What kind of recorder do you have? If a HD DVR then they cannot change the format of the program, your only choice is to record the SD duplicate channel(if one is available), I've done this for programs I know are only SD upconverts when my DVR is getting full.
SD DVDRs reencode HD channels to SD on the fly but they will not be able to directly tune any channel thats scrambled, although you can easily play your HD programs on your DVR and record them realtime(using line outputs) and then delete the program off your DVR freeing up space. A decent DVDR w/hdd starts ~$230 though.
Edit: looks like you have a DTVPal in which case your OTA. In this case your only choice using the Pal would be to record any duplicate SD sub channels. In my market FOX, CW and MyTV have duplicate SD sub channels. Nothing for CBS, ABC and NBC. If you were on cable most of the channels have a SD duplicate channel.
You could use a DVDR w/HDD and digital tuner to directly record things you wanted in SD but again they start >$200