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Blaupunkt test cassette 8 627 000 119

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Forum » Technique, Repair, Restoration, Home construction ** » Tools and measuring equipment, schematic collections » Blaupunkt test cassette 8 627 000 119
           
Roger Dircks
 
 
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11.Jun.09 16:05

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I am looking for a Blaupunkt test cassette (Meßkassette) te for adjusting my ACR 900 Blaupunkt car tape player. The part numer of this cassette is 8 627 000 119. Are these test cassettes still available?

The cassette should contains the following:

  • 3.15 kHz as well as 50 Hz for control of tape speed an sound fluctuations.
  • Noise for head adjustment
  • Test frequencies for amplifier

How can I make such a cassette myself, e.g. by using a PC and a cassette recorder?

Torbjörn Forsman
 
 
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13.Jun.09 00:03

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In the past, similar test cassettes were available from a lot of tape recorder manufacturers and instrument vendors. For instance, Philips, Teac and König were well known.

If you want to make your own test cassette, you should be aware that the recorded signals of a such cassette never can be better than the alignment of the recorder you use.

For tape speed adjustment, the most common frequencies are 50 Hz (for comparison with the mains frequency), 3 kHz and 3,15 kHz (for use with wow & flutter meters or frequency counters).

Apart from using white noise for the head azimuth adjustment, it is also common to use a tone at a frequency near the upper limit of the tape player's frequency range. For instance, the König test cassette has 6,3 kHz , 8 kHz and 10 kHz for this purpose. On stereo tape players, it is best to use a two-channel oscilloscope and adjust the azimuth so that both channels are in phase. Up to ± 45 ° of slow phase jitter is unevitable on all but the most expensive tape decks.

A test cassette also usually has a level reference signal of about 330 Hz, which is used for adjusting the playback gain and, where applicable, the VU meters. This adjustment is very important on tape players with Dolby or similar noise reduction features.

  
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