What's the best way to open an OCXO in the typical solder-sealed tinned
steel can?
Use a high wattage iron to melt the solder at one point, prise the gap
open with a flat screwdriver, then work along the join.
Solder is soft. so once you get it started you should be able to roll it
open
I'm not sure I'd want to go quite this far, but here's one option..
http://gerrysweeney.com/hp-53131a-hard-power-switch-modification/
Regards
Nigel
GM8PZR
In a message dated 02/02/2014 03:50:56 GMT Standard Time,
stanw...@verizon.net writes:
Hello The Net,
I just got in the
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.
You can also take the tip out of a soldering gun and apply the gun's two posts
directly to the can for resistance heating. I've used that method a time or
two on large items. You need to push firmly to get good contact. The voltage
is very low.
Bob
I've never opened an OCXO but I have opened several sealed HV power supplies
used on HP 5061A and 5061B CS Standards. These supplies are mounted by four
6-32 screw studs which make for easy 'holding' in a lightly tightened vise.
I used a very focused hand held propane torch to go around the very
Volker,
On 02/02/14 01:51, Volker Esper wrote:
Magnus,
I took an EBMPabst 624. Pabst has a good reputation.
Papst is known good brand. I have seen another brand fail miserably so
this is why I am asking.
The original fan is a Delta Electronics DFB0624 H, Dimensions are 60mm x
60mm x
On 02/02/14 03:43, Charles Steinmetz wrote:
Jarl wrote:
In my SR620 the fan is a Delta DBF0624H. It is a 60x60x25 mm fan, 24V
/0.11A.
Mine, too. Does anyone know the airflow rating of the Delta fan? It
does not appear to move as much air as it should (at least not if the
idea is to hold
Hi
If you are tossing the can, a mill is by far the best way to open up an OCXO.
That of course assumes you have a mill…
It’s not a chip intensive process. You can easily do it with an X/Y table on a
drill press. Of course that assumes you have all of that stuff….
Bob
On Feb 2, 2014, at 2:37
On 29/01/14 06:16, Hal Murray wrote:
Whenever I plot an ADEV chart for a given oscillator I see the diagonal line
descending from upper left to lower right.
However at near the end of the plot, in this case 3600 sec at 1 sample per
sec. the trend begins to reverse at about 1200 sec. in.
IMO, the easiest way (non-destructive too!0 is with a high wattage iron or
250 W gun, solder wick or a solder sucker, and an X-Acto knife.
Start in the middle of one side. Heat the joint area and suck out as much
of the solder from the joint area as you can. Slip the knife in the joint
and pry
Hi
I use wire cutters like on a Morion I find a small lip and start pealing it
away. No trauma for the OCXO and simple.
Bert Kehren
In a message dated 2/2/2014 10:07:36 A.M. Eastern Standard Time,
li...@rtty.us writes:
Hi
If you are tossing the can, a mill is by far the best way to open
One thing about soldering that many people don't know is
that the solder is attracted to the hottest part of the joint.
If you apply the soldering iron to the side of the can, the
solder will be sucked down into the can, leaving a gap where
the lid meets the can...
So, if you want to solder a
In general, I sandwich the solder wick between the joint and the iron. In
such a joint, the solder is mostly at the edge of the joint:
==OO --- Solder bead
===
You don't really want to heat the thing so the solder flows into the joint
more deeply.
-John
I've not opened on of these cans but I have opened some shield audio
transmitters. I just use my Hakko temperature controlled solder station at
a high setting and work my way around the edge. It can be done
non-detructivly. Solder wick helps a lot, use a bunch of it to get rid of
the excess
Magnus wrote:
If the heat sources where well coupled to the air-flow, which they
are not, and the flow-path as low air-flow resistance, which it also
doesn't have, requires the fan to work at high rate to get any air
move, and to get the thermistor happy.
My point was, the thermistor is
On 02/02/14 18:47, Charles Steinmetz wrote:
Magnus wrote:
If the heat sources where well coupled to the air-flow, which they are
not, and the flow-path as low air-flow resistance, which it also
doesn't have, requires the fan to work at high rate to get any air
move, and to get the thermistor
It has been a long time since I opened one of these, but at the time I remember
thinking it must be possible to open one of these without deforming it. Like
anything correct technique must be the key. Companies like Wenzel do this on a
daily basis and I would guess their technique would include
If I want to reuse the can I use a torch, very fast several HP 5061 HV cans
mainly
Bert Kehren
In a message dated 2/2/2014 1:52:06 P.M. Eastern Standard Time,
act...@hotmail.com writes:
It has been a long time since I opened one of these, but at the time I
remember thinking it must be
Magnus wrote:
My point was, the thermistor is never happy. It always wants more
cooling. So it spins the fan up to full speed and is still too hot to
reach equlibrium.
Which only means that the thermistor setup is shifted and needs to
be adjusted to achieve the goal.
* * *
So,
A little off topic but It seems many instruments (the SR620 and 53132A
included) would work best with an internal fan. (A closed system, not
exchanging outside air). Possibly with some sort of internal/external heat sink
if needed. Or in high power situations outside air would flow through a
Magnus,
Yes, and the EBM-Papst 624 matches it well. The Papst seems to have
much lower noise from the datasheet.
