I have a number of GPS L1 timing antenna up, and I suspect one of them is not
quite right.
As a test procedure, all I can come up with is a power-injector connected to
the feed line, the feed line connected to a DC block on the input of a 8566A SA.
Then connect a known good antenna and compare
Has anyone got a proven method to check a GPS timing antenna for reliable
operation?
Plug it into a known-good GPS receiver.
A while ago, I thought one of my antennas had died. Then the other died, or
something like that. Both antennas started working again after I power
cycled my
You might generate a CW RF test signal at a level that allows easy detection
on the SA. Maybe into a simple dipole antenna. A second dipole test antenna
could establish a reference that you could relate the GPS antenna gain to.
Tom
- Original Message -
From: Mark C. Stephens
Thanks Tom, but the only RF genny I have is a pair of HP 8568B and a HP 8567A I
think it is.
The fan runs all the time on the 8567A so it mainly stays unplugged..
The only thing I have that can go that high is an 8350B Sweeper with a 83522A
plugin (0.01-2.4 GHz).
Can I utilise the sweeper
It is impossible to see something on the spectrum analyzer, I use the
network analyzer (here at work) to test GPS antennas that our
customers send in to have them checked. You can use the spectrum
analyzer but then you must have something that transmits... maybe this
is the only case when a $10
Would this box work with the new WWVB format?
On 07/25/2013 04:07 AM, Mark C. Stephens wrote:
Oh my gosh, a 117A has popped up on eBay!
Looks in pretty good condition given its age...
Seller claims the antenna will be listed shortly!
Item # 281141315740
--marki
Oh my gosh, a 117A has popped up on eBay!
Looks in pretty good condition given its age...
Seller claims the antenna will be listed shortly!
Item # 281141315740
--marki
___
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Could not resist a look.
Its kind of what I have seen the units look like old stickers and such. My
2 were ugly. But that old soap and water and elbow grease cleans things up
very well.
No mention that it can't possibly work. $124 + $28 shipping + $25 manual. I
am thinking thats an awful nice
FYI, The MPSA18RLRAG is a stock item at Digi-Key, min beta 500 at 1 10mA, 45V
200mA rated, TO-92. $0.33 each.
http://www.digikey.com/product-detail/en/MPSA18RLRAG/MPSA18RLRAGOSCT-ND/1139919
From: paul swed paulsw...@gmail.com
To: Discussion of precise time
No pre 2012 phase tracking receiver will work.
So far I have not seen a single magical new receiver for the new modulation.
So if its a good price $20 including shipping buy it for a hole filler in
the rack. Or just because you always wanted one.
You have to build the d-psk-r to actually use them.
Since joining time nuts over four years ago I have not used a single MAX
232 chip. Two reasons MAX do not give me isolation and do generate noise in
critical applications. I prefer the use of two H11 opto couplers which work
perfect. On the receiving end the diode along with a current
Robert
I can't believe you found the transistor. When I pulled it out last night,
its actually a MPSA18!!! I had not had time to look it up but figured it
was a ebay leftover hunt. :-)
At that price I may order 20 of them. Like the gain.
Thanks.
On Thu, Jul 25, 2013 at 9:28 AM, Robert LaJeunesse
Very interesting list.
I wonder if that is a way to identify a cross from a manufacturer's P/N
(Tek, HP, Fluke, etc.) to a 'real' part?
Either that or all you need is a collection of NTE parts and never anything
else :).
I have used NTE parts to cross to 'unobtanium' in the past and, so far,
I always wanted on, but with the intention of using it. To bad it's
now useless now with the new WWVB format, otherwise I'd buy
it. Antennas I got.
Burt, K6OQK
At 06:14 AM 7/25/2013, time-nuts-requ...@febo.com wrote
Would this box work with the new WWVB format?
On 07/25/2013 04:07 AM,
Debating the band belive ideal for older is +-3V. But I would need to
check. And how old is old? Not to sure many of the old 1488 1489 devices
are around anymore.
I think more compatibility would be supported by the +-1.4 you mention.
Regards
Paul
WB8TSL
On Thu, Jul 25, 2013 at 9:39 AM,
NTE is actually a conglomeration of old parts cross reference stuff. Mostly
from the TV and radio days. They consolidated the consumer lines of
Motorola HEP, RCAs SK, and Sylvanias ECG lines to fill out the replacement
device business.
