I've a few "head in the cassette door" walkmen - the DD2 and aiwaPX547 for example - and they suffer from tape movement when the player is rotated in different orientations or by pressing lightly on the lid. This leads to a fluctuation of high frequency or stereo balance (just like adjusting the azimuth screw whilst live) Are there any common things that can fix this in these sorts of units ? I was thinking maybe the door latching or tape holder springs - or maybe it's a loosening of the head assembly wearing over time. I don't remember having this much trouble with them in the 80's.
Hey there, I’ll be including this in my reply to the WM-D3 Calibration Tutorial that @Valentin put together, but one thing I found while checking azimuth was that the WM-D3 I was working on didn’t include the small spring attaching the head block to the door. After each adjustment I would play back the tape and the azimuth would once again be out. After stealing that spring from another of my D3’s and installing, the stability of the azimuth came back. Not sure if they all came with that spring at one point, but I’d imagine so given my experience. If yours does include the spring already, it’s still possible that, like you said, there’s something about the mechanics of that particular section that’s become loose. Can you see any locking compound - blue or red or another color gel-like substance holding in place the azimuth adjustment screw?
Cheers, Taking a look at a Panasonic RQ-JA160 , one of the worst offenders - everything seems to be intact and present. Azimuth screw is well secured, but no spring visible ( I'm pretty sure this has not been serviced ever ) I'm beginning to think it may be the design of the head carriage that's the problem, this shares the same design as the Sony DD2 , an offset carriage made from a white metal alloy with a single pivot location at the top of the head/pinch roller rail. I'm seeing a lot of vertical play from this in both units. It's possible the pivot gets worn out over time. I'll have to do a full strip down of the heads to confirm, which isn't something I've accomplished yet - It's possible a thin plastic washer would tighten it, but I'm speculating now. I had this unit in the late 80's after going through several high end sony's and kenwoods and I'm positive it never waivered like this during movement.
I have to say I never encountered this azimuth instability problem on SONY DD walkmans. @JoFugd Does this problem happen when you tilt the unit or move its position ? Or just by pressing on the lid ? Something that is worth mentioning (because I have seen this in almost all belt driven walkmans) is this: the capstan-flywheel assembly usually has up and down play in its bushing, which will move the tape up and down when tiling the unit. This does create azimuth instability, but in only happens when moving the walkman. Unfortunately, on many models the capstans are secured with a C-clip or cut washer on the top and the only way to reduce this play would be to add another washer underneath it. On devices that have the flywheel secured from underneath, there's usually an adjustment screw for flywheel thrust play adjustment. That needs to be in the range 0.05mm-0.1mm. All the belt driven units I own or have serviced have a play much larger than that from factory (0.5mm-1.5mm). @Evilbunny The head carriage design issue you are talking about is on which unit: RQ-JA160 or Sony DD2 ?
@Valentin - The RQ is the one I'm looking at right now, I'm pretty sure the issue is with the carriage as I can see it happening now. With a transparent tape shell with the cassette lid removed, the head can be seen moving slightly as you tilt the unit. You might be right about the capstan in the Sony though, I know it's not belt driven, but I've serviced it recently and it looks like I may not have secured it properly.
I see. It would be interesting to see some pictures with the problem. Regarding the problem with the capstan, I only encountered it on belt driven walkmans, not on DD (in those the thrust play is within service manual specification).
I'm jumping the gun with the Panasonic, I'll give it a basic service before I check again , there's a lot of play in the hinges so it's possible there's a screw loose somewhere - although I have to say it's a well engineered device.
