Definitely a new antenna.. I bought a new VHF and antenna because my old one,vhf, was not working. After the new was installed I decided to take the Uniden to my local shop and he said it's fine. Got a new antenna and the old one now works well too. Splitting an antenna means if the antenna is the problem then both radios are hamstrung.
Some years ago I bought a handheld for which I bought a headset and used that for the VTS calls since I used to run in and out of Van. harbour every time we went anywhere. So the handheld can also serve. Use of the headset tell you without doubt which radio is blathering and the sound will be clear.
My main VHF is on a remote speaker so again it is absolutely clear which radio is active.
Before I got the remote speaker, when both radios were active I could not figure out which was which so I ,actually fairly often, missed important info by the time I sorted out the calls.
My old vhf will get its own remote speaker in a different location so again I know immediately which radio is most important and can turn the other down.
I also suggest the use of a remote speaker for each radio. My own experience has taught me that the remote speakers are light years ahead of the vhf built ins for clarity and volume. Simply because the remotes are larger and usually better speakers and also they can be aimed at the primary operator, not at your feet, or chest or the person opposite. Keep them well away from each other also, AND THE COMPASS, so you know immediately whcih radio you want to listen to.
The remotes were not expensive, about $20 20 yrs ago, from Radio Shack. I know that option is gone, R.S., but a decent one should not cost an arm and leg. I also have a powered speaker which now resides in the garage because I cannot throw anything out. A powered one is not needed unless the wheel house is extremely noisy. Not likely in your case unless the grandkids have taken over.
For a remote just check the impedance specs. of the radio and the speaker. For best performance they do need to be matched, usually either 4 or 8 ohm.
Sheesh, back again. Yes, antenna separation is needed. Check the radio spec.
I solder the plug/cable connection. Those press on MAY be ok for a few years but eventually minute oxidation occurs which degrades the signal, coming and going. I have gone through a few folks installations in the last few years and after getting rid of those press fit connections and soldering the radios perked up.
As for channel switching I do not consider the keypad an advantage. I now have one of each,a keypad and a rotary knob. The knob is faster and easier especially if rough.
You may not have a choice particularily if the rest of the radio is what you want. I would not turn my pad radio down for that reason but just don't see it as an great thing and not an improvement.
