The TEA5711T FM Stereo Receiver Project

Thanks to the gracious and friendly staff-team at Philips Semiconductors, I was given the opportunity to sample two of their RF chips during the summer months of 2005. Together... the TEA5711T AM/FM Stereo Receiver IC and it's sister chip... the TDA7050 Mono/Stereo Audio Amplifier IC, promote a fully functional AM/FM Radio.

Philips Semiconductors introduced the TEA5711T in the 90's. The TEA5711T is a fully operational AM/FM Stereo Receiver; with a stereo encoder built within. To amplify the small audio signal coming from the chip, I am also using the TDA7050 Mono/Stereo Audio Amplifier !

With an ordinary pair of headphones, clear, crisp stereo sound will produce unequaled marvel to your ears ! Below is a picture of the two chips. Both IC's are of the SMD (surface mount device) type. These two chips, together with a handful of external passive components and a few devices...make up a complete AM/FM Stereo Radio.

I have only used the FM portion of the chip, as my interest lies mainly in FM. I have all the needed information for you to make this exciting FM Radio project yourself. Yes, all the material is here for you to have your own 'hand-built' FM Stereo Receiver...together with an 'adjustable' half-wave dipole antenna. Plus it will also catch the VHF Aircraft Band at your local airport . So if you fancy new and exciting projects with up-to-date technology. . .this one is waiting !

I would also like to say...that should you take up the project, I will be more then happy to help you throughout the journey...should you need any kind of assistance along the way. Plus, I would love to put you and your story...once the unit is up and running, on my website. This will surely give other new-bee's and veterans to the field...an enlightened little project to take up on their own. Of course, only with your approval ! You may even want to continue your venture, by experimenting with the AM portion of the chip...once the FM is alive and kicking !

These two chips are of the 'Surface Mount Device' (SMD) type. Therefore, there are no holes to be drilled for the 2 Integrated Circuits. In fact, no holes have to be drilled for any of the external components, since all the components are on the same side as the IC's.

To the left is the complete circuitry encompassing the TEA5711T and the TDA7050 IC's.

The PCB, no larger then 1 3/4"X 2 3/8", will easily accompany the two chips, together with all of the other external components needed to make the project.

"Extreme care must be taken when soldering the chips to the PCB. Any small amount of 'splashed' solder droppings across adjacent pins, will warrant a 'no-go' when the time comes to turn the unit on. A 'stand-up' magnifying lens will definitely help you through the soldering of the two chips to the board. Once you have done this, it would be wise to take an ohm meter and make sure that each pin is showing 'no-continuity' from it's adjacent pin. The only two pins that will show 'continuity' are pins #6 and #7 of the TDA7050...and of course, pins that are all connected to common ground will also show 'continuity'."

These SMD (Surface Mount Device) chips are soldered on the same side as is the external components and the copper routing.

The voltage supply range for the TEA5711T IC is 1.7 volts to 12 volts. I have used two 1 1/2 volts batteries for the project...thus making the power supply 3 volts. The maximum FM oscillating frequency is around 140 MHz. Therefore, you are able to catch your local Aircraft Band.

Once you begin your own project, you may want to insert the PCB into a a wooden or metal enclosure...giving it it's due appeal to you and others.

Just as life goes on...your project will go on to give great incentives to other new-comers to the RF field...or even RF veterans who are eagerly awaiting a new fun project to make! As I have mentioned earlier...to let others see your handywork, I will personally put you and your project on the website, for all to witness! But only with your approval.

Let us now begin to give 'the breath of life' to both the TEA5711T and the TDA7050 Integrated Circuits.

The very first thing to do is to get all the required items for the task at hand. Below is a list of the items/components required for the project. Once you have acquired all the items that is in the list below, you are then ready to proceed to the next section.

NOTE: All items below can be found, in part, at Digi-Key, Mouser Electronics and Radio Shack. The three 10.7 MHz Ceramic Filters needed for the project is Mfg P/N SFELA10M7FA00-B0.

