Can Yaesu VX-5R be used with 13.8volts?

[VK3]

Can the vx-5r be operated from a 13.8volt source without incurring damage to the HT?  Have heard that the radio heats up during TX and causes damage.  Is this a design fault?  I would aprreciate any suggestions from owners of the unit.  73's Dan

[KC8AXJ]

According to Yaesu's spec.s:

 http://www.yaesu.com/amateur/vx5rtx.html

Supply Voltage: Nominal:  7.2 V DC, Negative Ground
Operating:  4-9 V DC (Internal Battery)  
10-16 V DC, Negative Ground  (EXT DC jack)

Handhelds, because of a lot of power options i.e. car battery, attached batteries of verious voltage, are desined to work without a "set" voltage. The only trade off is power out. Less power in.......less out.


I have a Icom T22 Which will put out 5 watts from a external sorce (13.8V) or it's 7.2V ni-cad.
If I do a lot of transmitting, it does get quite warm.
(Nice in the winter, Hi Hi)
The body of these things aren't that big as far as being a "heat sink". My mobile will even ge a LITTLE warm at 5 w out and that is quite a lot more iron than a handheld.
I wouldn't worrie about it too much, just try not to key up for long periods, even 15-20 seconds at a time can add up heat wise.
These things aren't really a good rag chewing device unless you can run on the low power setting.
Hope that helps!
73
Steve   kc8axj@arrl.net

[KC0IWV]

According to Yaesu you should be able to use a 13V source for this HT.  I own one myself and have used it in the car off of the battery.  It does dissipate a lot more heat.  I asked the technician at Yaesu about this and he said it is designed to handle 12V+ but will need to dissipate a lot more heat.  

I personally don't use mine this way - the unit gets hot enough with 7.2V input that I'm suspect that 13 Volts might not be the best thing for the rig.  

However, I know a lot of Hams who do run them off the car battery and have had no problems.  

So the answer to your question is yes.