[time-nuts] Active antennas for a Thunderbolt...

[Chuck Harris]

Hi Chris,

I agree, once is just anomalous, but twice makes my debugging
hat go on... especially when it is two different manufacture
antennas.

The first antenna is the exact antenna that Trimble recommends
for the TB.  It is a type 25045-10.  Surely it should be compatible?
The second antenna is a Micro Pulse 1934NW/C, 50dB model, designed
for +3 to +35V, and to test that it was being fed properly, I put
a BNC "T" right at the antenna, and measured +4.5V.

In the course of testing I have used cables that came out of my
test pool.  They are short, and have been proven good.

The Motorola hockey puck is about 20db of gain, and as such is a good
8dB less than the minimum recommended by Trimble.  It works very well
if it is out where it gets a clear view of the sky.  It works ok
sitting next to my window.... but nothing stellar.  I plan to put it
outside on my roof, but I am short of the needed "round tuits" for
the near to immediate future.

-Chuck Harris

Chris Albertson wrote:
> Once, I'd suspect a dead antenna.  But twice?  I wonder if your cable
> is bad?  Or something else.  Did you connect the working puck antenna
> to the end of the same cable you used  for the bullet antennas?  Are
> the bullet antenna designed for 5V (some want a lower voltage.)
>
> I'm using a 26dB bullet ant. mount on a long 1" diameter galvanized
> iron plumbing pipe.  It has a 360 degree view of the horizon and works
> perfectly.   But I think the location maters the more then the gain.
> If you could place your current ant. on a mast it would work better
> not only because of the beter view of the sky but reflections are
> deduced.
>
> On Mon, Jul 30, 2012 at 6:18 AM, Chuck Harris <cfharris at erols.com> wrote:
>> Ok, I'm getting a little puzzled.  I have a TB that came from one of
>> the early groups sold by John Ackermann and TVB as part of the TAPR buy.
>> It works nicely, but like all TB's, it is deaf as a post, and needs a
>> high gain antenna.... When I first got the TB, I tried it with a Motorola
>> hockey puck antenna, with about 17db gain, and if it is outside in the
>> clear, it works nicely... but LH shows the satellites signals are all
>> down in the mud.
>>
>> ...So...