I have been using a ChannelMaster 2001 antenna for almost five years with great success. About two months ago one channel (KVLY-DT) began having tuning issues. The signal strength will go from almost 80% to zero and back again and it stutters cutting in and out. Most of the time is bounces between 70-80%. The 2001 is a pretty small antenna so I upgraded to a CM 2018 and it did increase the signal strength but it still cuts in and out. The transmitter for KRDK-TV is literally less than 2 miles from KVLY-DT and it has a solid 98% signal strength.
Signal report
The CM 2018 antenna is mounted on my chimney about 25ft above the ground and aimed directly at the KVLY tower.
The coaxial is about a 75ft run into the house where it runs into a 8-port distribution amplifier left over from when we paid for cable.
When I installed the new 2018 I used the existing transformer and coaxial.
Any help is greatly appreciated!
Fun fact: The KVLY and KRDK towers are the two tallest man-made structures in North America and third and fourth tallest in the world!