Are 4 and 5 regulated? Or is the zener picked to compensate for the VBE
drops?
Any of these circuits where the output transistor is in an emitter
follower configuration will have its noise effected by the load current,
since that current directly effects the output transistor transconductance.
To time experts/EE's.
I would like to triangulate a position of a device which moves using 3
fixed positions devices of known location.
The idea is to have these operate on 915mhz or 434mhz or 2.4ghz or
appropriate frequency.
These two type of devices (fixed and mobile) are all under my control an
Fired up the SRS FS700 and auto found the GRI 89700 microsecond stations
in Dana Il (master)
and Seneca NY, (slave) both with equal signal strength of 63 db. Other
slaves were not to be found.
Noise margin of 32 dB and Rx gain of 72dB. So the Rx is all locked up.
Tomorrow I will have more data c
Hi all;
I set my FS-700 to 89700 GRI, and had initial acquisition within 5 minutes
here, and complete tracking and lock within 20-25 minutes. Not bad considering
that the noise level here is about equal to the signal in a receiver (ICOM
IC-725) with a 2.3 Khz bandwidth which is what I first tune
I have seen it used in a couple of Tektronix TM500 instruments but the
purpose may have been to generate a lower voltage power supply rail
instead of noise reduction. Tektronix often added LC sections on
their switching power supply outputs and distributed smaller LC
sections to prevent coupling b
ITAR has their own restrictions for GPS receivers. See here:
http://www.fas.org/spp/starwars/offdocs/itar/p121.htm
"(2) Designed for producing navigation results above 60,000 feet altitude and
at 1,000 knots velocity or greater;"
From: time-nuts-boun...@
You haven't seen it used because it doesn't work very well. It appeared in
a few pieces of Heathkit equipment but I don't think HP or Tek used it at
all. Any AC component of base to collector voltage has a small but definite
effect on Vbe which transfers voltage in the reverse direction from
One more thought: Many oscillators have internal regulators that are not
nearly as good as what you can build. No sense using an external supply
with 5 nV per root Hz noise density if it will be re-regulated inside
the oscillator by a circuit that has a noise density of 250 nV per root Hz.
Bes
What GRI should we be listening for ?
Stan, W1LECape Cod FN41sr
On 1/31/2013 9:56 PM, paul swed wrote:
Rich indeed its on the air. Warming up the FS700 to see if it will lock.
Have a pattern ram thats getting flakey and takes about 30 minutes to warm
up along with the oven.
Back when I was in product engineering there was a VCO design that used
a "superfilter" circuit. It consisted of a pass transistor and a filter
cap from base to ground. The gain of the transistor multiplied the
effective capacitance. I have not seen this configuration since.
--
Joe Leikhim
L
In Oregon Loran-C signals were much stronger than WWVB.
Loran-C could provide an alternative to WWVB that actually works in Oregon.
Not to mention a fall back to a navigation system that can be jammed
by something as small as a can of pop.
--
Chuck Forsberg WA7KGX c...@omen.com www.
Rich indeed its on the air. Warming up the FS700 to see if it will lock.
Have a pattern ram thats getting flakey and takes about 30 minutes to warm
up along with the oven.
Anyhow did reach out to UrsaNav and did get a response and actually had a
good conversation. They have released their first rc
Bob wrote:
An AD 797, a couple of metal film resistors, and a fairly large (say
47 uf) plastic cap work pretty well.
The band from 10 Hz down to 0.1 or 0.01 Hz is generally important
when testing oscillators. To keep the 797 input noise density below
a few nV per root Hz, the terminations m
This link may work.
http://www.insidegnss.com/node/2992
73,
Bill WA2DVU
Greetings All,
Loran station at Wildwood, NJ is up at 2118 EST on 100 KHZ. I guess they
are running surveys again. I am located 3 miles NW of Wildwood Crest NJ
where the station is located.
73,
Bill, WA2DVU
Cape May C
Greetings All,
Loran station at Wildwood, NJ is up at 2118 EST on 100 KHZ. I guess they
are running surveys again. I am located 3 miles NW of Wildwood Crest NJ
where the station is located.
73,
Bill, WA2DVU
Cape May Court House, NJ
-Original Message-
From: time-nuts-boun...@febo.com
Hi
If you are driving a spectrum analyzer, the 10,000X mentioned in the app note
simply is not needed. A gain of 10X or less will get you to below 2 nv /
sqrt(Hz) at 100 Hz and beyond. A 10 Hz blocking cap does not need to be a "24
hours to stabilize" device. An AD 797, a couple of metal film
Or a good battery as a source for the regulators as discussed in this
thread already.
It's quite nice to have all the different Voltages available at the same
time, with up to 200mA.
bye,
Said
In a message dated 1/31/2013 13:12:33 Pacific Standard Time, li...@rtty.us
writes:
Hi
For
Charles,
thanks for posting. That is the LTC application note I had in mind.
