[time-nuts] Improving performance of a GPS antenna...?

[Chris Albertson]

On Thu, Apr 5, 2012 at 2:28 PM, EB4APL <eb4apl at cembreros.jazztel.es> wrote:
> Hi,
>
> Are you sure that the Oncore VP sends the right voltage to the antenna?
>  This type needs 5 V and most pucks are designed for 3.3 V .  According to
> the manual the VP sends 5 V to the antenna but anyway it is easy to measure.
>
> Regards,
> Ignacio, EB4APL
>
>
>
> On 05/04/2012 3:43, Morris Odell wrote:
>>
>> Hi all,
>>
>> While we're on this subject, I have a related question.
>>
>> I recently bought one of those cone shaped Lucent GPS timing antennas from
>> a
>> vendor in China. I'm using it for one of my GPS controlled clocks which
>> contains a 6 channel Oncore VP receiver and is on the end of about 15 feet
>> of RG58. I mounted the antenna on a small Al plate about 10 X 20 cm
>> attached
>> to a balcony rail 3 stories from the ground with a clear view of about 75%
>> of the sky.

The typical timing antenna inside the pointed radome is a helix, not a
patch antenna.
Are helix antenna designed to be used with baseplates like the pie
tin?  (I'm not sure.) The obvious experiment is to remove the plate
and mount it as it was designed to be mounted on a pole.  It is very
easy to make a proper mount for this kind of antenna, just buy 3/4
pipe flang from any hardware store and a short section of 3/4 inch
pipe.  I was lucky to find the pipe flange had holes in the correct
location but one could also mount it to the flange using velcro or
double side foam tape.



Chris Albertson
Redondo Beach, California