2 - 0.33uF Electrolytic Capacitor - (*)	1 - 6pF Ceramic Disk Capacitor
3 - 0.1uF Ceramic Disk Capacitor	1 - 100uF Electrolytic Capacitor (*)
2 - 0.01uF Ceramic Disk Capacitor	3 - 10.7 MHz Ceramic Filter (3 leg type)
1 - 220 Ohm Carbon Resistor (1/4 Watt Rating)	1 - 4.7uF Electrolytic Capacitor (*)
1 - Mini LED (Your choice of color)	1 - 2.2K Carbon Resistor (1/4 Watt)
2 - 47K (hand-turn type) Potentiometer	2 - 10 Ohm Carbon Resistor (1/4 Watt Rating)
1 - 0.022uF Ceramic Disk Capacitor	1 - 47pF Ceramic Disk Capacitor
1 - Air-Core Coil - 4 turns/8mm diameter/7mm length (uninsulated 22 gauge solid copper wire)	1 - 0.022uF Ceramic Disk Capacitor
1 - Air-Core Coil - 5 turns/8mm diameter/9mm length (uninsulated 22 gauge solid copper wire)	1 - 68K Carbon Resistor (1/4 Watt Rating)
1 - 330pF Ceramic Disk Capacitor	2 - 3 foot telescopic antennas. (#)
1 - Variable Tuning Capacitor (%)	2 - AA Alkaline Batteries
1 - Stereo Audio Jack (&)	22 gauge insulated braided wire for hookup of all devices
1 - SPST Switch	This space is blank.............................................................

(*) A Voltage Rating of at least 3 volts is needed. The voltage rating may be higher...but not lower then 3 volts. The voltage rating on my electrolytic capacitors were 50v. But anything over 3 volts will do the job just as well.

(#) You may either purchase two 3 foot telescopic antennas...or just use two 3 foot pieces of wire for a substitute. Wire diameter is not critical. Refer to CHART II for proper installation.

This particular telescopic antenna layout forms a half-wave dipole. In fact, since the two antennas are adjustable, you can vary the length of each antenna, thus staying on your true resonant frequency...for whatever station you may want to listen to. The formula for a half-wave length antenna is 492 divided by the frequency. Let's say that you wanted to adjust the antenna for 105.1 MHz, then just divided 492 by 105.1, and you come out with 4.68 feet. Since each antenna will be half that length, adjust both antennas for a length of 2.34 feet, and you have just found the resonant frequency for your dipole antenna in relation to 105.1 MHz. If you want to really get precise, subtract 1/4 inch from each antenna. This is due to the fact that there is a 1/2 inch spacing between the two antennas (Refer to CHART II for proper spacing between antennas). Now you have perfected your true half wave length for 105.1 MHz.

(%) This particular tuning capacitor is typically found in small portable (hand carried) AM/FM receivers. They are of the tunable type...not the digital type. You may purchase one of these small radios at Wal-Mart at a very low cost. Then salvage the 6-lead tuning capacitor from it. You may also want to purchase a complete small portable AM/FM receiver with headphones...then you will not have to purchase headphones separately. Cost is usually under $10.00

Also, these 6-lead type tuning capacitors can come in different values of capacitance. It will be up to you to experiment and try each side of the 6-terminal device, to see which side gives you the recommended capacitance that you need. Also, the fixed capacitor coming from the variable tuning capacitor, may need also to be altered in capacitance...just a little. Should you need help with this area of the project, do not hesitate to call upon me. That is also what I am here for...to make sure your project goes as smooth as can be!

(&) The stereo audio jack will come with three terminals. Two terminals will be for the left and right speakers on your headphones. The remaining terminal will be for ground. Connect your left speaker terminal #18 in CHART I and connect your right speaker terminal to #19 in CHART I. Connect your ground terminal to #20 in CHART I.

Now that you have all the needed components/devices for the project, let us begin to make the PCB. Below is the PCB Layout of the copper routing. Download this drawing and then use a graphics program, such as 'Paint'...and sqeeze the drawing down...until all the pins of the TEA5711T (in the new compressed print-out you made) line up with your own actual chip. Once that is done, you are ready to make the PCB. RF hobbyists make PCB in different ways. Use your own style. I used 'Dry-Transfers' to do the job. Once the PCB is made, you may continue to the next step.

Refer to CHART I below, to know where each component is soldered on the PCB. You may also look at the following pictures, to give you an idea on how mine looks like.

Now comes the time to solder all the components on the PCB. Refer to the drawing and chart directly below, to find out where each component is soldered.

