Hi,Sorry if I caused confusion by calling the SCR/BC221 a wavemeter. Clearly
it's not in the wider usage of the term, and the manual and front panel call it
a frequency meter. However the similar British device was called a wavemeter
"Wavemeter Class D"
In a word,Wavemeters. Classic US onwas the BC221 with built in 100kHz crystal
calibrator
http://radionerds.com/index.php/BC-221
British was the "Class D"http://www.royalsignals.org.uk/photos/classDno1.htm
For UHF and Microwave it was Lecher lines or cavity wavemeters.
Robert G8RPI.
From:
One must remember the original use of these displays was displaying IRIG time
either distributed from a master clock, locally generated or from a recording
(tape) They long predate GPS. There are more sophisticated units that include
controls for the tape recorder so you could auto search to a
I've used the Dallas (now Maxim) Thermochron iButtons in several applications.
Looks like a thick coin with battery, ram and RTC built in. Even used dozens of
them map temperature distribution in a aircraft fuel tank. Also available as a
1-wire device. For precision I've used Pico Technology
One other tip. If the can and base are tight fitting you can file through the
corners of the can at 45 degrees to the sides. This breaks the stiffness of the
can and allows the sides to be folded out slightly. Straighten them before
re-assembly. You can build up the corners with solder to
Back in 1997 when working on a car project I saw several failures of AD595
Thermocouple converter chips due to sound. In all cases the bond wire to pin 8
of the CERDIP package failed, presumably due to resonance (I took the top of
the chips to check) A blob of non acid cure RTV silicone rubber
Hi Anders,
You can buy the 2013 QST CD-ROM from ARRL which includes QEX. I'm in the UK
and have this CD, international delivery was no problem. Cost was $25, see
http://www.arrl.org/shop/ARRL-Periodicals-DVD-2013/ The disk is well worth the
cost.
I've not built the project but have looked at
It's part No 05370-20206, no longer available from Agilent. I don't think you
will find one easily. Best bet is to buy some plastic and make one. The
proper plastic filter material is polarised to increase contrast but thin red
acrylic sheet will do OK. masking the annciators may be tricky. Try
From the construction and components used it isn't UHF ;-) It appears to be 7
two way splittters in series and the transformers look to have plenty of turns.
As you have a 10MHz source why not just try it out? You should get about 9dB
attenuation input to output with the other ports terminated
Hi Graeme,
A technique I've found useful is to first remove the corners of the outer can
by filling across them. I then rake out as much of the solder along the seams
with the back edge of a disposable snap-off craft knife / box cutter. Finally
wedging the sharp edge to break the joint.
Hi,
I looked at this a while ago. The spec only defines transmission levels, it
does NOT specify receive thresholds. All the receiver chips I've looked at,
ancient and modern, have only positive thresholds. Most have single supplies
and clamp the input at 1 diode drop negative WRT common after
Hi Javier,
Our posts crossed. However the 1489 has a positive threshold (they call it turn
off threshold) of 0.75 to 1.25V. They can be shifted to a negative trigger
range using the response control pin but this is just a voltage divider and
offset voltage, you still only get hysteresis of 1.1V
-nuts@febo.com
Sent: Tuesday, 28 January 2014, 2:01
Subject: Re: [time-nuts] Trimble Thunderbolt 1pps
On 1/27/2014 1:33 PM, Robert Atkinson wrote:
I looked at this a while ago. The spec only defines transmission levels, it
does NOT specify receive thresholds.
It certainly does...
2.1.3
Hi,
For a low cost startup have a look at a picPET
http://www.leapsecond.com/pic/picpet.htm and TimeLab
http://www.ke5fx.com/timelab/readme.htm
Less than $10 including shipping!
From: Wojciech Owczarek wojci...@owczarek.co.uk
To: Discussion of precise
Hi Mark,
late response, but I've been looking at the 3582A. Using a mixer for PN at
higher frequencies is OK, see
http://www.hpmemory.org/technics/bench/3048/pn_measrmt_single.htm
Pretty good for comparing a number of oscillators. You can use a doubler
(HP10115A
Hi Brett,
In the 5328A the unregulated 25V DC supply and OCXO run whenever the unit is
connected to power. The on/off switch controls the main circuits power supply.
The triac (Q12) and opto-coupler (U6) turn on the fan when the 3.5V DC supply
is present (its only active wthe the unit switched
Hi Antonio,
It should run when the ON/OFF switch is ON but not if it's OFF. If the fan runs
whenever the power is connected there is a fault, probably a shorted TRIAC.
