Hi
The answer is (as always) no free lunch. An op amp simulating a capacitor is
always going to be performance limited. Different limitations come in with
different circuits, but they all suffer from noise / drift / leakage. Put
another way - for a long time constant, you are just as good off
Kasper,
I like your style! Small ROM = no inessential features! I shall be
studying this code, getting capture working with no capture hardware
is a real pain.
On 2 January 2012 00:53, Kasper Pedersen time-n...@kasperkp.dk wrote:
On 01/01/2012 12:23 PM, Tom Harris wrote:
I too have been
: [time-nuts] Thunderbolt?
Looks to be a reasonable solution.
Not spectacular, cost wise . just reasonable.
Plug and play with multivoltage PS, active antenna, and T'Bolt.
All you will need is Lady Heather to whip things into shape.
Stan, W1LE Cape Cod
On 12/28/2011 7:50
Hi
If you do a quick Google search for insulation resistance you get to:
http://www.electrocube.com/support/insulation_resistance.asp
or a bunch of similar information. The capacitor it's self (no external
resistance at all) has a time constant between it's capacitance and internal
leakage.
Here is another analog control example based on the quick and dirty example
below.
It is a simple and Very poor GPSDO Rb design as far as noise jitter goes
because of the nonlinear and high Phase detector gain, and high 1e-8 noise
jitter on the PPS,
but still no problem to do with cheap
My FE-5680A and Thunderbolt have been well behaved for the
last 16 hours. The Thunderbolt is using 3.00 FW and had its
feedback settings optimized by Lady Heather. AMU mask is 7.0.
No adjustments were made to the Rb during this run.
--
Chuck Forsberg WA7KGX N2469R c...@omen.com
PI controllers can be implemented analog only. For the PPS they need
large capacitors that are the equivalent of averaging (sum and accumulate)
in a software implemented controller.
On Sat, Dec 31, 2011 at 7:54 AM, Chris Albertson
albertson.ch...@gmail.comwrote:
On Fri, Dec 30, 2011 at
In my opinion you have to look at it from the point of application.
Hopefully I will be able to share the test results soon. For us DNL is key, INL
is specked over the full range and since we use it in a filter application,
based on the data that I have, can be ignored.
In a Rb application
Chris
Here is a GPSDO I built that better fits Your definition of Simple. I used
this as my freq standard before getting a TBolt.
1) Feed the PPS output of an oncore GPS timing engine which has 1 Hz or
better yet 100 Hz output to the clk of a D FlipFlop (74HC74)
2) Feed the FF's D from a
I think this is the simplest design that can still work, just one flip
flop, divider and a capacitor.
What level of performance did you get?I think it depends on how big the
integrating capacitor is and how stable the VCXO is. I guess if you
switched to using the t-bolt the performance was
this to measure and/or manually set a Rb Osc to be on frequency if
you have an accurate 1PPS signal.
ws
[time-nuts] Thunderbolt? (re simple gpsdo.)
Chris Albertson albertson.chris at gmail.com
Sat Dec 31 20:34:14 UTC 2011
I think this is the simplest design that can still work, just
of D FF as a basic ns hi-low Phase
detector for low freq signals.
Remove the EFC feedback, Reduce the 100 to 1 divider to two or so and
you
can use this to measure and/or manually set a Rb Osc to be on frequency
if
you have an accurate 1PPS signal.
ws
[time-nuts] Thunderbolt
As soon as you say Software the device is no longer simple.Even a
microprocessor is a very complex device and so is its development system.
The software inside the uP is not simple either if you count the number of
possible paths through the code (2 raided to the power of the number of
On Sat, 31 Dec 2011 17:56:46 -0800, Hal Murray
hmur...@megapathdsl.net wrote:
This looks like fun to me, but I like writing that sort of code. Note that
it doesn't need an OS or even any libraries.
Both designs look fun to me but for different reasons. The analog
design requires attention to
On Sat, Dec 31, 2011 at 5:56 PM, Hal Murray hmur...@megapathdsl.net wrote:
As soon as you say Software the device is no longer simple.Even a
microprocessor is a very complex device and so is its development system.
The software inside the uP is not simple either if you count the number
: [time-nuts] Thunderbolt? (re simple gpsdo.)
