In October 2012 Darryl Scott Donohue was caught offering to pay a "hitman" $10,000 to kill his estranged wife.

Fortunately for Donohue's wife, the hitman was a police officer and the agreement, made in a Penny Royal Hotel room, was part of a police sting.

Yesterday in the Supreme Court in Launceston Donohue, 41, pleaded guilty to inciting to murder and stalking his wife last year.

Donohue wanted his estranged wife gone so he could get access to his children.

He suggested the undercover officer interfere with his wife's pacemaker to make her death look accidental.

He said the body could be dumped off the edge of the continental shelf where "no one would find her", the court heard.

Donohue said he wanted her dead but couldn't do it himself because he still had "feelings for her".

He gave the officer a copy of his wife's routine and her photo.

By this stage police had already advised the woman to leave the state, which she had done.

They began watching Donohue after learning he wanted her dead.

The previous month he had approached a stranger at a barbecue because he had heard the man had "certain capabilities", Crown prosecutor Daryl Coates said in court.

"I've got 10,000 grand cash (sic) and I want my ex-missus knocked off and taken out of the picture," Donohue told the man, who was cooking the barbecue.

Police learnt of the incident and confronted Donohue who denied it.

They organised an undercover officer to pose as a hitman and had his phone number delivered to Donohue.

The meeting at the Penny Royal was set up and secretly videotaped with Donohue telling the officer he could pay for the hit from his superannuation.

He was arrested after the meeting.

Mr Coates said it was premeditated and not in the "heat of the moment".

But it was "fairly amateurish" and always likely to draw the attention of police.

"Wandering up to a person you've never met before and asking them to kill your wife," he said.

Donohue's defence counsel Adrian Hall said the charge "must be less serious than attempted murder".

"It was all talk," he said.

Donohue did not have a serious criminal record and had acted out of frustration at not being able to see his children, Mr Hall said.

He had started to rebuild his life with a new partner - who sat at the back of the court - and take "legitimate steps to access his children rather than kill his wife".

As a mitigating factor, Mr Hall said Donohue had not given the undercover officer a weapon.

"Well you would expect the weapon to be provided by the killer, wouldn't you?" Chief Justice Ewan Crawford said.

"You pay him to kill and let him go about his business."

In what will be one of his last sentences before retiring, Justice Crawford had to look to Victoria for an incite to murder case.

He said he was unable to find one in the Tasmanian court database.

Both counsel also said they believed it was the first of its type in Tasmania.