82161A Digital Cassette with Audio Tapes?

[Les Bell]

Has anybody ever tried modifying audio dictation cassettes to work in the 82161A Digital Cassette Drive? I chanced to pick up some Phillips mini-cassettes from an office supply store, and they're mechanically near-identical to the HP digital cassettes, except for a notch cut in the opposite edge of the case to the heads opening. This aligns with a projecting tab in the drive recess, so that the digital cassettes will fit while the audio tapes won't.

Naturally, this has got me thinking. . . But before I do the experiment, I thought I'd ask if anyone else has done it first. I'm hoping that recently-manufactured high-quality audio tapes might be as good or better than aging salvaged digital tapes. The prudent course of action would be to cut a notch in one or two of the dictation tapes in order to test a) whether it works at all and b) the reliability. Only if results are good would I consider taking a scalpel to the drive itself.

Thoughts, everyone?

[cgh]

Hi Les,

I think I got the same cassettes from Phillips when I bought my HP-82161A. But, the cassettes did not enter into the digital tape reader. The seller said to me that these cassettes were used by his father and they stood into the box with the HP digital tapes.

I will have a look to the Phillips tapes to see if there is a notch cut on the tapes.

[Les Bell]

(05-23-2015 08:22 AM)cgh Wrote:  But, the cassettes did not enter into the digital tape reader.

What happens with the audio tapes is that they slide into the pop-up cover of the drive, which carries the tape, but then the cover won't close because of the projecting flange in the tape compartment.

(05-23-2015 08:22 AM)cgh Wrote:  I will have a look to the Phillips tapes to see if there is a notch cut on the tapes.

What you should find is a notch cut (actually, molded) in the digital tapes - no notch in the audio ones.

Unfortunately, I'm frantically busy with marking this weekend, so I probably won't get a chance to experiment until the end of the coming week.

[Paul Berger (Canada)]

One thing that is likely missing on the audio tapes is the holes to sense EOT and BOT, nor is it likely to have the small 45 degree mirror that reflects the light through that hole to the sensor.

I am not sure which tape you are referring to but I just compared a 82161A cartridge to a Sony MC-90 and the spacing of the holes for the spools is even different.

[Raymond Del Tondo]

(05-24-2015 03:46 AM)Paul Berger (Canada) Wrote:  One thing that is likely missing on the audio tapes is the holes to sense EOT and BOT, nor is it likely to have the small 45 degree mirror that reflects the light through that hole to the sensor.

I am not sure which tape you are referring to but I just compared a 82161A cartridge to a Sony MC-90 and the spacing of the holes for the spools is even different.

The HP data tapes and the audio tapes from other vendors may also have a different magnetic coercitivity, so even if they'd match physically (which I doubt), audio tapes (what tapes for dictation machines are) will be incompatible to the HP 82161A.

[Les Bell]

(05-24-2015 03:46 AM)Paul Berger (Canada) Wrote:  One thing that is likely missing on the audio tapes is the holes to sense EOT and BOT, nor is it likely to have the small 45 degree mirror that reflects the light through that hole to the sensor.

I am not sure which tape you are referring to but I just compared a 82161A cartridge to a Sony MC-90 and the spacing of the holes for the spools is even different.

You're absolutely right, Paul - I hadn't noticed that. They're quite different at the heads end of the case, there's no EOT/BOT holes, no mirrors, etc. I guess that kills that idea.

[Paul Berger (Canada)]

(05-24-2015 04:09 AM)Raymond Del Tondo Wrote:  The HP data tapes and the audio tapes from other vendors may also have a different magnetic coercitivity, so even if they'd match physically (which I doubt), audio tapes (what tapes for dictation machines are) will be incompatible to the HP 82161A.

That is true, however at least one member of this forum successfully replaced the media in a HP cartridge with audio tape, but I do not remember what sort of tape he used as there where different audio tape media coating each with a different coercitivity.

[Mark Hardman]

(05-24-2015 12:35 PM)Paul Berger (Canada) Wrote:  

(05-24-2015 04:09 AM)Raymond Del Tondo Wrote:  The HP data tapes and the audio tapes from other vendors may also have a different magnetic coercitivity, so even if they'd match physically (which I doubt), audio tapes (what tapes for dictation machines are) will be incompatible to the HP 82161A.

That is true, however at least one member of this forum successfully replaced the media in a HP cartridge with audio tape, but I do not remember what sort of tape he used as there where different audio tape media coating each with a different coercitivity.

Here's the old thread with Diego's method and results:

82161A Mini cassettes

[Les Bell]

(05-24-2015 03:53 PM)Mark Hardman Wrote:  Here's the old thread with Diego's method and results:

82161A Mini cassettes

Interesting . . . I'm not sure whether the tapes I've got are CrO2, but I might hang on to them, just in case. The big problem with the 82161's tapes so far has just been the pressure pad becoming detached, but if the tape itself ever dies, it would be worth trying a transplant.

Thanks to all.