Interestingly on the 5328B they added an RC snubber across the TRIAC which may
indicate they had problems with the A model.
Hmm,
Input dynamic range of 1.2V Pk-Pk and 125Msps, like that's going to replace ALL
my test equipment. It's also not clear if they are in Newport VA or Slovenia,
but the plug on the mains adaptor says Slovenia. I'm stunned that 826 people
would consider spending hundreds of dollars on this
Hi,
This is a known problem. It's leakage form the local oscillator (LO) of the
Ky197. The KYa97 has a 10.7 MHz IF and high side local oscillator. So the LO is
119.9 + 10.7 = 130.6MHz. 12th harmonic is in the GPS bandwith.
Cure is a notch filer on the KY197 antenna connector. examples are a TED
Here in the UK we had a version of this for nearly 40 years. It was called
Ceefax or TeleText. Chunky graphics with the time, weather and lots of other
information. it was also used for closed captioning. see
http://en.wikipedia.org/wiki/Teletext It was the best generally available
time
I know Goldmine would not sell duff stuff knowingly, but the Engineering
Sample label worries me a little. Often this is indicates a non-functioning
item for display or trial fit purposes. Then again it maybe not. I can't find
out as they don't ship outside the USA.
Robert G8RPI.
Hi,
John is correct. The plastic pin is used when a contact position is not wired.
You put the unwired pin in first and then insert the plastic pin behind it,
thick end first. It replaces the wire to seal that individual hole and also
maintain correct seal pressure on the other wires. Blue for
From: Robert Atkinson robert8...@yahoo.co.uk
To: j...@quikus.com j...@quikus.com; Discussion of precise time and
frequency measurement time-nuts@febo.com
Sent: Tuesday, December 10, 2013 12:27 PM
Subject: Re: [time-nuts] MS3106R10SL-4S connector question
Hi,
John is correct
The US Chemical Safety Board have released their report into the 2009 accident
at NDK's synthetic crystal growing facility in Belvidere IL
http://www.csb.gov/assets/1/19/CSB_CaseStudy_NDK_1107_500PM.pdf
It also describes the process.
Basically a 50ft autoclave failed, killing a member of the
November 2013, 14:25
Subject: Re: [time-nuts] Crude Survey Technique
On 11/21/13 11:32 PM, Robert Atkinson wrote:
I'd also go for a compass if you want magnetic north, but then I have a good
one, a medium landing compass. Mine dates from WWII but they are still made
http://www.sirs.co.uk
I'd also go for a compass if you want magnetic north, but then I have a good
one, a medium landing compass. Mine dates from WWII but they are still made
http://www.sirs.co.uk/ground/landing_compasses/patt2/landing_resource
These are used to align the standbay and remote reading compasses on
The simplest ones do it by difference in position from one fix to another. no
need for a map for True North, just trig. For Magnetic North you need a map
with variation data. More advanced units have magnetic sensors and
accelerometers. An interesting question that I once spent some hours
May be a bit of drift and reading back to front. Some years ago we bought a
quantity of moulded carbon compostion resistors from a top US manufacturer. A
sample check showed that none of them met the 10% tolerance. The maufacturer
said bake them for a day two! The resistors then passed. Why not
Hi,
Interesting investigation, thanks for sharing. Another option I have used was
+12V +5V with the -12V rail powered by a 9V output isolated DC-DC converter
from an old thin ethernet network card. These come in either 5V or 12V input
and are effecitvely free (you also get 10MHz isolaton
Hi Frank,
I would NOT put the spare TB on a PC powersupply. Check out both TB's on the
bench using decent linear supplies. I don't like using PC supplies on critical
equipment. They are typically designed for a specific (high) load on one output
(5V on early ones 12V on more modern) to maintain
Hi
Trimble recommend 75R CATV or similar cable for the Thunderbolt as it's lower
loss (even with the mismatch loss to 50R it's an advantage), hence the F type
plugs. Adaptors are cheap and available even here in the UK where the F type is
a fairly new entry into the market. Using 75R cable
Hi,
I built a number of the air spaced patch antennas,
http://www.express-builder.com/docs/gpsant/ , several years ago for APRS
mobiles and even with older GPS modules (Garmin), they gave usable performance.
Robert G8RPI.
