MAX2606 fm transmitter pcb

[steev]

hi all
i ordered some samples of max2606 to make a small home theater system.as this chip is available only in SMD i want to use normal components for the rest.

using google i found this ckt with pcb
**broken link removed**

problem with the pcb file is iam unable to get the printout of coper traces.is there any method to get the exact size so that all comonents and SMD chip fits in without any problem.
help pls
thanks

 

[Paul Obrien]

I have had a look at the MAX2606 circuit and datasheet, you do realise the circuit is mono. The left and right signals are simply added together. The png format and tools are available here http://www.libpng.org/pub/png/

 

[steev]

yes.no problem with mono.
in the pcb 2606 traces are IMP as its SMD.how can i take printout so that it matches exactly.express pcb file is available in the above site.but there is no option in it to take the print of only traces to make PCB

 

[audioguru]

The transmitter circuit doesn't have pre-emphasis (treble boost like FM and TV stations use) so when received on an FM radio the sound will lack treble frequencies, like your stereo with its treble control turned all the way down. Maybe a capacitor can be added across each 22k input resistor, if the signal source can drive it.

 

[steev]

capacitor in series?
what shld be the valuu of it...

 

[audioguru]

A capacitor in series with each 22k resistor would reduce bass frequencies, not boost treble frequencies.
Looking again at the schematic, boosting treble simply with a couple of capacitors across the 22k resistors won't work.
So the simple project will sound twice as bad as an AM radio.

 

[steev]

then why maxim said one chip Home-Entertainment Systems ???

 

[Nigel Goodwin]

then why maxim said one chip Home-Entertainment Systems ???

The Maxim datasheet is here **broken link removed**

and it says

A simple FM transmitter (Figure 1) links your home-entertainment system to a portable radio that can be carried around the house and into the back yard. For example, you can play music on the CD changer in your living room, and listen to it on a portable radio by the back-yard barbeque.

I don't see the connection with you wanting to "make a home theatre system"?.

 

[audioguru]

It is simple to add a treble boost transistor to the transmitter:

 

[steev]

thanks audio guru.
why i choosed it is it is single chip and uses less number of components.
but when i start soldering that SMD i understand how hard it is.
well is there any other ckt for this purpose.it shld be small and easy to built(with PBC layout will be great)
and no need to worry abt FCC something like that...
no one cares abt it in my area.

 

[Paul Obrien]

The BA1404 is/was a popular stereo FM transmitter, I think it has been superceded.

 

[steev]

mmm nice chip.
but as u said it has been stopped.
any more ideas,for a simple audio fm transmitter...

 

[Nigel Goodwin]

Your original post said you want to make a "small home theater system", I don't really see the relevence of a mono (low quality) single channel transmitter?.

 

[steev]

well first i thought that max2606 is streo and will serve the purpose.
as it is small in size and uses less power.(which is imp for me)
but audioguru's post changed my openion.

 

[audioguru]

Rohm company discontinued their BA1404 simple stereo FM transmitter IC after receiving many complaints about its poor performance. They replaced it with a few much better ICs and the problems are gone. The Micromitter in Silicon Chip magazine uses Rohm's BH1417 IC. Its package is surface-mount only and the circuit is fairly complicated.
https://electronics-diy.com/schematics/BH1417_fm_transmitter.htm

 

[steev]

yes it is quite complicated.and surface mount :-(