Thats when things could be repaired. So thats the reason the
Paul,
It's a buy it now at $124.00. That's an expensive rack filler or movie prop.
Burt, K6OQK
Subject: Re: [time-nuts] HP Agilent VLF Comparator Receiver 117A
Frequency Standard - 60 KHz
No pre 2012 phase tracking receiver will work.
So far I have not seen a single magical new
That's my HP 117A receiver that I listed. It's $120 and I pay for shipping.
It's the last of three I had. Shipping will cost between $20 -$25 depending on
where you live. I could either offer it for sale or send it to the landfill. I
chose to offer it to someone who might want to own a piece of
paul swed wrote:
I can't believe you found the transistor. When I pulled it out last night,
its actually a MPSA18!!! I had not had time to look it up but figured it
was a ebay leftover hunt. :-)
At that price I may order 20 of them. Like the gain.
Toshiba used to make a transistor with even
For short cable and non-critical use, CMOS levels (0-5V) work fine.
RS-232 receiver thresholds are actually similar to TTL levels
(0.8-2.7V), though the spec is for +/-3V minimum drive for noise
immunity. Phantom power can be gotten from the control lines - this is
how serial mice are
Yes it is but you did not add the $28 shipping and gosh you have to have
the antenna for $XX big bucks they are rare and the manual. I mean thats a
lot of cash for a tube radio.
Tbolt 14 watts superior accuracy and monitoring for the same or lower
price. Really easy to attach to a blank rack
I totally agree that a 123 will not replace it. A luck would have it I have
12 X 2n3390 xsistors Beta 400-1000. These are the older TO-98s and I will
try one tonight.
Regards
Paul
WB8TSL
On Thu, Jul 25, 2013 at 12:00 AM, Orin Eman orin.e...@gmail.com wrote:
I find it hard to believe that NTE
A lot of these questions can be side-stepped today because few to no modern
PC's have built in RS-232 serial ports.
And if you are going to add a serial port you can just put in a RS-422 PCI
card or RS-422 to USB interface instead. A big win, and it makes much more
sense to leach +5V off of USB
Hi Bert,
I am sure your circuit is clear in your head, but would you mind attaching
detail?
You have perked my interest with the low-noise keyword ;)
-marki
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of ewkeh...@aol.com
Sent:
Date: Wed, 24 Jul 2013 20:46:51 -0700
From: Hal Murray hmur...@megapathdsl.net
ja...@peroulas.com said:
Any ideas on where I can look to track down the discrepancy?
Dig out the kernel sources.
This would be my first time looking at kernel sources. Any suggestions as
to where to start?
ja...@peroulas.com said:
This would be my first time looking at kernel sources. Any suggestions as to
where to start?
I don't have a Raspberry Pi so I'm not familiar with how they do things.
The main Linux kernel sources are available at kernel.org. It's driven by a
config file, and there
I do not understand your question, I am referring to low noise applications
like counters for dual mixers or other AV measurements, but also Shera and
even Tbolt where external noise should be kept to a minimum. When you
chase 1 E-14, isolation is key and I always like to err on the cautious
Hi Bert,
My attitude is if you are going to provide an RS-232 port then do it
properly (min of +/- 3 volts max of +/- 25 volts). RS-232 is still a
popular item in the hobby controller world, although USB is gaining
ground. In so far as stability goes, RS-232 is much cleaner and easier
to
Bert pretty sure he is just asking for a diagram. He is interested in the
method of noise isolation.
Regards
Paul.
On Thu, Jul 25, 2013 at 3:32 PM, ewkeh...@aol.com wrote:
I do not understand your question, I am referring to low noise applications
like counters for dual mixers or other AV
ewkeh...@aol.com said:
David had the right answer using the power that the RS 232 mouse uses out
of a DB 9, started looking but I do not have one any more and I can not
find any data.
Some PCI cards have a jumper on one of the modem control signals to provide 5
or 12 V. It was used to
Diagram of the two opto couplers?
