Based on an ad in the May 1`973 Radio-Electronics, Meshna was selling them
for $2.50 for a pair of tubes with sockets and driver board with HV
transistors, or $1.25 per tube/socket/ckt board combo. These were clearly
pulls from the recently decommissioned NYSE stock tickers, so they probably
h
> On Monday, October 9, 2023 at 11:35:41 AM UTC-7 gregebert wrote:
> None of my 7971's has aged enough for the segments to get flaky; my
clock went into operation in 2017. Knocking on wood
On my first clock, my original version did have partially illuminated
segments when I used +170vdc.
So was the solution to change out the bad IC? Or was it something else?
On Monday, July 1, 2024 at 11:26:45 AM UTC-7 Mac Doktor wrote:
Problem solved. Big thanks to everyone.
Terry Bowman, KA4HJH
"The Mac Doctor"
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On Monday, January 25, 2021 at 9:30:49 PM UTC-8 gregebert wrote:
> Interesting notes from the seller, mentions slight ghosting. The
> clock-chip does the multiplexing, though it was probably intended for LEDs
> which dont have requirements for blanking time.
The chip is a National Semiconductor
If you have enough space, here is what I would do: I would take a DIP
header, some perfboard, a handful of MPSA92's, and a handful of 10k 1/4
watt resistors and replicate the circuit you show (ignoring the back-biased
diode which is probably a parasitic from the monolithic process). If there
On Tuesday, February 9, 2021 at 11:37:18 AM UTC-8 Christian Riise Wagner
wrote:
> They should be MPSA42 though, as MPSA92 are PNP.
Good catch! I really should know better.
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Did you ever get it t run at the correct speed? If so, how did you fix it?
On Monday, April 19, 2021 at 1:23:22 AM UTC-7 MrThe50sanchez wrote:
> I builded a Nixie watch, It works good, but I'm having a little bit of
> time delay, 1* min within 6 hours. *
>
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As long as you are still trying things, you should try different crystals.
Instead of New Old Stock from a surplus electronics dealer (probably from
the 1970s wen quality control was not very good), you could take one out of
a clock or watch mechanism that does a good job keeping time (the ones
All the cheap watches and clock movements seem to use the same small
cylindrical crystal. I got many of mine by taking them out of old watches
or clocks that had stopped working properly (like worn out gears in a
clock). If you do not already have any in your junk box, you should be
able to b
Isn't that the one used in the Marantz 10B (and presumably the Marantz
10)? You can probably infer a useful set of operating conditions from the
service manual.
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You can get a purple/UV glow with argon. I used to have an AR-1 lamp with
an Edison base that worked off the US mains, or something less than 400V.
(it had a built0in dropping resistor).
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On Thursday, August 11, 2022 at 9:53:33 PM UTC-7 Kevin A. wrote:
> I feel like PIRs are a must on most nix clocks. Why burn up tubes when no
> one is around to enjoy the glow? Seems like a total waste.
>
> This may be detrimental in some cases. For example, the B9771 spec sheet
projects a lif
I took a closer look at the picture. It looks like there is a small
4-digit number outside the octagon which I interpret as "5944". There is
a larger 4 digit number inside the octagon which I think is "7?25" (where
the 7 is clear, the ? is unreadable, and the 25 is my best guess). Both of
This may not apply to other tube types, but my 3 clocks built with 6 x
B7971s were MUXd at about 2 kHz, and they all produced enough acoustic
noise to be annoying in a quiet room, and RFI audible over the entire AM
band that was detectable on my transistor radio to about 20 feet. The
clock w
Get some small, sticky labels and write down the date and an "eBay" price
and put them in a discreet place. Let your heirs know and they can make a
more knowledgeable decision.
On Saturday, February 4, 2023 at 9:07:43 PM UTC-8 petehand wrote:
I've told my wife, when I'm gone, under no circumsta
On Friday, June 19, 2015 at 1:55:55 PM UTC-7, wb9jfr42 wrote:
>
> Has anyone built a clock using MM5309 or 11 chip with nixie tubes
> Using BCD to a 74141 but don't seem to be able to multiplex
>
> i would like to use the chips that i have had for many years
>
> Thanks
> jerry
>
I would steal ideas
On Monday, July 13, 2015 at 11:33:37 AM UTC-7, gregebert wrote:
>
> A good middle-ground if you are doing a custom design is to use a
> power-transformer with dual primary windings, then use one of the primaries
> for your HV supply.
>
> In the US, the 120V line-voltage will produce +170V when
I can think of two other minor advantages for the Hammond transformers,
neither of which I would consder deal breakers. First, the HV secondary
is rated at 125V, while using half the primary probably produces about
105-115V, so you might not need to use one of the LV secondaries to boost
the H
The lady in the Swap Meet Information booth said that they would be staying
"indefinitely" and that would be at least through all of 2016.
