My thoughts after servicing hundreds of these in the mid 1990s: they are JUNK for amateur use. Here's why: they are NOT, I repeat, NOT designed for typical hamateur "Gas bag" duty cycle. The heat sink is just enough for the rated 5/5/90 duty cycle. On top of that, they would incinerate themselves because they didn't fold back PA drive fast enough. Turning down the biasing just makes them put out weird Boaturd like spurs.
We stocked PA's for these and Radius M2xxx/GM300s as cab companies kept our bench busy and burned them up from drivers using them the way hams ragchew on simplex. Back in those days, cellular phones were expensive and airtime was per minute. I swapped out at least 5 a week.
Much better radios out there with far superior performance, easier to program (no museum computers required), and alot more tolerant of higher duty cycles. Kenwood TK-7180 runs circles around one of these turdboxes for RX sensitivity, has way more channel capacity, and runs cooler even at high power.