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Need help in 88-108MHz preamp circuit!!

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rahulan999 you shouldn't sell the bear's skin before you kill the bear :)

I think this guy will post pictures of his completed TEA5711 receiver tomorrow :D

His current project is a 'High voltage Induction coil' !
 
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looks like we have made TEA5711 receivers "a la mode" (in fashion), everybody wants to make them :D

High voltage induction coils, I love'em... They were first made by Nicola Tesla, if am not mistaken, an obscure electrical genious
 
Can u remember the communication range of a Tesla Coil based radio transmitter. How is the receiver is designed for that?
 
Can u remember the communication range of a Tesla Coil based radio transmitter. How is the receiver is designed for that?

I am a little rusty on the subject, but I think you are confusing this with the Hertzian transmitter, he used an ignition coil which produced sparks and transmitted the sparks to an open metal ring with 2 small balls a few feet away, he proved the existence of electromagnetic waves. I don't know if Tesla transmitted anything, he played around with induction coils of all sorts and some of them produced very large sparks all over the place :D Of course I can research the net and my books to sound more knowledgeable here, but I will not do that ;)
 
LM1036 also got in my pocket yesterday, very costly!
I have ordered it from Mumbai and the supplier told that only 5 number is available and no chance to find anymore. So all the remaining pieces shipped to Bangalore as per my order;) and I picked only one because the IC was very HOT!

Bought 10.7MHz filter(3pin) and discriminator(2pin). No one knows about the bandwidth whether its 150KHz or 450 like that. Its not written on the part also except the 10.7.
They told its from something Moratto, Japan company. Check on net for datasheet. But I didn't find anything.

455KHz Philips IFT is available for AM part. Is it necessary to use the same part no. mentioned on the datasheet?

Apart from IFTs every obsolete parts for this project is obtained! I'm very happy :)
 
Murata filters, not Morrato. You better know what the bandwidths are, u can't just use "whatever" in that circuit, and u shouldn't mix filters or your selectivity will be mashed potatoes ;)
The IFTs don't have to be philips, but u have to respect the turns number as mentioned in the sheet. Like I said before, don't expect good selectivity on AM with just 2 IF tuned circuits!
 
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150KHZ filters are good for this FM radio. Make sure the 2 filters are similar.

Selectivity on AM will not be great with only 2 IF tuned circuits, but the sound quality will be nice with a wide bandwidth, and you will get a lot of birdies from adjacent stations beating with each other from lack of selectivity... a real symphony :D
 
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LM1036 also got in my pocket yesterday, very costly!
I have ordered it from Mumbai and the supplier told that only 5 number is available and no chance to find anymore.
National Semi has the LM1036 in full production.
Digikey has 367 in stock today for only $2.75US each (the cost of a cup of coffee in a restaurant).
Newark has 246 in stock today for only $2.62US each.
 
Here, coffee is a very cheap item, so we not at all bother abt the price. Even in my house also coffee production plant is there. So if restaurants want to increase the price also nobody will mind :D

My filters are marked as: SFA10.7MF
and discriminators: 10.7FGF
Can u differentiate it?

Is that MKA293,294...numbers on datasheet represents IFT part no.?
If I have to strictly follow the turns then, probably re-winding of IFT core is the only option. The highest gauge available for me is 49SWG. I think that specified .07mm may be something 52-54SWG ranges.
 
Is that MKA293,294...numbers on datasheet represents IFT part no.?
If I have to strictly follow the turns then, probably re-winding of IFT core is the only option. The highest gauge available for me is 49SWG. I think that specified .07mm may be something 52-54SWG ranges.

I don't know about the MKA... again, do a search on the net. For the oscillator coil (L4), I would use a can with the red core, and for the 1st and 2nd IFT coils (L5 and L6), I'd use cans with the white and black cores respectively. You can canibalize these coils from a cheap AM radio. I wouldn't advise you to re-wind the coils, you don't need to re-invent gun powder man! As far as the windings, you can test resistances at the pins to decide which pin goes where. Larger windings will have more resistance and vice versa.
 
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Yea, I have old 2in1 boards with IFTs on them. Also I already have a set of general purpose transistor radio IFTs.
Once I will try to rewind for an experience, otherwise I will get a Philips part.
50KHz filter will degrade the audio fidelity though the selectivity is at extreme level. The specified part no. is 455KHz BW with moderate selectivity and excellent audio quality.
Here's a link:
How to select a tuner for 88-108 MHz broadcast FM DX
 
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