| T O P I C R E V I E W |
| Badar |
Posted - Sep 15 2009 : 4:09:32 PM
Hi.
Plz cn sum1 tell me that if the inductor told in circuit of transmitter told in aran's site i.e 28AWG Enamel coated magnet wire is not available.
Can i use any simple wire as inductor.
Also cn i get the working theory ¤t and voltage dessipation of each component of device.
Waiting 4 quick rply.
N thanks in advance.
U cn also mail me at
badarsuhail@gmail.com. |
| 15 L A T E S T R E P L I E S (Newest First) |
| audioguru |
Posted - Dec 05 2009 : 09:51:18 AM
The circuit is designed for an electret mic that has an output level of about 10mV. The resistor that powers the mic must be removed.
But an MP3 player or CD player has an output of about 270mV so an attenuator can be used that also mixes the stereo channels into mono like this:
Download Attachment:  attenuator.PNG
4.7 KB
 |
| nhardy |
Posted - Dec 05 2009 : 03:31:24 AM
Hi again.
I was just wondering if you could use a 3.5mm mono audio jack instead of an electret microphone.
Any ideas? |
| Yerboogieman |
Posted - Dec 03 2009 : 11:03:01 PM
As you all know, I am constantly updating Aaron on his mistakes. This forum topic is too much. If he uses firefox he must be underlined red with mistakes throughout the whole thing. |
| audioguru |
Posted - Dec 03 2009 : 5:24:48 PM
20pF might limit the lowest frequency to 94MHz. To go lower then simply squeeze the coil tight.
4.2pf might limit the highest frequency to 104MHz. To go higher then simply spread apart the coil. |
| nhardy |
Posted - Dec 03 2009 : 3:44:46 PM
quote:
Originally posted by audioguru
quote:
Originally posted by nhardy
Hi, I have just gotten into electronics recently and I LOVE it. I wish to build the FM Radio Transmitter but cannot find the 3-18pf adjustable capacitor. Is there any substitution for this part?
Electonics parts distributors like Digikey in Canada and the US have hundreds of trimmer capacitors. It does not need to be exactly 3-18pF but could be 5-30pF or anything that can be adjusted from 0pF to about 50pF.
I am not from Canada or the US but thanks for the advice. I have found an adjustable cap that does 4.2-20pf |
| audioguru |
Posted - Dec 03 2009 : 09:42:18 AM
quote:
Originally posted by nhardy
Hi, I have just gotten into electronics recently and I LOVE it. I wish to build the FM Radio Transmitter but cannot find the 3-18pf adjustable capacitor. Is there any substitution for this part?
Electonics parts distributors like Digikey in Canada and the US have hundreds of trimmer capacitors. It does not need to be exactly 3-18pF but could be 5-30pF or anything that can be adjusted from 0pF to about 50pF. |
| nhardy |
Posted - Dec 03 2009 : 03:39:14 AM
Hi, I have just gotten into electronics recently and I LOVE it. I wish to build the FM Radio Transmitter but cannot find the 3-18pf adjustable capacitor. Is there any substitution for this part? |
| audioguru |
Posted - Nov 08 2009 : 8:28:27 PM
quote:
Originally posted by mrgone
Here is a single chip FM Broadcaster I just found:
http://electronics-diy.com/Single_Chip_FM_Transmitter.php
It is tuned by voltage so it needs a regulated power supply to keep its frequency stable.
It doesn't have pre-emphasis like FM radio stations so treble frequencies will not be received. |
| mrgone |
Posted - Nov 08 2009 : 7:36:23 PM
Here is a single chip FM Broadcaster I just found:
http://electronics-diy.com/Single_Chip_FM_Transmitter.php
|
| mrgone |
Posted - Oct 07 2009 : 10:58:55 PM
Yeah you can use any wire. You can stretch the coil to change the frequency. The diameter will not effect it much at that frequency. |
| Badar |
Posted - Sep 16 2009 : 11:48:52 PM
Thanks |
| audioguru |
Posted - Sep 16 2009 : 1:55:33 PM
I don't know of a coil that is more simple than the coil in this project.
If you purchase an inductor then it might work only at a lower frequency than the FM radio band.
My FM transmitter uses 1mm enamelled wire that I "borrowed" from the crossover coil in a speaker enclosure.
It has 8 or 9 closely spaced turns around a 3mm former. It is spaced away from other parts and away from the circuit board. It is tuned with a 5pF to 35pF trimmer capacitor. |
| Badar |
Posted - Sep 16 2009 : 1:41:11 PM
Thanks.
But using a simple coil instead of 28 AWG enameled wire will make any difference to the working of circuit?
I am very grateful for your concern. |
| pebe |
Posted - Sep 16 2009 : 11:15:52 AM
If you change the wire diameter it will alter the diameter and (if close spaced) also its length. This will result in a change of inductance that will change the frequency.
Use this calculator http://www.66pacific.com/calculators/coil_calc.aspx
Enter the coil sizes specified in the article and calculate the inductance. Now choose the wire size you want to use and alter the number of turns, diameter, or length until you get the same inductance. |
| Badar |
Posted - Sep 16 2009 : 08:48:57 AM
sorry to say but this not the answer to my question.
i am not the only one in the world to use short mobile language.
For your convenience i will repeat my question.which i have been trying from the start to know but have not got a satisfactory answer.
what i get is just information about my grammar or spellings mistakes.
that is not cool.
but no hard feeling from my side.
THE QUESTION IS:
i asked that can i use any coil or only specified in the diagram.
Circuit tells me to use a 28 AWG enameled coated magnet wire.
But it is not available in my area.
Can i used any other coil?
waiting for a reasonable reply to my question.this time. |
