Hello All I have a R-1051F/URR and I need to change one of the tubes, but nothing I have tried worked. I have also tried to get a R-390 tube puller, they seem to be truly rare. I tried to use heatshrink, and it just slides off when you apply heat. I don't know what to do. Any ideas? BTW if there is anyone with a manual for the my R-1051F please hollar Best of 73's Lee.