Cassette tape speed adjustment
in [Repair]
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From: N_Cook on 8 Dec 2009 11:32 Assuming my test tape is stretched (I doubt it , as it would have to be even stretch the whole length). I normally test speed monaurally so the beats are unmistakable. That is 1KHz test tape output and floating accurate 1KHz sine signal both fed into one headphone cup. Easily gives 0.1 percent resolution (assuming test tape is ok). If I record accurate 1KHz tone onto a blank tape for exactly ( to human reaction time accuracy) 100 seconds. Then replay for beats of 1Hz or so and output lasts for 100 seconds +/- reaction time then is the speed correct? I suspect that repeating this process with the speed regulator changed , say 5 percent, would also give "correct" speed, that time also Does anyone know how much effect types and thickness (play duration C30 to C90) have on replay speed perhaps in conjunction with too soft or too hard pinch wheel rubber ?
From: AZ Nomad on 8 Dec 2009 12:04 On Tue, 8 Dec 2009 16:32:52 -0000, N_Cook <diverse(a)tcp.co.uk> wrote: >Assuming my test tape is stretched (I doubt it , as it would have to be even >stretch the whole length). >I normally test speed monaurally so the beats are unmistakable. That is 1KHz >test tape output and floating accurate 1KHz sine signal both fed into one >headphone cup. Easily gives 0.1 percent resolution (assuming test tape is >ok). >If I record accurate 1KHz tone onto a blank tape for exactly ( to human >reaction time accuracy) 100 seconds. Then replay for beats of 1Hz or so and >output lasts for 100 seconds +/- reaction time then is the speed correct? I >suspect that repeating this process with the speed regulator changed , say 5 >percent, would also give "correct" speed, that time also >Does anyone know how much effect types and thickness (play duration C30 to >C90) have on replay speed perhaps in conjunction with too soft or too hard >pinch wheel rubber ? none at all.
From: Ron on 8 Dec 2009 12:07 AZ Nomad wrote: > On Tue, 8 Dec 2009 16:32:52 -0000, N_Cook <diverse(a)tcp.co.uk> wrote: >> Assuming my test tape is stretched (I doubt it , as it would have to be even >> stretch the whole length). >> I normally test speed monaurally so the beats are unmistakable. That is 1KHz >> test tape output and floating accurate 1KHz sine signal both fed into one >> headphone cup. Easily gives 0.1 percent resolution (assuming test tape is >> ok). > >> If I record accurate 1KHz tone onto a blank tape for exactly ( to human >> reaction time accuracy) 100 seconds. Then replay for beats of 1Hz or so and >> output lasts for 100 seconds +/- reaction time then is the speed correct? I >> suspect that repeating this process with the speed regulator changed , say 5 >> percent, would also give "correct" speed, that time also > > >> Does anyone know how much effect types and thickness (play duration C30 to >> C90) have on replay speed perhaps in conjunction with too soft or too hard >> pinch wheel rubber ? > > > none at all. Tape speed depends on the rotational speed and diameter of the capstan. On a properly maintained deck all other factors are irrelevant. Ron(UK)
From: Arfa Daily on 9 Dec 2009 04:35 "N_Cook" <diverse(a)tcp.co.uk> wrote in message news:hflv4c$p04$1(a)news.eternal-september.org... > Assuming my test tape is stretched (I doubt it , as it would have to be > even > stretch the whole length). > I normally test speed monaurally so the beats are unmistakable. That is > 1KHz > test tape output and floating accurate 1KHz sine signal both fed into one > headphone cup. Easily gives 0.1 percent resolution (assuming test tape is > ok). > > If I record accurate 1KHz tone onto a blank tape for exactly ( to human > reaction time accuracy) 100 seconds. Then replay for beats of 1Hz or so > and > output lasts for 100 seconds +/- reaction time then is the speed correct? > I > suspect that repeating this process with the speed regulator changed , say > 5 > percent, would also give "correct" speed, that time also > > > Does anyone know how much effect types and thickness (play duration C30 to > C90) have on replay speed perhaps in conjunction with too soft or too > hard > pinch wheel rubber ? > > I just use a speed test tape from Konig. It has a strobe wheel behind what would normally be the tape viewing window. Very easy to see an accurate setting for the speed, and virtually instant comparison between forward and reverse. Also easy to see any cyclic variations in speed, or long term drift. Arfa
From: N_Cook on 9 Dec 2009 06:32
Arfa Daily <arfa.daily(a)ntlworld.com> wrote in message news:vbKTm.64350$Dl4.48926(a)newsfe08.ams2... > > "N_Cook" <diverse(a)tcp.co.uk> wrote in message > news:hflv4c$p04$1(a)news.eternal-september.org... > > Assuming my test tape is stretched (I doubt it , as it would have to be > > even > > stretch the whole length). > > I normally test speed monaurally so the beats are unmistakable. That is > > 1KHz > > test tape output and floating accurate 1KHz sine signal both fed into one > > headphone cup. Easily gives 0.1 percent resolution (assuming test tape is > > ok). > > > > If I record accurate 1KHz tone onto a blank tape for exactly ( to human > > reaction time accuracy) 100 seconds. Then replay for beats of 1Hz or so > > and > > output lasts for 100 seconds +/- reaction time then is the speed correct? > > I > > suspect that repeating this process with the speed regulator changed , say > > 5 > > percent, would also give "correct" speed, that time also > > > > > > Does anyone know how much effect types and thickness (play duration C30 to > > C90) have on replay speed perhaps in conjunction with too soft or too > > hard > > pinch wheel rubber ? > > > > > > I just use a speed test tape from Konig. It has a strobe wheel behind what > would normally be the tape viewing window. Very easy to see an accurate > setting for the speed, and virtually instant comparison between forward and > reverse. Also easy to see any cyclic variations in speed, or long term > drift. > > Arfa > > Strobing of what rotational part against what reference? How do you know if the tape is stretched? |