I have a few questions I'd like to ask the experts.
I am currently using a Diamond 771+ with a Winlink N76, and I want to increase the range (reach) for connecting to a repeater. However, due to objective limitations, I cannot increase the antenna height.
1. I've seen many people say that car mats are good, and that using car mats can improve connectivity. Are they made of glass fiber material, and does this affect their performance?
2. Although increasing power doesn't seem to have a significant effect, I was wondering if it's worth buying a power amplifier and using 25W.
Geographic conditions: I live on the fourth floor, which is quite far from the repeater (probably around 40-50 kilometers), and the highest building in the school is five stories. The surrounding buildings are mostly low-rise (around six stories), with few high-rise buildings (20-30 stories). However, there is a large telecommunications building (very tall, inaccessible, and blocked by security personnel).
I haven't been able to make contact with a repeater yet, but I can receive the signal from the repeater clearly. I can also work local repeaters (power unknown, but they have good elevation).