Sonny Day, 56, of no fixed address, pleaded guilty in the Hobart Supreme Court to three child pornography charges.

Day was caught following a covert operation that began after he was released from jail in June.

In August, Day booked into a backpackers' hostel where he met Danny, an undercover Tasmania Police officer.

In their conversation's Day spoke of a three-year-old girl at the hostel, claiming they had "the hots for each other", the court heard.

Day showed the officer, who was wearing a wire, child exploitation material on his phone.

Day had previously been jailed in December 2010 on 66 child pornography charged, which former Justice Alan Blow described as a particularly "bad case".

"He apparently developed a strong interest in child pornography because it gave him an outlet that involved online contact with like-minded people, unaccustomed popularity, and unaccustomed status amongst the users of child pornography websites," Justice Blow said during sentencing.

At the time of his latest offending Day had a 2 1/2 year sentencing hanging over his head if he breached his bond.

This week Justice Shan Tennent ordered he serve out that sentence.

For his fresh offences, Justice Tennent sentenced him to 1 1/2 years' jail.

Day will be eligible for release in August 2016 on condition he pay $2000 and agree to be of good behaviour for three years.