One of the designs using the 10 kHz output from a Jupiter gps engine
and a simple PLL to discipline an ocxo might be good starting point if
suitable gps engines are still available. There won't be much to tweak but
the performance could be quite
The analog computer is the standard good-old-PLL: if you have the 10KHz
from a Jupiter than your analog filter will be simple to build. If you have
only the PPS (or 100PPS from an Oncore) your analog filter will require
more attention (and large capacitors) but I think it is realizable. You
analog
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
One of the designs using the 10 kHz output from a Jupiter gps engine and a
simple PLL to discipline an ocxo might be good starting point if suitable gps
engines are still available. There won't be much to tweak
On Thu, Dec 29, 2011 at 8:24 PM, Mark Spencer mspencer12...@yahoo.ca wrote:
One of the designs using the 10 kHz output from a Jupiter gps engine and a
simple PLL to discipline an ocxo might be good starting point if suitable gps
engines are still available. There won't be much to tweak but
PM
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
One of the designs using the 10 kHz output from a Jupiter gps engine
and a simple PLL to discipline an ocxo might be good starting point if
suitable gps
Yes, it can be done based on a PPS only timing. You must design a PI (maybe
PID) regulator: the EFC must stay steady when the phase difference between
the two PPSes is zero (integral action). Then you must move the EFC (when
there is a difference) proportionally with the difference itself and only
There is no reason you can not do that.
It is tricky because the low comparison frequency limits the loop
bandwidth like any sampled data system and the analog requirements for
the low frequency design become an issue do to leakage and the
impedance levels needed. The long time constants
What is the simplest design for a GPSDO that uses only the PPS signal from
a modern GPS?
Some sort of oscillator with a voltage control.
CPU with a timer/counter that can capture the PPS.
DAC.
Software.
Drive the CPU from the osc so you can count cycles between PPS pulses. Use
the DAC to
acquired used on an auction site.
--- On Fri, 12/30/11, Hal Murray hmur...@megapathdsl.net wrote:
From: Hal Murray hmur...@megapathdsl.net
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Received: Friday
, see
www.dlpdesign.com/images/bit-bang-usb.pdf
From: Mark Spencer mspencer12...@yahoo.ca
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Fri, December 30, 2011 2:13:41 PM
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo
Hi Chris,
I just finished reading about that one. It requires no longer
available GPS reciever. Maybe I should r-phrase the question:
Most of us get (re)used stuff... Ebay #300437642776 has some Rockwell era
receivers. Many time-nuts find HP5065A rubidiums and 5370 counters
available and
What is the simplest design for a GPSDO that uses only the PPS signal
from
a modern GPS?
Some sort of oscillator with a voltage control.
CPU with a timer/counter that can capture the PPS.
DAC.
Software.
How about MSC1200 : http://www.ti.com/lit/ds/symlink/msc1200y3.pdf
Stanley
www.dlpdesign.com/images/bit-bang-usb.pdf
From: Mark Spencermspencer12...@yahoo.ca
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Sent: Fri, December 30, 2011 2:13:41 PM
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
On a related
May I suggest use of small controllers such as the Picaxe series? I find
them very useful around the lab for small tasks such as this. Easily
programmed, very reliable, and the software application can be as simple
or complex as needed, for example the suggested PID controller. No
soldering, no
I believe those Rockwells have a 10 KHz output. Not a bad price.
73 es HNY, Dick, W1KSZ
-Original Message-
From: b...@lysator.liu.se
Sent: Dec 30, 2011 12:42 PM
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt? (re simple
, 2011 12:42 PM
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
Hi Chris,
I just finished reading about that one. It requires no longer
available GPS reciever. Maybe I should r-phrase the question
The DAC and it's voltage reference looks to be the weak link in the digital
control and the simple goal. The CPU I mentioned before on closer look
doesn't have a good DAC. The 20 bit TI DAC1220 looks better but not sure you
can find it in the same package as the CPU. The cheap Rb standards with
On 12/30/11 11:39 AM, Robert LaJeunesse wrote:
How about USB to an FT232 that talks SPI to a low-cost DAC or digital pot? Would
need a stable reference, though.
There's a bunch of eval boards from LTC, etc. which use this strategy.
Looks like a serial port to the computer, simple ASCII
Yes, the DAC+reference is challenging and one way to go may be the
coarse+fine approach to avoid large (18bit and beyond) DAC. My last GPSDO
has an 18bit DAC but now I'm thinking to try the 8bit digital pot + 16bit
DAC op-amp combined. The reference can't be overlooked anyway.