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On Sep 20, 11:24 am, jb-electronics
wrote:
> Hi there,
>
> > On Thu, 20 Sep 2012, threeneurons wrote:
> >> Other than brightness, some have observed mechanical 'singing' coming
> >> off the larger tubes, like IN-18s.
>
> > This is the most annoying thing about multiplexing. You can hear the
> > in
I just got a new catalog from Ramse. Among the featured products are
a series of 6-digit and 4-digit Nixie cloks, available as kits or
assembled from about $300 to about $400 (seems high to me, but I paid
$1 each when I got my B-7971s). The most interesting thing to me is
the GPS-disciplined opti
On Apr 19, 2:04 pm, kay486 wrote:
> Please let me know what you think about this!
I would makl one out of the HV supply in one of those elecrtonic fly
swatters. Depending on your patience waiting for discount coupons,
they cost $1.99 to $4.99 at Harbor Freight.
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On May 27, 6:22 am, Marcin wrote:
> Could somebody explain me how the discoloration around cathodes is
> supposed to appear during the tube operation? I understand that the
> common knowledge is that only used B7971 have it. The new ones should
> have a uniform back-plate.
> Marcin
One the B7971s
On May 28, 2:13 am, Nick wrote:
> Has anyone ever had one fail in operation (assuming it was being run within
> spec)?
>
> Nick
Not yet. As a reminder, I built three 6-digit clocks that have been
running almost 24/7 since the mid 1970s (one down briefly for a bad
electrolytic). I plan to use the
>
> I have had a cheap Lloyd AM-FM-cassette clock radio for over 30 years.
> The VFD clock is still going strong.
>
>
>
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They weere only about $1 each (sockets included) when I got mine from John
Meshna in the 1970s. In a few years, I will be able to sell my 20+
leftover tubes and sockets (spares that I never needed to use) to finance
my retirement.
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On Sunday, July 13, 2014 3:39:26 PM UTC-7, Dman777 wrote:
>
> Ya, I did but didn't get a reply.
>
> I guess at this point, assuming the plug size is standard...what is a high
> quality power supply recommended? When I do research on Google, I only get
> research hits on PC power supplies.
>
>
One more suggestion. I had ghosting in some multiplexed B-7971s. I could
affect the degree by varying the high voltage, and I eliminated it by
increasing the anode voltage by about 15V above its original value. Try
adjusting your +12V. I would feel pretty safe in the 10-15V range.
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My first question is “How hot is it?” If you can keep your finger on it,
it is probably OK, but you should use a thermometer instead of just saying
“hot”.
My prejudice is that the only likely sources of excessive heat are the 7805
and the cpu, but they are both too far away. The only co
On Friday, October 10, 2014 2:16:47 AM UTC-7, Paul Parry wrote:
>
> I have built lots of PV Electronics clocks 60+ and not had an issue with
> any of them
>
First, I do not think there is a real problem. It looks like the case
already has plenty of holes on the top and bottom, more than shoul
On Friday, October 10, 2014 6:53:05 PM UTC-7, Arne Rossius wrote:
>
> The brown gooey-looking stuff is probably flux residue from soldering
> the component (which is on the other side). The component warms up the
> flux residue and it turns from transparent or yellow-ish to brown. This
> is not
On Saturday, October 11, 2014 1:31:07 PM UTC-7, Dman777 wrote:
>
> After doing research, I see that
> from:
> http://www.fda.gov/ICECI/Inspections/InspectionGuides/InspectionTechnicalGuides/ucm072859.htm
>
>> The more active the flux the easier a solder connection can be made and
>> the fewer r
One of the vendors at today's DeAnza swap meet told me that this August
will be the last TRW swap meet. Is there any news on a replacement venue?
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According to this note, posted May 19,
http://w6trw.com/index.php/2015/05/19/swap-meet-changes-the-latest-as-of-may-2015/
they have not yet found a new venue, but they intend to keep it in the same
vicinity.
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My experience is with B7971's multiplexed at a 2kHz rate. There was
no obvious flickeing. But there was a lot of acoustic noise and radio
frequency interference that was clearly produced by the
multiplexing.
In another discussion, someone raised a concern about reduced
lifetime. I don't know ab
Have you tried changing the voltage on your HV power supply? My
B-7971 clock showed similar symptoms on some segments when it was
originally built. I increased the HV by about 10V, and it has run
fine ever since (about 35 years, or over 300khours).
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On Mar 4, 8:39 am, N0UU wrote:
> A HV kill/activate input line would be nice. These priceless tubes
> have a lifetime and I would attach a motion detector to activate the
> display only when someone was looking. Would keep these around longer.
Paranoia. I built three clocks (18 tubes) with B797
On Mar 4, 7:54 pm, stosk...@tri.net wrote:
> Guess the data sheet is very conservative.
