1623 or 1715 replace 1621



I see from a previous post that the antenna cable for the 1715 is the same as the old 1621 which I have to replace.
1. Is this true of the power cable also? Also applicable to 1623?
I'm sure it would be best to replace the cables but this is a boat I may be selling in a year or two and I am thinking in terms of ease of installation.
2. I saw in the install instructions where to test Magnetron Heater voltage. Is this OK to do while the mast is down, essentially hotwiring the unit? Or is this a test of the wiring to the magnetron?
3. Instructions say to keep out of the sun. My 1621 was at the binnacle for 20 years and that's where I would like the replacement to go.
4. Also says not to run power and antenna cables parallel. Existing install has both running up one of the binnacle rack tubes.
Thanks for your help.
Yes, that is true about the scanner cable being the same for the 1621, 1623 and 1715.
1. Yes, the same power cable can be used for with the 1623 and 1715.
2. No. You will need to have the system up and in stand-by to properly complete the mag heater voltage check.
3. Keeping the unit out of the sun is probably suggested because these units could overheat in direct, constant sunlight. With any electronics there are operating temperature limits.
4. Running power and antenna cables next to each other can cause electronic interference. Noise could be induced from the power cable into the scanner cable. It's not a good idea to have them run together, however it's not necessarily a safety problem.