gsteinb...@aol.com wrote:
Weather projections for California this winter are WET, which implies
local power failures (lasting up to perhaps eight hours).
What do time-nuts do for backup power? I have one of the TAPR TBolt
systems along with numerous other toys (OCXOs that should probably
One option for a small setup (few hundred watts) is to use one of the small
domestic UPS's connected to a larger external battery bank. Even the big
server UPS's are only rated for minutes at full load. This is enough to switch
to a generator or a claen shutdown. Unfortunatly efficency at low
Re-read Jim's posts.
To me it seems clear that he is talking about the 2N1701 Q3 in the upper
right corner of fig. 5-12.
He mentioned that +18 measures high, around 26V.
So, the problem is NOT in the battery charger circuit.
The purpose of that Q3 is to generate +17.4V (and +7V) from +26V,
I use even a smaller set up.
A 10 watt solar panel charges a 12V 20AH standby battery.
A home brew OCXO at 1MHz takes about 1 Watt and is periodically
disciplined by hand against a TBOLT or other GPS disciplined oscillator.
The battery also runs a couple of pendulum clocks which are being
The 18V regulator is still not directly replaceable with an LT1581 which
has an inadequate voltage rating.
Replacing either of the 2N1701's with a more modern transistor may well
lead to oscillations due to the much higher ft of the replacement
transistor.
Bruce
Adrian wrote:
Re-read Jim's
Hi all,
Latest update.
With some help and phone calls from Bill the fault seems to have been
isolated. I have removed Q11 from inside the oven and it is cactus. Q9
is also very suspect so I'm going to replace that for good measure.
Q9 is a 2N1701 in a T08 package. Thanks to various people I
Keep in mind that the batteries are not the only thing on small cheap Domestic
UPS's that are rated for minutes. Same goes with their electronics, Heatsink
etc.
You would have to seriously derate them for continuous duty, and even then it
may not be save.
And in some cases the equipment
On 8/8/09 10:45 PM, Hal Murray hmur...@megapathdsl.net wrote:
Weather projections for California this winter are WET, which implies
local power failures (lasting up to perhaps eight hours).
What do time-nuts do for backup power? I have one of the TAPR TBolt
systems along with
In message c6a429c0.99e5%james.p@jpl.nasa.gov, Lux, Jim (337C) writes:
Not only that, but because they're designed to run for only about 20
minutes, their thermal design depends on mass as much as actual conduction
or convection. At low load, they're not very efficient, either. It's
cheaper
Hello Joe,
Put a bid price on it that reflects the associated risk.
Or delay the purchase till you can test it with a load.
I suspect that if it powers up, it would probably work in your application.
I have a few bench type HP power supplies and they are all nice and RF
quiet,
but are rated
Double check: Q11 is marked as 1854-0003. I can't find it in any of
the HP cross references.
Brian - KD4FM
Jim Palfreyman wrote:
Hi all,
Latest update.
With some help and phone calls from Bill the fault seems to have been
isolated. I have removed Q11 from inside the oven and it is cactus.
- Original Message
From: Jim Palfreyman jim77...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Sunday, August 9, 2009 7:31:31 AM
Subject: Re: [time-nuts] HP 106B quartz frequency standard...the story so, far
Hi all,
Latest update.
With
Jerry,
My favorite are golf car batteries, Trogen brand if not too expensive :
http://www.trojan-battery.com/Products/GolfCart.aspx
Second on my list would be 12volt RV/Marine Batteries, not the marine starting
battery.
Get mine at Sam's, shop around they went up in price last year with the
Hi all,
Latest update.
With some help and phone calls from Bill the fault seems to have been
isolated. I have removed Q11 from inside the oven and it is cactus. Q9
is also very suspect so I'm going to replace that for good measure.
Q9 is a 2N1701 in a T08 package. Thanks to various people I
When considering a battery backup you really have two ways to go:
Battery -- Inverter -- Load
Battery --- Load
The first option is generally easy to implement, but a lot of the battery
capacity goes up as heat in the inverter. As others have pointed out,
inverters are not very efficient or
1854-0003 is a good part number. I have a few here that were removed
from equipment.
Possibly someone with the proper equipment could characterize this
part and determine a suitable parametric substitute.
73
Glenn
WB4UIV
At 11:43 AM 8/9/2009, you wrote:
Double check: Q11 is marked as
In message 1214.12.6.201.198.1249837157.squir...@popacctsnew.quik.com, J. Fo
rster writes:
There are even purpose built battery backup supplies available for running
oscillators, receivers, and such. Sadly, the NiCds tend to be bad and are
quite expensive to replace.