On Fri, Dec 30,
Yes, the DAC+reference is challenging and one way to go may be the
coarse+fine approach to avoid large (18bit and beyond) DAC. My last GPSDO
has an 18bit DAC but now I'm thinking to try the 8bit digital pot + 16bit
DAC op-amp combined. The reference can't be overlooked anyway.
Be careful,
Over the last two years along with two list members that may want to pipe
in, I have spend a large amount of time on D/A's and we went as far as
developing a test board using the LTC 2440 and testing numerous D/A's taking in
to consideration performance, solderability, cost, availability
No free lunch, of course, but I want to avoid dithering DACs. The 18bit DAC
(AD5680) is a 16bit+dithering, I think to use the AD5660 + AD5241 (already
available) the pot has a tempco of 30ppm/degree and a noise of
14nV/sqr(Hz). Maybe I have to find something better but to make the first
try is
...@megapathdsl.net
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Fri, December 30, 2011 5:35:56 PM
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
Yes, the DAC+reference is challenging and one way to go may be the
coarse+fine approach to avoid large (18bit
: time-nuts-boun...@febo.com
Date: Fri, 30 Dec 2011 17:48:24
To: time-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
Over the last two years along with two list members that may want
I was thinking ... starting with a 5680a and a GPS with
accurate 1pps but no 10 MHz ...
Feed both 1pps signals to a 74ls123 to stretch the pulses to something
longer.
A 74ls74 is strobed by one of the one-shots, its D input being the other
one-shot.
Connect both one-shots and the 74 to an
Did you test the LTC1655 INL? The data sheet says plus or minus 20
counts maximum.
I suspect Linear Technology designed those low DNL high INL parts for
just this sort of application where only monotonic behavior really
matters. Their equivalent current output DAC costs about twice as
much not
Don't need to stretch, use the two hardware interrupt pins...
Don
Chuck Forsberg WA7KGX N2469R
I was thinking ... starting with a 5680a and a GPS with
accurate 1pps but no 10 MHz ...
Feed both 1pps signals to a 74ls123 to stretch the pulses to something
longer.
A 74ls74 is strobed by one of
On Fri, Dec 30, 2011 at 10:16 AM, Hal Murray hmur...@megapathdsl.net wrote:
What is the simplest design for a GPSDO that uses only the PPS signal from
a modern GPS?
Some sort of oscillator with a voltage control.
CPU with a timer/counter that can capture the PPS.
DAC.
Software.
As soon as
The era of cheap Thunderbolts appears to be history.
What is the simplest GPSDO you can build? There are many designs
around but when the T-Bolts came out I think people lost interesting
building.
I think something very simple could work. If your local oscillator is
at all decent it will
One of the designs using the 10 kHz output from a Jupiter gps engine and a
simple PLL to discipline an ocxo might be good starting point if suitable gps
engines are still available. There won't be much to tweak but the performance
could be quite good.
My first gpsdo was a manufactured version
@febo.com
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
One of the designs using the 10 kHz output from a Jupiter gps engine and a
simple PLL to discipline an ocxo might be good starting point if suitable gps
engines are still available. There won't be much to tweak but the performance
Spencer mspencer12...@yahoo.ca
Sent: Dec 29, 2011 9:24 PM
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt? (re simple gpsdo.)
One of the designs using the 10 kHz output from a Jupiter gps engine and a
simple PLL to discipline
I am interested in increasing my lab accuracy from the Rb units by using
a Thunderbolt. I see kits advertised on feebay, such as
http://www.ebay.com/itm/270515147719
and I was wondering if this was a good choice. I would certainly have
to get a compatible antenna anyhow, and the power
Looks to be a reasonable solution.
Not spectacular, cost wise . just reasonable.
Plug and play with multivoltage PS, active antenna, and T'Bolt.
All you will need is Lady Heather to whip things into shape.
Stan, W1LE Cape Cod
On 12/28/2011 7:50 PM, Peter Gottlieb wrote:
I am
measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt?
Looks to be a reasonable solution.
Not spectacular, cost wise . just reasonable.
Plug and play with multivoltage PS, active antenna, and T'Bolt.
All you will need is Lady Heather to whip things into shape.
Stan, W1LE
and frequency
measurementtime-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt?
Looks to be a reasonable solution.
Not spectacular, cost wise . just reasonable.
Plug and play with multivoltage PS
and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt?
