Jim Lux wrote:
On 9/9/12 9:37 PM, li...@lazygranch.com wrote:
What am I missing here? Vce = Vbe, so the diode connected transistor
isn't saturated.
I think it's where the diode is fully conducting, and into the linear
part of the V/I curve, not in the square law part any more.
In normal
On 9/9/12 9:37 PM, li...@lazygranch.com wrote:
What am I missing here? Vce = Vbe, so the diode connected transistor isn't
saturated.
I think it's where the diode is fully conducting, and into the linear
part of the V/I curve, not in the square law part any more.
In normal use the LO port
Not transistor saturation but mixer saturation where the RF input is
sufficiently that for a given LO level the IF output level is saturated
(ie doesnt increase (or increases very slowly) with increasing RF signal
level).
Bruce
li...@lazygranch.com wrote:
What am I missing here? Vce = Vbe, s
What am I missing here? Vce = Vbe, so the diode connected transistor isn't
saturated.
-Original Message-
From: Bob Camp
Sender: time-nuts-boun...@febo.com
Date: Sun, 9 Sep 2012 19:16:22
To: Discussion of precise time and frequency measurement
Reply-To: Discussion of precise time and fre
On 09/10/2012 02:14 AM, Bob Camp wrote:
Hi
Except that on the same basis, the non-timing GPS gear is in the $10 to $20
range…
True, but better performance is reachable on a private budget.
Cheers,
Magnus
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Hi
Except that on the same basis, the non-timing GPS gear is in the $10 to $20
range…
Bob
On Sep 9, 2012, at 7:55 PM, b...@lysator.liu.se wrote:
> Hi Bob,
>
> This argument has been done before on time-nuts... sorry for repeating.
>
> There are geodetic quality GPS reveivers, like the Ashtech
Hi Bob,
This argument has been done before on time-nuts... sorry for repeating.
There are geodetic quality GPS reveivers, like the Ashtech Z12-CORS (with
external 5-20MHz input - not the true Z12 Metronome) available for a few
hundred dollars occasionally. I got my Z12 CORS for free, from a site
On 09/10/2012 01:28 AM, Bob Camp wrote:
Hi
Indeed true for most non-geodetic gps units. Put another way - true unless you
have a lot of money.
Well, you raise up from the normal noise just by adding carrier phase
support and external clock. Can you do double frequency it's even
better. Doub
Hi
Indeed true for most non-geodetic gps units. Put another way - true unless you
have a lot of money.
Bob
On Sep 9, 2012, at 7:25 PM, b...@lysator.liu.se wrote:
> Hi Bob,
>
> Probably true for Motorola Oncores. Not very true for geodetic receivers.
>
> Until you have a receiver clock that i
Hi Bob,
Probably true for Motorola Oncores. Not very true for geodetic receivers.
Until you have a receiver clock that is on par with the satellite clocks
AND you are short on visable satellites. This might be true if you can
load up a modern cesium in your vehicle, and go for a downtown "urban
v
On 09/09/2012 11:05 PM, Chris Albertson wrote:
On Sun, Sep 9, 2012 at 1:14 PM, wrote:
True for a cheap oem navigation receiver. Not true for a geodetic quality
receiver, who usually have some options (external frequency input, PPS_in)
to make them the best timing receivers available. However t
Hi
….. and of course, once you go into saturation the mixer doesn't look much like
50 ohms any more. Sort of gets us back to terminations again.
Bob
On Sep 9, 2012, at 6:21 PM, Bruce Griffiths wrote:
> NIST have indicated that mixer PN noise measurements with a non dissipative
> terminations
> On Sun, Sep 9, 2012 at 1:14 PM, wrote:
>
>> True for a cheap oem navigation receiver. Not true for a geodetic
>> quality
>> receiver, who usually have some options (external frequency input,
>> PPS_in)
>> to make them the best timing receivers available. However they are much
>> more expensive
On 09/10/2012 12:21 AM, Bruce Griffiths wrote:
NIST have indicated that mixer PN noise measurements with a non
dissipative terminations (even RF) are intended to be made.
