radio interference

[ryanglover1969[_2_]]

I have a question for all the electronically minded pilots out there.
Every time I transmit my vario goes crazy. The funny thing is that
when the colibri and or the Ipaq isn't connected it doesn't go crazy.
My set up is as follows: LX 1600vario
Dittle FSG 2T radio
Colibri data logger
Ipaq 3600 running SeeYou mobile

What's the solution? I got some ferrite beads and put them in various
locations with no success.
should I shield the cables from the vario to the colibri and Ipaq???

[GM]

On Apr 28, 7:02*pm, ryanglover1969 > wrote:
> I have a question for all the electronically minded pilots out there.
> Every time I transmit my vario goes crazy. The funny thing is that
> when the colibri and or the Ipaq isn't connected it doesn't go crazy.
> My set up is as follows: LX 1600vario
> * * * * * * * * * * * * * * * * * * Dittle FSG 2T radio
> * * * * * * * * * * * * * * * * * * Colibri data logger
> * * * * * * * * * * * * * * * * * * Ipaq 3600 running SeeYou mobile
>
> What's the solution? I got some ferrite beads and put them in various
> locations with no success.
> should I shield the cables from the vario to the colibri and Ipaq???

Ryan,
have you checked the stability of your power supply? I run a very
similar set-up: Becker 3201, LX20, LX1600 and an iPAQ but have a very
good battery. Place a digital voltmeter between and a digital ampere-
meter inline (both with min.-max hold function) with the power leads
and key the microphone. There is a good chance that the power supply
collapses momentarily below the minimum required to run everything
properly.
Uli

[Brian Whatcott]

ryanglover1969 wrote:
> I have a question for all the electronically minded pilots out there.
> Every time I transmit my vario goes crazy. The funny thing is that
> when the colibri and or the Ipaq isn't connected it doesn't go crazy.
> My set up is as follows: LX 1600vario
> Dittle FSG 2T radio
> Colibri data logger
> Ipaq 3600 running SeeYou mobile
>
> What's the solution? I got some ferrite beads and put them in various
> locations with no success.
> should I shield the cables from the vario to the colibri and Ipaq???

It's just possible I suppose, that the cables from the colibri and/or
Ipaq are resonating in the VHF - if their length is about 23 or 46
inches: if so, shielding or loading them might help.

Brian W

[Paul Remde]

Hi,

GPS data cables can be quite noisy electrically. That is why all Goddard
cables are shielded. I've never had a customer complain about electrical
noise with a Goddard cable or the PS-5a power converter.
http://www.cumulus-soaring.com/goddard.htm

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

"ryanglover1969" > wrote in message
...
>I have a question for all the electronically minded pilots out there.
> Every time I transmit my vario goes crazy. The funny thing is that
> when the colibri and or the Ipaq isn't connected it doesn't go crazy.
> My set up is as follows: LX 1600vario
> Dittle FSG 2T radio
> Colibri data logger
> Ipaq 3600 running SeeYou mobile
>
> What's the solution? I got some ferrite beads and put them in various
> locations with no success.
> should I shield the cables from the vario to the colibri and Ipaq???

[JJ Sinclair]

On Apr 28, 4:02*pm, ryanglover1969 > wrote:
> I have a question for all the electronically minded pilots out there.
> Every time I transmit my vario goes crazy. The funny thing is that
> when the colibri and or the Ipaq isn't connected it doesn't go crazy.
> My set up is as follows: LX 1600vario
> * * * * * * * * * * * * * * * * * * Dittle FSG 2T radio
> * * * * * * * * * * * * * * * * * * Colibri data logger
> * * * * * * * * * * * * * * * * * * Ipaq 3600 running SeeYou mobile
>
> What's the solution? I got some ferrite beads and put them in various
> locations with no success.
> should I shield the cables from the vario to the colibri and Ipaq???

Some component is putting out RF, you can find which one by turning on
your radio with no squelch then one by one turn on each component,
GPS, vario, computer, recorder, etc. Each will add to the background
noise, look for the one that makes the greatest increased noise. I
recently found the new USB (stick) adapter for the SN-10 was pumping
out RF. I fixed the problem by moving it away from the radio antenna
lead.
Hope this helps,
JJ

[Paul Remde]

Hi,

On a related subject. I have a customer with a new TruTrak Pictorial Turn
and Bank that is complaining of noise on the radio when the unit is turned
on. I've sold a fair number of these units with no previous complaints.
The unit has only 12V power connections -so there are not GPS RS-232 data
signals to make noise. Has anyone else had any electrical noise issues with
this product? Any suggestions? My guess is that his radio antenna or other
radio wires are poorly shielded and/or running past the TruTrak unit. Or
the TruTrak's power leads are putting noise into the radio antenna. The
unit has a small motor inside.

The manufacturer suggested sending it back to them for warranty repair. But
they didn't sound like they were confident that they could fix the problem.