The era of cheap Thunderbolts appears to be history.
On 12/28/2011 05:07 PM, shali...@gmail.com wrote:
All you will need is Lady Heather to whip things into shape.
Don't forget my Thunderbolt Monitor
Looks to be a reasonable solution.
Not spectacular, cost wise . just reasonable.
Plug and play with multivoltage PS, active antenna, and T'Bolt.
All you will need is Lady Heather to whip things into shape.
Stan, W1LE Cape Cod
On 12/28/2011 7:50 PM, Peter Gottlieb wrote:
I am
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt?
The era of cheap Thunderbolts appears to be history.
On 12/28/2011 05:07 PM, shali...@gmail.com wrote:
All you will need is Lady Heather to whip things into shape.
Don't forget my Thunderbolt Monitor if you do not want to keep a PC
I still think anything under $250 for a full kit with a decent antenna
is a great price.
-pete
On Wed, Dec 28, 2011 at 5:01 PM, Stan, W1LE stanw...@verizon.net wrote:
Looks to be a reasonable solution.
Not spectacular, cost wise . just reasonable.
Plug and play with multivoltage PS,
For that money I'd want to know the make and model of the antenna (:
--
On Wed, 28 Dec, 2011 9:39 PM EST Pete Lancashire wrote:
I still think anything under $250 for a full kit with a decent antenna
is a great price.
-pete
On Wed, Dec 28, 2011 at 5:01 PM, Stan,
On 25/11/2011 22:55, Justin Pinnix wrote:
Nuts,
A while back, I scored an old Compaq iPaq Pocket PC for cheap at an
auction. Recently, I wrote a program for it that reads the time and health
information from a Thunderbolt and displays it in real-time. More info
available here:
On 28/11/2011 04:00, Justin Pinnix wrote:
Sounds like a good idea for a modern handheld, but the relics we are
talking about don't have WiFi or any means of networking except for serial
and IR.
I've been wondering what to do with an old HP HX4700 for ages so it
looks like it may have a new
On Sun, Nov 27, 2011 at 8:00 PM, Justin Pinnix jus...@fuzzythinking.com wrote:
Sounds like a good idea for a modern handheld, but the relics we are
talking about don't have WiFi or any means of networking except for serial
It's 2011, almost 2012. I assumed every human over the age of 10
Chris, I think you and I are trying to accomplish different goals. I want
to be able to glance up and see (exactly) what time it is. It's just a
glorified wall clock that's always on and displaying a time. The health
information is just to validate the time.
I do have an iPad. Yes, the same
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Thunderbolt Monitoring for Pocket PC
Nuts,
A while back, I scored an old Compaq iPaq Pocket PC for cheap at an
auction.
Recently, I wrote a program for it that reads the time and health
information from
.
From: Justin Pinnix jus...@fuzzythinking.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, 25 November 2011, 22:55
Subject: [time-nuts] Thunderbolt Monitoring for Pocket PC
Nuts,
A while back, I scored an old Compaq iPaq Pocket PC
cost.
Thank you for making this avialable.
Robert G8RPI.
From: Justin Pinnix jus...@fuzzythinking.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Friday, 25 November 2011, 22:55
Subject: [time-nuts] Thunderbolt
On Nov 25, 2011, at 3:55 PM, Justin Pinnix wrote:
A while back, I scored an old Compaq iPaq Pocket PC for cheap at an
auction. Recently, I wrote a program for it that reads the time and health
information from a Thunderbolt and displays it in real-time. More info
available here:
...@febo.com] On
Behalf Of Kevin Rosenberg
Sent: 26 November 2011 17:13
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Monitoring for Pocket PC
On Nov 25, 2011, at 3:55 PM, Justin Pinnix wrote:
A while back, I scored an old Compaq iPaq Pocket PC for cheap
: Saturday, 26 November 2011, 17:12
Subject: Re: [time-nuts] Thunderbolt Monitoring for Pocket PC
On Nov 25, 2011, at 3:55 PM, Justin Pinnix wrote:
A while back, I scored an old Compaq iPaq Pocket PC for cheap at an
auction. Recently, I wrote a program for it that reads the time and health
information
: Kevin Rosenberg ke...@rosenberg.net
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Saturday, 26 November 2011, 17:12
Subject: Re: [time-nuts] Thunderbolt Monitoring for Pocket PC
On Nov 25, 2011, at 3:55 PM, Justin Pinnix wrote:
A while back, I scored an old
...@febo.com] On
Behalf Of Justin Pinnix
Sent: Friday, November 25, 2011 2:56 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Thunderbolt Monitoring for Pocket PC
Nuts,
A while back, I scored an old Compaq iPaq Pocket PC for cheap at an auction.
