For all the ion pumps I am familiar with (particularly one I built for an
airborne radar), the power supply regulation is intentionally very poor,
i.e. at the max specified current, the voltage should be down to something
like 500V or even less, otherwise the pump will overheat. The best curve is
n
Morning update.
The voltage on pin 4 is now -1.082 VDC and the HV is up to 2118 VDC. The
+3500 V power supply is not 'hot' and therefore, there appears to be
progress.
Thanks for all the suggestions. I like the idea of the multiplier. I've
known about these but never knew they had a name and h
FWIW, I'd just let it run.
-John
=
> Morning update.
>
> The voltage on pin 4 is now -1.082 VDC and the HV is up to 2118 VDC. The
> +3500 V power supply is not 'hot' and therefore, there appears to be
> progress.
>
> Thanks for all the suggestions. I like the idea of the multiplie
The small modules are nice, but many PMT supplies do not go to 5 mA. 5 mA
@ 4 KV is 20 Watts output, more at the input. That's a lot for a PMT
supply.
Also, remember that some supplies designed for gas lasers have a HV "kick"
at startup that may go to 20-30 KV.
-John
==
>
>> Since
Alberto,
The Z3815A is certainly less common - except down here in VK/ZL. I have
one, and can try to answer your questions. The oscillator used in the
Z3815A is generally the HP E1938A, although mine is a more recent
Symmetricom version with a Milliren 260 OCXO adaptation. Power supply is
20 - 60V
The best advice. Its making progress.
Give it 2 weeks of steady on time and watch the voltage as you are doing.
I just tried to recover HP 5061A form the US Naval Observatory and though
the tube pumped down fine, unfortunately for me after tons of checking the
tube is bad. Very very low CS emission
The small Bertan modules in particular are extremely stable and
well-behaved. You get exactly the voltage that you program, accurate to
within about a tenth of a percent. No spikes, no drift, and no obnoxious AF
whine like you get from the HP modules.
The smaller ones are good for 500 uA, and th
I just looked at eBay and most everything suitable is well over $200.
-John
> The small Bertan modules in particular are extremely stable and
> well-behaved. You get exactly the voltage that you program, accurate to
> within about a tenth of a percent. No spikes, no drift, and no
As I said its slowly seems to be pumping down.
Let it go for 2 weeks.
I have had to do that with travelling wave tubes...
Cost $2 for electricity.
If that doesn't work go for the big guns.
On Sun, Jan 17, 2010 at 5:03 PM, J. Forster wrote:
> I just looked at eBay and most everything suitable is
Loran C shut down slightly more info
Looks like the Canadian chains may indeed survive
SPECIAL NOTICE
SUBJ: TERMINATION OF ALL U.S. LORAN-C SIGNALS
1. IAW THE 2010 DHS APPROPRIATIONS ACT, THE U.S. COAST GUARD WILL TERMINATE
THE TRANSMISSION OF ALL U.S. LORAN-C SIGNALS EFFECTIVE 2000Z 08 FEB 2010.
I completely agree, and said so at the outset.
Best,
-John
===
> As I said its slowly seems to be pumping down.
> Let it go for 2 weeks.
> I have had to do that with travelling wave tubes...
> Cost $2 for electricity.
> If that doesn't work go for the big guns.
>
>
> On Sun, Jan 17,
Canada shutdown on or before oct 1 2010
The Loran-C systems in Canada and U.S. work in tandem. Once the U.S. service
is discontinued, the Canadian system will not be operational. Consequently,
Canada will also decommission its Loran-C system in 2010. The official date
for termination in Canada has
True, which is unfortunate -- when I was shopping for mine, there were at
least a half-dozen known-good HV modules selling at less than $100, coming
from a couple of different vendors.
You're right, though, in that you don't get above 1 mA without dropping more
cash. The only >1 mA supply I have
Slightly off topic -- but perhaps suggestive: A couple of years ago I
needed to re-train some nocturnal raccoons who were toppling our garbage can.
I purchased an inexpensive and very compact fence charger at a farm
supply. Opening the lightweight unit out of curiosity, I found that it
c
What is the operating voltage of the magnetron in a domestic microwave oven?
Although VERY HAZARDOUS, it might be possible to adapt the PSU from an old
one?
