I don't think Heather v5.0 ever worked with the ACE-III. Heather uses the TSIP
primary and secondary timing messages to drive the display. The ACE-III (and
SV6) don't output those messages. The next release of Heather has SV6 support
and also supports the Trimble TAIP protocol that these
I have worked out a design for using an LCD display in the 531xx counters.
Basically it's a replacement front panel board with a micro and graphical LCD.
I'm probably not going to build it until my VFD goes bad... maybe by then OLED
displays will have their lifetime flaws worked out...
The RFTG-m units don't speak SCPI. They have an undocumented binary control
language. I reversed engineered the protocol and the latest version of Lady
Heather can talk to them. The v5.0 release of Heather does not support these.
If you run something linuxy or can compile the v5.0
The 15 pin cable is wired reversed from a straight through cable: 1 -> 15,
2->14, ... 15->1.
http://www.prc68.com/I/KS-24361.html
I think ko4bb.com also has info on these.
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The latest version of Heather does support the SV6 in both TSIP and TAIP mode.
If you are running Linux, etc or can compile the current Windows version I can
send you the latest source code to compile.
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Maybe:
https://www.ebay.com/itm/Symmetricom-X72-Rubidium-Oscillator-10-32V-DC-10MHz-USED/132116702248?epid=1023910441=item1ec2c4e428:g:2p8AAOSwXYtYvKWc
I don't know if RDR Electronics still have any X72's.
There used to be a lot of X72's for sale that were pulled from something. They
came
For you, nerd dick waving.
For her, bragging rights! She will have the most accurate egg timer on the
block (assuming she is the head chef in the house).
> Have to do a cost/benefit analysis for the wife...
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I stopped by a local electronics store today and came across a heatsink that is
the perfect size for the X72. To mount the X72 to it you would need to drill
four holes in the corners and do a little Dremel work on the outer fins to get
to the screw heads. The store owner says he has a case
I did hack together some code to GPS discipline a HP-5071. But it only
disciplines the oscillator if the unit is in standby and the cesium tube is
off... I did say it was a hack...
--
> You can (or course) do a GPS disciplined Cs standard. That’s not easy to do,
> but some are
I have finished my breakout boards for the X72 oscillator. It consists of two
boards connected by a ribbon cable (or you can remove a header and replace with
a female and directly connect them or solder the boards together). Power
input is through a 2.1mm barrel connector. Input caps are
Here are Wenzel's input circuits:
http://www.wenzel.com/documents/waveform.html
The TAPR TICC uses a slightly modified version of the two transistor circuit.
Also check out the LPRO-101 manual for their versions of the single CMOS gate
squarer. One thing they do is add an RC filter to the CMOS
There is also a nice pdf out there by Peter Garde that tells how to add a GPS
receiver to the non-GPD RFTG. It involves moving around 6 0-ohm (?) resistors
and plugging in an old Motorola (UT+) receiver. I found the pdf on EEVBLOG.
Trying to further compensate a TCXO can be a losing proposition. Your control
loop and the TCXO's control loop can easily get their panties all twisted in a
wad.
You are probably better off compensating a plain XO... which yields a TCXO that
you can actually manipulate to your hearts
Lady Heather did the change, but triggered a hour early. D'oh!
A while back I changed the way Heather kept dates and times internally from
separate hh,mm,ss,month,day,year variables to keeping all times as double
precision Julian dates. That change caused the DST code to not account for
the
That looks like the device is defective. I'd see if the seller will replace
it.
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I put a UCT8663 DOCXO in my HP-53132A counter (using Gerry Sweeny's adapter
board). I bought a bunch of those DOCXOs around 10 years ago. It was never
powered up during that time. Here are the notes that I made:
UTC 8663 mounted on Sweeny DOCXO card in a HP 53132A counter. The 8663 had
I have an analytical balance that reads down to micrograms. The weigh chamber
is surrounded by three layers of IR absorbing glass so that radiated body heat
does not induce convection currents in the air. I worked on a balance that
had nanogram resolution (mostly wishful thinking in that
The PCB's for the new (and hopefully improved) time interval calibrator board
have shipped. They should be here early next week.
