Pleeeeez help me to build a TDA7000 Reciever! I'm in trouble

ahmad_abdulghany · Post by **ahmad_abdulghany** » Sat Apr 22, 2006 4:29 pm

Guys!
Please help me in my problem, I'm really in harry and trouble due to my graduaiton project!!!
I need to build high bit rate digital data link using TDA7000 in its Rx end,

I heared that TDA7000 can be modified somehow to allow wide band transmission, but i don't know how,

I thought that the problem is in two main limitations:
- IF stage is narrow band also it works at 455KHz which may disable the desired high bit rate to be achieved..
- AF stage has LPF action

I thought in disabling the internal IF stage by connecting externally another IF amplifier (but with higher BW) from pin 7 to pin 12, but i don't know how much is the impedance of that pins!! Can i do that?

I think that the second problem is easier, I may take demodulated unfiltered output from pin 4 instead of pin 2.. do you agree with me?

Pleeeeeeeeeeeeeeeeez help me fast ..
Any information will be highly appreciated with many thank

You can find TDA7000 Datasheet here:

http://www.semiconductors.philips.com/a ... _CNV_2.pdf

Will anyone help me??
Thanks alot in advance,
Ahmad,

Post by **pcs** » Sun Apr 23, 2006 10:56 am

You ideas are bad, it cannot be done that way. You did not really read the datasheet
carefully.

Use another IC.

ahmad_abdulghany · Post by **ahmad_abdulghany** » Sun Apr 23, 2006 11:06 pm

pcs wrote:You ideas are bad, it cannot be done that way. You did not really read the datasheet
carefully.

Use another IC.

Okay, First, Thank you Mr. Administrator, and i want to tell you that i did read the data sheet carefully as well as the application note AN193 many times before i post this post, and i didn't find a solution to my problem, then i asked for help!!!

I think that I didn't make something wrong even if i didn't read the datasheet, however i did as i said above..

Anyway, thanks again for your reply, but can you kindly suggest another good idea either discrete solution or suggest another suitable IC?

Thanks alot,
Ahmad,

Post by **pcs** » Sun Apr 23, 2006 11:52 pm

TDA7000 is a very special design with 75KHz IF frequency, you cannot just change
this to 455KHz or any other IF frequency.

There are a number of ready-made modules sold by all major electronics vendors.
Usually working at 433MHz. This is your best way.

ahmad_abdulghany · Post by **ahmad_abdulghany** » Mon Apr 24, 2006 12:12 am

pcs wrote:TDA7000 is a very special design with 75KHz IF frequency, you cannot just change
this to 455KHz or any other IF frequency.

There are a number of ready-made modules sold by all major electronics vendors.
Usually working at 433MHz. This is your best way.

Thank you for your immidiate reply

For the TDA, I don't want to change its IF frequeny, I want to change its IF filter, which will work on the same IF frequency but with higher BW,

For other solution of the 433MHz, Can you kindly name some ICs that i can use for that purpose? Also if you can provide a discrete solution it may be better for me..

Thanks in advance,
Ahmad,

Post by **pcs** » Mon Apr 24, 2006 12:23 am

You cannot change the BW significantly.

I could design a discrete solution, but it would take time and money.
But since this is for your thesis perhaps you should design it to earn the degree.

433 modules are out there, thousands of them:
http://www.google.com/search?hl=en&q=43 ... tx+modules

Google is your friend. Learn to use it.

ahmad_abdulghany · Post by **ahmad_abdulghany** » Mon Apr 24, 2006 12:51 am

pcs wrote:You cannot change the BW significantly.

I could design a discrete solution, but it would take time and money.
But since this is for your thesis perhaps you should design it to earn the degree.

433 modules are out there, thousands of them:
http://www.google.com/search?hl=en&q=43 ... tx+modules

Google is your friend. Learn to use it.

Can't you please share your discrete solution? It will help me.. please do!

I am really in trouble, how can I make you believe that?!

Post by **pcs** » Mon Apr 24, 2006 1:29 am

I said I could.

Unfortunately I can't afford to give you a week of my time for nothing.

ahmad_abdulghany · Post by **ahmad_abdulghany** » Mon Apr 24, 2006 1:35 am

pcs wrote:I said I could.

Unfortunately I can't afford to give you a week of my time for nothing.

I agree with you in that in fact, You're absolutely right... but...
But I may really be unable to pay mony for it, because i have no credit card and i wont be able to have one at this time, I'm ashamed indeed to ask you about it again, You're a succeeded man, and i admire you and your site, i discovered it just after reading your post, and saw your amazing topics here, i didn't think that you make advertisements to some of your wonderful projects and products..

I am sorry if i disturbed you, And if you have further help to me, tell me, if you want me to stop posting my boaring posts here, i will..

Thank you,
Ahmad,

Post by **pcs** » Mon Apr 24, 2006 1:46 am

Its best you find a already-finished solution.

I do not have time to develop one for you.

ahmad_abdulghany · Post by **ahmad_abdulghany** » Mon Apr 24, 2006 1:49 am

Best Wishes from my heart to you...
Good Bye,

Ahmad,

Post by **pcs** » Mon Apr 24, 2006 1:58 am

Earn your degree. What kind of engineer asks other to do his job?

It will be a worthwhile experience, you will thank me one day, maybe.

CoolFM · Post by **CoolFM** » Thu Apr 27, 2006 2:41 pm

check site;

http://web.telia.com/~u85920178/rx/tda7000.htm

greetz!

CoolFM