Can I connect multiple signal boosters (like Hawkings HSB1) and a high-gain antenna together to get an even stronger signal?
It all depends on how strong a signal your current equipment has. To stay within FCC requirements, signal boosters limit their output power to 30dBm or 1W (or in the HSB1’s case, 20dBM or 0.5W). If one booster amplifies your signal up to its limit, adding another won’t help and could hurt by distorting the signal and raising the error rate. Depending on the signal booster design, you could also damage the second booster by overloading its input. Adding a higher-gain antenna, on the other hand, will increase gain, no matter what the power level, since its gain doesn’t use active (powered) amplification and doesn’t have power output limiting.