Hi,
I've been looking for a bit with no luck so I thought I'd try here.
I wish to mount my HP/Agilent 5370B and 3325B in a rack. Now the HP part
5061-0077 (also known as 3325B-908 or 5370B-908) and called a "Rack Flange
Kit" (no handle version - although the handle version would be fine) looks
li
Dear Didier,
Didier Juges wrote:
> In my unqualified opinion, Trimble did something very smart with the
> Thunderbolt.
>
> Most previous GPSDOs use a stand alone GPS receiver, with its own CPU clock,
> to generate the 1PPS signal, to which a separate OCXO is servoed via PLL and
> occasionaly sma
In my unqualified opinion, Trimble did something very smart with the
Thunderbolt.
Most previous GPSDOs use a stand alone GPS receiver, with its own CPU clock,
to generate the 1PPS signal, to which a separate OCXO is servoed via PLL and
occasionaly smart software.
The basic problem I see with thi
[EMAIL PROTECTED] wrote:
>
> In a message dated 20/07/2008 23:33:28 GMT Daylight Time, [EMAIL PROTECTED]
> writes:
>
> Somebody had to pose this question... given the respective sizes of the
> Trimble Thunderbolt and the HP Z3801A, the
> simplicity of the first and the complexity of the s
Rick Karlquist wrote:
> We didn't use the epoxy for encapsulation. We used to in place
> of soldering to see if we could replace solder with epoxy. Nope.
>
> Is polyimide or PTFE board less hygroscopic than FR-4? Anyway,
> we didn't try that (too much trouble).
PTFE is very hydrophobic. Also h
Hi Rick,
Rick Karlquist wrote:
>
> My tests showed that epoxy has no effect whatsoever on humidity.
> Goes right through it, right away.
That is not generally possible. Some epoxies will hold a vacuum
for an extended period of time. I know of no mechanism whereby epoxy
could hold back both ni
If it is only the rapidity of humidity transients that concern you ,
it is possible
to "insulate" the HP10811 against humidity fluctuations.
0.25 inch of wool felt all around the unit will provide a hygral buffer
with a time constant, probably as long as 8 hours.
Wool has an equilibrium moisture
In a message dated 20/07/2008 23:33:28 GMT Daylight Time, [EMAIL PROTECTED]
writes:
Somebody had to pose this question... given the respective sizes of the
Trimble Thunderbolt and the HP Z3801A, the
simplicity of the first and the complexity of the second, it comes natural
to ask ourselv
We didn't use the epoxy for encapsulation. We used to in place
of soldering to see if we could replace solder with epoxy. Nope.
Is polyimide or PTFE board less hygroscopic than FR-4? Anyway,
we didn't try that (too much trouble).
Rick Karlquist N6RK
Mike S wrote:
> At 03:42 PM 7/20/2008, Ric
Somebody had to pose this question... given the respective sizes of the Trimble
Thunderbolt and the HP Z3801A, the
simplicity of the first and the complexity of the second, it comes natural to
ask ourselves, what advantages does the HP
unit have to justify the differences ? Is the Z3801A really
At 03:42 PM 7/20/2008, Rick Karlquist wrote...
>Obviously, the first thing I tried was to replace the trimmer with
>a fixed capacitor. Didn't help.
Did you do any testing of encapsulation materials, other than epoxy?
Surely 3M has some fairly impermeable stuff in their kit. AIR from last
time I
A non sealed 10811 responds to humidity in a few minutes.
The speed is nearly limited by the rate of change achievable
in the environmental chamber.
Rick Ksrlquist N6RK
Tom Van Baak wrote:
> It would seem to me that a perfectly hermetically sealed oscillator
> is not a requirement for a typical
Neville Michie wrote:
> Silicon rubber is quite transparent to water vapour, at least in the
I believe it is Viton, not silicone
> concentrations that are
> important to the HP 10811. The seal on the screw will only slow the
> response of the oscillator to humidity.
> Epoxy is a much better barri
Hi,
I've just acquired a Trimble (Nortel) NTGS50AA GPSTM (another flavour of
GPSDO), and it supports the Trimble TSIP protocol, as used by the
Thunderbolt. Apart from one message, it works fine with the TBOLTMON
software.
TBOLTMONWorks fine, can post-process using the log, no
grap
Rick Karlquist wrote:
> Ed Palmer wrote:
>>> If their intent was to hermetically seal the oscillator, why would they
>> leave the screw in the front that covers the adjustment hole (which
>> nobody could possibly get to!)? Would the seal around the screw be good
>> enough to make it worth the effo
In message <[EMAIL PROTECTED]>, "Tom Van Baak" writes:
>It would seem to me that a perfectly hermetically sealed oscillator
>is not a requirement for a typical GPSDO.
Spot on.
All you need to care about, is making the changes slow enough that
the GPSDO can deal with them.
I think I have mentio
It would seem to me that a perfectly hermetically sealed oscillator
is not a requirement for a typical GPSDO. Environmental effects
to the oscillator that work slowly will be absorbed by the GPSDO
tracking algorithm.
If someone wants a fun project -- measure a 10811-60158 while
changing the humidi
> The way to make a HP10811 immune to humidity is to seal it in a metal
> container with glass leadthrough seals
> after it has been flushed with dry nitrogen for a few days.
Or perhaps pump it down to a vacuum, hold for a couple of hours, then
fill with dry nitrogen?
Just don't power it during
Neville Michie wrote:
> Hi,
> surely an oven that controls to 1*C limits the inner xtal oven from
> the outside 0 - 50*C,
> so with a finite gain on the inner oven the oven the XTAL is
> controlled 50 times as well?
> Thats why they use double ovens.
>
> cheers, Neville Michie
How do you know that
Viton is good enough to keep moisture out and air pressure constant.
It is however permeable for light hydrocarbons and fluorocarbons.
And for hydrogen, (as most metals are also).
It is a matter of definition...
Predrag Dukic
At 16:14 20.7.2008, you wrote:
>Ed Palmer wrote:
> >> If their
Silicon rubber is quite transparent to water vapour, at least in the
concentrations that are
important to the HP 10811. The seal on the screw will only slow the
response of the oscillator to humidity.
Epoxy is a much better barrier but not perfect. Vapour barriers must
be perfect.
Water vapou
Ed Palmer wrote:
>> If their intent was to hermetically seal the oscillator, why would they
> leave the screw in the front that covers the adjustment hole (which
> nobody could possibly get to!)? Would the seal around the screw be good
> enough to make it worth the effort to seal the rest of the u
At 01:17 AM 7/20/2008, Ed Palmer wrote...
>If their intent was to hermetically seal the oscillator, why would
>they
>leave the screw in the front that covers the adjustment hole (which
>nobody could possibly get to!)? Would the seal around the screw be
>good
>enough to make it worth the effort t
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