(1) 0.33uF Electrolytic Capacitor (Observe Polarity)	(17) 6pF Ceramic Disk Capacitor
(2) 0.33uF Electrolytic Capacitor	(18) 10 Ohm Carbon Resistor (1/4 Watt Rating)
(3) 0.1uF Ceramic Disk Capacitor	(19) 10 Ohm Carbon Resistor (1/4 Watt Rating)
(4) 0.1uF Ceramic Disk Capacitor	(20) 100uF Electrolytic Capacitor (Observe Polarity)
(5) 0.01uF Ceramic Disk Capacitor	(21) 10.7 MHz Ceramic Filter (Use all three legs)
(6) 0.01uF Ceramic Disk Capacitor	(22) 10.7 MHz Ceramic Filter (Use all three legs)
(7) 220 Ohm Carbon Resistor (1/4 Watt Rating)	(23) 10.7 MHz Ceramic Filter (Use only the two outside legs. Snip off the center leg.
(8) Mini LED (your choice of color)	(24) 2.2K Carbon Resistor (1/4 Watt Rating)
(9) 100k Potentiometer (3-leg type) center leg marked in red.	(25) 4.7uF Electrolytic Capacitor (Observe Polarity)
(10) 0.022uF Ceramic Disk Capacitor	(A) Goes to right leg on RIGHT 47K Potentiometer
(11) 330pF Ceramic Disk Capacitor	(B) Goes to right leg on LEFT 47K Potentiometer
(12) 68K Carbon Resistor (1/4 Watt Rating)	(C) Goes to center leg on RIGHT 47K Potentiometer
(13) 0.01uF Ceramic Disk Capacitor	(D) Goes to center leg on LEFT 47K Potentiometer
(14) Air-Core Coil (4 turn/diameter 8mm/length 7mm/uninsulated 22 gauge solid copper wire)	(E) Goes to left leg on LEFT 47K Potentiometer
(15) 47pF Ceramic Disk Capacitor	(F) Goes to left leg on RIGHT 47K Potentiometer
(16) Air-Core Coil (5 turn/diameter 8mm/length 9mm/uninsulated 22 gauge solid copper wire)	(G) Goes to one terminal on the switch. The other terminal on the switch will go directly to the positive side of one battery. The negative side of that battery will then goes to the positive side of the other battery. Then, the negative side of that battery will go to H on CHART I. Also, use CHART II for a visual look on how all this hooks up. Use your 22 gauge braided wire for hookups between devices.
((25) Refer to IMPORTANT NOTE below this chart.	(H) Goes to negative side of batteryH)
This space is blank.	(I) Refer to Chart II for proper hook-up of the two antennas..
This space is blank.	(J) Refer to Chart II for proper hook-up of the two antennas.

IMPORTANT NOTE: This receiver can be used either in the MUTE or NO MUTE condition. In the MODE condition, Pin #32 goes to ground. In the NO MUTE position, Pin #32 is not connected to anything. Purchase a SPST switch, and have this switch soldered in between Pin #32 and ground. So, when the switch is in the ON position, your receiver will be in the MUTE position, and when the switch is in the OFF position, the receiver will switch itself into the NO MUTE position. Keep leads as short as possible.

In the MUTE positon...When the switch is ON, the receiver will be in the MUTE position. This MUTE position means that the unit will only receive the stronger stations, thereby 'muting' the weaker stations. You will also notice that the receiver will have relatively 'no noise'...in between stations. This is because the signal to noise (S/N) ratio is high.

In the NO MUTE position...When the switch is OFF, the receiver will be in the NO MUTE position. This NO MUTE position means tha the unit will receive all stations...the stronger and the weaker. You will also notice that the receiver will form a hissing sound..which will form in between stations and also on the weaker stations. The very strong stations will surpress this 'hissing' sound. This hissing sound has become pronounced because the S/N ratio is diminished...thereby causing the receiver to become extremely sensitive to all sound/noise.

So you have the choice...by using your ON/OFF switch, to dictate to the receiver if you want the MUTE or NO MUTE condition.

Refer to the chart below, to properly place all of your devices on the PCB. Use your 22 gauge braided enamel-coated wire for hookups.

NOTE: The following pictures and words will give you a 'general sense' on where the components are to be soldered on the PCB. But 'always' refer to CHART I before you actually solder each component on the PCB. The chart specifies exactly where each component is to be soldered. Also, the second-the-last picture on this webpage will give you a bird's eye view on how all the components should look like, once you have finished your component soldering.

Let's begin by soldering a three-pin ceramic filter to the PCB. These three pins will be coming from terminals #11, #12 and #13 of the TEA5711T chip.

Next, solder another three-pin ceramic filter to the PCB. These three pins will be coming from terminals #7, #8 and #9 of the TEA5711T chip.

Once that is done, continue with another three-pin ceramic filter by snipping off the center pin on the ceramic filter. Then go ahead and solder it to the PCB. This filter will be coming from terminals #5 and #6 of the TEA5711T chip.