> > Well would having the display deactivate save power or is that an
> > oxymoron?
>
> > On 4 Mar, 17:24, "jf...@my-deja.com" wrote:
> >> Paranoia. I built three c
On Jul 27, 6:26 pm, jerry kimento wrote:
> has any one ever used the mm5309 or mm5314 chips
Sure. Burroughs used the MM5314 in their SP332 Panaplex clock kit.
It works OK, except that it teded to run fast. Rightly or wrongly, I
attributed it to inadequate noise filtering on the 60Hz derived from
On Aug 7, 1:41 am, jb-electronics wrote:
> I know there are some radio Nixie
> tube clocks out there, so there's got to be a way.
They probably are not multiplexed. All my nixie clocks with
multiplexed displays produce lots of RFI that wipes out AM band
reception (I would
On Mar 1, 7:00 pm, Terry Kennedy wrote:
> Despite what is listed by sellers, I have never seen a truly NOS
> B7971. As they are run, the background areas around the elements
> become lighter.
I agree.
>
> The original datasheet (of which I have several) claims a service life
> of 50,000 hours. Th
I remember seeing some at the famous flea market in Clignancourt. But
the place is huge and there really was only a little bit of radio
stuff scattered in different booths. I do not recall seeing any
concentrated area devoted to electronics.
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You don't need a "Nixie tester". All you need is current-limited high
voltage. In the US, a 100K resistor in series with 120-150 Vac (use an
isolation transformer; do not connect directly to the mains!) should light
one or two digits at a time.
Are you sure they are new? Can yo see any longi
On Monday, April 2, 2018 at 11:04:16 AM UTC-7, Jeff Aylesworth wrote:
> The lowest hanging fruit seems to be the plasma ball proximity test.
> Jeff
Along the same lines, you could use your toy Tesla coil or van de Graaf
generator...
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Early LEDs were not bright enough to be seen in broad daylight. That was
one of the advantages of numitrons.
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On Friday, April 13, 2018 at 8:27:35 AM UTC-7, Jens Boos wrote:
>
> Is there a datasheet for this LED? I am really interested in the current
> draw. (The voltage is fixed, more or less, by the wavelength. So the
> current will tell us something about the efficiency.) Jens
>
Google "GaAs LED effi
On Thursday, August 30, 2018 at 2:14:01 PM UTC-7, iavine wrote:
>
> One problem other people have had with such projects is mechanical
> vibration causing cathodes to short out
>
> IanV
>
If you want to review an earlier discussion, see
https://groups.google.com/forum/#!msg/neonixie-l/Vw1dwR_C
On Wednesday, September 5, 2018 at 7:50:55 AM UTC-7, Jim KO5V wrote:
>... My guess is that this is more than just adding in a circuit with a
battery - a frequency source may also be needed.
If you want an integrated solution instead of adding an outboard UPS,
consider this:
All my ideas are st
The MM5369 produces a 60Hz signal from a 3.579545 MHz crystal, not 1 pps.
I vaguely recall that there was a version that produced 50 Hz from a PAL
crystal.
The MM5369 can be found on ebay for about US$1 in medium quantities. These
may be Chinese counterfeits, but it is not a technologically
I made the pilgrimage to Bletchley Park. It may have been because it was
Remembrance Day, but it seemed to emphasize the war memorial aspects with
an acknowledgment to the origins of electronic computing.
I did not see the Disneyland aspects, and there were no actors in period
clothes sp
I don't know about these specific devices, but I have a commercial
(Lloyd's) clock radio with VFD digits, and it has been running continuously
for at least 30 years (maybe 40). YMMV.
On Thursday, December 20, 2018 at 10:19:17 PM UTC-8, gregebert wrote:
>
> Has anyone here built a device with th
Does it also produce RFI on the AM band? My 6-digit B-7971 clock sings and
produces RFI at the MUX rate
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If I had to use the 6V transformer, I would make a voltage doubler.
Then I would use the switching mode regulator in a USB car charger adapter
to produce the regulated 5V. My Dollar Tree carries them. Sometimes,
Fry's has these for under US$1. Or you can probably find one at your
favorite
If all you want is to get 5Vdc rom the mains, a USB charger seems like a
very attractive option. They are usually less than US$5 and occupy about
1cu in (plus the power plug). My initial concern would be safety
isolation, but some of these will surely be UL listed or CE qualified.
However, if
On Tuesday, March 26, 2019 at 7:10:17 PM UTC-7, Pramanicin wrote:
>
> I used to think they weren’t proper nixie tubes way back when i got into
> this hobby. You know, back when they were going for under $20 dollars each.
> What a muppet i was.
>
> Burroughs called them "Alphanumeric Nixie Tubes
I built three six-digit clocks using that chip and B7971 nixies. I was
inspired by the article “Behold the Giant Nixie Clock - using a minimum of
new parts” that appeared on page 70 of the July 1976 issue of 73 magazine.
