We have a 90 35.5 and decided on new eletronics as well. we are at the install process now. here is my big mistake. the radome is installed about 3/4 between the spreaders. the cable comes in 15meters. it is to long to end up at the mast step. you cannot buy female/male connectors. we therfore had to splice the radar cable in the dome and attach. this was the first mistake. second, the tubing on the deck, through the step mast, is not wide enough to for an extension cable to past trough. once again another splice had to be done. third, the distance to the helm from the deck mast in approx. 35 feet or 15 meters. raymarine dose not make a cable this long. you need to buy two extnsion cable 5 and 10 meters to make the distance. with all that, i cannot imagine not loosing some tolerance on the radome even though the splices were resolder by the best.
the right fix would have been to be more patient since i made quick decision and wanted mast re strepped and the boat back in the water right away.
Fixes:
First buy a ten meter extension cable. splice one end at least a 2 feet from the connector. use this for your mast. take the end of your original cable (15m) that comes with the dome and have the pins re-attached to the 10meter extension so that there are no splices. this gives you a nice clean run to the end of the mast.
Second you should have the original 15meter cable with one end spliced. start from the helm and fish this back to the mast decking. it will be easier than trying to fish the larger extension connector to the helm. run under the steering box in some type of jacket back to the starboard batteries. then chase the battery cables to the motor. looking down toward the motor,on the starboard side is a channel which runs under the floor decking and up to the eletric pannel. there you can chase the radio cable back to the mast decking. pull the spliced end up through the tubing channel and resolder the connector from the 10 meter extension cable you cut off. pull the cable back through the decking and re cualk the tube closed.
Finished, you have now saved yourself from buying and additional 5 meter cable and only one splice. i would expect the tolerence to be much better. let me know if this helps, as tomorrow we will try to finish the c80 install at the helm with sea talk to the auto helm and depth finder. p.s. run a RAM mic to your pod as well. its cheap and will follow the same run as the radome. good luck frank