I've not seen 110v fans in 'ultraquiet'.
On Feb 10, 2011, at 11:37 PM, "Rick Karlquist" wrote:
> It isn't clear why you need to change to 12V fans.
> Why not "modern" 120V fans?
>
> Rick
>
>
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It isn't clear why you need to change to 12V fans.
Why not "modern" 120V fans?
Rick
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Not to mention improvements in motor design. The brushless motors have
gotten better and the change to lighter plastics has put much less
burden on the bearings, which while they might not last as long, sure
are a lot quieter. One of the parameters you can use now to select
fans is the noise factor
That's odd. I just went to the TAPR.org web site and can still
seem to order an LPU kit for around $43 US.
I'm using a TAPR/OpenHPSDR LPU to run two Thunderbolts. The LPU
is operating on 13.6 volts off the house battery. The -12 volts
is switching, the other two voltages are linear.
I use
rich...@karlquist.com said:
> I don't see why changing the operating voltage of the fan would make
> bearings last longer, move more air, or make less noise, unless it allows
> the fan to run at a different RPM. Even then, more air and less noise would
> seem to be mutually exclusive.
Somewhere
I use a Heathkit IP-2718. It only goes to 500 mA on the +12 supply but when
the TBolt is turned on, the current goes off scale for a few minutes, the
voltage drops about a volt or half volt, but then all comes back on scale as
the OCXO warms up.
I think I built one years ago but I found several o
Bob Bownes wrote:
> Ian,
>
> I've dropped the temp and the noise level in my 'lab' by replacing
> many of the old 110V fans whose bearings are getting on with more
> modern 'silent' 12V fans that use less power, move more air, and are
> far quieter than the 110 fans ever were. You can find them fro
I use a 16 Volt Laptop power supply followed by Low Noise LT1764A linear
regulator for +12 and a 7805 for the logic. If you want to splurge use a
LT1764A also for the +5.. To generate the -12V a Microchip TC962 followed by
a 79L12 does a nice job. The +5 and -12 are not that critical. That
Larry--
I use a +12 volt linear supply (an open-frame leftover) with a 7805 for the +5
rail. For -12, I use a 2 watt isolated dc-dc converter (leftover from another
project).
As others have stated, the +12 rail seems to be the noise sensitive one.
73 bob k6rtm in silicon valley
--
Hi
I have so many of them that I run them off big lab grade linear supplies.
That's not to good for a single unit.
The neatest way is to run some low drop out linear regulators off of a
switcher. That way you get it all. The tolerances on the supplies are such
that an LDO with a hundred mv d
Hi
HP 5371A 2828 dated 08 July 1988
Put another way, no it does not have the free update from ~ 1991. I wonder
if HP will drop by and put it in mine I have a strong suspicion the
answer is no.
Bob
-Original Message-
From: Poul-Henning Kamp
Sent: Thursday, February 10, 2011 8:0
Hi Larry,
I use a linear supply for mine.
My supply is actually a headphone amp supply kit from JayCar Electronics
here in Australia. Its basically two LM317's and a 7805 for 5v. I
changed the resistor that set the output voltage from 15v to 12v and
also selected an appropriate toroid trans
Certainly, I'd prefer a linear 3-output supply. But, I've not found a
suitable one yet, in linear or switching. TAPR offered one in the past
but has no more. So, I'm asking for recommendations and where to get one.
Larry
On 2/10/2011 3:32 PM, J. L. Trantham wrote:
I favor a linear regulated
Larry,
I favor a linear regulated supply rather than a switching supply. I had a
TBolt die while connected to a switching supply in an environment where
there were frequent power outages.
The +12 VDC current drops significantly after the OCXO warms up, probably
down to about 200 mA or so.
Good
Greetings! I am a new member of the mail list. I've been using a HP
Z3801A GPS-steered standard but have just acquired a Trimble Thunderbolt
GPS Disciplined Clock.
I'm seeking a recommendation for a power supply for this Thunderbolt
receiver. There is much discussion about noise from some swit
Good point Bob.
I was planning to fit a 'like for like' replacement, but there is no need to do
so
A modern 2.2W 12V fan performs to the same spec as the original 15W 115V fan.
(PAPST 8312 vs PAPST 8500d)
cheers,
Ian
> From: Bob Bownes
> Subject: Re: [time-nuts] time-nuts Digest, Vol 79, Is
I ended up with the 5372A first one of those $50 and forget bids on
the E. the $140 shipping is another story.
BTW took the bottom of one of the 5370B and about 4 or 5 dehydrated
spiders and other insect remains fell
out. The smell is mouse urine but there is no evidence of mice. The
dog finally
Hi
On a variety of levels, yes, the 5370 is the box to get first (and maybe
second and third).