In a message dated 7/25/2013 4:10:54 P.M. Eastern Daylight Time,
paulsw...@gmail.com writes:
Bert pretty sure he is just asking for a diagram. He is interested in the
method of noise isolation.
Regards
Paul.
On Thu, Jul 25, 2013 at 3:32 PM,
Bill
Thank you I am only looking for a solution that is simple in Corby's case
we used a separate power source, but the question is, is it necessary. That
is why I brought it up to the list. Shopping for ideas.
Bert
In a message dated 7/25/2013 4:06:03 P.M. Eastern Daylight Time,
Bert
I will add back in here. The max232 has the internal switching oscillator
and that makes the noise. But you know that. So an external +/-supply
linear is cheap and simple. Full wave bridge and 2 caps. No regulation
needed. Using your opto isolator provides complete noise and electrical
After all the discussions about the cost of power, I'm getting my act
together and replacing my old power hungry PCs with new/modern Atom boards.
I found one that has 2 RS232 connectors. Looks good.
http://www.mini-box.com/Intel-D2500CCE-Mini-ITX-Motherboard
The catch is that they are only
I made the second on on this page some years ago and somehow it manages to
survive the junk box. It only uses 2 transistors and 4 resistors and doesn't
require an external power source. It it feeds the negative voltage through
from the TD pin, so I don't think it can be used on full duplex.
Thank you Paul. This is exactly what I wanted to know, as I said I already
use the opto couplers the only thing is where to get the power from for the
transmitting side and you answered that. I will not use it but some others
may. I will stay with opto USB..
In a message dated 7/25/2013
Do you have a good solution for USB? Not just a cable with an adapter and
wires hanging out of it, but a clean solution. I had trouble finding USB
B-type female chassis-mount connectors and wound up ordering one from some guy
in the UK. It's actually an extender cable that can be chassis
Agreed, nobody should be using RS232 for anything nowadays. USB doesn't
seem to cause noise problems in equipment that works at the -170 dBc/Hz and
below level (ahem) so it will be good enough for most other sensitive
applications, assuming good design/layout practices are followed.
USB support
There are a bunch of little boards like these. This one has USB-B socket
that faces your computers and TTL Serial that faces your project. When
you plug your project into a computer the computer sees it as a serial port.
https://www.sparkfun.com/products/718
If all you need is the USB-B
Maybe low-profile rs232?
Something like: http://www.cablestogo.com/product/52138
On Thu, Jul 25, 2013 at 1:51 PM, Hal Murray hmur...@megapathdsl.net wrote:
After all the discussions about the cost of power, I'm getting my act
together and replacing my old power hungry PCs with new/modern
Make your own cable from a bare DB-9 connector, solder and shrink tube.
On Thu, Jul 25, 2013 at 2:54 PM, Eric Williams wd6...@gmail.com wrote:
Maybe low-profile rs232?
Something like: http://www.cablestogo.com/product/52138
On Thu, Jul 25, 2013 at 1:51 PM, Hal Murray
Although your description,
I prefer the use of two H11 opto couplers which
work perfect. On the receiving end the diode along with a current limiter
and blocking diode for the negative level works perfect. On the output side
a power source is needed. Is a perfect circuit description, I'd
I'm looking for something more like this auction, but with a USB-TTL adapter on
the back of the panel mount socket. When I was searching the only one of these
I found was in the UK.
Contact me off list and I will make a scetch
In a message dated 7/25/2013 6:34:58 P.M. Eastern Daylight Time,
ma...@non-stop.com.au writes:
Although your description,
I prefer the use of two H11 opto couplers which
work perfect. On the receiving end the diode along with a current
on some of my projects some prefer to use RS 232 and I am not arrogant
enough to say that RS 232 is not an option but try to help them and that was
why I asked the original question to make it for them as simple as possible.
I combine opto with USB but if you want to run 10 devices at the
j...@miles.io said:
Agreed, nobody should be using RS232 for anything nowadays.
RS232 works much better for capturing PPS timing.
Another advantage of RS232 over USB is that the configuration is stable when
things get unplugged and replugged, or powered off, or ... Of course, that's
a
Or mold some Polymorph https://www.sparkfun.com/products/10951 around the
DB-9.
