power supply voltage

[AE5RD]

I got my Yaesu FT-840 today and i was going to hook it up to my power supply. I decided to measure voltage at my supply and I was concerned because I got 16.9 volts. This is too high according to the specs for my radio. If i were to hook the radio in my mobile then it would be hooked up to charging voltage. About 14.5 volts on my truck. How much is too much voltage? Do I need to buy a regulated power supply now. And what about mobile usage? More money...it never ends!

 

[Robb]

Usually when a power supply loses it voltage regulator, the voltage will spike upwards. But you might pop it open and see if there is an adjustment pot inside. I set mine at 13.8v's - but 14.1v's is also acceptable. If the voltage won't come down to the right level, then replacing it or fixing it will be in order. I would also buy more power supply than the radio requires, to ensure that it runs cool and lives longer. But that's me...

 

[W5LZ]

What you are seeing isn't all that unusual for an unregulated power supply. The range of voltage 'excursions' with unregulated power supplies is sort of 'wide'. A difference of something like 3 volts between no-load and loaded, isn't unusual at all. The biggy is what does that voltage drop to when the power supply is under load? That's the voltage you need to worry about. Most, if not all, radios have a limiting circuit that can handle that just fine. But there are limits, naturally. No idea what yours are.
- 'Doc

 

[Moleculo]

If i were to hook the radio in my mobile then it would be hooked up to charging voltage. About 14.5 volts on my truck. How much is too much voltage?

That's in the normal range for a vehicle. Your radio will be happy with that. For the house, get yourself the correct power supply.

 

[AE5RD]

I read some other posts about voltage under a load but if the voltage is too high at idle the damage would already possibly be done. Right? I mean i'm sure I would notice damage very quickly. I think I will just get a good power supply. I burnt up a Golden Eagle Mark5 once by running it with an extension cord to my shed. Transformers for those seem to be priceless.