GPS intrference from Zaon PCAS ??

[Carl]

My GPS-NAV has been reliable until a few weeks ago with my Aero 1550
running GN2 when I started using my Zaon PCAS velcro mounted on my
instrument panel cover which has it about 3-4" above the GPS-NAV. My
GPS-NAV now goes into GPS wait frequently and has problems locking up
to the constellation. Has anyone else had this experience? Could the
oscillator in the PCAS be an interference source or its harmonics.
I'll try to do some experimenting with and without it this weekend.
Thanks - Carl
V2b-7E

[[email protected]]

For what it's worth I use an MRX in several different gliders
different GPS systems including a Cambridge 302 mounted close under
where the MRX sits and I have no GPS problems.

When you say 3"- 4" above the GPS Nav - do you have a model 20 or the
25 with the antenna mounted right on top? Are you sure you are not
simply obscuring the signal? Other things nearby might obscure other
parts of the sky and the MRX might be the final straw? Does the
problem go away if the PCAS is turned off?

Darryl

On May 29, 7:47 pm, Carl > wrote:
> My GPS-NAV has been reliable until a few weeks ago with my Aero 1550
> running GN2 when I started using my Zaon PCAS velcro mounted on my
> instrument panel cover which has it about 3-4" above the GPS-NAV. My
> GPS-NAV now goes into GPS wait frequently and has problems locking up
> to the constellation. Has anyone else had this experience? Could the
> oscillator in the PCAS be an interference source or its harmonics.
> I'll try to do some experimenting with and without it this weekend.
> Thanks - Carl
> V2b-7E

[01-- Zero One]

Hey Carl,



Are you using the internal battery or connecting it to ships power?



See previous threads here on RAS regarding interference when powering it
from the ships power.



Larry





"Carl" > wrote in message
ups.com:

> My GPS-NAV has been reliable until a few weeks ago with my Aero 1550
> running GN2 when I started using my Zaon PCAS velcro mounted on my
> instrument panel cover which has it about 3-4" above the GPS-NAV. My
> GPS-NAV now goes into GPS wait frequently and has problems locking up
> to the constellation. Has anyone else had this experience? Could the
> oscillator in the PCAS be an interference source or its harmonics.
> I'll try to do some experimenting with and without it this weekend.
> Thanks - Carl
> V2b-7E

[[email protected]]

I've been flying with the Zaon PCAS for over 1 year and I have never
had this problem. It is literally mounted 3-4" away from my Cambridge
Model 20 on my glarehield. I do use the internal batteries to power it
up. It works like a charm with no interference....Thanks - Renny




On May 29, 8:47 pm, Carl > wrote:
> My GPS-NAV has been reliable until a few weeks ago with my Aero 1550
> running GN2 when I started using my Zaon PCAS velcro mounted on my
> instrument panel cover which has it about 3-4" above the GPS-NAV. My
> GPS-NAV now goes into GPS wait frequently and has problems locking up
> to the constellation. Has anyone else had this experience? Could the
> oscillator in the PCAS be an interference source or its harmonics.
> I'll try to do some experimenting with and without it this weekend.
> Thanks - Carl
> V2b-7E

[Nyal Williams]

What does the Zaon do if two or more aircraft are within
range?

At 05:00 30 May 2007, wrote:
>I've been flying with the Zaon PCAS for over 1 year
>and I have never
>had this problem. It is literally mounted 3-4' away
>from my Cambridge
>Model 20 on my glarehield. I do use the internal batteries
>to power it
>up. It works like a charm with no interference....Thanks
>- Renny
>
>
>
>
>On May 29, 8:47 pm, Carl wrote:
>> My GPS-NAV has been reliable until a few weeks ago
>>with my Aero 1550
>> running GN2 when I started using my Zaon PCAS velcro
>>mounted on my
>> instrument panel cover which has it about 3-4' above
>>the GPS-NAV. My
>> GPS-NAV now goes into GPS wait frequently and has
>>problems locking up
>> to the constellation. Has anyone else had this experience?
>> Could the
>> oscillator in the PCAS be an interference source or
>>its harmonics.
>> I'll try to do some experimenting with and without
>>it this weekend.
>> Thanks - Carl
>> V2b-7E
>
>
>

[Tom Gardner]

On May 30, 5:24 am, "01-- Zero One" > wrote:
> Hey Carl,
>
> Are you using the internal battery or connecting it to ships power?
>
> See previous threads here on RAS regarding interference when powering it
> from the ships power.