The boards can do the Offset, Gain, and Fine time interval calibration steps in
the HP 531xx calibration menu and replace the unobtainium HP-5-J06 time
The X72 rubidium oscillator interface board sets have (finally) been shipped to
everybody that paid for them. I had hoped to get them out a couple of weeks
ago, but ran into a couple of annoying snags...
First, the assembly house built a couple of test articles that were great and
were
I recently got in a Spectrtime SRO100 rubidium oscillator. It is a very small
(2.75 x 4") Rb that runs on 11-19V. The firmware has the ability to
discipline itself to a 1PPS input and can self-optimize the loop time constant
depending upon the stability of the input PPS.
I now have Lady
Versions of these oscillators prior to firmware version 1.96 had a user
programmable DDS in them that could generate up to 20 MHz on pin 11 of the DB25
connector. All references to the commands to program this output have been
removed from the current documentation. Does anybody have any
A 30 cm daily vertical offset is pretty typical. I've seen over 45 cm.
Horizontal offsets are usually less than +/- 75 mm per day with the longitude
displacement typically twice the latitude displacement.
Heather uses a standard model (see
http://geodesyworld.github.io/SOFTS/solid.htm) to
In the standards definitions that include "at sea level", the question these
days is "which sea level?". As ocean temperature changes sea level will change
(except maybe in Washington DC). Will the standards be amended to include
something like "at sea level in 1990" or will the value being
Which gets real fun with things like solid earth tides getting involved. Lady
Heather can now calculate and plot solid earth tides. Over the last 48 hours
my place moved up/down 315 mm and gravity changed 186 microgals... and that
was a rather stable period.
--
> A 1
Yep, to paraphrase Bunker Hunt's "a billion dollars ain't what it used to
be"... a nanosecond (or picosecond) ain't what it used to be. Things that used
to be insignificant n'th order theoretical nuisances are now very real
significant problems.
> But it's not one-to-one as
Lady Heather will also work with the Ublox modules and can be used to configure
the units. Heather can easily be compiled to run under Linux/macOS/freeBSD.
You might have the SNR and/or elevation mask filters set improperly for indoor
operation.
___
> No, you set up an oscillator so that is why you have that problem.
I hooked the two rubidiums together just to see what would happen. It pretty
much did what I expected... chaos... the time-nut equivalent of a naughty
schoolboy putting a microphone up to the speaker of the public address
I did a quick silly experiment where I took a PRS-10 disciplined by an X72
which was disciplined by the PRS-10. The result seemed to have created a
rupture in the space-time continuum. Nobody was happy... they didn't seem to
agree on who was in charge.I need to try it again now that I
Well, the X72 uses a DDS instead of a DAC... not much different except you have
no DAC to freq math to worry about. The DDS res is 60 MHz / 8192
-
> I've been thinking about a GPS receiver experiment
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The SV6 has three different firmware versions for the following protocols:
NMEA, TSIP, and TAIP.
The latest Lady Heather code(5.01 or later) does support all the SV6 versions.
You could pull the receiver and wire it to a TTL-RS232 converter and maybe get
some more info on what it is
The SV6's are all well past their rollover date.
A common problem with the SV6 (and the Motorola 6 and 8 channel receivers) is
the TCXO has drifted out of range. Some have an adjustment cap that can be
tweaked.
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http://www.theregister.co.uk/2017/10/31/google_gnss_analysis_tool_accurate_to_nanosecond_movements/
I wonder how well it works on a $20 Android tablet / phone?
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And it's the only way to be sure... never trust a simulation, particularly
for such flighty and subtle things like noise. Simulations can be useful for
pointing you in the right direction for a design, but where the rubber meets
the road there is nothing like real hardware to get to the true
You could add doppler to the RINEX file. All the receivers with raw messages
seem to output that.
I am playing with the Furuno GT87 output. It does not output carrier phase
data (only pseudorange / doppler / SNR). CSRS-PPP can still process that.
On the first run (3 hours of data,
I just added support for the Z12 to Lady Heather and fired up my Z12 for the
first time in a few years. It powers up in some kind of a weird loopback mode
and you have to reset the receiver memory to get it working.
Does the Z12 have an internal memory backup battery? Mine is currently
The "new" Z12 from Ebay came in today. Works fine (except bad memory backup
batteries). So antenna, power supply, cables are OK. Replacing the memory
backup batteries is fairly easy, except for the gazillion and three screw to
open it up. A pair of memory batteries costs around $15.
I
I have Lady Heather's RINEX writer working fairly well. Handles GPS and
GLONASS (should also do Galileo when the M8T comes in from Germany... was "in
stock" but it took them over a week to ship it).
I just did a run on the Furuno GT-8736. It only outputs pseudoranges. A 2.5
hour run @ 1Hz
Well, my Z12 stopped tracking sats yesterday. It passes all self-tests. I
then replaced the memory backup batteries... it fixed the bootup error problem,
but still won't track sats.
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Antenna is good... it is feeding an HP amplified splitter which goes to 7 other
receivers.
And yes, it died in the middle of a run.
I have another Z12 coming from Ebay...
--
> Rats. Is the antenna known to be good? Is the Z12 providing bias on the
antenna cable? Did the Z12
Does anybody know how Ublox maps their reported PRNs for Galileo and Beidou
satellites to the true satellite PRNs. What little there is on the web
appears on the web is rather incorrect.
For Galileo I have seen Ublox PRNs from 212 to 240. That seems to imply it
might be ACTUAL =
Although it does not measure propagation delays, Lady Heather can now estimate
propagation delays. You can enter the lat/lon/alt of the station or specify
the station name. You can enter the ionosphere height, or Heather will
estimate it depending upon the month.
---
>
Most of the post-processing services use reference stations that are surveyed
and verified to mm level accuracy. The 13 reference stations used by AUSPOS
were uncertainties all less than 4/4/8 mm. Unfortuenatly some of the
baselines were rather long.
My antenna is swimming in multi-path and
The main significant difference between the M8N and M8T is the fact that the
M8T can output raw data (and sawtooth). The hardware is the same so there
should not be much difference PPS wise between the two.
I have Lady Heather's RINEX writer working pretty well. Tested with the
I was losing messages for up to 4 seconds on some of the receivers (ResT?) so I
commented out that message request. I need to go back and do some tests to
see which ones are actually affected.
---
> By "hosing" do you mean that you lose messages for the next second? That
was
Lady Heather can configure the various time pulse / PPS outputs on the Ublox
receivers. (P keyboard menu) If the receiver supports sawtooth data, the
current sawtooth value will be shown at the top of the screen (second column).
It can also be shown in the plot area (GD will toggle the
Yes, the Ublox sends ps... whatever software that is processing the message is
scaling it wrong. And labeling it wrong... qErr:-0.00105210 ps... that
aint' right... no way... no how..
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It looks like you have slipped a decimal point somewhere (also that "ps" label
is wrong). I have an M8N running here and the report sawtooth errors are all
within a +/- 10 ns span. (and LEA-5T is +/- 5ns).
---
> Class: TIM(0xd) ID: TP(0x1), len: 0x10
One thing to look out for when messing with sawtooth messages is the question
of does the message come out before or after the PPS pulse... good look
finding the answer in the receiver documentation...
"After" seems to be the most common answer. That makes hardware/delay line
compensation
A related question is: Do you use positive or negative numbers to set the
antenna cable delay value? Again, most GPS receiver documentation does not
say.I think that I've only seen it explicitly mentioned in the Trimble
documentation and the Oscilloquartz Star-4 documentation.
Also there
I recently got in a Ublox M8T board in from CSGSHOP. The M8T supposedly
outputs raw measurements (carrier phase, pseudorange, doppler) for all the sat
systems it supports, but I am only getting raw measurements for GPS and SBAS...
no Glonass or Galaileo.Any ideas why? Has anybody gotten
I have it working now.The problem was the way I was interpreting the
satellite system gnssid:svid values in the RAWX message. Basically the data
for all the sat systems were being mapped to GPS prns.
Heather has a command for configuring which GNSS constellations that you want
to use.