From: Attila Kinali
Hi Bob,
You say you are not ready to go GPS. I assume you mean a GPSDO. If you have a
'scope you can use just about any GPS with a 1pps output. trigger the scope
from the 1pps while monitoring the 20MHz sine wave and adjust for minimum drift
of the trace. A timing GPS module will be better (you
Hi Corby,
What pins are the line and the neutral connected to at the moment? What pins
are linked?
What you describe is typical of a 110/120/220/240 setup with the windings
between 1 8 and 29 being the 10V taps.
You could try connecting a low voltage AC supply (between5 and 15 v from a
Hi Corby,
I had a look at some circuits and it’s pretty much what I expected. The 120V
tap supplies control relays including the external pressure relay (pin F on
rear panel connector, pin E is neutral) and neon indicators. The supply to the
HV transformer is relay controlled so you would have to
Hi Corby,
How's it wired now? Basically it should be two windings in series, say line to
1, 2 linked to 3 and neutral to 4. To set to 120V leave line and neutral were
they are and link 2 to 4 and 3 to 1. As a double check for phasing when you
lift the link between 2 and 3 check for winding
Be aware,
Googling helibowl at work may take you to websites selling glassware used for
recreational purposes that may not be appreciated by the IT police ;-)
Robert G8RPI.
From: Jim Lux jim...@earthlink.net
To: time-nuts@febo.com
Sent: Tuesday, 17
Hi John,
I use one of the 26dB active timing antenna like ebay item 271266449940 or
170889540720 but a quick look shows fluke.l is selling a 38dB one 300956651110
that might be good if you have a long antenna run. You don't say what
receiver(s) you have, but the Thunderbolt needs a gain
Hi Bob,
Many of the midrange antennas have one or more significant differences from the
cheap pucks. Firstly they generally have better filtering, many pucks have
none. This is important if you are co-located with transmitters. Secondly many
use quad-helix antenna elements rather than the
Hi,
I thought one post was OK (just), but by the third advert I thought the
questions should be asked.
Sorry for lowering the S/N.
Robert G8RPI.
From: Burt I. Weiner b...@att.net
To: time-nuts@febo.com
Sent: Friday, 13 September 2013, 6:08
Subject:
Hi Adam,
If you do not normally monitor this email reflector or contribute to it, why
are you using it it promote your commecial product?
Are you going to make the circuit and code (or programmed MCUs) available to
list members?
Robert G8RPI.
From: Adam
say that you do
not contribute anything (I said you did not contribute to the Time nuts list,
by your own admission you don't). I asked three questions. Obviously these
touched a nerve.
G'day,
Robert Atkinson CEng MRAeS G8RPI.
From: Adam Maurer m
Hi Edesio,
Welcome to the group. The HP 5316A you are looking at is an excellent little
counter. While not up to extreme time nut standards, they work well and in my
opinion would make a much better first counter than (say) one of the modern low
end (not known brand) new counters or
Sorry for confusion caused by my using the L H words :-) it's called
Thunderhead and is a lot cheaper than some solutions if you just want a desktop
monitor or can hack an iPaq handheld into your Thunderbolt's case.
Details including complied EXE for PocketPC and source code is
Sorry to reply to my own post.
I was wrong on the name of the PocketPC software. It's called Thunderhead see
http://fuzzythinking.com/projects/thunderhead/
Robert G8RPI.
From: Robert Atkinson robert8...@yahoo.co.uk
To: Discussion of precise time and frequency
. I used
an SD card to store the exe file. A quick check on ebay shows
2200 iPAQs on buy it now for $25.
Robert G8RPI.
From: Chris Albertson albertson.ch...@gmail.com
To: Robert Atkinson robert8...@yahoo.co.uk; Discussion of precise time and
frequency
Hi Chris,
I've posted this before, but it's worth saying again. I use the PocketPC
version of Lady Heather on an IPAQ. These are available for next to nothing on
Ebay and can run in a dock on the bench or you can gut it and embed it in a
cased Thunderbolt. worn out batteries are not an issue as
Hi Dave,
The old thin pin 75R BNC sockets are rare these days. Most equipment now uses
intermateable sockets that use the same size contact as 50R but with reduced
diameter dielectric to maintain the impedance match. Fully compatible with 50R
without damage. The only small drawback is that the
Hi
Most of the British Racal standards are 5MHz. It may well have been down to
what was the best performance of the nationally avilable crystals. Everthing is
a compromise.
