Another tool I've found indispensable for setting up and troubleshooting phased vertical RX arrays is a two-port VNA. I use an Array Solutions VNA-2180 (now discontinued) for critical measurements. I also have a NanoVNA H4 (https://nanovna.com/) which is a very "affordable" VNA that can be used as a portable, handheld, standalone instrument and that you can take out in the field. In most cases, the NanoVNA H4 is more than good enough.
There is a learning curve to using a VNA. However, once you learn it, you'll be able to make very accurate measurements of delay line lengths, preamplifier gain and phase, phase combiner gain and phase. Most VNA's also have a TDR function, although it is usually based on frequency domain measurements that are transformed to the time domain. I'm running a homebrew RX array and it would have been almost impossible to get it running as well as it is now without a VNA. 73, John W1FV _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector