Commo in the jungle is usually difficult due to the terrain; mountians tend to make FM commo very difficult since FM is line of sight and mountains interfere with that. Long haul HF shots become difficult when a "take off" angle is needed to make the long shot. For commo under 300 miles a Near Verticle Incidence Skywave (NVIS) antenna can be used or you can simply make one with an inverted-V and a counterpoise.
Just guessing here, but they probably also set up some type of Base Station in country for the patrols to talk to. Message traffic was routed from that Base at the FOB/ AOB and then sent on to higher in Panama. They may have also split the team and needed more commo guys to cover the different "slices" that went out.
Commo back then was made using a hand-cranked generator, but I'm told that's what the XO/ CO were for.
The worst place that I've ever heard of making commo was the desert with rocky terrain. Something about the minerals in the rocks creating "dead zones." Usually, the drier the soil, the harder it is to make commo.