It is easy to double a 5MHz output to 10MHz. One way is to pass it through a
bridge rectifier (high speed diodes of
/wiki/TACAMO
http://en.wikipedia.org/wiki/Ground_Wave_Emergency_Network - some converted
to DGPS
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
Robert Atkinson wrote:
Hi Tim,
Three possible reasons for needing a Rb standard,
1/ Coherent
Not true,
Many aircraft OMEGA / VLF navigation systems used Rb clocks. Most if not all
the FRKs on the surplus market with the 10MHz output on the multipole connector
rather than a SMA came from OMEGA / VLF units. I used to fix the systems.
Robert G8RPI.
Hi Tim,
Three possible reasons for needing a Rb standard,
1/ Coherent detection with a local clock
2/ Hyperbolic navigation (local reference improves the fix and holdover)
3/ Secure communications.
Robert G8RPI
From: Tim Shoppa tsho...@gmail.com
To:
It seems you can't rely on the human backup. The UK Marine accident
Investigation Branch Has recorded numerous accidents due to poor lookout. See
http://www.maib.gov.uk/cms_resources.cfm?file=/KarinSchepersReportWeb.pdf
http://www.maib.gov.uk/cms_resources.cfm?file=/CoastalIsle.pdf
Hi Chris,
See http://www.leapsecond.com/pages/tbolt/power.htm and
http://www.leapsecond.com/pages/tbolt/noise.htm
I use a Condor / PowerOne HTAA-16W triple output linear. Technically it low on
current for the +12V, but as full current is only drawn during warm up and the
-12V is virtually
Hi Chris,
It is very likely that the cause of interference pick-up (not the actual
source) is BT's odd wiring scheme. The extensions use a third wire for the
ringing signal. This unbalances the wiring making pick-up more likely on
extensions. The ringing signal is basically just the incomming
Interesting idea.
Capacity equates to about 115mAH (.310WH / 2.7V) and thats to zero output, so
not an endurance option.
Robert G8RPI
From: David t_list_1_o...@braw.co.uk
To: time-nuts@febo.com
Sent: Thursday, 11 July 2013, 22:17
Subject: Re: [time-nuts]
Hi,
Not quite, The raduim is still very active. The glow stops because the ZnS
breaks down. The light emissson relies on the crystaline structure of the ZnS
plus a small amount of doping, typically silver. The alpha particles break down
the crytaline structrure causing the glow to weaken. Most
I'd guess that NiMH cells would be similar to Nicads. Cadmium has been banned
in the EU, except where it is essential. The power tool manufacturers
successfully negotiated an exemption, so they are still available.
I did note that the paper only considered Johnson and shot noise. The very low
of Rb87
Rb cells are perfectly safe for all practical purposes. An injury from the
broken glass is probably much more of a risk!
HTH,Robert G8RPI.
From: Hui Zhang ba...@163.com
To: Robert Atkinson robert8...@yahoo.co.uk; Discussion of precise time
Hi Hui,
Most bulbs use a mix of Rb87 and Rb85 with an activity of around 1500 Bq/gram
with less than half a millgram in a typical bulb, that's less than a Bq per
bulb (about 20 picocuries). You will get more ardiation from using low sodium
salt (potassium chloride) on your food. Potasium is
Hi
Why are so many people radiophobic? As in ionising radiation. There are far
more hazardous things in our hobby, electrocution and falling from a height be
two of the big killers. I defy anyone to come up with a confirmed case of death
caused by radiation as part of our hobby. Lead, solder
.
From: Mark C. Stephens ma...@non-stop.com.au
To: Robert Atkinson robert8...@yahoo.co.uk; Discussion of precise time and
frequency measurement time-nuts@febo.com
Sent: Saturday, 6 July 2013, 22:39
Subject: RE: [time-nuts] HP 5370B dropping mains voltage
How Does that Work
For those of us who would have to navigate a long way, there is a on-line
http://timeandnavigation.si.edu/
Robert G8RPI.
From: Jim Lux jim...@earthlink.net
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Monday, 1 July
As a side note, I'd use lithiums rather than AA's
(alkaline) purely because they don't tend to leak corrosive electrolyte all
over your expensive electronics if (when) you forget to change them. Lithiums
have a longer shelf life too.
From: mike cook
It actually even easier than ever now. Ebay.com do a global postage programme
http://pages.ebay.co.uk/shipping/globalshipping/buyer-tnc.html#paymentsplit
The seller ships it to a US processing center (an item I just won went to
Kentucky) and they preprocess the customs. I prepaid which saves
Hi Bob,
As adrian has said, 20V off load is not really excessive. Assuming you are
using the blue wires and associated bridge rectifier, this was designed to run
a pair of +5V and -5V regulators, a 7805 and 7905. This means if anything the
voltage is a little low for 12V output. Try bolting the
Doh,
It's late here, that should have been ...bolting the 7812 to the existing TO3
heatsink..