On Thu, Jul 25, 2013 at 3:28 PM, Chris Albertson
albertson.ch...@gmail.comwrote:
Make your own cable from a bare DB-9 connector, solder and shrink tube.
On Thu, Jul 25, 2013 at 2:54 PM, Eric Williams
Hi James,
We have done some measurements of the stability of the STC clocksource that the
kernel relies on to build its system clock. I believe this link could be the
answer to your question:
http://www.synclab.org/?post=blog/2012/11/radclock-raspberry-stability-nic-noise.html
Please note that
I still would like to find one of the HP antenna's just for the looks. Even
the 10509A with 13CW4's .. ok the FET version would be better.
At least give those passing by something else to point at :-)
-pete
On Thu, Jul 25, 2013 at 7:09 AM, Burt I. Weiner b...@att.net wrote:
I always wanted
Hi Hal, according to ntp.org the parallel port is also usable for PPS:
http://www.eecis.udel.edu/~mills/ntp/html/pps.html
Also, Take a look at this gentleman's page (Chrome will translate):
http://www.finetune.co.jp/~lyuka/interests/radio/gps/
there is quite a difference between the amount of
Hi Pete, I have a 14 diameter choke ring GPS L1 with a big spike on the top of
it, on the peak of the roof :)
That certainly gets some stares!
As the HP antenna is VLF, is the Antenna Huge?
I can't reliably get WWVB in Australia.
Lots of fading etcetera, or I'd be in there like a shot :)
We
Well lucks not so good do have the voltage closer but as Bob C said. That
ain't the issue.
Darn I hate when he is right. By the way the oscillator draws 26 ma approx
as a reference. Reassembled everything and let the oven heat up it settles
at 81C 15 min after start and within a respectable range
The HP 117A antenna is a circular shielded loop, about 1 meter or 3' in
diameter. I never bothered to measure it. It looks to be made out of
roughly 1 OD aluminum electrical conduit components, a Tee at the top and
a pull box at the bottom. There are three conduit sections, one a diameter
that
Marki the antennas are about 3 foot as I recall not huge, really. But
Australia is a bit far away. I would think JJY might be better for you.
That said to actually improve the signal at that distance build a serious
loop. Mine is 10' by 10 ft 800 ft of wire and preamp. Does a heck of a job
for the
On 7/25/2013 8:32 PM, paul swed wrote:
Well lucks not so good do have the voltage closer but as Bob C said. That
ain't the issue.
this may is a dumb question:
Lower than expected frequency means some extra capacitance in parallel
or not enough in series with the crystal... ?
Would that put
I had one of those antennas some years ago. sold it to an outfit in
Washington State (I was in Boston). IIRC, it was over $300 to ship
it UPS due to the size.
73, Dick, W1KSZ
On 7/25/2013 6:23 PM, paul swed wrote:
Marki the antennas are about 3 foot as I recall not huge, really. But
Australia
I have made a number of effective loop antennas for various frequencies
tuned with variable capacitors going into the gate of a FET. A large
number of turns on a ferrite rod will tune to 60 KHz and pick up a
good signal if located away from noise sources. Or you could get a
Hula Loop and paint
the side loops are insulated at the top to prevent forming aa shorted
turn. It's a loop antenna that works on the magnetic field component of
the incoming wave, rather than the electric field, like a whip. So, if
you put a bunch of turns inside the loop of conduit, a complete loop of
conduit will
j...@miles.io said:
Agreed, nobody should be using RS232 for anything nowadays.
RS232 works much better for capturing PPS timing.
Unless you are watching it with a ring-0 (kernel) driver, and/or using a
hard realtime OS to run the client software, it really won't matter that
much. Anyone
On Thu, Jul 25, 2013 at 8:40 PM, John Miles j...@miles.io wrote:
j...@miles.io said:
Agreed, nobody should be using RS232 for anything nowadays.
RS232 works much better for capturing PPS timing.
Unless you are watching it with a ring-0 (kernel) driver, and/or using a
hard realtime OS
From: Chris Albertson
[]
In just normal UNIX (including Mac OS X) and linux you can see the
difference in the log files between USB and RS232. There is three orders
of magnitude difference. It's micro vs. milli seconds.
[]
Chris Albertson
Redondo Beach, California
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