My network analyzer test for the GPS antennae is approximate, of course,
but nonetheless you can find out if the antenna is defective. Better to
have a known good antenna handy to compare, when using this setup. I'm
planning to build a frame (to hold the emitting antenna and the DUT) to
find out
I already posted a picture of the Trimble antenna a few
months back. To get to the active bits, you really have
to fillet the antenna. Everything is boxed into tinplate
channels. I haven't done that yet.
-Chuck Harris
Tom Miller wrote:
Can you open them up and see how they are made and
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
Hi Chuck:
See:
http://www.prc68.com/I/ThunderBolt.shtml#Ant
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
Chuck Harris 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
Hi Brooke,
Lots of nice information, but I already have most of it. The question
left unanswered is: Is it usually that hard to find a good working
active antenna that works with the TB? Thus far, I have several hockey
puck antennas that work fine... albeit a bit deafly, as would be
expected..
cfhar...@erols.com said:
I suspect that I have just had the bad luck to buy two bad antennas, but I
am naturally curious what happens when the sample set gets larger.
I have 2 TBolts using the small Motorola antenna from TAPR in a not-good
location. The sheet says 24 dB of gain. I have 6
Have you any other GPS unit to test your antennae? You can test GPS
antennae with a network analyzer or a spectrum analyzer with the tracking
generator... yes, first you have to find one.
On Mon, Jul 30, 2012 at 5:12 PM, Hal Murray hmur...@megapathdsl.net wrote:
cfhar...@erols.com said:
I
On a window sill, my Motorola hockey pucks will get a useable satellite
every few minutes, for a few minutes. If the antenna is out in the yard,
it does much better, but all satellite signals are really low.
The system would like another 10 or 20db of gain... which is what the
Trimble bullet
Have you used Lady Heather to automatically set the Default settings?
To allow the Tbolt to work with weak signals from any antenna that I've
tried, even when indoors,
I start by setting the TBolt's AMU level from the default of 4 down to 0.
This can be done with the Tbolt S/W or LH.
My
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
I use one just like auction #180518378555. It is only 26dB but the
thing is very reliable. It is a helix antenna inside and the mounting
holes on the bottom line up with a standard iron pipe flange so
mounting is easy. I filled the flang flat them glued autommotive type
gaskit mmaterial to the
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
Chuck,
I have one of the original red box TB. It came with the Trimble Bullet antenna
that is specified in the TB datasheet.
The antenna works but gives extremely poor results. The TB works much better
with the Symmetricom antenna that is sometimes available on eBay.
The Bullet antenna
: [time-nuts] Active antennas for a Thunderbolt...
Chuck,
I have one of the original red box TB. It came with the Trimble Bullet
antenna that is specified in the TB datasheet.
The antenna works but gives extremely poor results. The TB works much better
with the Symmetricom antenna
My first Thunderbolt related GPS antenna was the mushroom model
that came with my first kit from China. It had a length of 50 ohm
rg58 attached. I added another 50 feet of rg6 to reach the Thunderbolt
in my office. It worked fine but needed an amp to drive two Thunderbolts.
I then bought one
Hi Warren,
I am not battling weak signals, I am battling no signals from
two mushroom type antennas.
-Chuck Harris
WarrenS wrote:
Have you used Lady Heather to automatically set the Default settings?
To allow the Tbolt to work with weak signals from any antenna that I've tried,
even
when
Hi Azelio,
How would you use a network analyzer to test an active antenna
like these? I have the ANA, but I am not sure how to couple
the input to the antenna effectively.
-Chuck Harris
Azelio Boriani wrote:
Have you any other GPS unit to test your antennae? You can test GPS
antennae with a
Quad RG6, under 10 feet. And RG223 under 10 feet.
-Chuck Harris
Tom Knox wrote:
Hi; Is your coax 50 or 75 ohm? Is it microwave rated? and have you tried
changing
coax length? None of these should be a major factor but could make a difference.
Best Wishes; Thomas Knox
Hi Didier,
I don't quite know what to say about that. Trimble seems to think that bullet
antenna is the right thing to use. Somehow, I would think they should know.
It is possible that they are prone to failure, I guess...
