, 2006 11:05 AM
To: Eric Ellison; [EMAIL PROTECTED]; FlexRadio@flex-radio.biz
Subject: RE: [Flexradio] A question on Frequency stability vs. Temperature
Eric et al,
Thought this tread might be a good place to post an update on the oscillator
project.
I assembled the PLL using the card I designed
At 05:17 PM 1/1/2006, [EMAIL PROTECTED] wrote:
Actually, you need to synthesize TWO signals in the passband, because
errors in the A/D sample clock can't be calibrated out with a single marker.
Jim,
Well, I have to ask why two markers are needed or can you give a reference
text I could
At 06:25 PM 1/1/2006, Tom Clark, W3IWI wrote:
KD5NWA wrote:
The project being discussed for the Xylo is;
1. Thermal isolation with a accurate heater to reduce the drift.
2. Use the Xylo to connect to a GPS and have a accurate 1 pps clock
3. Use the 1 pps clock to measure the DDS
Jim,
Thank you for an excellent explanation of the two markers required. I'll be
back with the next question after I digest the information.
What I need is an accurate measure of frequency in the AM broadcast band, 500
to 1700 KHz, so I would think 1-10^7 is good enough for me. It needs to
need to get my beauty rest.
73, Larry K2LT now a Numbhead
From: KD5NWA [EMAIL PROTECTED]
Date: 2006/01/01 Sun AM 04:27:55 WET
To: [EMAIL PROTECTED]
Subject: Re: [Flexradio] A question on Frequency stability vs.
Temperature
The scheme outline below in steps 1 through 5 does not correct
: Saturday, December 31, 2005 11:02 PM
To: FlexRadio@flex-radio.biz
Subject: [Flexradio] A question on Frequency stability vs. Temperature
Xyloonians,
Build a selectable output frequency standard referenced to GPS or WWV. M/N
type thing. Have its frequency output within the range of the soundcard
the OCXO
that Joe has for sale on E-Bay?
Thanks
Eric
-Original Message-
From: Bob Tracy [mailto:[EMAIL PROTECTED]
Sent: Sunday, January 01, 2006 11:05 AM
To: Eric Ellison; [EMAIL PROTECTED]; FlexRadio@flex-radio.biz
Subject: RE: [Flexradio] A question on Frequency stability vs. Temperature
PROTECTED] Behalf Of Eric Ellison
Sent: Sunday, January 01, 2006 8:18 AM
To: [EMAIL PROTECTED]; FlexRadio@flex-radio.biz
Subject: Re: [Flexradio] A question on Frequency stability vs.
Temperature
Larry
The last I heard from Bill - KD5TFD on Teamspeak yesterday, was that his
weekend goal
At 10:15 PM 12/31/2005, [EMAIL PROTECTED] wrote:
You and I are headed in the same direction. I'm saying that the Xyloonia
world should creat a known stable frequency within the passband of the
soundcard that the PowerSDR can measure continuously to creat the offset
needed to display the
Actually, you need to synthesize TWO signals in the passband, because errors
in the A/D sample clock can't be calibrated out with a single marker.
Jim,
Well, I have to ask why two markers are needed or can you give a reference text
I could study to see why? Warning, KISS please as I
KD5NWA wrote:
The project being discussed for the Xylo is;
1.Thermal isolation
with a accurate heater to reduce the drift.
2.Use the Xylo to
connect to a GPS and have a accurate 1 pps clock
3.Use the 1 pps clock
to measure the DDS 200MHz clock, integrate multiple reading to make for
finer
: Sunday, January 01, 2006
9:25 PM
To: KD5NWA
Cc: FlexRadio@flex-radio.biz
Subject: Re: [Flexradio] A
question on Frequency stability vs. Temperature
KD5NWA wrote:
The project being
discussed for the Xylo is;
1.Thermal isolation with a
accurate heater to reduce the drift.
2.Use the Xylo
Wouldn't this constitute a GROUND loop? Ok that was cruel and unusual
punnishment.
In all seriousness, Marti RPU transmitters have a small styrofoam box around
the crystals (and heat element) on the modulator board. Would taking a small
styro block, hollowing out one side and placing it over
Bill Guyger wrote:
Wouldn't this constitute a GROUND loop? Ok that was cruel and unusual
punnishment.
Pun ignored ;-)
... Would taking a small styro block, hollowing out one side and placing it
over the oscillator be a quick and dirty (there's that word again) fix? It sure
wouldn't be as
That is precisely what will occur, the reading will occur over
decades of seconds.
At 08:25 PM 1/1/2006, you wrote:
KD5NWA wrote:
The project being discussed for the Xylo is;
1. Thermal isolation with a accurate heater to reduce the drift.
2. Use the Xylo to connect to a GPS and
I have a question about frequency stability of the SDR1K in regard to
variable temperatures inside the SDR1K. The reason for concern is
frequency drift while working digital modes. For the sake of this
argument and staying on point, let's assume that the frequency delta is
significant, although
I've heard it on Teamspeak that when a scheme like that has been
tried it worked very well.
Thermal stability like you mentioned, along with electronic
compensation of the clock by comparing it to a GPS clock is one of
the projects the Xylo will be used for.
At 12:49 AM 12/31/2005, Tim
Folks
Yes, Bob N4HY mentioned on Teamspeak that he had 'insulated' the osc with some material which cut down on drift. Perhaps he could elaborate a bit more on the scheme he used.
Eric2
-- Original message -- From: KD5NWA [EMAIL PROTECTED] I've heard it on Teamspeak
Insulation will slow down the response to external temperature
variations, but unless there's a heat source inside the insulated area,
it won't prevent the change (sooner or later, the internal temperature
will match the external).
One very simple answer, that I think Gerald has been playing
You can find 60 deg C thermisters at:
http://www.downeastmicrowave.com/Catalog.htm
They are quite inexpensive @ $1.50 a pop.
The DEMI catalog links to:
http://www.thermometrics.com/assets/images/ptcnotes.pdf
I've been adding them to my various VHF transverters that do
not yet have them. They
Tim, Eric2, et al
You canenclose the oscillator canwithin a thick block of
material that hashigh thermal resistance(high thermal
inertia). You do not want to have airmoving around the
oscillatorbecause the heatconducted away from the oscillator will
vary as the air flow varies and that
The project being discussed for the Xylo is;
1.Thermal isolation
with a accurate heater to reduce the drift.
2.Use the Xylo to
connect to a GPS and have a accurate 1 pps clock
3.Use the 1 pps clock
to measure the DDS 200MHz clock, integrate multiple reading to make for
finer resolution.
4.Use
At 08:20 AM 12/31/2005, KD5NWA wrote:
The project being discussed for the Xylo is;
1. Thermal isolation with a accurate heater to reduce the drift.
2. Use the Xylo to connect to a GPS and have a accurate 1 pps clock
3. Use the 1 pps clock to measure the DDS 200MHz clock,
Xyloonians,
Build a selectable output frequency standard referenced to GPS or WWV. M/N
type thing. Have its frequency output within the range of the soundcard by
looking at but offset from the frequency tuned to at the moment. Maybe have it
outside the pan adapter window so it doesn't
The scheme outline below in steps 1 through 5 does not correct the
frequency by changing the hardware oscillator, it does not require a
VCO to replace the current oscillator, it measures the errors and
feeds it digitally through a USB port to the PC who will make
software corrections.
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