Chris wrote:
can I T off the T/Thunderbolt 10MHz feed to
this board and take a second sine wave output direct from the
Thunderbolt, to drive a transceiver GPS disciplined 10 MHz frequency
standard input as well as having it feed the divider baord
The input impedance of the divider board is nom
On Fri, Mar 27, 2015 at 10:29 AM, Chuck Harris wrote:
> The biggest problem I see is the crystal oscillator in the
> rocket is going to notice the G forces during acceleration
> in a pretty big way.
But all of the ground stations will see the same frequency shift on the
rocket's transmitter.
The telco equipment that all these Tbolts came from had the
10 Mhz output feed 2 different modules using a MicroCircuits
ZFSC-2-1-S two-way 0° 50 ohm power splitter. There are some
of these splitters for sale on Ebay but almost any other
similar unit should work.
___
27/03/2015 17:14
My T/Thunderbolt has operated flawlessly for some years feeding a
David Partridge frequency divider board. The board gives 10Mhz and
lower divisions of 10MHz down to the KHz level out, as square waves.
What I need to know is, can I T off the T/Thunderbolt 10MHz feed to
this bo
>Luke, the HP5335A was introduced in around 1980 and has an early
>(pre-IEEE-488.2) HP implementation of IEEE-488 which requires a
>terminator character at the end of each string. According to the manual,
>this terminator can be a comma, semicolon, space, carriage return, or
>line feed character.
The biggest problem I see is the crystal oscillator in the
rocket is going to notice the G forces during acceleration
in a pretty big way. Time nuts easily notice the reversal
in a 1G force on a laboratory oscillator caused by flipping
it on its back for service.
But all is not even close to los
Your second method is by far the best. But it can be simplified. All you
need is two very stable oscillators, one in the rocket and one some known
fixed location. Then you ground stations can be just dumb recorders that
record both signals. In post processing you compare the relative phases.
L
Robert;
It seems that a Doppler system should work for you.
But first, you have a problem. If you want to track your rocket
to 100K feet (20 miles) using some form of triangulation then you
need your receiving stations further apart than 1 mile. Your
triangle is too extreme and any measuremen
NASA uses the Doppler effect for deep space navigation, by integrating
the velocity.
You'd need a very stable oscillator, but you don't need a powered oven,
due to the short duration of the flight.
You only need one receiver. In fact, if it's possible for the rocket to
hear a ground signal and ret
Many thanks for all the comments and help with this comparison - I have now
updated the page, and the results are more in keeping with what would be
expected. The BBB is better if time serving is its only function, although
keep it well away from any GPS antennas!
http://www.satsignal.eu/ntp
On Thu, 26 Mar 2015 12:32:33 -0500
Robert Watzlavick wrote:
> Thanks for the suggestion. Does the DSSS make it easier to correlate
> between ground stations? I'm not sure how to handle the phase offset
> on the 10 MHz ref clocks.
The DSSS allows you to make the integer ambiguity, you have with
On Thu, 26 Mar 2015 18:57:25 -0700
"Willis" wrote:
[u-blox LEA6-T]
> Is it possible that this also has a systematic offset or is this just
> contributing to the observed noise level around the mean?
No, the PPS is calculated from the time send by the satellites.
In worst case, the PPS is off
On 3/25/2015 10:50 PM, Dave Martindale wrote:
Perhaps a trip to Connecticut is in order this fall ...
I grew up in CT. Mystic is a very beautiful place and the Seaport
Museum was pretty nice the last time I was there. Wow...that was 20
years ago...how time flies...
thanks and 73,
ben, kd5
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