Why no signal occurs on some channels in DISH

If your DD free dish is getting half channel, no signal is coming on half channel. This means the signal in your dish is low. There is no signal at some 1 ferqincy. To fix that, you have to press the signal button from your remote. The signal will be displayed in front of you. If you do not know about it, you can see in the image below, if you want to buy it, you can also buy it from the link below.