I have heard a lot of old school hobos eschew the use of scanners, claiming that you won't hear anything useful. I would beg to differ. For me it's been worth the weight and the hassle of having another thing to charge. I bought a cheap little baofeng (don't buy something fancy that you'll be upset about breaking when you drop it from a train) and it's been indispensable to me. I don't like getting on the wrong train, so being able to ID trains is really important. There are a lot of ways you learn to ID intermodal trains, but junk trains are not as easy to figure out. As a working example, from Allentown to Harrisburg(Enola yard), you want to get on the H73 train (https://railroadfan.com/wiki/index.php?title=NS_Train_Symbols). How do you know which of the junk trains leaving that yard are H73? Well you could rely on the time that train is supposed to leave, but if you have been at this a while, you should probably know by now that trains don't always leave when they are supposed to. There are actually several trains that leave within a few hours of each other and they don't all go to Harrisburg. You can rely on distinguishing features. H73 will often have several gondolas, porchless grainers, coal cars and if you are lucky a couple canadian grainers. Thats not terribly reliable though because sometimes it has car racks as well. Sometimes it's almost entirely grainers. It's not always the same train composed of the same cars. What has helped me every time is to listen to the scanner frequency for the yard (In this case 160.860 seems to be the best channel to listen on for ID's). They (usually) ID the train at the time of departure. If they say something about H73 or Harrisburg during the departure and it is close to around the time it should be leaving, you can be pretty certain that is your train. It always feels good to get some confirmation about a train before you get on it and it turns off in some direction you hadn't planned to go in.