David Jordan wrote:
> Hi folks,
>
>
>
> This one is a bit odd. My buddy has a Ford F-150 and installed in the truck
> is his TM-D700 dual band VHD/UHF radio. We chat during our drive into work
> in the mornings.
>
> Almost without fail when he is transmitting at least once during the 30 min.
> drive I will hear what sounds like a siren on his audio Whrrrrrrrrrrr
> starting at a high pitch and slowly going down in audio tone freq. He has
> grounded the radio, etc., yet the weird noise continues to occur. Last week
> I installed a TM-D700 in my Ford Sport Trac and guess what - now he says I
> have the same odd occurrence of the erratic whine syndrome.
>
I have one of the very early TM-D700s and have used it in a Trans Am, an
old Eagle Summit, Toyota Prius, and Toyota 4-Runner. I've never had a
moments problem with it. However, I have noticed in the Prius where I
had to use the car's wiring that low voltage would cause this sound. It
also does it with the TM-V-7A that's in there now. When it was doing
that with the low voltage, switching to low power cured the noise.
I've seen battery connections get corroded internally (where the cable
fits into the lead molding) so they still looked good, but going high
power on either the Kenwoods or Icoms caused the this kind of noise. So
two more thoughts would be the battery connections, or the battery itself.
Of course there is always the possibility of loose grounding inside the
rig as has already been mentioned.
73 and good luck,
Roger (K8RI)
>
>
> My radio is also grounded extensively as I run 1KW on 75 and 40m.
>
>
>
> Thoughts and recommendations welcome.
>
>
>
> 73,
>
> Dave
>
> Wa3gin
>
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>
>
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