Next, take your 4.7uF electrolytic capacitor and solder the positive side of the capacitor to the PCB, coming from terminal #4 of the TEA5711T. Then solder the negative side of the capacitor to ground.

Following that, take one 0.1uF ceramic disk capacitor and solder one leg to the PCB coming from terminal #3 of the TEA5711T chip. Then take another 0.1uF ceramic disk capacitor and solder one leg to the PCB coming from terminal #2 of the TEA5711T chip. Solder the other leg to ground.

Next, take one 0.01uF ceramic disk capacitor and solder one leg to the PCB coming from terminal #2 of the TEA5711T chip. Solder the remaining leg to ground. Take another 0.01uF ceramic disk capacitor and solder one leg to the PCB coming from terminal #3 of the TEA5711T chip. Take the other leg and solder it to ground.

Next, take your 2.2K carbon resistor (1/4 watt rating) and solder one leg to it's rightful spot (refer to Chart I) coming from terminal #31 of the TEA5711T chip. Solder the other leg to it's rightful spot referring to Chart I.

Then, take one of your 0.33uF electrolytic capacitor and solder the positive side to it's correct placement (directly after the 2.2K carbon resistor) coming from terminal #31 on the TEA5711T chip. Solder the negative leg to ground. Take your other 0.33uF electrolytic capacitor and solder the positive side to it's correct placement from CHART I, coming from terminal #31 of the TEA5711T chip. Solder the negative side to ground.

Once that is done, continue by soldering the negative side of the mini LED coming from terminal #30 of the TEA5711T chip. Solder the other leg (anode side) of the mini LED to it's correct placement spot referring to Chart I.

Then, solder in the 220 ohm carbon resistor (1/4 watt rating) directly after the mini LED. Refer to Chart I for correct placement. Once that is done, continue by soldering in the 0.1uF ceramic disk capacitor coming from terminal #28 and #29 of the TEA5711T. Refer to Chart I for correct soldering placment on the PCB. Then solder in the 330pF ceramic disk capacitor. One leg will be coming from terminal #28 and the other leg to ground. Refer to Chart I for correct soldering placement. Then, coming from terminal #27, soldering in the 68K carbon resistor (1/4 watt rating). Refer to Chart I for correct soldering placement onto the PCB. Next, take your 100K potentiometer and solder in it's three legs, by using Chart I for correct soldering placement onto the PCB. One outside leg and the center leg with both be going directly to ground. The other outside leg will be soldered onto the PCB, coming directly after the 68K resistor. Refer to Chart I for correct soldering placement. Once that is soldered into place, take your 0.022uF ceramic disk capacitor and solder one leg coming from terminal #25 of the TEA5711T chip. The other leg will go directly to ground.

The last gathering of components to be soldered on the board begins with a 4 turn air-core coil. This is to be handmade. Use 22 un-insulated copper sold wire. The diameter of the coil should be 8mm's. The overall length of the coil should be 7mm's. Stretch the coil windings to acheive this overall length. Then solder into place. This coil will be coming from terminal #23 of the TEA5711T chip. Use Chart I for correct soldering placement onto the PCB. Next, take your 47pF ceramic disk capacitor and solder it to the PCB, using Chart I for correct placement. Then make another air-core coil. This coil will be the same as the other coil, in all respects, except for the number of wraps. Make 5 turns. Then stretch out the coil to have an overall length of 7mm's. Then go ahead and solder in your 6pf ceramic disk capacitor. Refer to Chart I for correct soldering placement.

Now we direct out attention to the TDA7050 chip. Begin by taking your 100uF electrolytic capacitor and solder it into place, using Chart I for proper soldering placement. This capacitor will be coming from terminal #5 of the TDA7050 chip. After that, take your two 10 ohm carbon resistors (1/4 watt rating for each) and soldering them onto the PCB. Again, use Chart I for proper soldering positioning onto the PCB. One resistor will be coming from terminal #6 of the chip and the other resistor will be coming from terminal #7 of the chip. Now that all the components are soldered to the PCB...

...the picture below is a bird's eye view of the project. View each component in the drawings and see if it matches up with yours. Should you find anything not right...now is the time to correct it !

If you have come this far, you are on your way in having music where ever you go. Plus, always maintaining the most optimal resonant frequency with your adjustable half-wave dipole antenna...at whatever frequency you tune to !

And so the journey comes to an end of mastering the project...and the beginning of listening to beautiful stereo music !

Well, my friend...there you have it. Like I have stated, should you need help of any kind during the project, I am only but a keyboard away!