There's yet another problem: the mechanical construction conducts the
fan noise to the case, so the noise is kind of amplified by the case. I
felt somewhat disappointed after
On 02/02/14 20:16, Charles Steinmetz wrote:
Magnus wrote:
My point was, the thermistor is never happy. It always wants more
cooling. So it spins the fan up to full speed and is still too hot to
reach equlibrium.
Which only means that the thermistor setup is shifted and needs to be
adjusted
On 02/02/14 20:28, Tom Knox wrote:
A little off topic but It seems many instruments (the SR620 and 53132A
included) would work best with an internal fan. (A closed system, not
exchanging outside air). Possibly with some sort of internal/external heat sink
if needed. Or in high power
On 02/02/14 20:13, Volker Esper wrote:
Magnus,
Yes, and the EBM-Papst 624 matches it well. The Papst seems to have
much lower noise from the datasheet.
There's yet another problem: the mechanical construction conducts the
fan noise to the case, so the noise is kind of amplified by the case.
Magnus wrote:
I agree. You need both, but just tossing in a stronger fan isn't
going to cut it either.
Very true. You need to attack all of the problems to fix it.
Best regards,
Charles
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To
Magnus wrote:
These days I would assume that heat-pipes would be used to move heat
to a large external heat-sink. It's fairly cheap these days.
I have looked into heat pipes for several projects, and in the end
have never used them. The main problem is that almost every solution
is
Charles,
On 02/02/14 21:06, Charles Steinmetz wrote:
Magnus wrote:
I agree. You need both, but just tossing in a stronger fan isn't going
to cut it either.
Very true. You need to attack all of the problems to fix it.
Well, maybe not all of them, but there is several key areas that
Magnus wrote:
Also, the fan-noise did not change a lot by drying to damp the top
lid, so it seems the fan emits it mostly as a direct mode.
The older unit has a high hiss to its fan
That is what I have observed, as well. The noise is mostly fan blade
noise and some bearing noise coming
On 02/02/14 21:34, Charles Steinmetz wrote:
Magnus wrote:
These days I would assume that heat-pipes would be used to move heat
to a large external heat-sink. It's fairly cheap these days.
I have looked into heat pipes for several projects, and in the end have
never used them. The main
Charles,
On 02/02/14 21:58, Charles Steinmetz wrote:
Magnus wrote:
Also, the fan-noise did not change a lot by drying to damp the top
lid, so it seems the fan emits it mostly as a direct mode.
The older unit has a high hiss to its fan
That is what I have observed, as well. The noise is
With an internal fan I think the covers actually can make a great heat
exchanger as well. Often an instrument that is overheating will have portions
of the case still cool. Perhaps the worst example of fan cooling is the
Symetricom 512XA Phase Noise Test set. It is kind of out of place on such
Subject says it all. Does anyone have a script I could use as a starting point
to calculate/plot the ADEV for my GPSDO?
Bob - AE6RV
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I suggest to use the TVB's
http://www.leapsecond.com/tools/adev1.c
C source and derive your script from it... but first, your GPSDO has
to put out the time interval error samples or you have a reference and
a TIC to measure your GPSDO (better this last setup).
On Mon, Feb 3, 2014 at 1:02 AM, Bob
Hi Azelio,
What I have available to me is a time-stamped, per second, file of DAC values
and wrapped phase error (as compared to 1PPS) values. Is there anything I can
do with that? It's not quite a frequency loop and it's not quite a phase loop.
I figured with a starting point I could learn
Magnus, please, can you elaborate this:
A common mistake is to assume you can average it out, but that gives you a
different measure which does not represent the ADEV values you are comparing
with. The time between samples will scale down the relative impact of the
time-noise, but not really
Thanks for all of the assistance.
I will initially use a separate power strip for similar parasitic AC loads.
Firmware version is 3703.
Stan, W1LE on Cape Cod
z
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Hi Hendrik,
My house is on a slab of concrete, so about 8 hours ago, I moved it from the
top of the HP stack to the floor. The net phase error for the past 7 hours is
about 180 degrees with no change to the DAC value. So, I think it's found a
stable home. I'll put the low temp coeff
Hi:
There are some radios where the internal power supply heat degrades performance. The fix is to remove the power supply
to an external box.
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
___
I suggest to use the TVB's
http://www.leapsecond.com/tools/adev1.c
C source and derive your script from it... but first, your GPSDO has
to put out the time interval error samples or you have a reference and
a TIC to measure your GPSDO (better this last setup).
Correct. That code, like most
That code, like most ADEV calculations, assumes you have phase data...
In my case, the phase data wraps at each DAC change. Do I need to unwrap it,
or change it to delta values? I haven't read enough about ADEV to get a feel
of what I want, or what this group means when someone say ADEV of
I recently copy/pasted/googled together this Python library:
https://github.com/aewallin/allantools
patches, sample datasets, and new tests are welcome!
Anders
On Mon, Feb 3, 2014 at 2:02 AM, Bob Stewart b...@evoria.net wrote:
Subject says it all. Does anyone have a script I could use as a
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