Redknapp, who has hardly set the Toon alight with antcipation since being linked with the Newcastle manager´s job, admitted he would have found it hard to sleep at night if he had joined the Magpies.
Despite being offered what he described as a "fantastic opportunity" he decided to stay at Pompey.
Redknapp: "It's not all about money. People don't know me but money is not my God. I'm happy, I enjoy it here and I have a great relationship with the fans," he said.
"It would be difficult to sleep at night. You have to look at yourself and say 'the club's been good to me and I've got to pay them back'.
"This is a club I feel comfortable at. I have a fantastic relationship with the fans, a fantastic relationship with the owner and with Peter (Storrie, chief executive).
"When you bring in players - and I signed a lot of good players in the summer with some terrific backing from the owner (Sacha Gaydamak) - some of them could have gone to big clubs. To walk away half way through (the season) is the wrong signal; it's not fair. My heart is with Portsmouth.
"I had no intention of leaving here. The job now is to take this club forward.
"I had a great offer from them and to be offered the chance at a fantastic club like Newcastle was a terrific opportunity for me but at the end of it I couldn't do it.
"The owner (Mike Ashley) seems to me to be the most ambitious guy you could hope to meet and they are good people up there.
"Newcastle is a massive club with great supporters - they get 50,000 every game and it's a great job for somebody, but I won't be going.
"The fans have been good to me and I've had to win them back when I left once before. Only a maniac would have done what I done, go up the road and come back again.
"I'm very ambitious, football is my life but my ambitions are all for Portsmouth."