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

"Paul Remde" > wrote in message
...
> Hi,
>
> GPS data cables can be quite noisy electrically. That is why all Goddard
> cables are shielded. I've never had a customer complain about electrical
> noise with a Goddard cable or the PS-5a power converter.
> http://www.cumulus-soaring.com/goddard.htm
>
> Best Regards,
>
> Paul Remde
> Cumulus Soaring, Inc.
>
> "ryanglover1969" > wrote in message
> ...
>>I have a question for all the electronically minded pilots out there.
>> Every time I transmit my vario goes crazy. The funny thing is that
>> when the colibri and or the Ipaq isn't connected it doesn't go crazy.
>> My set up is as follows: LX 1600vario
>> Dittle FSG 2T radio
>> Colibri data logger
>> Ipaq 3600 running SeeYou mobile
>>
>> What's the solution? I got some ferrite beads and put them in various
>> locations with no success.
>> should I shield the cables from the vario to the colibri and Ipaq???
>

[Darryl Ramm]

On Apr 29, 6:56*am, "Paul Remde" > wrote:
> Hi,
>
> On a related subject. *I have a customer with a new TruTrak Pictorial Turn
> and Bank that is complaining of noise on the radio when the unit is turned
> on. *I've sold a fair number of these units with no previous complaints..
> The unit has only 12V power connections -so there are not GPS RS-232 data
> signals to make noise. *Has anyone else had any electrical noise issues with
> this product? *Any suggestions? *My guess is that his radio antenna or other
> radio wires are poorly shielded and/or running past the TruTrak unit. *Or
> the TruTrak's power leads are putting noise into the radio antenna. *The
> unit has a small motor inside.
>
> The manufacturer suggested sending it back to them for warranty repair. *But
> they didn't sound like they were confident that they could fix the problem.
>
> Best Regards,
>
> Paul Remde
> Cumulus Soaring, Inc.
>
> "Paul Remde" > wrote in message
>
> ...
>
> > Hi,
>
> > GPS data cables can be quite noisy electrically. *That is why all Goddard
> > cables are shielded. *I've never had a customer complain about electrical
> > noise with a Goddard cable or the PS-5a power converter.
> >http://www.cumulus-soaring.com/goddard.htm
>
> > Best Regards,
>
> > Paul Remde
> > Cumulus Soaring, Inc.
>
> > "ryanglover1969" > wrote in message
> ...
> >>I have a question for all the electronically minded pilots out there.
> >> Every time I transmit my vario goes crazy. The funny thing is that
> >> when the colibri and or the Ipaq isn't connected it doesn't go crazy.
> >> My set up is as follows: LX 1600vario
> >> * * * * * * * * * * * * * * * * * *Dittle FSG 2T radio
> >> * * * * * * * * * * * * * * * * * *Colibri data logger
> >> * * * * * * * * * * * * * * * * * *Ipaq 3600 running SeeYou mobile
>
> >> What's the solution? I got some ferrite beads and put them in various
> >> locations with no success.
> >> should I shield the cables from the vario to the colibri and Ipaq???
>
>

The first suspect should always be coupling through the power supply,
put a ferrite toroid or choke on the line right near the device
suspected of causing the noise, or as a test power it from a separate
battery and see if the problem is still there, if it is then it's RF
coupling not via the power supply. If it is not the powerr supply then
check cable/wiring routing, coax connectors and coax and wiring
shielding.

To be clear, since the TruTrak uses a solid state gyro, it does not
contain a motor to spin a gyro. The "motor" may mean the mechanism to
move the display background. That all may be irrelevant and the issue
if there is one from the unit may be simply RF noise from digital
electronics.

Darryl

[Andy[_1_]]

On Apr 28, 4:02*pm, ryanglover1969 > wrote:
> should I shield the cables from the vario to the colibri and Ipaq???


I think I'd first verify the problem can be reproduced using a hand
held TX. Then start disconnecting leads to/from the vario. Try
disconnecting each end of each lead in turn. Try powering the vario
from a local battery rather than ships power and wiring.

When you have pinned down the route the rf is entering the vario then
you are in a better position to work out how to fix it.

Large ferrite cores as close as possible to the vario may be a good
starting point. (They work best if the wire is looped rather than just
threaded) Changing wire routing many be another (make sure no vario
wiring is close the radio coax). If the vario outputs are typical
data and ground then screened twisted pair may be the next thing to
try. It may also help to ensure all leads feeding the vario are run
together as far as is possible. Having them spread out, or even
forming a large loop will increase the risk of RFI.

Perhaps the first question should be - did it always do this? If not
what was added or changed, or has something (perhaps rf filtering
components in the vario) failed.

Andy (GY)

[John Smith]

> To be clear, since the TruTrak uses a solid state gyro, it does not
> contain a motor to spin a gyro.

I don't know the TruTrak, but I suspect it uses an oscillating piezo
crystal, which implies a pretty high frequency electronic circuit, which
might or might not interfere with the radio.

[Darryl Ramm]

On Apr 29, 1:44*pm, John Smith > wrote:
> > To be clear, since the TruTrak uses a solid state gyro, it does not
> > contain a motor to spin a gyro.
>
> I don't know the TruTrak, but I suspect it uses an oscillating piezo
> crystal, which implies a pretty high frequency electronic circuit, which
> might or might not interfere with the radio.

I don't know what MEMS gyro sensor is in the TruTrak but may only be
10s of kHz or so. And with very low drive current so not much power
involved, and the oscillator electronics tends to be integrated onto
the sensor assembly so not much chance for harmonic leakage.

If the device is putting out RF, specially on the power supply leads I
am much more prone to think of a failed DC/DC (switchmode) converter
where the power involved is much more significant than the oscillator
circuit inside the MEMS sensor, and possibly chopped at a higher
frequency, and all conveniently close to the input wiring to leak back
if something has gone wrong.

Diagnosing the culprit here should be straight forward.

Darryl