Skip to main content

DIY Portable FM Radio (Part 1) Tuner Front End

It is started when I have spare time in home and try to figure out what is on my storage box. I usually throw my ex. DIY project to this big cardboard box. I think I will not use it, or I just explore something related to electronic device then put it in the box for future need.

Sometimes like this day, I open up again the box and it is kind of nostalgic moments. So this is what I found.


By looking this board, I am pretty sure this is a radio module. Perhaps it is from old radio kit or anything else. So I figure it out and found the Blue IFT coil is absolutely for a FM radio.

Then I taken out the IC, it is show the TA7358P. It is absolutely for the front end FM radio as per datasheet from Toshiba.

If you don't want to read all this post, then this is the full schematic of the FM radio front end.

Making a radio is something that anyone will enter before going deeper to this DIY audio hobby. Just like me, I started make my own radio when I was twelve. And it is not working. I trying many times even I have to stop buying school lunch for saving money. I remember after several times trying, I succeed make my first MW radio using YS414. Then I jump to make FM radio using several transistor. Again it is a failed project. Make radio is hard, but it is tempting.

Back to the schematic, you will need the explanation for the circuit. The IC pin 1 is the antenna input after the 10pF capacitor. You need to pay attention for the IC pin 3 is marked 'A'. This pin should connected together to other 'A' marked after the L2 Same with the marked 'B' should be connected together with the IC pin 8.

Please pay attention to the input-output of this module:
1. The AFC out contain radio signal is from the blue IFT and IC pin 6.
2. The radio tuning pin is for the voltage variable sensing tuning. This pin will function as radio tuning frequency.
3. Then the 3 volt is for voltage in. The 68 ohm can be adjusted up to 2k for greater voltage requirement. The default from original board is 1,2 k.
4. The ground is the negative voltage.

The coil is explain as above photo. All coil diameter is about 6 mm and the wire diameter is about 0,4 mm. L1 is 5 turn, L2 & L3 is 4 turn.

As usual, my habit is put all components to the new universal board. It is all point to point connection.

The front end FM radio is now done. Part 2 will be publish soon for the FM modulator. Stay tune:)

Disclaimer: Any statement and photos in this article are not allowed to copy or publish without written permission from the writer. Any injury or loss from following tips in this article is not under writer responsibility.

Comments

Popular posts from this blog

OPA1622 Vs. OPA627 High Performance Op-amps Comparison

This op-amps comparison topic is actually boring, but at the same time, many of us still curious about what others think about it. The reason is simply because of the op-amps variation are hundreds and they are depends by the implementation. The op-amps are considerably cheap and an interchangeable electronic components but they are not built for the same function. So in this discussion, I will focus on the modern Vs. vintage high performance op-amps in the simple non-inverting pre-amplifier gain stage.

Vintage Multibit R2R DAC Tier List

At the very beginning of this year, I committed to explore the best multi-bit R2R DAC. This is simply because I have plenty of the resources (from broken old unit CD player of course) and ability to build them up. If you think this kind a recycle from old un-used unit to become something useful, than I should stated myself giving contribute for greener world:) After all DAC that I built in this year, I think it is better for me to list them up again in one single page like this. Then I will rank them up in a simple tier list. The reason for this, so you all know what my opinion about of those vintage multibit R2R DAC especially in the sound quality.

TDA1543 DAC Review In 2021

It is a fine day and as usual I am reading and searching online contents related to almost anything I like. During my search, I stop to the few online forum discuss about a simple DAC using TDA1543 DAC IC. The discussion about this DAC was about 3 years ago, and the latest was about a year ago. Quite new and overall discussion about this DAC sound quality mostly are positive. It is interesting topic anyway especially I was built this TDA1543 DAC long time ago in 2016. At that time, I combine this DAC with Tripath amplifier  here  and  here  before it sold in 2019. That is also my first DIY DAC and I am quite enjoyed this DAC so much, at that time. The background story about this, previously I was using Sony Playstation SCPH-1002 as my reference CD Player. The reason I moved to this TDA1543 DAC is because the CD optic inside the Playstation is wear out and I cannot find the replacement for it. I pretty remember the sound quality of this TDA1543 DAC is quite comparable...