Greetings To All,
Please accept my apologies in advance if this is off-topic. I have just
acquired an aircraft clock, which I've tentatively identified as coming from
a Boeing 747. It's way cool looking and would make a perfect dust collector
in my ham shack if I could only power it up.
Hi Brooke,
Check Ebay # 270386792376 #200243560108
They are probably dual frequency splitters. Then you connect your Z12 to a
DC-block port and either just DC-power or a fitting GPS receiver to power
the antenna through the DC-through port.
http://gpsnetworking.com/GPS-antenna-splitters.asp
Sounds like you need to know more about the instrument power in a 747,
perhaps starting with Boeing. You could be needing DC or AC in one or
three phases, more likely at 400 Hz. OTOH, the VCR players for movies
looked like stock items.
The AC generators in aircraft are not likely to have the
Most likely, the clock needs 5V for the internal lighting. Many aircrft
clocks are mechanical, but some are lectrical and need 28VDC.
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on
Behalf Of Charles Rushing
Sent: Thursday, May 21, 2009 1:45 AM
Hi Chuck,
This is an electromechanical clock. Should just need 24V DC to operate and 5V
(ac or dc) for lighting. I'll try to dig out connections for you.
--- On Thu, 21/5/09, Charles Rushing crushin2...@austin.rr.com wrote:
From: Charles Rushing crushin2...@austin.rr.com
Subject:
I was going to suggest using a GPS splitter too, but with a twist.
You can find a Bias Tee to block the DC current from the Ashtech (and
optionally sink it to ground if it monitors current). That way
there is no chance the 10v will reach your antenna.
Jason
Hi Charles:
It's probably a standard connector. You need to look at it closely with
a magnifying glass at all the surfaces for ID information. 99% of the
time there's printed or engraved or moulded information that is enough
to ID the panel receptacle. Then it's straight forward to find
Thanks Björn:
I've got both of them on order and it's a way to start using the Z-12. But my
L1/L2 antennas are military patch types and for the Z-12 I'd like to use a
geodetic grade (ground plane or choke ring) antenna long term.
Have Fun,
Brooke Clarke
http://www.prc68.com
These clocks are generally driven by 24 volts, not AC 400Hz- BUT they
almost all have an external time base which provides a two-phase 60Hz
signal. I have several of them, and have been able to find one timebase
to power em with I have some documentation squirreled away and I'll
look it up
Mark Sims wrote:
I have done quite a bit of work replacing fans in old equipment with modern
fans.
I have never seen a case where replacing a hurricane level fan with a
whisper
quiet fan made any real difference in the cooling inside the unit...
typically
one sees less than +/- 5C
In message 4a15808f.4090...@karlquist.com, Richard (Rick) Karlquist writes:
Modern fans obey the same laws of physics as the original equipment.
They don't magically produce more airflow for less noise.
Agreed: there is no magic to it.
But a lot has happened in aerodynamics since Hermann Papst
-Original Message-
From: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Richard
(Rick) Karlquist
Sent: Thursday, May 21, 2009 9:26 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 5070B once more (actually 5370A
Hi Charles,
I had a dig, but could only find info on the current clocks that receive time
info on an ARINC 429 serial bus, and an earlier hybrid LCD / mechanical model
that needs an external 1PPS (I'd like one of those).
I've never seen an aircraft clock that needed an external 60Hz signal.
Part of the problem is that in some equipment (not all, but based on my
experience, most), the noise comes from not from the fan itself, but from
poor air routing inside the equipment itself. The air moving around
encumbered passage makes noise. As someone pointed out earlier, take the fan
out of
This is incorrect. ECL components require a minimum airflow velocity
that is rather high. The purpose of the large fan is to maintain this
velocity. If a smaller fan is used, the ECL components will get
hotter, even though the air flowing past them is not much hotter.
When you say the fan
Hal Murray wrote:
How much ECL is used in a 5070?
A bunch
How tightly are they packed?
You need a high cooling velocity even if just one chip.
How much of
the heat goes directly from the chip to the air rather than from chip to
board to air?
A substantial amount of cooling is from DIP to
Hello Karl,
When I tested my quiet 12V fans in the 5370As, I placed 6 thermocouples around
the guts of the machine. I made a point of sticking a couple of them on
heatsinked chips. The new fan made no significant difference in the readings
on any of the thermocouples. All the readings
When I worked in RD at HP's Microwave Division (1972 ~ 1976) and HP LaserJet
Division (1976 ~ 2000) we designed all our products to meet specifications
across a temperature range of -20 to +55 degrees Centigrade. I would assume
this was a standard requirement across most if not all HP products
The ECL and EECL chips are located on A22 (arming board), A19 + A20
(interpolator boards), A18, A17 (count chain assembly) A8 (reference
buffer), A21 (multiplier assembly).
The interpolator boards are more or less directly in line with the
ducted airflow from the fan as are the reference buffer
A8? Reference buffer? Gee, I thought was the electrostatic dust magnet ;-)
That puppy can grow more fuzz than a sheepdog. In all the machines I have
worked on, it was utterly disgusting.
BTW, the best way to locate where to drill the access hole for the oscillator
tuning pot is to look
I came home one day to find *that* smell in my workshop. It turned out to be
my HP 3325B. It had been on for ages and it had also been a warm day. I
looked at the back and found the intake completely blocked up with dust.
It seems to still work, but I need to open it right up and check it out
I had shown some previous data on 74HC390 dividers (10 Mhz input and
using them to generate 5 Mhz, 1 Mhz, and 1 PPS) and John had asked about
some longer term data.
So here it is, 100K ADEV with the 5370B on internal clock
Mean nS, Min nS, Max nS, STD pS
77.3434 76.82 77.83 213
76.9330
Well, I found some stuff on this clock... from a few handwritten notes I
made several years ago, there exist both types; those that have an
internal timebase, and those that require an external timebase. The
clock that I can put my hands on right now is an A15586; I have a couple
more. The
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