And here is Bruce's contribution to low noise PS design and measurement:
http://www.ko4bb.com/~bruce/LowNoisePowerSupplies.html
Don't miss to scroll fully down. There is a link to an IEEE paper
discussing chemical ba
tvb wrote:
I'll answer the question with anther question -- how does one
properly measure power supply noise? Does it boil down to a single
number, a couple of key numbers, or is it a plot, or several plots?
There are a number of "standard" ways, some of which have been
mentioned by others,
Hi all;
I'm hearing Loran C signals @ 7:00 pm EST hear northern Indiana this evening.
Anyone else?
Rich
W9ENG
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In message , "Tom Van Baak" writes:
>We have rigorous ways to compare and report oscillator performance;
>both as numbers and as plots. Is there something equivalent for
>power supplies?
Phase Noise measured on a 0Hz carrier ?
If you want the
> I know for sure my handheld Garmin works at 27000 feet, at
> 530mph... ...I was actually surprised it worked up there.
> It made me wonder what the actual limits are.
What are the limits of your hand held unit or what are the limits of
GPS in general. I think GPS works as long as you are u
There are at least two methods.
First, the broadband or time domain method that uses a low noise
amplifier and oscilloscope, and specifies noise voltage within a certain
bandwidth. For details check application notes from LTC and Analog Devices.
The narrowband or frequency domain method speci
Hi
For $393.75 does it come with a wall wart?
If not I would definitely go for a "medical" ground isolated / low leakage
version to power the beast. The added cost over a plain jane wall wart won't
add much to the purchase price percentage wise.
Bob
-Original Message-
From: time-nuts-b
I think it's supposed to work up there.
Cocom limits used to be 50,000 feet and 1000 knots if I am not mistaken.
Most GPS will likely support those Cocom limits even if they state something
like 2000 meters max altitude etc.
A commercial flight should certainly work, besides the problem of
Not sure if anyone posted this here yet, but Abracom has a very low noise
(7nV/RtHz at 1KHz) power source for VCO's etc, with various outputs. It's
sold on DIgikey or Mouser I think.
Here is a review of that unit:
_http://jaunty-electronics.com/blog/category/reviews/_
(http://jaunty-electro
Tom
Thanks for the very fine scan and reading material. I have none of this
equipment actually. But have to say a good read.
Regards
Paul
WB8TSL
On Thu, Jan 31, 2013 at 9:24 AM, Tom Van Baak wrote:
> Hi Girard,
>
> I scanned the GR manual with operation and schematics for: 691c 690d 694c
> 696c
Bob,
I have a pair of HP-3551A's*. I'm very familiar with making
transmission lines measurements, and it seems that measuring power
supply noise would be the same, except that you want to block the DC
from the input of the instrument. What has your procedure been and
what numbers have you
Oops,
that should be HP4945(6)A not 3945
Robert.
From: Robert Atkinson
To: Discussion of precise time and frequency measurement
Sent: Thursday, 31 January 2013, 18:46
Subject: Re: [time-nuts] Low noise power supplies?
A non-standard but repeatable way to
A non-standard but repeatable way to measure power supply noise is to use a
Transmission Impairment Measuring Set (TIMS) such as the HP3945(6)A or 3551
(2)A. These were intended for use in pairs to assess analog telephone lines for
data use. As well as an AF generator, frequency counter, amplifie
On 31 January 2013 17:11, John Ackermann N8UR wrote:
> And this (very interesting) thread brings up the question of measurement
> methods. Some time ago I searched around and didn't find much on a standard
> way to measure noise on low voltage DC supplies.
>
> John
Did you try the volt-nuts mail
Hi
A very common way to check one is to use the HP 3561 off of the old 3048
phase noise test set. With a simple op amp based preamp you can easily get
down below 3 nv / sqrt(Hz). With more exotic amps you can get well below
that.
Volts over a bandwidth really don't tell the story very well. In t
On 31.01.2013 09:05, Adrian wrote:
Rick,
the E3610A is really clean.
The discussion is interesting, but the original question did ask about
off the shelf so I have been watching for any mention of HP/Agilent
precision power supplies. The E3610A specification says 200 uVrms, 2mv
pp ripple
And this (very interesting) thread brings up the question of measurement
methods. Some time ago I searched around and didn't find much on a
standard way to measure noise on low voltage DC supplies.
John
On 1/31/2013 11:36 AM, Bob Camp wrote:
Hi
I think the comparison of PSD on a power
Gang,
I'm following this thread with great interest, but, just for my own
reference, what is considered low power supply noise? Can you give
me some numbers and over what bandwidth?
Thanks,
Burt, K6OQK
Subject: Re: [time-nuts] Low noise power supplies?
Hi
To answer the origi
Hi
I think the comparison of PSD on a power supply to phase noise and phase
noise plots is a pretty good one in this case.
