOD! YOU GOT IT TO WORK.

If radio stations are far away they are hard to hear. Are you in or near a city with many stations?

The instruction book for the radio tells how to adjust (tune) it on pages 34, 35, 36. Did you do that?

VERY GOOD! YOU GOT IT TO WORK.

If radio stations are far away they are hard to hear. Are you in or near a city with many stations?

The instruction book for the radio tells how to adjust (tune) it on pages 34, 35, 36. Did you do that?

I did, but i don't understand that magic wand, i rely don't understand, there come in kit one small metall and one plastic like antena, but i don't understand what to do with that?

 

[Tom.G]

I did, but i don't understand that magic wand, i rely don't understand, there come in kit one small metall and one plastic like antena, but i don't understand what to do with that?

Long story here. It tells how this radio works and why you have the Magic Wand.

Maybe you know that to tune in a station the radio needs a coil and a capacitor of the right value. To tune a different station you change the value of the capacitor (the tuner). You can also tune a different station by changing the value of the coil, but changing the capacitor is easier.

Your radio has 5 different tuned circuits made of a coil and a capacitor.
Three of those are the "IF transformers", T6, T7, T8. They are tuned by turning the screw on the top. Turning the screw changes the value of the coil inside of them. After these are adjusted they do not need to change again.

The other two tuned circuits are the Oscillator and the Antenna. When you tune to a different station both of these circuits change because you turned the tuning knob on the tuner. The Oscillator and Antenna circuits must follow each other when you change stations. To make sure they follow each other, the coil and the capacitor in both circuits must be adjusted.

This is what pages 34, 35, 36 do.

The Oscillator is adjusted with the Oscillator Trimmer on the tuner and coil L5.
The Antenna is adjusted with the Antenna Trimmer on the tuner and by sliding the coil (L4) on the antenna rod.

Now the Magic Wand.
When a piece of metal is put near a coil, the value of the coil changes. A piece of Iron will make the coil value bigger. A piece of Brass will make the coil value smaller. The Magic Wand has a piece if Iron in one end and a piece of Brass in the other end. It is an easy way to test if the Antenna coil needs a higher value or lower value to follow the Oscillator circuit.

That is what page 36 in the instruction book is doing. If the station gets louder when the Brass end of the Magic Wand is put next to the Antenna, then the coil value needs to be smaller. Then the book says to move the Antenna coil closer the the end of the Antenna rod.

If the station gets louder when the Iron end is put near the Antenna Coil, move the coil towards the middle of the rod to make the coil value bigger.

If the station gets quieter with both ends of the Magic Wand, the Antenna coil does not need to change.

30 minutes after midnite again. Goodnight.

Cheers,
Tom

 

[michael1978]

Long story here. It tells how this radio works and why you have the Magic Wand.

Maybe you know that to tune in a station the radio needs a coil and a capacitor of the right value. To tune a different station you change the value of the capacitor (the tuner). You can also tune a different station by changing the value of the coil, but changing the capacitor is easier.

Your radio has 5 different tuned circuits made of a coil and a capacitor.
Three of those are the "IF transformers", T6, T7, T8. They are tuned by turning the screw on the top. Turning the screw changes the value of the coil inside of them. After these are adjusted they do not need to change again.

The other two tuned circuits are the Oscillator and the Antenna. When you tune to a different station both of these circuits change because you turned the tuning knob on the tuner. The Oscillator and Antenna circuits must follow each other when you change stations. To make sure they follow each other, the coil and the capacitor in both circuits must be adjusted.

This is what pages 34, 35, 36 do.

The Oscillator is adjusted with the Oscillator Trimmer on the tuner and coil L5.
The Antenna is adjusted with the Antenna Trimmer on the tuner and by sliding the coil (L4) on the antenna rod.

Now the Magic Wand.
When a piece of metal is put near a coil, the value of the coil changes. A piece of Iron will make the coil value bigger. A piece of Brass will make the coil value smaller. The Magic Wand has a piece if Iron in one end and a piece of Brass in the other end. It is an easy way to test if the Antenna coil needs a higher value or lower value to follow the Oscillator circuit.

That is what page 36 in the instruction book is doing. If the station gets louder when the Brass end of the Magic Wand is put next to the Antenna, then the coil value needs to be smaller. Then the book says to move the Antenna coil closer the the end of the Antenna rod.

If the station gets louder when the Iron end is put near the Antenna Coil, move the coil towards the middle of the rod to make the coil value bigger.

If the station gets quieter with both ends of the Magic Wand, the Antenna coil does not need to change.

30 minutes after midnite again. Goodnight.

Cheers,
Tom

Hey my friend i change the battery, AM i don't pickup nothing, but fm i pick up 8 stations good, but speaker don't wrok also AM
have a nice sleep

 

[michael1978]

Long story here. It tells how this radio works and why you have the Magic Wand.

Maybe you know that to tune in a station the radio needs a coil and a capacitor of the right value. To tune a different station you change the value of the capacitor (the tuner). You can also tune a different station by changing the value of the coil, but changing the capacitor is easier.

Your radio has 5 different tuned circuits made of a coil and a capacitor.
Three of those are the "IF transformers", T6, T7, T8. They are tuned by turning the screw on the top. Turning the screw changes the value of the coil inside of them. After these are adjusted they do not need to change again.

The other two tuned circuits are the Oscillator and the Antenna. When you tune to a different station both of these circuits change because you turned the tuning knob on the tuner. The Oscillator and Antenna circuits must follow each other when you change stations. To make sure they follow each other, the coil and the capacitor in both circuits must be adjusted.

This is what pages 34, 35, 36 do.

The Oscillator is adjusted with the Oscillator Trimmer on the tuner and coil L5.
The Antenna is adjusted with the Antenna Trimmer on the tuner and by sliding the coil (L4) on the antenna rod.

Now the Magic Wand.
When a piece of metal is put near a coil, the value of the coil changes. A piece of Iron will make the coil value bigger. A piece of Brass will make the coil value smaller. The Magic Wand has a piece if Iron in one end and a piece of Brass in the other end. It is an easy way to test if the Antenna coil needs a higher value or lower value to follow the Oscillator circuit.

That is what page 36 in the instruction book is doing. If the station gets louder when the Brass end of the Magic Wand is put next to the Antenna, then the coil value needs to be smaller. Then the book says to move the Antenna coil closer the the end of the Antenna rod.

If the station gets louder when the Iron end is put near the Antenna Coil, move the coil towards the middle of the rod to make the coil value bigger.

If the station gets quieter with both ends of the Magic Wand, the Antenna coil does not need to change.

30 minutes after midnite again. Goodnight.

Cheers,
Tom

Tom one more time me ho does not work AM, but FM is working perfect also with speaker, how to fix am,