The Trimble Thunderbolt has a message (0x5A) that outputs raw receiver
measurement data. One value is "code phase" (along with PRN, sample length,
sig level, dopple, and time-of-measurement). This is a single precision
floating point number in units of 1/16 of a chip. Does anybody know how
Well, not strictly L1. I have a 58517A connected to an Ashtech Z12. It
does report good signal levels on the L2 data (same range as the L1 signals)...
but the Z12 L2 results are rather noisy and I don't get a very accurate
solution.
Also the '517A does seem to work OK with Galileo and
Lasy Heather can read a receiver data capture file as a "simulation" file. Use
the /rs=filename command line option. You can also specify the /0 command
line option (don't use serial port) and /rx= command line option to specify the
receiver type. The simulation file reads in at around
Many thanks Peter for confirming what I suspected. The problem with the
Trimble receivers is that requesting the satellite C/A code data can hose up a
lot of them. So, I'm stuck with calculating the integer number of
milliseconds. How to do that? I do know my position to a few feet.
I
I think what Gary really wants is a GPS receiver with the most stable PPS
output available. That is probably the Furuno GT-8736... 1.7 nsec sawtooth
error. Typical PPS span is +/- 4 nsec. Also, the Trimble Thunderbolt has 0
sawtooth error.
___
The sawtooth value is in the 0x0D-0x01 (TIM-TP) message. Third value, called
qErr. 32-bit dword. In picoseconds.
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There is a guy selling some (5) PRS-10's on Ebay for $170. Says pulled from
decommissioned systems, but sold for parts. No telling if they are any
good... They are listed as being "used" and not "for parts"... which I think
means Ebay says you can return them.
Well, no. Green laser pointers convert a rather high power 800 nm laser to
1600 nm in one crystal then divide it to 533 nm in another one. The physics
and manufacturing of them is best described as black magic. They are cheap
because China developed the process to grow the crystals in bulk
You could also run Lady Heather on a PI with NTP and select one of the zoomed
full screen clock displays (analog watch or digital clock).
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Ok, I did the experiment. I took an 8 hour M8T RINEX file with
GPS,SBAS,GLONASS,GALILEO data in it. I then used to TEQC to extract GPS only
and GLONASS only data (CSRS-PPP ignores SBAS and GALILEO data). The 95%
confidence error ellipse estimates ("rapid" orbits) were:
GPS+GLONASS:lat
I finally got in the Ublox M8T and have been testing its RAW data measurements
(carrier phase / pseudorange / dopper) data by having Lady Heather write a
RINEX file and sending it to CSRS-PPP.
Collecting GPS, SBAS, GLONAS, and GALILEO data (CSRS-PPP ignores GALILEO and
BEIDOU data) for 2 hours
Well, with a little prodding and help from Magnus, I now have the Trimble
devices outputting RINEX files. They have pseudorange, doppler, and signal
strength observations. A 5 hour 1Hz run was sent to CSRS-PPP and the
lat/lon/alt error ellipses were in the 250/250/700 mm range... that
I haven't done any extensive testing of how accurate the results are, but
comparing them to the position produced by a L1/L2 (error ellipses < 50mm) they
seem to be correct.
One issue to be aware of is that some receivers want altitude in othometric
height (MSL) and others use geoid (GPS)
I did a test on a 1 second vs a stripped out 10 second rate from the same 24
hour run. The differences were down in the noise. Some people have actually
reported slightly better results with 30 second vs 1 second data... but I
doubt that... I suspect they used different data sets and the
As far as I'm concerned anything that you can do to improve the position
accuracy, environmental changes, noise environment, etc is a good thing.
Minimizing errors and disturbances can't hurt and may even improve things. How
much any improvement provides ... ??? But time nuts tend to
I did another test to see if the M8T offered any positioning advantage over the
old (and cheap) LEA-4T and LEA-5T devices. I drove the M8T and LEA-4T with
the same antenna, collected data for 12 hours, beamed the RINEX files to
Canada.
The results matched to within 3mm... so, again, the
I repeated the two-receiver test, this time comparing 10 hours of 1 Hz
measurements from an LEA-4T with NVS-08C measurments. The NVS has higher
resolution RAW data measurements. But, again, the differences in the error
ellipses were in the 2-4 mm range.
