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7. When to take breaths:
One must take a breath between each blow. Each individual blow must be done in one breath. The Shevarim- Teruah of Tashrat is to be done in one breath, although making a small break between the Shevarim and Teruah. In Musaf the Shevarim-Teruah of Tashrat is to be done in two breaths although one is not to delay more than the amount of a single breath between the two blows.
 Admur 590:8-9