Robert.
From: Robert Atkinson robert8...@yahoo.co.uk
To: Bob Stewart b...@evoria.net; Discussion of precise time and frequency
measurement time-nuts@febo.com
Sent
Hi Perry,
While I agree with everything else you say, you CAN have too much filter
capacitance. At least where dc rectifier / filter (smoothing) circuits are
concerned. Increasing C causes increased ripple current and inrush current and
can overstress rectifiers and transformers. Not actually a
Hi Mark,
According to the manual, YES you can select different frequencies. See
http://www.rdrelectronics.com/skip/feb/SA22c.pdf
The seller doen't ship to the UK, fancy forwarding one for me?
Robert G8RPI.
From: Mark C. Stephens ma...@non-stop.com.au
To:
Hi Magnus,
According to the datasheet 10MHz is a standard output. The Manual say you can
change the factory setting using SSIP ( Symmetricom Serial Interface Protocol).
Unless of couse the particular units have been restricted. I don't thnik so as
both the factory set frequency and 10MHz are
Hi Jason,
Firstly I'm pro PIC so what I say is likely biased ;-)
Look at one of the Microchip PicKit 3 (or even PicKit 2) starter kits. See
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGEnodeId=1406dDocName=en538340
The
Hi Charles,
I'm biased, but here goes.
With regard to long term support it's hard to beat Microchip products. They
still supply (or at least a pin equivalent) and support all their controller
products.
They built their business on support and low cost, reliable development tools.
You are not
Hi Alec,
Well done and thanks for the credit. I had not looked under the board for the
crystal or spotted the divider.
One comment. in your blog and ebay description you say that the unit runs on
15V. The M suffix 5650A is actually designed for a normal aircraft 28V DC
supply (typical
Hi Alec,
Well done and thanks for the credit. I had not looked under the board for the
crystal or spotted the divider.
One comment. in your blog and ebay description you say that the unit runs on
15V. The M suffix 5650A is actually designed for a normal aircraft 28V DC
supply (typical
: Alexander Wright ale...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Saturday, 20 April 2013, 12:11
Subject: Re: [time-nuts] Changing FE-5650A frequency?
On 20/04/13 10:03, Robert Atkinson wrote:
Hi Alec,
Well done and thanks for the credit. I had
Me too,
Didn't say anything before to keep the noise down.
Robert G8RPI.
From: Alan Melia alan.me...@btinternet.com
To: time-nuts measurement time-nuts@febo.com
Sent: Tuesday, 16 April 2013, 0:40
Subject: Re: [time-nuts] Brooks Shera ASM release
Bert I am
Hi Rick,
According to 3M the self amalgamating tape (130) is not UV resistant. They
recommend covering it with 33+ to keep the light off. Not sure about the
ScotchKote. The self amalgamating tape forms an air and watertight seal. It has
no sulpher so no silver tarnishing. The trick with the
Hi Dave,
Not quite, they do use irradiation crosslinking to make the heatshrink tube,
but the hotmelt adhesive is a completly separate layer. They do different
combinations of tube and glue for different applications. Really cool are the
pre-forms that look like a parallel tube but shrink down
Hi Rob,
See my earlier post on using repeaters / re-radiators in the UK. Ofcom are
insitituting a light licencing scheme for GPS / GNSS repeaters. The
transmit antenna must be inside and the licence fee is £75. No mention that
I've seen of type approval but they should of course meet CE
Hi Alan and Tom,
Note that under the Wireless Telegraphy Act 2006 here in the UK, active GNSS
repeaters have to be licenced. See
http://194.33.160.59/radiocomms/ifi/enforcement/gpsrepeaters/
and
http://stakeholders.ofcom.org.uk/enforcement/spectrum-enforcement/gpsrepeaters/
Even a normal
Hi,
IIRC the early Trimble Placer vehicle tracking GPS receivers used the SVee6 and
SVee8. I think the Placer 400 used the SVee6. These units turn up on ebay etc
at very low cost.
Robert G8RPI.
From: gandal...@aol.com gandal...@aol.com
To:
Hi Alex,
These units were used as timing references for secure communication systems
(Havequick). see ebay item 130832014630. Unfortunatly they are an older design
with a two chip DDS. The other problem is that the M designation is for
military and means they have been partially encapsulated
Hi Herbert,
These units are different to the picture at
http://www.qsl.net/z/zl1bpu/PROJ/FE5650-2.jpg
They have dip switches and no PIC. The option is covered in one of the manual
out there but I'm sitting at the wrong computer to dig out the details.
