[Yaesu] New VX-5R

[Eric Lemmon]

Ron,

It is normal for a small, high-power handheld to get very warm- if not
hot- on long transmissions.  Although an SWR mismatch may make the
problem worse, even a perfect match to the RF power amp will still cause
significant heating.  The smaller the radio frame gets, the hotter it
will become with the same RF output.  Even the old Motorola HT-200
"bricks" of yore would get a little warm at 5 watts output, but that
heat was radiated from nearly a square foot of case area.

If I were you, I'd cut the max power setting back to 3.5 watts or so,
just to give the RF power amp a little more heatsink margin.  Long
key-down times and max power setting impose a significant risk of power
amp failure.

73, Eric Lemmon WB6FLY

Ronald Walters wrote:
> 
> Santa was good, a new VX-5R arrived.  When operating on 440 Mhz at 4.5 watts
> I notice that the metal back top case closest to the antenna is getting warm
> if not even hot to the touch. PS - Yaesu and AES have a great sale on these
> units.
> 
> Background
> 
> 1.  Using the standard unit mount antenna that comes with the unit.
> 2.  Operating at 4.5 watts
> 
> Questions
> 
> 1.  Is it a problem and should I be concerned?
> 2.  Could it be a high SWR with the built in antenna?
> 3.  Is this typical for 440 Mhz with a handheld?
> 
> Anyone else notice this?
> 
> Appreciate your input.
> 
> Happy Holidays and a very Happy New Year
> 
> Ron - W4LDE
> 
> Moderator: Ray Brown, KB�STN
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