Using a discrete mixer using diode connected transistors may also be
useful at least for 5MHz and 10MHz input frequencies in
In the late 60s I built a VLF upconverter using a ring mixer.
I tried a few different devices for the diodes.
The base/collector junctions of germanium switching transistors
gave the best results.
On 09/09/2012 03:21 PM, Bruce Griffiths wrote:
NIST have indicated that mixer PN noise measurements
NIST have indicated that mixer PN noise measurements with a non
dissipative terminations (even RF) are intended to be made.
Using a discrete mixer using diode connected transistors may also be
useful at least for 5MHz and 10MHz input frequencies in that their
flicker noise can be significantly
Sounds like the Heisenberg Uncertainty principle at work :-)
jerry
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Bob Camp
Sent: Sunday, September 09, 2012 5:53 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [
Hi
Position accuracy and timing accuracy are two very different things. Firmware
is optimized to improve either one. "Position" firmware is often pretty poor
for timing.
Bob
On Sep 9, 2012, at 5:05 PM, Chris Albertson wrote:
> On Sun, Sep 9, 2012 at 1:14 PM, wrote:
>
>> True for a cheap
Hi
In general, you terminate the mixer in 50 ohms at the RF frequencies (say 10
and 20 MHz). Termination at the "IF" (in this case audio) frequencies is what
turns out to be tricky. Any time you terminate a source in a high impedance,
you get a higher output voltage. Reactance rarely adds noise
Bruce is correct. For best RF performance in an "rf" environment
the use of 50ohms for all ports is a
good start. However, even in RF designs
you can often optimise a mixer spec
with something other than 50 ohms.
With a VLF IF freq like a DMTD, each
mixer model might have an ideal
termination impe
I have a Junghans. I can't say it is easy on the batteries. Otherwise they
work. I regret not getting the glows in the dark version.
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On Sun, Sep 9, 2012 at 1:14 PM, wrote:
> True for a cheap oem navigation receiver. Not true for a geodetic quality
> receiver, who usually have some options (external frequency input, PPS_in)
> to make them the best timing receivers available. However they are much
> more expensive than the typi
David Kirkby wrote:
On 9 September 2012 18:28, Pascual Arbona wrote:
Hello Brian,
I am a radio amateur and and also in the Time nuts list, At the
moment I am planning to bild a DMTD for experimentation. and as you have a nice
experience in this field , for me
The waveceptor's are okay but I can't wear mine much because I tend to
cross timezones a lot. The hands only run in one direction so when
going to the west, it has to spin 11 hours forward. This takes 20
minutes. I guess it's one way to kill time on an airplane.
-Bob
On Sun, Sep 9, 2012 at 1:
On 9 September 2012 18:28, Pascual Arbona wrote:
>
>
> Hello Brian,
> I am a radio amateur and and also in the Time nuts list, At the
> moment I am planning to bild a DMTD for experimentation. and as you have a
> nice experience in this field , for me will be very wellc
Chris,
> On Sun, Sep 9, 2012 at 6:18 AM, Don Oconnor wrote:
>> Hello,
>>
>>
>>
>> I would like to design and build a microcontroller based GPSDO. And I
>> have a couple of questions some of you may be able to answer.
>>
>>
>>
>>
>>
>> 1. I am going to use Trimble SMT GPS timing module but
For this particular application a capacitive termination (NIST used such
a termination in their DMTDs) of the IF port followed by a low pass
filter is advantageous.
For precision work screw connectors (SMA, TNC, N etc) are more stable
than bayonet connectors like the BNC.
Bruce
J. Forster wro
I have a $49 Casio Wave Ceptor, white face black numerals, analog hands
including second hand, date, alarm and WWVB syncing in the middle of the night.
Only had to replace the battery once and it ticks are closer than I can discern
when comparing to WWV @ 10or 15 Mhz.
