
Dismantling Jing Tong JT-208 and Mic Modification
Introduction
Update - January 2008 - VK2FHHS kindly pointed my to a very nice description of the Mic Mod which includes some useful tips for getting it apart - Thanks.
January 2nd 2006- Following on from Jing Tong JT-208 VHF Hand Held. Received some helpful notes from Dave G3VFP. After a Seagram Gin and Tonic (Tesco's Tonic with a hint of lemon.. not my favourite Tonic and as for the lemon! let's not even go there). I started prising things apart.
Dave G3VFP - "Well it isn't too difficult to take apart, just be careful that you don't lose the fittings around the ear socket and ptt in the process hi.

Remove the knobs, then you can remove the top surrounding cover by inserting a finger nail between the top cover and the radios body shell, and gently prising it out of the guide it sits in.
Then with the same dexterity, or using a small screwdriver blade, start to prise the plastic cover away from the metal heat sink chassis, and the two upper halves of the case apart. They snap together as you will see. No screws need removing at all.

I only use the radio to monitor my gateway frequency, so don't depend on
it's audio quality particularly. Making the hole above where the mic insert
sits definitely improves the tx audio. Although if you don't want to do anything
that drastic, the remote insert and earphone do work
well too. I modified a Nokia type remote unit to plug into it.
I am including a drawing which shows you where the hole actually is located. Looking at the name JINGTONG the hole centre is to the left of the J, and the diameter of the hole is the same height as the letters, about 4.5 or 5mm, and the right hand edge of the hole comes to the centre of the vertical part of the J. You could drill in from the top cover, but if you do, make sure you have everything secured so that you don't penetrate through the outer cover more than a millimetre, as the insert sits below it.
Food for thought anyhow Nicolas. Course if you slip, don't blame me hi.
Cheers,
Dave."
January 8th - Mic Mod - Removed the covers and drilled the case, found the speaker wires had both broken off, and one of the soldered posts that holds the two main boards together had come away. I expect this is a result of even very gentle prising apart.. I unsoldered the other pin and the two main boards then easily unplugged from each other.
Main Board | |
CHMC S46 D386 | Unknown |
Second Board | |
EM78P447SAM-G | High Speed 8-bit RISC Microcontroller equipped with 1K*13-bits Electrical One Time Programmable Read Only Memory (OTP-ROM). |
RC 4558 | Dual General-Purpose Operational Amplifier. |
ATMEL 420 24C08AN SI27 |
Unknown |




