You can set the scan setting for that channel to "skip". That means that the channel will still be programmed into the radio, but when you scan channels, the radio will ignore that channel. That and the squelch setting are how I deal with the common problem of a perpetually-noisy channel interrupting channel scans.
That per-channel setting doesn'...
This is a harder question to answer than you think for a number of reasons. I'll start off with the ideal answer:
The Diamond RH-771 claims that it has 2.15 dBi gain at 70cm (or 0 dBd). Most rubber ducks are significantly worse than quarter wave antennas, and often exhibit negative gain. A short antenna like the SRH-701 has no gain (or -2.15 dBd). The ...
You might try changing the Tone Mode from TSQL to just Tone.
TSQL mode does two things:
sends a tone on transmit
requires a tone on receive to break your radio's squelch
Tone mode only does one thing: send a tone on transmit.
The most likely scenario is that all four radios have the same problem. It's possible that the problem is a manufacturing defect, but that's unlikely, especially if you got the radios from different sources. It doesn't sound like a hardware problem, because the radios hear fine when the menu is open, so the problem sounds like a firmware or configuration ...