Chris Stake
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John Miles
Sent: 17
In message <1ec43.3bd0d37a.3884e...@aol.com>, brucekar...@aol.com writes:
>Slightly off topic -- but perhaps suggestive: A couple of years ago I
>needed to re-train some nocturnal raccoons who were toppling our garbage can.
>
Many years ago I lived in a small studio-apartment in the center o
- Original Message
From: Chris Stake
To: Discussion of precise time and frequency measurement
Sent: Sun, January 17, 2010 5:05:01 PM
Subject: Re: [time-nuts] 4 KV Power Supply Recommendations
What is the operating voltage of the magnetron in a domestic microwave oven?
Although VERY
Hi Murray,
Do you know how the Z3805A fits into the scheme of things?
73
Steve Rooke - ZL3TUV & G8KVD
2010/1/18 Murray Greenman :
> Alberto,
>
> The Z3815A is certainly less common - except down here in VK/ZL. I have
> one, and can try to answer your questions. The oscillator used in the
> Z3815
Hi
You also could leave the windings as is and feed the secondary voltage into a
voltage multiplier. Still not very safe to wire up.
If you did wire it up, the available current would be pretty massive. I
certainly would not attach it to an ion pump I cared about.
Bob
On Jan 17, 2010, at 6:
Just use lower value caps in the multiplier and/or add a suitably rated
resistor in series with each diode.
Bruce
Bob Camp wrote:
Hi
You also could leave the windings as is and feed the secondary voltage into a
voltage multiplier. Still not very safe to wire up.
If you did wire it up, the a
You can get brand new MOTs (microwave oven transformer) from eBay for quite
cheap, or simply scavenge them from old microwaves.
As has been stated, they have magnetic shunts between the windings on either
side. These shunts make the transofmer non-ideal and horribly mess with the
tranaformers r
Steve,
No, I've not seen a Z3805A at all. Not that I know all there is to know
about the Z3815A either.
73,
Murray ZL1BPU
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an
The lightbulb wattage can be selected accordingly to limit the current as
needed.
You'll notice if you dead short the seconday, the light bulb will glow
brightly, but that you won't be lighting your MOT on fire like you would if you
had no current limting.
Sent via BlackBerry by AT&T
-Orig
Hi
I would worry a bit about the voltage rating of the resistors. I do indeed have
some that would do the job, but they aren't what you would find down at Radio
Shack.
Bob
On Jan 17, 2010, at 8:48 PM, Bruce Griffiths wrote:
> Just use lower value caps in the multiplier and/or add a suitably r
This is just nuts. A light bulb in the primary side will not render a
microwave oven transformer safe, either to an ion pump or to you. If you're
lucky, by the time the filament comes up to temperature and starts to limit
the current, the ambulance will already be on its way.
Just feed it 100 uA
I'm not saying its safe. I'm just saying its a lot safer than MOT that isn't
ballasted at all.
You can ballast one MOT with another mot. You can add in all kinds of things to
keep the current limited.
But I wasn't saying that its safe to play with. When is 2kV ever safe to play
with?
I never
Keep in mind that the typical microwave oven power supply will be able to
deliver about 100 times more power than sufficient to blow the ion pump to
bits, in addition to the operator if he is not careful.
I would advise against even trying, even though operating the transformer
with a 40W incandes
Dear fellow time-nuts,
In my effort to implement the suite of ADEV and friends, I have been
implementing various forms of them along with the 1000 frequency sample
test sequence out of NIST SP1065:
http://tf.nist.gov/timefreq/general/pdf/2220.pdf
However, I seem to be unable to perfectly matc
Yes even with the mods odds are good the secondary is not well isolated from
the frame and even with the extra secondary windings the primary loading is
high per turn and load regulation is poor. Over all microwave transformers are
not very good, if you goggle them plenty of info and speculation
The more I read about this, the more I think I will just let it 'pump'.
This evening, the voltage on pin 4 is -1.039 VDC and the HV is up to 2151
VDC.
I was wondering how to limit the current capacity of an old HV transformer,
say 750 VAC, power supply and I suspect it is all in the size of the
c
Just a heads-up: As of 19:30 PST, 17-Jan-10, Blue Feather's FTP and web
systems will be going down for system upgrade. I don't anticipate being off the
air for more than a couple of hours, tops. The FTP library itself is in no
danger because the server merely acts as a front-end to anoth
Joe,
Use Linear Technology's SwitcherCAD to simulate the operation of the
multiplier. It is a great tool, and it is free, and you will learn a valuable
skill.