Rich, W9ENG
__
Charles,
maybe I did read your email wrong, I apologize for that. To me it came
across as negative toward the seller and the listings, and it seems this is
not how it was meant, my appologies.
Bye,
Said
In a message dated 9/8/2012 23:05:30 Pacific Daylight Time,
charles_steinm...@lava
Most all of this kinda stuff is built using 50 Ohm 'building blocks'. You
can almost plug them together like Legos.
The HP 10514A is no different:
http://www.ko4bb.com/Manuals/HP_Agilent/HP_10514_Mixer_Jan_1967.pdf
Mini-Circuits (among others) sells loads of different wsuch components.
Your big
Hello Brian,
I am a radio amateur and and also in the Time nuts list, At the
moment I am planning to bild a DMTD for experimentation. and as you have a nice
experience in this field , for me will be very wellcame your help. My ask is
¿whitch is te best temination for
Stan,
You want a Casio Waveceptor WVA470J-1ACF, ana-digi/solar/wwvb.
I have a WVA105HDA-2A, no-solar, no sweep hand, been a solid performer.
73,
Ed
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Stan, W1LE
Sent: Sunday, September 09, 20
On Sun, Sep 9, 2012 at 6:18 AM, Don Oconnor wrote:
> Hello,
>
>
>
> I would like to design and build a microcontroller based GPSDO. And I have a
> couple of questions some of you may be able to answer.
>
>
>
>
>
> 1. I am going to use Trimble SMT GPS timing module but I'm curious.
> Does
Just do a Google image search for analog atomic watch. Pick the one
you like. There are several in the $50-$60 price range that are
attractive. Many are solar so there are no batteries to replace.
They're all set by WWVB nightly (usually) so they're well within a
second of accuracy.
-Bob
On Su
> Since the determining factor in the accuracy of a wrist watch these days
> is you reaction time in setting it to the announcements on WWV,
> I'd go to Walmart or Target and find something cheap.
In a way it is sad. But that is what I did. Bought a $16 watch at target.
Then I compare the watch
On 09/09/2012 07:05 AM, Stan, W1LE wrote:
Hello The Net:
I need to consider getting a new wrist watch, but I need a second hand
and a digital display is unacceptable.
What would you consider in the < 150$ price range ?
Would be nice to have state of the art accuracy with a "lifetime
battery
On 9/9/12 7:05 AM, Stan, W1LE wrote:
Hello The Net:
I need to consider getting a new wrist watch, but I need a second hand
and a digital display is unacceptable.
What would you consider in the < 150$ price range ?
Thunderbolt driving a stepper motor?
Would be nice to have state of the art
Hello The Net:
I need to consider getting a new wrist watch, but I need a second hand
and a digital display is unacceptable.
What would you consider in the < 150$ price range ?
Would be nice to have state of the art accuracy with a "lifetime
battery" and high reliability.
Thanks, Stan, W
Hi Bob,
On 09/09/2012 02:49 PM, Bob Camp wrote:
Hi
Ok, you have the fast port working. I assume with some sort of GPIB adapter. Is
this correct?
No. Flip a DIP-switch and it's there. There is a few connectors on the
motherboard and that hooks up to the connector panel. I've checked and
I'v
Hello,
I would like to design and build a microcontroller based GPSDO. And I have a
couple of questions some of you may be able to answer.
1. I am going to use Trimble SMT GPS timing module but I'm curious.
Does a GPS timing receiver produce a more precise 1 PPS output than a s
Hi
Ok, you have the fast port working. I assume with some sort of GPIB adapter. Is
this correct?
If so is this just a matter of taking the code you already have and folding it
into one of the existing programs? That would make the 5371's and 5372's a
*lot* more useful.
There obviously are go
Hi Bob,
On 09/09/2012 03:55 AM, Bob Camp wrote:
Hi
It would be nice if somebody came up with a fast port adaptation to one of the
standard data collection programs.
It would not be all that hard to do an adaptation board which creates a
live USB stream for instance. Either using an FPGA or
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