Industrial units are
From what I've found, the Trojan and Deka golf cart batteries
seem to perform the best. Also good are Superior Battery and
Crown Battery. I have two Deka GC-15 in series to run the
equipment and house LED power-failure lighting.
Other brands may be manufactured out-of-country, even though
Keep in mind that the batteries are not the only thing on small cheap
Domestic UPS's that are rated for minutes. Same goes with their
electronics, Heatsink etc.
If you are interested in times measured in hours, you will be running a
typical small UPS at well below full load.
For example,
The inverter efficiency drops below 90% for loads of less than 30% of
the rating (as shown by graph on the linked page).
However the battery discharge characteristics also have to be taken into
account.
The capacity of the battery used increases as the load current
decreases, the net effect being
On Sun, 9 Aug 2009
Robert Darlington wrote
I use a 100 pound APC UPS (Smart-UPS 2200XL) that I was given a few years
ago. I suspect it will run a thunderbolt for a month. Check eBay and you
can probably pick one up cheap.
-bob
I tried to use a Trust UPS to transport a GPSDO for a
A good test would be to load it down to its rated current and voltage
and monitor noise with a clamp on current probe ( on one lead)
to a low frequency spectrum analyzer
I don't have a spectrum analyzer. I emailed a friend about using his.
Open it up and look for tell tale signs of the
Joseph Gray wrote:
A good test would be to load it down to its rated current and voltage
and monitor noise with a clamp on current probe ( on one lead)
to a low frequency spectrum analyzer
I don't have a spectrum analyzer. I emailed a friend about using his.
Open it up and look for tell tale
Ordinary car batteries are not tolerant of deep discharge. In a car they
get charged almost constantly and even after a cold morning start they
immediately get charged again. They are not designed for deep discharge and
if used in such a service will not last long.
Regards.
Max. K 4 O D
The list price of these was $US839 and they are fan cooled.
See HP Journal April 1975 for a description of the 62605M.
Bruce
Joseph Gray wrote:
A good test would be to load it down to its rated current and voltage
and monitor noise with a clamp on current probe ( on one lead)
to a low
J. Forster wrote:
When considering a battery backup you really have two ways to go:
Battery -- Inverter -- Load
Battery --- Load
The first option is generally easy to implement, but a lot of the battery
capacity goes up as heat in the inverter. As others have pointed out,
inverters are not
I thought I'd share some recent results for 2 useful frequency dividers.
For frequencies above 50MHz, an A-D 9513; and a 74HC4059 for
40 MHz below. The A-D 9513 likes higher slew rates works
best above 100MHz. I cheated and bought an evaluation board for
the A-D 9513; layout is really
Pete
You can probably do much better with the AD9513 at lower frequencies if
you use a couple of cascaded longtailed pairs each with carefully
selected gain (series feedback R between the longtailed pair emitters)
and bandwidth (capacitor between the collectors) to condition the low
frequency
Thanks a lot for finding this. I did a search of that page for
supply but didn't turn this up. That is indeed the model series that
I have.
On Sun, Aug 9, 2009 at 4:29 PM, Bruce
Griffithsbruce.griffi...@xtra.co.nz wrote:
The list price of these was $US839 and they are fan cooled.
See HP Journal
Over the years, I have gotten several APC Smart UPS for next to
nothing. In every case, all they needed were new batteries. Unless
they are physically damaged or a circuit board is toasted, they seem
to work fine. The attitude seems to be The battery died, throw out
the UPS and buy a new one.
On
I remembered this series from the 70's but couldn't immediately find the
article.
The required search term was power supplies.
Joseph Gray wrote:
Thanks a lot for finding this. I did a search of that page for
supply but didn't turn this up. That is indeed the model series that
I have.
On
Thanks for that! - I do have a number of the 5254L units and one of
them is now being eyed off for organ donation. So thanks to all offers
for the 1854-0003.
The 2N1701 in a T08 is my next quest...
2009/8/10 Dave M masond...@comcast.net:
Hi all,
Latest update.
With some help and phone calls
carefully crack open the old to8 can to expose the leads internally, strip
out the old transistor and cobble the to220 on top with appropriate leads.
The to220 should fit under one of the old mounting screws? one direction
will give the base and emitter connections properly.
Don
Jim Palfreyman
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