Sony HST-49A Repair!:

The vintage Sony Cassette Receiver repair series on my Youtube channel is gradually getting done, but its taking way longer than expected. I have just started filming part 6!!! Hopefully, this will be the last part... Check it out on my youtube channel:- Warf's Workbench

Info & Prelude:

The Motorola T82 Extreme is quite a nice 16 channel PMR446 handset, but it does have some stupidly annoying things. There is a 1 minute TOT (transmit Time Out Timer) which you can't extend or disable. You cannot turn the volume completely down and the display goes off after 10 seconds, leaving a tiny digit that flashes on once every few seconds. It looks like the radio is turned off. It's supposedly for power saving, but I'm sure it wouldn't take much more energy just to leave that tiny digit illuminated all the time. If I had the choice I would leave the display illuminated, but dim it right down. It's an LED display so it can't use that much power, especially if its dimmed down, so this is one power saving step too far.

All the info on this page was worked out by me, on radios with version 1 and version 3 mainboards. At this stage, I don't know if radios with version 2 mainboard will respond as the v1 or v3.

The Motorola Talkabout (not TLKR) T82 Extreme has a micro USB port which you can use to charge the 700mAh battery pack. I put some standard NiMh cells and was puzzled why it would not charge them.

I looked at pictures of the rechargeable battery pack, to see if there was any clues as to how the radio detects it has a rechargeable pack in it

There was nothing obvious, and I pondered the problem for a few moments, then it came to me. The radio detects voltage across the middle cell, which is not connected when the rechargable pack is used.

So, to get the radio to charge standard NiMh cells we just need to disconnect one end of the middle cell from its contact in the radio. However, that connection is also linked to the adjacent cell and thats how the cells are connected together. We need to electrically link the 2 cells together, then isolate them from the radio contacts.

I have tested this and it works, but have not actually done the job yet. One thought is to use a thin piece of metal from a drinks can or something, stick some insulating tape on one side and wedge it in. This should create a good solution, without needing to do any permanant modifications to either the radio or battery pack.

EDIT 27/06/2020: I have now done the job. I used some aluminium foil tape (as used to seal air conditioning ducts and stuff), I left the backing paper on one side and cut it to fit, placed it in the radio (paper side facing the radio contacts) and carefully re-installed the NiMh cells. It works perfectly and with the tape/paper being so thin, it doesn't affect the radio detrementally in any way.

An elegant and effective solution, though the alu-foil tape is quite expensive. Thankfully I had some here from a previous repair to my air-con ducting.

IMPORTANT UPDATE 15/10/2021: There is a more permanent way to do this mod, which works better and more reliably(the alu-foil tape sometimes gives poor connection).

To do the mod, you need to open the radio and simply unplug the wire connected to the middle cell.

This also disconnects the 2 charge points which are used when you put the radio in a charge dock, but since you are doing a mod to be able to charge from a USB cable, you probably wern't using them anyway.

If you do intend using a charge dock, just de-solder (or cut) the wire connected to the middle cell.

The Motorola Talkabout T82 Extreme is a 16 channel radio, but when you receive it you may be disapointed to find it only has 8 channels.

The other 8 channels need to be unlocked by the user if it is legal in their region. Its a way that Motorola can ship the exact same radio to all countries and dont have to make different radios for each region.

To unlock the full 16 channels; turn the radio on, press the menu button once so that the channel number flashes, then immediatly press and hold both the + and - buttons, after about a second the radio will display 16 CH. That's it, your radio is in 16 channel mode. However, be sure you want the radio in 16 ch mode, because at the time of writing this, there is no known way to revert the radio back to 8 channel mode

Turn the radio off, Press and hold both the Menu button and the Lock button, then turn the radio on, then once you have noted the firmware version release the buttons. The radio should display a big U on the top line (U = V for version) and then a number on the bottom line such as 012.

Update 14/12/2024:This only works on radios with version 1 (& possibly 2) mainboards.

This only works on radios with V3 (& possibly 2) mainboard, to check, try getting the firmware version as above. If the radio gives you its version number this won't work for you.

Turn the radio off, Press and hold both the Easy Pairing button (side of radio above emergency button) and the Lock button, then turn the radio on. When the channel number is displayed, release both buttons and press the Easy Pairing button again. The radio should display 2 on the top line and 101 on the bottom line.

Pressing Easy Pairing again will cycle through menu options which are:
2 101
P1 0-1
P2 1
P3 92
P4 19
P5 5
P6 5
P7 120
00 -00
Full Display
PA ON
Pb 160

Most values can be changed by pressing the + or - buttons. What each option does is currently unknown, so be careful messing around because you could destroy your radio if you do something you shouldn't.

The FULL DISPLAY seems to be a brightness control, it shows 883 at the bottom, the 3 changes when +- are pressed and display brightness changes. Also in this option RX flashes when any button is pressed.

When you have finished looking at all menu options, turn radio off and on again to enter normal mode.

Update 20/12/2024: I have now tried changing some settings, but they always seem to revert to standard when you re-enter the menu. Nothing I did would get my changes to stick, so I don't know whats going on and to find any information from Motorola is entirely impossible.

This is by design, for some reason the Motorola engineers decided not to allow you to turn the radio fully down. This is very annoying and I cannot understand their logic for doing it.

The Fix: In Version 1 (& possibly V2) radios, you can simply short the bottom end of the volume pot to ground. This bridges out the resistor they added to stop it turning down fully.

For Version 3 radios, bridging the pot to ground does not work, so they have changed the way it works. I will be investigating this sometime soon.