I don't know what you mean when you say "chew chew"?
Does it appear when receiving radio or always?
The power supply is a switcher. It induces large AC currents on its
supply lines and it contains a transformer that radiates as well. I
don't know the switching frequency. It should be beyond hearing.
Kuntzleman does not say.
The output should just be a single discharge once per second or so with
no AC component..
The "chew chew" could be the power supply charging its capacitor after
each discharge?
How did you prove that it is radiation coupling to the antenna?
5V USB switchers are made to behave in the presence of AM radio mainly
by a filter on the input (2 capacitors and an inductor).
On 12/23/2015 1:15 AM, Kingsley Hurst wrote:
> Assembled wisdom . . . .
> I have the standard dipole aerial for the radio in the closeout of the
> fin as per Europa instructions with the cable running down the
> Starboard side of the fuselage.
> The strobe is from Kuntzleman with the power supply fitted under the
> baggage bay and the cable to the fin running down the Port side of the
> fuselage.
> By necessity, the two cables are closer together in the fin and in the
> upper part of the fin would be running fairly parallel to each other.
> The Kuntzleman strobe wires are not shielded.
> The problem is a CHEW CHEW noise in the headsets and by
> experimentation, I have proven the noise is coming in via the radio
> aerial.
> My question is . . . . What is the likelihood of success if I was to
> replace the unshielded wires to the strobe with a shielded cable?
> I realise moving the strobe to another location would likely be a
> solution but the fin is my preferred location if I can have it.
> Thanks in anticipation
> Kingsley in Oz
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