Fta channel records scrambled ?

[darrenduds20]

For some reason when i record on the history channels i get a stuttering and blocky/ jumpy picture . Its fine when i watch the channels but records like it doesnt have much signal . Anyone know why ?
snr - 85
agc 85

[darrenduds20]

Anyone ? The picture is perfect when watching the channel but not when its recorded

[Peterj]

Is it recording from the same tuner as the one you are watching?

[chaser]

Also, are you recording / playing back from a network location or a local HDD / USB?