I’ve been thinking of ways to get more power to W3GMS, and coax might be the weakest link. I have about 75ft of RG-58 outside and maybe 8 ft of RG-174 inside. I took down the flag pole Yagi to replace the coax.
I learned how to measure loss with a “through measurement” on the nanoVNA watching Youtube:
- The old coax run measured at least -6.5dB loss total
- -4.5dB for the RG-58 by itself
- -2.0dB for the RG-174 by itself
- The new coax, 100ft of KMR-400, by itself measured -1.5dB, and -3.3dB with the patch of RG-174
- SWR sweep of antenna on old coax showed lots of wiggles and hung generally low, because of all the loss.
- SWR sweep of the antenna with the new coax runs much higher on the 100MHz side, and takes a nice dip at the resonant frequency.
- Incoming signals look good and strong by the S-meter on the TYT-9800
