There is different varistor tuning required for 1/2 inch reels on the
ATR-100 (than that which is... for 1/4"). When you calibrate the session
tension, you aim for performance which favors one or the other width tape.
This will cause twice the tension for 1/2" tape in forward and reverse
modes. If you use 1/4" reels with the machine calibrated for a 1/2"
session, or vice versa, there will is the possibly of issues with packing
and or cue-ability.
The machine tries to keep constant tension on both sides of the
pinch-rollerless capstan. When I unwind a small reel (that is "tails out"),
I use a matching size empty reel for (playback) "supply," just to make it
simpler for the logic. Might not matter, since it has to sample and
resample the whole time, but I don't want to make it think too hard. (L;
I tried using plastic, locking NAB adapters figuring that they would
hold the reel more stable with the shaft rotation. But this proved in some
cases counter-productive. Best action on my model was with the mash down
holders, since they hold it down well, while still allowing "micro-slip"
during the odd, momentary servo spasm. Also, the alu reel hold downs are
meant to conduct static to ground - at least that's what I've read.
On 6/15/12 6:54 PM, "Goran Finnberg" <[log in to unmask]> wrote:
> Alex Kroh:
>> I am using an ATR-102 that has very sensitive and
>> unforgiving tensioning system and I have noticed
>> that it doesn't handle too little weight very well.
>> In fact, it won't play back 7'' reels without the
>> added weight of the NAB adaptors. However, it does
>> handle 5'' reels seemingly without compromise while
>> using the NAB adaptor.
> You are drawing the wrong conlusion here.
> If there is any movement whatsoever between the reel and the motor shaft in
> servo tension controlled tape machines such as Ampex ATR102 and the Studer
> A820 then the servo will misbehave badly.
> The mash down NAB adaptors used in the ATR102 will see to it that the
> plastic reels are securely bonded to the reel motor mounting plate thus
> there will be no movement between the motor shaft and the actual reel.
> Thus reel weight has nothing at all to do with the observed misbehaving of
> the ATR 102 servo system.
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