This model number corresponds to an old Optimus AM/FM/TV/SW multi band portable that covers 3.8-12.5 mhz. In broadcasting terms (in North America, anyway), that would include the 49, 41, 31 and 25 meter bands. There are transmissions in certain segments of the bands (like 3.8-4.0 mhz) that use a mode that the radio won't copy, and will sound like distorted voice.
These 2 links from DXing.com will help explain the bands a little bit.
Frequency Vs Wavelength
Tuning 150 kHz to 30 MHz
Due to how the sun interacts with the upper regions of our atmosphere known as the ionosphere, certain bands are open during the day, others at night. As we get closer to the summer months, the 25 m band will begin to stay open later and later. 31 is something of a transition band - it can be open day or night, depending on exactly where the signal happens to be coming from at the time. 41 and 49 are primarily nite time bands.
You would probably benefit from a very short wire clipped to the whip - however don't make it too long, or overloading will likely result. This is easy to spot - stations showing up in odd parts of the dial are a prime indicator. 10 or 15 foot tops.
As for stations - this greatly depends on what time of day or night you are listening, and what the time is at the target station. In general, for you to have a chance at hearing a station, both you and the station must be in the same daylight zone; either both in darkness, or both in daylight. This is deliberately a broad generarlization; this can be a fairly complex topic, but you really don't need a degree in solar physics to understand it. This website gives a pretty good introduction into the topic of HF propagation...
Propagation Primer - Flash Movie by AE4RV
Make sure you have your Flash software up and running.
I think that's enough for now - please feel free to ask more questions - that radio will allow you to hear the stronger stations such as the V of America, BBC, Iran and more - but how and where to look is a much more detailed topic...(and please folks, let's not blow his mind with the master spreadsheet just yet...)
best regards..Mike