If it is interference coming down the power cable, then it might be
worth
using a ferrite toroid to reduce the interference. The technique is
quick, simple, cheap and non-invasive, but there's also a reasonable
chance
that the equipment already has such filters fitted internally. It will
reduce
both RF interference and also power spikes (the classic example being
clicks on audio amplifiers caused by fridges turning on.

Here's an handy example, but they are widely available.
<http://www.maplin.co.uk/module.aspx?ModuleNo=32799&doy=30m5#overview>

[[email protected]]

On May 29, 7:47 pm, Carl > wrote:
> My GPS-NAV has been reliable until a few weeks ago with my Aero 1550
> running GN2 when I started using my Zaon PCAS velcro mounted on my
> instrument panel cover which has it about 3-4" above the GPS-NAV. My
> GPS-NAV now goes into GPS wait frequently and has problems locking up
> to the constellation. Has anyone else had this experience? Could the
> oscillator in the PCAS be an interference source or its harmonics.
> I'll try to do some experimenting with and without it this weekend.
> Thanks - Carl
> V2b-7E


Yesterday, I experienced the same problem with my newly installed Zaon
working with a Cambridge 302 with GNII on my Aero 1520.
The Zaon was powered from the ship's battery. The GNII indicated "GPS
Wait", the Cambridge 302 showed only two GPS receive bars instead of
the normal three bars, and the GNII wind calculation immediately went
to about 60 kts.
The Zaon was mounted on the top of the instrument panel cover just
above the Cambridge 302. I'll try one of the filtering or internal
battery solutions offered here and previously.

Dave
Discus CS -9Q

[jeplane]

Nyal Williams
> wrote:
> What does the Zaon do if two or more aircraft are within
> range?

The Zaon will display the greatest threat. Should it determine that
there is a new threat than the one currently displayed, "-NEW-" will
be displayed for 2 seconds, followed by the new aircraft information.

It follows the rule "accidents can only occur at your altitude", so it
will display the aircraft with the least separation, however, vertical
trend is also used to prioritize when two aircrafts are converging and
both are within +-1000'.

EX: If you are descending and another aircraft is below (within
+-1000'), it will be the primary threat, even if another aircraft is
closer in range and/or relative altitude above you and level.

[jeplane]

, Nyal Williams wrote:
> What does the Zaon do if two or more aircraft are within
> range?

The Zaon will prioritize the threat.Should it determine that a new
aircraft has become a greater threat than the one currently displayed,
"-NEW-" will be displayed for 2 seconds, followed by the new aircraft
information.

It follows the rule that "accidents can only occur at your altitude".
The aircraft with the least separation will be the primary threat,
although it also uses vertical trend to prioritize when two aircrafts
are converging and both are within +-1000'.

EX: if you are descending and another aircraft is below within 1000',
it will be the primary target, even if another aircraft is closer in
range and/or relative altitude above you and level.

Richard
ASW19
Phoenix AZ

[COLIN LAMB]

I do not know what the circuitry in the Zaon is like, but assuming there it
is the cause of the problem, then it would likely either be because it
shielded the other unit or is putting out a signal that interferes with it.

Assuming the Zaon is emitting a signal, my first thought is that it is as a
result of a mix in the front end of it. That could be another transmitted
signal - either by a nearby transponder or any other transmitter. That
would require two signal sources, but the resultant signal could be in the
band received by the gps receiver.

Do some detective work. See if you can cause the signal level on the gps to
change - or if the change is full time or only under certain conditions.

If there is a spurious signal being emitted by the Zaon, then it could be
through the power lead - and that could be attacted with ferrite beads.

Colin