For most applications nV/sqrt(Hz) is a pretty good way to check things out
on a supply or regulator. It's not quite the same thing as dbc / sqrt(Hz)
but it conveys the same
On 31 January 2013 04:28, Chris Albertson wrote:
> On Wed, Jan 30, 2013 at 6:16 PM, Richard (Rick) Karlquist
> wrote:
>>
>> I know this topic has been discussed in the past on the list, but
>> a colleague is asking if there are any off the shelf low
>> noise power supplies for testing oscillators
Hi Rick,
I'll answer the question with anther question -- how does one properly measure
power supply noise? Does it boil down to a single number, a couple of key
numbers, or is it a plot, or several plots?
I ask because without some sort of standard test and reporting method it just
becomes a
> As Adrian and Bob pointed out, W. J. Riley's site has all the information
> needed to make the higher cost TPLL version he did including his PCBs.
Ah, sorry, I didn't see that 2nd PDF! I see the design is significantly
different than the TPLL that you made. Any idea why?
> The bigger mystery
Rick,
the E3610A is really clean.
If that isn't good enough, there are some audio-related circuits like
the ALWSR.
http://www.andrewweekes.talktalk.net/Manuals/ALWSR_rev2.9_Iss005s.pdf
It's based on a Walt Jung design (Analog Devices).
Here's the man himself with tons of valuable information
Hi Girard,
I scanned the GR manual with operation and schematics for: 691c 690d 694c 696c
698a 692b
It's now filed under: http://leapsecond.com/museum/GenRad-C21-HLD/
This 6 foot tall rack was one of the best frequency standards for many decades.
/tvb
> I'll look through my collection of old G
If the main concern is about low-frequency noise the LT1763 might be worth
considering for a simple solution, as it is capable of lower noise than the
data sheet shows. With a bypass capacitor (Cbyp) fitted, the noise floor is
~30nV/rtHz. Although the data sheet only recommends up to 10nF for Cb
Hi
To answer the original question - Power Design makes some pretty quiet bench
supplies. If you are doing low noise testing, batteries often will let you
get rid of one more ground loop. Even well built power supplies are not as
well line isolated as a battery.
Bob
-Original Message-
Fr
I know for sure my handheld Garmin works at 27000 feet, at
530mph... ...I was actually surprised it worked up there.
It made me wonder what the actual limits are.
On 1/30/2013 12:00 PM, time-nuts-requ...@febo.com wrote:
How to check if a GPS works at 60,000 feet: send up a balloon:
Am 31.01.2013 05:28, schrieb Chris Albertson:
For once the "best" is also cheap: Batteries.
But not all batteries are the same. You want one with low internal
resistance, so a lead acid flooded battery will be the best.
Fred Walls & Co have done tests on batteries. The article is
somewhere o
Am 31.01.2013 03:16, schrieb Richard (Rick) Karlquist:
I know this topic has been discussed in the past on the list, but
a colleague is asking if there are any off the shelf low
noise power supplies for testing oscillators. Something
The E5052B signal source analyzer has low noise power
and c
Lester wrote:
For a regulated power supply, make one using a 723. The 723 has
far lower noise out than the monolithic regulators.
If you are willing to design your own regulator using a 723, you may
as well use a few more parts to get a much better result. Neither
the internal reference nor
PTAT == Proportional To Absolute Temperature
Dave
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On 1/31/2013 12:20 AM, Bruce Griffiths wrote:
With some care its possible to make the emitter current of the shunt
transistor approximately PTAT so that, at least for small signals the
temperature dependence of the rejection is reduced significantly.
Sorry, what does PTAT mean? I'm not familia
This news is old, refers to Yahoo Voices. IF you had anything to do with this
service then you need to worry.
You can check here to see if your password has been stolen:
https://www.dazzlepod.com/yahoo/
The S pam we are receiving is from a XSS exploit that steals your cookie if I
am not mistake
Poul-Henning Kamp wrote:
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In message, Tom Knox writes:
Starting with a hp supply this finesse regulator will really clean
up the output. http://www.wenzel.com/documents/finesse.html
I've played with that, and it can do impressive th
I've measured AA nicad impedance at a few kHz, but it was years ago. My
recollection is it was in tens of milliohms.
ESR does have a frequency dependency. In the same time frame, I was
trying to find a simple non-instrusive way to detect alkaline cells
versus nicads. The key was in impedance v
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In message , Tom Knox writes:
>
>Starting with a hp supply this finesse regulator will really clean
>up the output. http://www.wenzel.com/documents/finesse.html
I've played with that, and it can do impressive things.
However, to big caveats:
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In message , Mark Sims writes:
>
>A123 20Ah LiFePO4 cells have an internal resistance in the milliohm
>range. Their M1 26650 format cells are around 8 milliohms. Most
>high capacity (>3000 mAh) 18650 style lithium cells are around 10-15
>milli
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