Guys, I need your precious feedbacks !

Problem 1

I have a 3PK with HRS receiver. Futaba S9451 steering and KO 2144 throttle / brake servos. Symptom is when I get to about 50 feet from my Tx and car, the car looses signal and the throtte servo goes into fail safe mode.

Problem 2

When I swap my HRS receiver to the PCM one, I was able to control the servos like normal after switching from HRS to PCM mode on the Tx.

But if I go like 150 feet away, I find that especially the throttle input is pretty slow. I could notice this from the sound of the engine revs of the engine I get compared to the throttle input I give it. Sometimes, the throttle input seems like it's stuck to partially open and takes some time to get back to neutral position.

Summary

I don't know if the two problems above are related and that would mean either my servo or my Tx module is toast. My suspect with the first one is the antenna wire of the Rx wire is probably broken halfway. As to the second problem, I suspect that my KO throttle servo is a little off !

Any inputs to this is much appreciated.