I experienced some problems I believe are related to this RFC-400. For example, the solid center core is aluminum with what seems to be very thin copper layer. I have a sample of Times Wire LMR-400 on the way (10ft) to check out. I'm going to switch to the flex type this time.
One test I've conducted is with the SWR. Two meters is fine, but using UHF connectors on 440 -- Never again! Unfortunately, I failed to listen and purchased a dual-band, RX-503 with M connectors rather than N's. I failed to read-their-lips! "UHF connectors > 300MHz is problematic!" I just replaced the UHF chassis connector with a N-type on my TM-V71A, dual bander.
-k2qde