I bought an SDR jumper a few months ago but it seems the connector has slipped off from the jumper coax. What would be the best way to perminately fix this? I tried to reheat the shrink wrap on it but it just keeps sliding off
Buy another jumper. That is the easiest way. Those jumpers use RG-174. I'm assuming the BNC side is the side that had slipped off, it's far easier to just buy another.
It's a series of two crimps that holds the connector together. One on the center pin and one on the shield. Your conductor had been broken you have replace the bnc connector. Usually cheaper and easier just to purchase a replacement pigtail.