Feature:
You can see that there are 8 blue digital dots on it. What are their respective functions I will introduce here.
Point 1, the power supply is connected to 15VAC/DC. AC use12V
The second point is to switch between stereo and mono. In mono, the sound of the two channels is the same and the sensitivity is high. When the switch is pressed, the stereo works, the tuning is quiet, and the weak stations may disappear
The third point is to connect the frequency display. Pay attention to the voltage and OSC line not to be reversed, otherwise it will not work
The fourth point is to connect a 20K tuning potentiometer. Here you can use a multi-turn potentiometer or an ordinary potentiometer. If you use an ordinary potentiometer with a larger knob, you can call up the detail table, which is more convenient and multi-turn. The imported quality is better
Points 5 and 6 are the midweek of frequency discrimination, and point 5 is the key. Minor changes at point 6
The seventh point is the squelch potentiometer, which determines whether there is a rustle when tuning. (Now Level 4)
(This function is disabled in the middle release)
The eighth point is to connect the signal strength indicator. Generally, there is this kind of meter on the Japanese machine. You can see the tuning letter.
No. intensity, the above 100K adjustable resistor, is for adjustment. I will go home and study this part on my own.

How to debug LA1235 radio headboard?
First connect the display screens and potentiometers like 3 and 4, and then connect the power supply of 1.
Adjust to the high end to see if it reaches 108MHZ, if not, adjust the 10K adjustable resistor above 4.
Then turn to the low end to see if it reaches 88MHZ, if not, adjust the 10K adjustable resistance above 3
Then turn to the high-end to see if there is a running frequency. If there is, then adjust the high-end, and then look at the low-end, so you can
In order to meet the frequency range of 87.5-108MHZ, all are rich, so don't worry. Unless the voltage is too low.
The following are some of my experience in the debugging process:
The key point is to pay attention here. In the fifth point of frequency discrimination, first find the frequency of a strong station and press Stereo switch, the stereo light is on, (if it is not on or no sound is normal), use a multimeter to DC gear Connect to TP1 and TP2 respectively, and use a non-inductive screwdriver to gently turn the No. 5 middle circle to make the value 0.
The stereo lights are on and the sound is the best. Generally, you can first turn the number 5 midweek to make the sound come out, three-dimensional
The sound indicator lights up, let's fine-tune again. Generally, 0.58V slowly drops to 0V, which can be fine-tuned with the 6th midweek
At the same time, fine-tuning the multi-turn potentiometer here can also reach about 0.01V.
Slow product)
After the frequency is normal, you can listen normally, and you don't need to debug the others, they have been adjusted
The seventh point adjustable resistor is no longer capable of squelch control in the current four-middle amplifier situation
Connect the 12-meter whip antenna and have a pleasant reception.

Specification:
Material: PCB
Size: 16*7*3cm
Colour: Black

Package Included:
1*Motherboard
1*Display
 
Note:
.Manual measurement, please allow 1-2cm difference! Thank you!