Recently, I wrote
Rosenberg ke...@rosenberg.net
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Saturday, 26 November 2011, 17:12
Subject: Re: [time-nuts] Thunderbolt Monitoring for Pocket PC
On Nov 25, 2011, at 3:55 PM, Justin Pinnix wrote:
A while back, I scored an old Compaq
25, 2011 2:56 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Thunderbolt Monitoring for Pocket PC
Nuts,
A while back, I scored an old Compaq iPaq Pocket PC for cheap at an auction.
Recently, I wrote a program for it that reads the time and health
information
Hi Justin:
Unsure about the Jornada - there were numerous models. If you don't
have a
serial port, that's going to be a problem. Perhaps you do and it's a
matter of cabling? Which model number is yours?
I have a 568, and there is a serial cable, also USB for sync.
I can try it out when I
Nuts,
A while back, I scored an old Compaq iPaq Pocket PC for cheap at an
auction. Recently, I wrote a program for it that reads the time and health
information from a Thunderbolt and displays it in real-time. More info
available here: http://www.fuzzythinking.com/projects/thunderhead/
I may
Anyone know what bit 11 (0x0800) of the Thunderbolt's minor alarm field
is? My documentation stops at bit 8 (test mode).
Thanks,
-JP
___
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To unsubscribe, go to
I do assume this is because of the 1024 week cycle? if so would it be
possible to tell the GPS what cycle it should be?
Would the 10MHz out still be accurate?
BR. Thomas.
2011/10/20 Mark Sims hol...@hotmail.com:
On July 30, 2017 all our Thunderbolts turn into back-dated pumpkins...
Hi gang
I'm getting an error message of vco near rail or vco at rail.
Is this saying my thunderbolt is dying or can this be fixed?
-Rix Seacord
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Rix
If you are using LadyHeather, Post or send me a screen shot using W S
Cr
Maybe just that the min or max Dac values are not set to - + 5V, or
something else easily fixed.
ws
[time-nuts] Thunderbolt error?
Rix Seacord eseacord at verizon.net
Hi gang
I'm getting
are using LadyHeather, Post or send me a screen shot using
W S Cr
Maybe just that the min or max Dac values are not set to - + 5V, or
something else easily fixed.
ws
[time-nuts] Thunderbolt error?
Rix Seacord eseacord at verizon.net
Hi gang
I'm getting an error message of vco
Rix
Nothing looks wrong in that snap Shot
Your osc (which is the main cause of the out of range error) is working fine
and under control and has near zero volts on it's EFC.
Take a look at the screen when you key , that has the screen with the
Max and min DAC setting info on it.
Should be
Warren
When I had the temp set at a higher gain and the offset to center the
trace, it would basically flat line then suddenly be all over the place.
Are the chips available anyplace? I do have a bit of experience of
soldering.
Thanks again.
Ewing (Rix) Seacord K2AVP
Putnam County RACES Radio
Hey, folks -
I have one of the first lot of time-nuts Thunderbolts for sale.
It's a revision E and still works perfectly. $140. including
shipping to the US.
Contact me off list at w5juv at arrl dot net.
Doug
___
time-nuts mailing list --
To: 'Discussion of precise time and frequency measurement'
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt hardware revisions
Hi
The real question is what's the date code on the unit? If the rev E part
is
old enough to have the good thermometer chip in it - that's the one to
get
-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of George Dubovsky
Sent: Thursday, August 11, 2011 7:23 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt hardware revisions
All,
The Label you are referring to is applied
, August 09, 2011 10:19 PM
To: time-nuts@febo.com
Subject: [time-nuts] Thunderbolt hardware revisions
Hi,
I'm brand new to the time-nut odessy thing so please bear with me. ;-)
I'm in the market to buy a used Thunderbolt, I have found a vendor that's
selling used Thunderbolt receivers and states
' time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt hardware revisions
Hi
The real question is what's the date code on the unit? If the rev E part is
old enough to have the good thermometer chip in it - that's the one to get.
Bob
-Original Message-
From: time-nuts-boun...@febo.com
(or even cares) where to find it.