I did Lady Heather's 48-hour precision survey on an NVS-08 receiver and
collected RINEX data at the same time. The NVS was tracking GPS and SBAS
satellites.
The RINEX result had lat/lon/alt error estimates of .175/.153/.396 meters.
The difference between Heather's precision survey results and
The tripod is a survey grade tripod on a limestone terrace (in a horrible
location for an antenna).
Heather's precision survey uses the receiver's reported position data. It
does not take advantage of carrier phase/pseduorange/doppler data and
post-processing. Unlike the simple averaging
The typical receiver default self-surveys of 30 minutes to 2 hours are not
ideal. They will not include a lot of satellites or the effects of multi-path
over time. A survey of at least 12 hours is needed to include all the sats.
24-48 hours is even better.
The effects of things like
That is exactly what it should be doing... it shows the time of arrival of the
receiver time message is varying by around a millisecond.
---
> However, when entering this command the three
millisecond digits do appear but only alternate back and forth every
several seconds between
I added some debug log info that shows how many bytes the receiver sent between
time messages. The LEA-6T sends around 500-600 bytes every second. That fits
easily into 9600 baud. The M8N tracking all sats and with all the raw
messages enabled spews around 4000 bytes. That would require
There are some sellers on Ebay LEA-5T receivers on Ebay for cheap. They are
pin and layout compatible with the Trimble Resolution-T devices. I bought a
couple from this guy ($24 each) and they do output the RAW and SFRB messages.
He also has LEA-4T and Trimble boards. There are also other
The goal is to make it as simple as possible and have Heather do all the
receiver configuring, data capture, and RINEX making... with none of that
tedious mucking about in RTKLIB Currently all I have to do is fire up Heather
and tell it to write a log file with the .obs extension.
Well, I processed the Lady Heather .raw capture file from the $24 LEA-5T
through RTKCONV and submitted it to CSRS-PPP and it worked. Using the less
precise instant orbits it says the 95% sigma errors are: lat: 0.169m
lon:0.148m alt: 0.399m
My antenna is that Chinese L1/L2/Glonass/etc
For the orbits is says "Precise", so maybe not even the hourly ones. I could
not find any mention of emu, emr, or igs.
Heather can now spit out Rinex 3.02 files (at least for GPS/SBAS sats).I
am currently feeding Heather the .raw capture file I sent to Canada and
outputting a RINEX .OBS
I tried submitting Version 3 files to several services... none support Version
3!Heather now creates the uglier/less readable Version 2.10 RINEX,
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G... Canada lives in the dark ages and does not accept RINEX version 3...
I'm now trying Australia...
Version 3 is cleaner and easier to write than Version 2...
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Woohoo! Success!I sent a RINEX 2.10 formatted .obs file generated by
Heather from a Ublox 5 to Canada for post-processing. The results matched
those from RTKLIB processing to within 1mm. Oh, and on noth cases the
post-processing used the "emu" orbit info.
I haven't heard back from
You will probably have a some difficulty finding a surveyor that does
geodetic/mm accuracy surveys. Most surveyors that use GPS seem to work down
to inches/a few cm.
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Coincidentally, yesterday I tweaked up Lady Heather's Ublox code to enable all
of the necessary raw data messages. Heather also enables the raw messages from
Trimble TSIP speaking receivers, the NVS CSM24 receiver, and the Furuno GT87
receiver (if baud rate is >=115200).
Heather can write a
Heather now requests the RAW and RAWX messages... those output carrier phase,
doppler, and pseudo ranges.The M8N does not support either, but the M8T
supports RAWX.
Heather now requests the SFRB and SFRBX messages... those output the satellite
navigation messages. All the M8's output
I once spent way too much time trying to get Heather to spit out a RINEX file
from a Thunderbolt. I could never get any of the post-processors to accept
it. The Thunderbolt's raw data needs to somehow be tweaked to be compatible
and I didn't really know what I was doing.
