I never turn mine off either altho’ I do unplug it every now and then for 20 seconds or so as ‘they’ told me it refreshes the signal and helps relieve congestion … same as a mobile phone I guess … ( I know nothing …just do as I’m told 
) anyway… never had any problems with it
Always off in my house - I don’t have wifi!
I was a TV (and video recorder) engineer too. 1961 to 1995.
I was told by Manx Telecom to leave the router switched on - but I do switch it off now and again, not really sure why though.
To be honest, I don’t know if the AC power adapters supplying the voltage to routers are soft-start when they are first switched on but as with phone chargers and power adapters of this type, they rarely go wrong. The voltage coming out of the AC adapter to a router etc is low and probably even regulated. No more than about 9 to 12 volts maybe? Components don’t tend to go wrong at that sort of voltage level these days.
The only part that could give trouble is the AC adapter itself because that’s the only place where mains voltage is present. Even so, it seems these too are very reliable if the one supplied with the modem/router is used. There have been cases of these giving trouble but they do so whether they are run continuously or switched on and off.
All in all, I don’t think switching off and on will cause a breakdown to occur more frequently than it otherwise might have done.
The only concern is security. Whoever does the configuration for the router/cable modem, make sure they use WAP2 to set a security password. This password will secure your network. Never run a router without password protection. Also, I would try to put the router a distance from where you use your computer. The radiation lessens with distance.
What radiation :shock:
Didn’t you know? Routers create radiation which is bad for you, just like everything else in this world, or so “studies” would have us believe.
Ridiculous, isn’t it?
Oh nothing to really worry about (so they tell us). The router uses the same frequency range as microwave ovens. I saw a video on youtube where a person had an instrument that measured the radiation output. It is very strong right next to the router. The signal strength descreases significantly the further you get away from it.
If birds get too close to wifi towers they get cooked like they would if in a microwave oven. I’ve seen vid where a person had a laptop sitting next to a microwave. The laptop has wifi active and then started downloading a file. Turning on the microwave oven made the download slow down. They use the same frequency so when both are working they share the frequency range, evident by the download slowing. So I keep my router in the back room of my house and use my laptop elsewhere.
I’ve also watched and read other info about this. Since so many homes have wifi, the signal is overlapping all over the place when you go outside, so you can’t really get away from it. I settled for just being aware of my distance from the router in my home and don’t worry about it beyond that because there is nothing you can do about it.
I have just got a new router from Virgin media …I never turn it off or have turned off… My old system which was a separate modem and router i did turn off occasionally so the router and modem could re sync…if they are left on they can receive software updates and also your service provider can tell when your router is on line and diagnose any connection faults …