Panasonic RQ-CW03 portable cassette player belt change and speed adjustment
2024-Jun-19, Wednesday 12:02 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
chebeThe Panasonic RQ-CW03 portable cassette player is a basic (stereo) tape player from the turn of the millennium. It plays tapes, even has an extra-bass switch, but that's it. No recording, no radio. I remember having to go out and buy this, because I had moved on to CDs, but unfortunately my Irish language exam prep hadn't. As a result, this has largely sat in a drawer unused, slowly yellowing, since that exam. And, predictably, when I last pulled it out to listen to some tapes it was no longer functioning.
One of the benefits of transparent housings is that you can see when the belts have come loose without even having to open it up. So even before picking up a screwdriver I ordered replacement belts.
Once they arrived it was time to get stuck in. It's really simple; remove any batteries, and then there are four phillips head screws (eye-glasses or mobile phone repair kit sized) on the back. The back half of the blue housing has clips into the white centre on both of the long sides. I found the easiest way to open it is to apply pressure on the battery-compartment side, towards the belt clip, and then it just slides apart. Lo and behold, one of the belts had stretched so much it had slipped off the gear. The other was overly loose as well. Good thing I'd gotten replacements.
But before we get to work, since we're here and all, let's have a look at the other side of the circuit board. It isn't held on with anything (just supported by four stand-off posts), but the tight wiring allows for limited manoeuvrability. (You'll notice one half of the battery connections is directly attached to this board, which will come up later.)
Okay, let's get those old belts off, and replace them with the new belts. It is just a case of making sure you know exactly which narrow grooves on which wheels they need to go into. The larger, lower belt needs to go on first, then the shorter one. Making sure there are no twists in the belts. Then when you turn one of the three belted wheels the other two should move as well. Job nearly done.
If you change the belts, you need to check the playback speed. We already learned how to do this with the Bush KCS-317 cassette recorder. You need a speed calibration tape, and then just to follow the instructions.
This player does actually have a speed adjustment trimpot as described in the speed adjustment instructions. But it is on the underside of the board. To have access to it you need to have the board out and flipped over, which leaves the battery terminals out of a useful configuration. Which is a problem because I need to be playing the tape to adjust the trimpot accurately. So I had to get creative with my power set up. Enter crocodile leads. I have an external 4xAA battery pack, so removed two of batteries and jumped those slots with crocodile leads, and then clipped onto the cassette players power terminals. While having the audio output next to the measurement app.
A delicate arrangement but workable. Unfortunately, every screwdriver I had was either too big or too small for the trimpot, except, oddly, the one on my Leatherman (Free T2). It fits almost perfectly, like, suspiciously so. A bit like how the Bic biros are (still) exactly the right size and shape to wind the cassettes. But I'm lucky it did fit as it enabled me to adjust the speed, which was wildly out.
Then I partially reassembled the player, and tested with a music tape. The extra-bass still works, but the volume pot is scratchy. I hit it with some electrical contact cleaner spray, worked the wheel back and forth, and let it dry. Cleared that crackling right up.
And this friends is everything I remember tape being. The sound is amazing, and the extra bass mode really delivers. All while conveniently attached to my belt/waistband. I think it's incredibly sad that this quality of player is no longer readily available. Especially considering the low cost of it when brand new. But I'm delighted to have mine working again!
Front of the RQ-CW03
Photo by chebe
Back of the RQ-CW03
Photo by chebe
One of the benefits of transparent housings is that you can see when the belts have come loose without even having to open it up. So even before picking up a screwdriver I ordered replacement belts.
Back of the RQ-CW03, belt clip removed
Photo by chebe
Once they arrived it was time to get stuck in. It's really simple; remove any batteries, and then there are four phillips head screws (eye-glasses or mobile phone repair kit sized) on the back. The back half of the blue housing has clips into the white centre on both of the long sides. I found the easiest way to open it is to apply pressure on the battery-compartment side, towards the belt clip, and then it just slides apart. Lo and behold, one of the belts had stretched so much it had slipped off the gear. The other was overly loose as well. Good thing I'd gotten replacements.
The belt mechanism and one side of the circuit board
Photo by chebe
But before we get to work, since we're here and all, let's have a look at the other side of the circuit board. It isn't held on with anything (just supported by four stand-off posts), but the tight wiring allows for limited manoeuvrability. (You'll notice one half of the battery connections is directly attached to this board, which will come up later.)
The other side of the circuit board
Photo by chebe
Okay, let's get those old belts off, and replace them with the new belts. It is just a case of making sure you know exactly which narrow grooves on which wheels they need to go into. The larger, lower belt needs to go on first, then the shorter one. Making sure there are no twists in the belts. Then when you turn one of the three belted wheels the other two should move as well. Job nearly done.
Replacement belts in place
Photo by chebe
If you change the belts, you need to check the playback speed. We already learned how to do this with the Bush KCS-317 cassette recorder. You need a speed calibration tape, and then just to follow the instructions.
This player does actually have a speed adjustment trimpot as described in the speed adjustment instructions. But it is on the underside of the board. To have access to it you need to have the board out and flipped over, which leaves the battery terminals out of a useful configuration. Which is a problem because I need to be playing the tape to adjust the trimpot accurately. So I had to get creative with my power set up. Enter crocodile leads. I have an external 4xAA battery pack, so removed two of batteries and jumped those slots with crocodile leads, and then clipped onto the cassette players power terminals. While having the audio output next to the measurement app.
Speed adjustment test setup
Photo by chebe
A delicate arrangement but workable. Unfortunately, every screwdriver I had was either too big or too small for the trimpot, except, oddly, the one on my Leatherman (Free T2). It fits almost perfectly, like, suspiciously so. A bit like how the Bic biros are (still) exactly the right size and shape to wind the cassettes. But I'm lucky it did fit as it enabled me to adjust the speed, which was wildly out.
Then I partially reassembled the player, and tested with a music tape. The extra-bass still works, but the volume pot is scratchy. I hit it with some electrical contact cleaner spray, worked the wheel back and forth, and let it dry. Cleared that crackling right up.
And this friends is everything I remember tape being. The sound is amazing, and the extra bass mode really delivers. All while conveniently attached to my belt/waistband. I think it's incredibly sad that this quality of player is no longer readily available. Especially considering the low cost of it when brand new. But I'm delighted to have mine working again!
Speed trimpot adjustment procedure
Photo by chebe