73, Dick, W1KSZ
-Original Message-
From: Bob Camp li...@rtty.us
Sent: Aug 10, 2011 9:59 AM
To: 'Discussion of precise time and frequency measurement'
time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt hardware revisions
Hi
The real
Hi,
I'm brand new to the time-nut odessy thing so please bear with me. ;-)
I'm in the market to buy a used Thunderbolt, I have found a vendor that's
selling used Thunderbolt receivers and states one can have the choice of
PCB
revisions A, B or E.
Does anyone have any specific info or
I finally took the plunge and ordered a thunderbolt on eBay and it
showed up on my doorstep today.
Of course, I haven't saved those old emails about where to get things
such as GPS antennas and power supplies. If someone could please point
me to sources, I'd appreciate it.
Also,
Hi
You obviously will need +12, -12 and +5 supplies at the proper current levels.
Any GPS antenna that will run on 5 volts will work for checkout. There are good
pictures on the web showing what power goes to which pins. Current levels are
10 ma on -12, ~ 300 ma on +5 and a bit under 1A at
with a Neg supply less than -3 volts, It
may of been able to go even lower, I just wanted to insure it was reliable
with -5 volts for my application.
**
[time-nuts] Thunderbolt no usable sats.
Arthur Dent golgarfrincham at yahoo.com
It may or may not be used for tuning voltage
I bougth an Thunderbolt off E-bay some time ago, to use as
reference for my spectrum analyzer and signal generators.
I had it connected up with a couple of power supplies and it
worked as it should. Today I put together an voltage inverter
to get the -12V to the GPS in order to use it with an
the -12 VDC is also used by the OCXO as tuning voltage! Bert Kehren
In a message dated 6/12/2011 6:05:01 A.M. Eastern Daylight Time,
golgarfrinc...@yahoo.com writes:
I bougth an Thunderbolt off E-bay some time ago, to use as
reference for my spectrum analyzer and signal generators.
I
Arthur Dent-The -12 VDC is used for the RS-232 so if that
was giving you the problem you wouldn't see anything on your
com port (note it will work at -7 VDC or so)...
the -12 VDC is also used by the OCXO as tuning voltage! Bert Kehren
It may or may not be used for tuning voltage but
The -12V is almost certainly used for deriving the tuning voltage. The unit
can generate a tuning voltage of -5V to +5V. To do this it needs a negative
supply... and there does not seem to be an on board bias generator for
generating the negative DAC supply. Becuase of this, for best
Thank you Mark. It is not almost certain it is a fact.
Bert
-Original Message-
From: Mark Sims hol...@hotmail.com
To: time-nuts@febo.com
Sent: Sun, Jun 12, 2011 10:04 am
Subject: [time-nuts] Thunderbolt no usable sats.
The -12V is almost certainly used for deriving
It may or may not be used for tuning voltage but what I said is
100% correct. The Andrew/Grayson units these T-Bolts were
used in provided -7 VDC for this negative supply and the same
T-Bolts work properly on -12 VDC. If this voltage is missing, the
com port will not work.
+++
Please
IF you do not need the DAC output to go all the
way to neg -5Volts.
ws
PS I did not test for the effects with a Neg supply less than -3 volts, It may
of been able to go even lower, I just wanted to insure it was reliable with -5
volts for my application.
**
[time-nuts
.
**
[time-nuts] Thunderbolt no usable sats.
Arthur Dent golgarfrincham at yahoo.com
It may or may not be used for tuning voltage but what I said is
100% correct. The Andrew/Grayson units these T-Bolts were
used in provided -7 VDC for this negative supply and the same
T-Bolts work properly on -12
WarrenS-.As long as the Dac out (OSC EFC input) is than a
couple of volts above the neg supply (or the EFC is positive) all
worked fine at any Neg supply down to -3 volts.
This is because most RS232 receivers don't need their input to swing
negative.
Your -7 volts statement agrees well
I bougth an Thunderbolt off E-bay some time ago, to use as reference
for my spectrum analyzer and signal generators.
I had it connected up with a couple of power supplies and it worked as
it should.
Today I put together an voltage inverter to get the -12V to the GPS in
order to use it with an
Hello Thomas,
The first question is did you measure the minus 12 output of your inverter to
make sure it was not being loaded down too far when powering the Thunderbolt ?
If it was working on the original minus 12 volt supply properly, then it would
seem that there is a problem with your
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