On Sat, Apr 02, 2011 at 04:13:55PM -0400, Chuck Harris wrote:
Unlike simply stabilizing the BFO crystal as you propose.
Has anyone given any thought to an alternative - phase locking
the original BFO Xtals with a very narrow bandwidth loop to something
derived from the 10 Mhz standard
On Mon, Apr 04, 2011 at 02:00:14AM -0400, David I. Emery wrote:
On Sat, Apr 02, 2011 at 04:13:55PM -0400, Chuck Harris wrote:
Unlike simply stabilizing the BFO crystal as you propose.
Has anyone given any thought to an alternative - phase locking
the original BFO Xtals with a very
Pete, contact me direct, I am in Miami but I may be able to talk you
through it. If you do it to sell, check prices first, they do not get much
money
now a days. I did recently salvaged some.
Bert
In a message dated 4/4/2011 12:57:54 A.M. Eastern Daylight Time,
pet...@standingwave.org
A couple of years ago I picked up a surplus Aeroantenna choke-ring GPS
antenna that I think was intended for surveying use. I finally got it
installed today and noticed that it has an arrow on the bottom
indicating that the antenna should be oriented with the arrow facing
north.
Most
Basically, the higher the division ratio in a PLL synthesizer,
which is what you are describing, the greater the phase noise.
You can think of it this way: Both the reference, and the oscillator
being controlled, need to be divided down to some common frequency
that you feed to the phase
Hi Brooke,
Hi John:
Exactly. There are about a dozen specific antennas that have been
thoroughly characterized for phase center at L1 and L2. I think to the
mm level.
Have Fun,
Brooke Clarke
http://www.PRC68.com
There are a lot more than a dozen antennas that are characterized. See
You cannot change impedance without changing geometry or dielectric, and any of
these changes will affect vop.
Didier KO4BB
Sent from my BlackBerry Wireless thingy while I do other things...
-Original Message-
From: Joseph Gray jg...@zianet.com
Sender: time-nuts-boun...@febo.com
Date:
Basically, the higher the division ratio in a PLL synthesizer,
which is what you are describing, the greater the phase noise.
In that case, that may not be a problem. Since the oscillator is a crystal,
phase noise should be low enough.
One other issue is that most crystals only want to move in
Maybe it's not truely omnidirectional? Maybe like a cardioid pattern?
Didier KO4BB
--Original Message--
From: John Ackermann N8UR
Sender: time-nuts-boun...@febo.com
To: Time-Nuts
ReplyTo: Time-Nuts
Subject: [time-nuts] GPS antenna with direction orientation?
Sent: Apr 3, 2011 7:42 PM
A
Hi Didier,
If you want to convert the Xtal to a VCO, you will have to adjust the parallel
capacitance so that the crystal can get above the desired frequency, and then
design the varactor circuit so that it can pull from there to below the desired
frequency...which should be possible if the
Hello Didier;
I don't have a copy of the schematic however I was
wondering if there are trim caps installed for these
crystals?? If so, then a varactor can tune above and
below in place of the mechanical cap if you remove it.
Undoubtedly there is some loading cap in the circuit
that could be
What is the normally expected oven temperature range of the Thunderbolt?
Over the past year the temperature of my Tbolt, as reported by Lady Heather,
has slowly increased from the low 40s C to the high 40s. The maximum
temperature has now crept up to 50 C and is shown today at 50.8 C. At
50 C
On Mon, Apr 04, 2011 at 11:50:55AM -0500, msproul wrote:
What is the normally expected oven temperature range of the Thunderbolt?
I generally see mine run at 33-40 C depending on the ambient
temperature of the room.
What's the temperature of the environment it's in? It's going
Maury--
Mine hovers around 36 degrees C +/- about 1.5 degrees C. Given the time, I'm
going to start working with LH's active temperature control, and will be
looking to settle on something between 34 and 38 degrees C, at least that's my
current guess.
Over 45 definitely seems warm to me!
Mine typically runs in the low to mid 30 deg C range.
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Mine runs 36-37 degrees.
On Mon, Apr 4, 2011 at 12:50 PM, msproul mspr...@suddenlink.net wrote:
What is the normally expected oven temperature range of the Thunderbolt?
Over the past year the temperature of my Tbolt, as reported by Lady
Heather,
has slowly increased from the low 40s C to
What is the normally expected oven temperature range of the Thunderbolt?
Over the past year the temperature of my Tbolt, as reported by Lady Heather,
has slowly increased from the low 40s C to the high 40s. The maximum
temperature has now crept up to 50 C and is shown today at 50.8 C.
That's
On Mon, Apr 4, 2011 at 9:50 AM, msproul mspr...@suddenlink.net wrote:
What is the normally expected oven temperature range of the Thunderbolt?
Over the past year the temperature of my Tbolt, as reported by Lady Heather,
has slowly increased from the low 40s C to the high 40s. The maximum
On 04/04/2011 02:42 AM, John Ackermann N8UR wrote:
A couple of years ago I picked up a surplus Aeroantenna choke-ring GPS
antenna that I think was intended for surveying use. I finally got it
installed today and noticed that it has an arrow on the bottom
indicating that the antenna should be
On Mon, Apr 04, 2011 at 07:19:38AM -0400, Chuck Harris wrote:
Basically, the higher the division ratio in a PLL synthesizer,
which is what you are describing, the greater the phase noise.
No question about that, indeed.
But I am talking about a very low bandwidth loop
Hal,
Here are the results I got using your suggestion. The numbers may be a
bit different than last night as I'm not sure I'm using the same
cable.
A+, B+ = 18.9 ns
A-, B- = 19.4 ns
Obviously there is some difference in delay between the A and B
channels. Otherwise, the two numbers would have
Original Message
Subject: Re: [time-nuts] GPS antenna with direction orientation?
From:Tom Van Baak t...@leapsecond.com
Date:Sun, April 3, 2011 6:58 pm
To: Discussion of precise time and frequency measurement
I'm keeping the newbie question in the subject for those who wish to
ignore this thread. To those who respond, your contribution to the
diminution of my ignorance is appreciated :-)
I had borrowed two different 5328A counters. I just compared them,
using the exact same coax, connectors and
Does the counter have setable input threasholds? Most do. Are they set the
the same?
-John
I'm keeping the newbie question in the subject for those who wish to
ignore this thread. To those who respond, your contribution to the
diminution of my ignorance is appreciated :-)
I
Here are the results I got using your suggestion. The numbers may be a bit
different than last night as I'm not sure I'm using the same cable.
A+, B+ = 18.9 ns
A-, B- = 19.4 ns
Obviously there is some difference in delay between the A and B channels.
Otherwise, the two numbers would have
John,
Yes, they both do. However, only one has the DVM option that lets me
measure the voltage trigger levels. When I turned off preset and set
the levels manually to match, I got similar numbers to using preset.
On Mon, Apr 4, 2011 at 10:13 PM, J. Forster j...@quik.com wrote:
Does the counter
Hal, replies inline.
On Mon, Apr 4, 2011 at 10:21 PM, Hal Murray hmur...@megapathdsl.net wrote:
Here are the results I got using your suggestion. The numbers may be a bit
different than last night as I'm not sure I'm using the same cable.
A+, B+ = 18.9 ns
A-, B- = 19.4 ns
Obviously there
Another interesting measurement would be to use the timebase output and
external reference to compare the readings using the same timebase.
Or are you already using a gpsdo?
On Apr 5, 2011, at 12:08 AM, Joseph Gray jg...@zianet.com wrote:
I'm keeping the newbie question in the subject for
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