Checking power supplies and cleaning contacts goes a long way on a 5370. Who
knows what to do on a 5371 or 5372. Just finding the service manuals on them
is no easy task (yes, I have a copy, not lookin
Ian,
I've dropped the temp and the noise level in my 'lab' by replacing
many of the old 110V fans whose bearings are getting on with more
modern 'silent' 12V fans that use less power, move more air, and are
far quieter than the 110 fans ever were. You can find them from a
number of sources online,
On 10/02/11 21:57, Pete Lancashire wrote:
Even though the manual says not field installable, can one do it ?
Yes. :)
Cheers,
Magnus
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I second that 1000%
Now to figure out whats wrong in the two dead 5370Bs. Glad it is them
and not the 72A !
On Thu, Feb 10, 2011 at 1:11 PM, Bert, VE2ZAZ wrote:
> To All who have contributed,
>
> Your answers have been very informative, and I appreciate the time the people
> have taken to answer
Thanks for the comments and suggestions.
I've dropped the heatsink temp to 69C simply by swapping the side panels (a
small step in the right direction).
The internal fan makes a fair howl, so a small fan or two will hardly be
noticed! The original fan is moving plenty or air, but it's sound
To All who have contributed,
Your answers have been very informative, and I appreciate the time the people
have taken to answer my initial request on the differences between the HP 5372A
and 5370A T.I. Counters/Analyzers.
The bottom line I get out of this thread is that both are useful to own,
Even though the manual says not field installable, can one do it ?
-pete
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Hi
They all get better as time increases. 20 ps always beats 200 ps. 200 ps
always beats 2 ns. What level you do or don't need at what tau will always
be a "that depends" sort of thing. Pictic's resolution is a "that depends"
thing as well.
The idea is to have one gizmo do the whole range of tau
Ed,
On 10/02/11 00:00, Ed Palmer wrote:
Magnus Danielson wrote:
The Frequency vs. Time view is lovely.
The 5372A does calculate ADEV but does not provide ADEV plots.
Since they don't specify, I'm assuming that it uses the original,
non-overlapping calculation. True?
Well... it does care si
So, they know where you are, but not your frequency.
That is, how often you go there.
So it's off topic. :-)
Bill Hawkins
-Original Message-
From: Charles P. Steinmetz
Sent: Thursday, February 10, 2011 12:52 PM
-- %< --- I think the GPS-based systems fall back
on tri
On 10/02/11 06:13, jimlux wrote:
On 2/9/11 2:08 PM, Tijd Dingen wrote:
The autocorrelation processing is O(N^2) while the DFT can be done in
O(N log N) when using FFT. As usual these can be implemented in reversed
order such that first the FFT is done to the phase jitter and
auto-correlation
John wrote:
I had thought of building a very small one to jam the gps in my
cellphone so AT&T couldn't tell where I was. But, I believe they use a
time difference of arrival system. Verizon, on the other hand does use
an embedded GPS for E911 purposes.
The carriers used to use triangulation fr
I have a GPS jammer I got from China a while back. I would never jam
anyone's GPS. I just got it to play with my own GPS receivers with. It
is a simple sweeper and it devastates my Z3801 but my Garmin Nuvi is
totally immune. So, anyone buying one of these hoping to keep from
being tracked needs to
My 5372A is firmware version 3127 [12 July 1991] e/w option 040. Serial
number prefix is 3301.
Ed
Poul-Henning Kamp wrote:
In message <539fb2cd-a764-4825-8932-970d4253b...@rtty.us>, Bob Camp writes:
The 5371 / 5372 are never going to be as popular as the 5370 in
terms of people needing
I don't understand why you need something like the 537x counters for
long-term measurement.
The 200 ps resolution of the 5372A gives you a noise floor of about
5e-14 @ 4000 seconds. Something like the Pictic II gives you better
resolution at a fraction of the size, heat, noise, and power. Ev
Now that I'm getting settled in the Atlanta area, I thought it would be
interesting to set up a way for local time-nuts to communicate, share
resources (calibration parties, anyone?), and perhaps work on some group
experiments (anyone interested in creating UTC(ATL)?).
So, I've set up time-nut
In message <539fb2cd-a764-4825-8932-970d4253b...@rtty.us>, Bob Camp writes:
>The 5371 / 5372 are never going to be as popular as the 5370 in
>terms of people needing support. They just aren't that common.
>
>Getting binary dumps into one of the software packages would be
>very nice. The rest of t
Hi
The 5371 / 5372 are never going to be as popular as the 5370 in terms of
people needing support. They just aren't that common.
Getting binary dumps into one of the software packages would be very nice. The
rest of the stuff is much further down my list. Without a binary dump, you
can't do
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