A LEA-6T seems to
To give an idea about the possible improvement in antenna location available by
post-processing the data, I first did a 2 hour self-survey and that put the
receiver into position hold mode. Then I collected RINEX data for 16 hours.
The post-processed lat/lon/alt values differed around 1/1/3
The Thunderbolt, Star-4, Trueposition, and HP GPSDOs/Smartclocks are all known
to do this. Typically the learning period is around 24 hours before the
compensation is allowed to run. My HP GPSDO seems to take a week for best
performance.
Separating tempco and aging drift seems to me to be a
Many years ago I tried to add some code to Lady Heather to calculate the
tempco and aging of the oscillator in a normally running Tbolt. Although the
equations would theoretically work (using SVD decomposition) it seldom worked
properly. Failure seemed to be caused by noise in the small
The 4530 GPSDO arrived, but was dead. Looks like the DC-DC that makes 5V is
bad. The seller sent a replacement unit that seems to be working.
Also a list member sent me a copy of the 4531 manual. The commands listed are
very similar to the Star-4 commands. But sending any of the 4531
I disassembled the unit and found that +5V is shorted to ground on the top
board. No shorted tantalum caps or obvious failed parts. I am beginning to
think it may be power/ground planes are shorted on the four layer board (all
boards are four layer)... probably wasted $20 on a DC-DC. It's
There are two types of Oscilloquartz GPSDOs appearing on Ebay:
For now, I would avoid the OSA-4530. I have been unable to talk to it. The
version being sold now may have non-standard firmware. All commands return
an "unknown command" error.
The Oscilloquartz GPSDOs that use the Star-4
Since NiMH cells typically have over twice the capacity of NiCad cells, a C/10
charger will charge them at less than C/20.It's best to trickle charge NiMH
cells in the C/30 to C/40 range, but depending on the cell C/20 might be OK.
Measure your charge current on a discharged pack and
Looks good and quite useful.
If you ever re-spin the board, I would recommend including a place for range
limiting resistors on the ends of the EFC adjustment pot. That way they can
be low TCR resistors and the TCR effects of the pot can be minimized and the
EFC adjustment can be made less
That's what I thought, but in a real world application I got better results
with the resistors/pot. It could have just been the pots I were using.
What also worked quite well was to thermally bond the pot to the OCXO case...
poor man's oven stabilization.
---
> When used as a
Another very irritating "feature" of pots is that over time the wiper can
deform the resistance element. When you go to adjust a pot (like when making a
calibration adjustment on an old piece of equipment) it can be very difficult
to get (and keep) the setting where you want it to be if the
On the 531xx counters the priority is the external input, the OCXO option, and
the (terrible) on board crystal. I seem to remember coming across a menu
option for forcing a particular source.
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I never decided on a particular display to use. I was thinking along the lines
of 192x32 LCD displays. LEDs could be used, but I didn't see any alphanumeric
LEDs on Ebay that were small enough. I didn't check places like Digikey.
Also, doing the annunciators with LEDs adds some complexity
I have a bunch of small, cheap antennas that look like this one. I bought them
for testing some Glonass capable receivers:
https://www.ebay.com/itm/NEW-GPS-GLONASS-Antenna-car-navigation-dvd-C-receiver-Waterproof-gps-antenna-SMA/262621649740?hash=item3d25785b4c:g:OHkAAOSwglZZcC8~
They seem to
I have worked out a design for a replacement 531xx front panel that uses a
micro and LCD module to emulate the VFD display. I was going to do it when my
VFD died, but just bought a couple of spare VFDs off of Ebay.
The 531xx front panel board basically has a bunch of elastomer switch contact
My adapter board for connecting an LPFRS / LPRO / OCXO to my BNC (and now SMA)
connector board has a place for a 10K EFC adjustment pot (0.375 x 0.175"
footprint). I'm looking for recommendations for a cheap, low-ish tempco pot.
I have a few nice ones with a house number on them, but the
If you have a TADD2-mini you can just replace the divider chip with the 10 KHz
version. That doesn't get you a 10 V output, though.
--
> I am trying to duplicate one channel of the TADD2 so I can bring 10Mhz down
> to 10Khz.
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