That is good to know.I had good success with the radio shack 800MHz antenna on a pro-164, alot better than the stock duck. I also have a diamond RH77CA and it caused front end overload on the 164. Maybe it was because I live in a very hilly/mountain area, but the 164 was struggeling with the diamond on it.
The Diamond antenna will work great for those frequencies. Your best bet is to get an antenna tuned for that range. A good 2m--140-165mhz 5/8 wave antenna should give you much more listening pleasure. A magmount sitting on top of a file cabinet makes a good ground plane. Understand, if you live on top of the mountain, receive will be good to very good. Half way down, or at the bottom, it will be greatly diminished. I am using my 163 in a RF rich environment--paging towers and cell towers within a mile of my house. I use a homemade wide band scanner antenna that allows me to hear most of what is being monitored by the radio. It is as always, a personal choice for antenna/radio combo. It will take experimenting to find out the solution to your monitoring needs. Each of on this site have our own personal ways of picking signals out of the air. As will you.)Just the antenna that came with it. I am trying to get most channels that are in 140.000 - 160.000
It appears that most of the public safety is conventional VHF/UHF. The radio will perform well with an external antenna. If you don't have an amatuer radio dealer near you, I would go with the RS $35 magmount multiband antenna. I had one for years that worked quite well. The whip sections are now mated to an old Wilson 1000 base. It works quite well on the vhf/uhf bands, as well as, the lo-band vhf.The larger the antenna, the more you will hear. The fact that you have a handheld (I have the mobile version), will allow the use of a ht antenna.North of Rockford Michigan