Does the Tram 1185 need tuning?

No. It comes pretuned for 144-148 MHz and 435-450 MHz, so you can mount it and connect it right away.

Will it work with my 50-ohm ham radio?

It is rated at 75 ohms, which is unusual for ham gear. Most users report it works fine on receive and local transmit, but a 50-ohm antenna is the better match for full-power use.

How well does the magnet hold?

The 3.5-inch magnet holds well in normal driving. On rough roads or at high speed some owners report it can slide, so check it before long trips.

What bands does it cover?

It covers 144-148 MHz on VHF and 435-450 MHz on UHF. It is not designed for other bands.

The antenna, the magnetic base and 12 feet of RG58/U coax ending in a UHF male PL259 connector.

Can I use it indoors or on a balcony?

It needs a metal surface to grip and to act as a ground plane. A car roof or trunk lid works best; a balcony rail or non-metal surface will not perform well.