And it is a lot safer than breadboarding a 4kV supply.
Didier KO4BB
Sent from my BlackBerry Wireless thingy
Hi
I agree that Switcher CAD is a great little SPICE program. Well worth every
dime I've paid for it ..
The only issue I see with using it for this kind of thing is not knowing the
details of the transformer. All kinds of fun things can happen if you
accidentally resonate the secondary inducta
Bob Camp wrote:
Hi
I agree that Switcher CAD is a great little SPICE program. Well worth every
dime I've paid for it ..
The only issue I see with using it for this kind of thing is not knowing the
details of the transformer. All kinds of fun things can happen if you
accidentally resonate the
No simulation tool will ever alleviate the need to know what the heck you are
doing.
It is great fun to observe those who ignore that simple rule :)
Didier
Sent from my BlackBerry Wireless thingy while I do
other things...
-Original Message-
From: Magnus Dani
For a Cockroft_Walton multiplier with m stages with all capacitors equal
except for the first which has twice the vale of the others the output
resistance is
~ (2/3)*m*m/f*C
Where the first capacitor = 2C and all the other capacitors =C
f is the line frequency
The accuracy improves as m incr
Pictures of my breadboard microwave transformer power supply diode and resistor
strings covered in heat shrink but don't touch as it is not good at HV. One end
of resistor string is used to sample voltage. Don't have the parts for the
voltage doubler yet. A metal cage and more insolation is need
- Forwarded Message
From: Stanley Reynolds
To: did...@cox.net; Discussion of precise time and frequency measurement
Sent: Sun, January 17, 2010 10:58:16 PM
Subject: Re: [time-nuts] 4 KV Power Supply Recommendations
Pictures of my breadboard microwave transformer power supply diode
Mark would you know how to tell the positional accuracy of a GPSDO after it has
completed it's self survey?
Where can I download Lady Heather from?
And can I compare two GPSTM at the same time using lady heather?
Thanks Ray VK4TFT.
___
Ray,
I think you need to join the Time Nuts group and troll back through the
archives. Just do a google search.
Best 73's
Nic
VK2KXN
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Ray Hudson
Sent: Monday, 18 January 2010 4:06 PM
To: tim
Whoops, Can I take that back. I thought I was replying to someone in an APRS
group!
Sorry
Mark would you know how to tell the positional accuracy of a GPSDO after it
has completed it's self survey?
Where can I download Lady Heather from?
And can I compare two GPSTM at the same time using lady
Hi Magnus -- Any possibility that there is some math package subroutine error
of some kind? In yours or theirs?
Best,
Dick Moore
>
> Message: 3
> Date: Mon, 18 Jan 2010 03:29:49 +0100
> From: Magnus Danielson
> Subject: [time-nuts] Modified Total Deviation calculation
> To: Discussion of preci
Hi Dick,
Dick Moore wrote:
Hi Magnus -- Any possibility that there is some math package subroutine error
of some kind? In yours or theirs?
Well, wherever the error is, for a known series of 1000 frequency
samples (or equalent 1001 time samples) I expect the error to be
algorithmic rather th
Ever see the spectrum of a typical microwave oven that is powered by a switching
power supply? It is so broad and messed up that it will wipe out the wireless
routers that share the same band. At least the old style ovens had a fairly
narrow
60Hz spur somewhere around 2450MHz.
-Chuck
Didier J
I know many time-nuts use FreeBSD. Is there anyone interested in devoting some
spare time to help port the GPL2 Sage maths software Sage
http://www.sagemath.org/
to FreeBSD?
There is someone else doing this (Peter, who I cc'ed this to), but I suspect
Peter's efforts are somewhat hampered by t
Murray,
I've not heard of a Z3815A before, just the Z3801A, Z3816A and the
Z3805A which I have, and for which there seems to be a complete lack
of information about apart from some bits and pieces from Bob
(fluke.l) in China.
73
Steve ZL3TUV & G8KVD
2010/1/18 Murray Greenman :
> Steve,
>
> No, I
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