Robert G8RPI.
Hi Nigel,
I've had a couple of early Placers and am fairly sure it was a SVee6 but it was
some time ago. I bought it surplus in the USA in 1998. I may still have one up
in the attic. I'll go and dig.
Robert G8RPI.
From: gandal...@aol.com gandal...@aol.com
Hi Nigel,
Had a dig and did not find a placer (yet, I've a lot of stuff up there :-) Did
find a small Nav-Guide 4700 that seems to be a VHF differential system with a
Trimble ACE GPS. Can't find any info on it.
Robert G8RPI.
From: gandal...@aol.com
Hi Bill,
The rated voltage is probably 26V AC rather than 28. I bulit a 3 phase inverter
for a test rig last year and just used 3 cheap MOSFET power amplifier kits off
ebay. Changed the feedback C's to limit high frequency response and it was nice
and stable. When testing put a automotive stop
Hi Bill,
The amp I used was similar to this circuit
http://www.circuitstoday.com/100w-mosfet-power-amplifier which is a common
design. Supply is 45V (unregulated rectified and filtered 30V transformer) so
will drive 26V out OK.
I've also used modules from ILP in the past, sometimes with a
I've not tried it and am not endorsing it but it looks a good low cost starting
point.
Robert G8RPI.
From: Robert Atkinson robert8...@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Thursday, 28 March 2013, 12:20
Hi all,
Not totally timenut, but I have a PLGR for sale and thought I' offer it here
before putting it on ebay. it's a bit of an odd one, model HNV561A part
no.822-0766-002. This appears to be the British version of the HMV560C. It is
not stolen, I obtained it from official UK disposal
Hi Chuck,
some early 75R BNC designs did use a smaller diameter center contact. The 75R
male can make intermittent contact when used with a worn or top of limit 50R
female. The 75R female can be damaged for use with the small contact male if
used with a 50R or large contact 75R male. The do
Hi Bert,
No need to block the DC. These instruments already have DC blocks (and a
switchable low current DC sink to hold the line from the exchange) because
the telephone line has a DC voltage of typically 48V on it already.
For comparison I just use 600 ohm termination and dBm, dBmV can be
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,
Oops,
that should be HP4945(6)A not 3945
Robert.
From: Robert Atkinson robert8...@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Thursday, 31 January 2013, 18:46
Subject: Re: [time-nuts] Low noise power supplies
My answer to this problem was to buy a old IPAQ handheld device on ebay ($30
including a bluetooth GPS mouse) and run the PocketPC version of lady
heather. You could put the IPAC in its cradle and set it on the bench as a
remote monitor, but I gutted it and built it into my cased Thunderbolt.
Hi,
I just found an FEI FE5650A which has an older DDS board in it. The board has
an AD9955 DDS chip and 4 8way DIP switches. There is no serial port. It appears
to be the universal DDS board shown in the manual. The unit is partially
potted so tracing the circuit is not ideal. Does anyone have
Hi Jim,
If space is an issue have a look at PC/104 format boards. These are designed
for embedded applications and are rugged. Another advantage is that they
pypically have a long product lifetime. No developing your product, testing it
and then finding the PC motherboard you used is obsolete
Hi,
While it may be a waste of time and money for time nuts, it may be a good
introduction for others. It may even spawn a few time nuts. Better someone
build this and learn something than just buy a cheap Chinese counter on ebay.
I've seen much worse projects published. I do agree that not
Several years ago I bought a very nice 24U EMC screend cabinet at auction. It
had an Odetics SatSync GPSDo with a rubidium reference, dual redundant power
supplies, a logic box and an AN/ARC164 UHF transceiverin a 19 rack chassis. It
was a shipborne havequick timing reference. I still have the
Hi Nigel,
Connect did have some recently by this came from another? seller who is from
the same town. WoodsGroup are also selling them (item 390489973647 ) but at
excessive prices and without the antenna. The GPS mod seems to replace the PLL
board and loops the LF signal through. The GPS
Hi all,
I recently gave in and bought one of the EES (european electronic systems)
RC1454 Radio Clock units that have been on ebay.co.uk for a while. The one I
snagged came with a GPS antenna unit. The main unit has a label saying GPS
Modified The main box appears to be a MSF receiver but has
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