It is surprising to me that the only antenna I can get to work is a
On 7/30/2012 6:39 PM, Chris Albertson wrote:
I use one just like auction #180518378555. It is only 26dB but the
thing is very reliable. It is a helix antenna inside and the mounting
holes on the bottom line up with a standard iron pipe flange so
mounting is easy.
That's exactly the same
I use a small power supply to feed the antenna (use a bias tee) and a DC
block for the analyzer input. I have made a quadrifilar helix for the
analyzer output. Set a suitable frequency range (1400-1700) and test. Yes,
I have (at work) an analyzer with the S-parameter test set, so that no
Subject: Re: [time-nuts] Active antennas for a Thunderbolt...
Hi Didier,
I don't quite know what to say about that. Trimble seems to think that
bullet
antenna is the right thing to use. Somehow, I would think they should know.
It is possible that they are prone to failure, I guess
: Mon, Jul 30, 2012 9:52 pm
Subject: Re: [time-nuts] Active antennas for a Thunderbolt...
Hi Warren,
I am not battling weak signals, I am battling no signals from
wo mushroom type antennas.
-Chuck Harris
WarrenS wrote:
Have you used Lady Heather to automatically set the Default settings
Chuck wrote:
I don't quite know what to say about that. Trimble seems to think that bullet
antenna is the right thing to use. Somehow, I would think they should know.
I normally use a choke-ring survey antenna, but I also have a Trimble
Bullet III, P/N 41556-00 (RoHS version is P/N
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Active antennas for a Thunderbolt...
I use a small power supply to feed the antenna (use a bias tee) and a DC
block for the analyzer input. I have made a quadrifilar helix for the
analyzer output. Set a suitable
Ok, that's about what I thought you would do. Since it isn't in a
controlled antenna farm, you get a functionality test, with an approximate
example of the gain.
Thanks!
-Chuck Harris
OBTW, any luck fixing bad antennas?
Azelio Boriani wrote:
I use a small power supply to feed the antenna
To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Active antennas for a Thunderbolt...
Hi:
What is the GPS bandwidth at 1575.42 MHz? For a band-pass filter
? Is it microwave rated? and have you tried
changing coax length? None of these should be a major factor but could
make a difference.
Best Wishes;
Thomas Knox
From: shali...@gmail.com
Date: Mon, 30 Jul 2012 13:46:40 -0500
To: time-nuts@febo.com
Subject: Re: [time-nuts] Active antennas
Put a capacitor across the diode. 0.01 uF should be fine.
- Original Message -
From: li...@lazygranch.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Monday, July 30, 2012 7:58 PM
Subject: Re: [time-nuts] Active antennas for a Thunderbolt
Didier,
What is the model number of the Symmetricom antenna? Do you happen to
know the difference in gain between it and the Trimble Bullet antenna?
Steve K8JQ
On 7/30/2012 2:46 PM, Didier Juges wrote:
Chuck,
I have one of the original red box TB. It came with the Trimble Bullet antenna
2012 20:06:01
To: li...@lazygranch.com; Discussion of precise time and frequency
measurementtime-nuts@febo.com
Reply-to: Tom Miller tmil...@skylinenet.net
Subject: Re: [time-nuts] Active antennas for a Thunderbolt...
Put a capacitor across the diode. 0.01 uF should be fine.
- Original Message
Chuck
I have 3 TBs here at the moment. The other two were group buys, therefore
more recent than the red box.
The two group buys use magnet puck antennas. One is a Trimble (small but
heavy, all metal, looks well made) the other a no name Chinese model. Both
are inside the house in my
Looks like my bullet might be bad.. .
Didier
Charles P. Steinmetz charles_steinm...@lavabit.com wrote:
Chuck wrote:
I don't quite know what to say about that. Trimble seems to think
that bullet
antenna is the right thing to use. Somehow, I would think they should
know.
I normally use a
HP58532A
The manual is on my web site
Www. KO4BB.com/Manuals
The Bullet antenna specs are also on my site.
Didier
Didier
Steve stev...@suddenlink.net wrote:
Didier,
What is the model number of the Symmetricom antenna? Do you happen to
know the difference in gain between it and the
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