This
can be found on the internet. That was more than 40 years ago,
On Sunday, April 21, 2019 at 10:19:03 AM UTC-7, Kevin A. wrote:
>
> . Over 50 bids, most of them the same low feedback bidder. Another
> sleazeBay special!
>
> It looks more like a product of the automatic bidding process where the
lower bids are instantaneously by the previous high bid, w
Assuming 2000 hours/year, the tubes would have had 20,000-50,000 hours of
use on them (maybe even a lot more).
On Friday, May 10, 2019 at 3:29:05 AM UTC-7, Paolo Cravero wrote:
>
> On Fri, May 10, 2019 at 12:23 PM Paul Andrews > wrote:
>
>> EUR? How vintage is it?
>>
>
> It has been relabeled on
Back in the old days, a polarizing filter was used to suppress the Fresnel
reflection.
On Friday, June 7, 2019 at 12:55:20 PM UTC-7, gregebert wrote:
>
> Any tips on how to take good-quality photos ? Mine always turn out looking
> horrible, partly due to reflections from the various glass surfac
Keep in mind that the insurance company will try to reimburse as little as
possible. They might give back the documented purchase price if the tube
is NIB. You might be able to argue a higher value based on a recent
auction sale (think ebay).
For used tubes, they may apply straight-line depre
That's what I did: opaque black plexiglas for the sides and the ack, opaque
white plexiglas for the top and bottom, and clear red for the front. It
gives it a mid-20th century modern or Bauhaus look with the digits floating
inside the box instead of a steam-punk look, and emphasizes its functio
My three B7971 clocks all produced RFI in the AM and SW radio bands, and I
kept my radios at least 5m away. They were based on the CT7001 clock chip,
so the MUX rate was about 2 KHZ. The RFI (and the acoustic singing from
the tubes) seemed to change with the digits displayed. I assumed that i
ISTR that the real sockets are preferred. The argument I remember hearing
is that the pins in the socket "float"; the disadvantage is that you may
need to jiggle the tube as you insert it into the socket, but the advantage
is that the pins float and do not stress the glass-to-metal seal thereby
On Sunday, September 29, 2019 at 10:50:16 PM UTC-7, Richard Scales wrote:
> ...
> I too love the B-7971 - if only I had invested when they were super
affordable - what was I thinking?
>
I got mine when they were cheaper than the LED alternative: US$1 per tube
including sockets, versus about US
...and B-A was generally not the low-cost junque dealer; John Mishna and
Poly-Paks were usually cheaper.
On Monday, September 30, 2019 at 12:20:48 PM UTC-7, Terry Kennedy wrote:
>Here's the ad (original scan by David Forbes):
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Do they both run fast? Designs that simply count the mains are susceptible
to noise pulses adding to the total, and most early designs were prone to
this defect. If this is the case, I would try filtering out the noise
spikes: ferrites on the primary side, and a low-pass on the rectified line
On Friday, February 7, 2020 at 8:59:19 AM UTC-8, gregebert wrote:
>
> ...Some folks in this group have reported audible noise from
> multiplexing
>
I am one of the people who reported singing in my multiplexed B7971s. More
than 40 years ago, I also had a Panaplex/MM5314 clock that was sold a
On Thursday, February 27, 2020 at 1:14:35 PM UTC-8, Robert G. Schaffrath
wrote:
>
> ...the whine from the multiplexing bothers me now. ...
>
I reduced the audibility of the acoustic noise by putting the clock inside
a box made of 1/4" Plexiglas. This did not do much to reduce the RFI...
--
On Thursday, March 19, 2020 at 1:46:21 PM UTC-7, Pramanicin wrote:
>
> Hi folksI have some RCA KD2127 IC'sthese used to be supplied with
> DR2000 numitrons as the driver IC. I can't locate a data sheet at the
> moment, but probably a rebadged TTL driver of some form?
>
> If anyone is in
On Saturday, March 21, 2020 at 4:33:05 AM UTC-7, newxito wrote:
>
> Nice device, and it uses a 2N3055 transistor!!! I built an amplifier with
> these transistors 45 years ago, probably the last time I have seen one of
> them. I remember that they were very popular in Spain in the 1970s.
>
You ca
So the pictures I intended did not et posted on the Google Groups version.
The first image is the "fast" picture from
https://www.ebay.com/itm/VINTAGE-4-Giant-Nixie-Tubes-Working-B-7971-Burroughs-from-NYSE-in-Project-I-made/283830338480?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D
When I had partially it segments, I was able to fix it by increasing the
anode voltage to about 180-190V. Others have reported fixing shorted
segments by hitting the tube, gently; you almost have nothing to lose.
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Back in those days, the GBP was about US$2, so they were much more
expensive in the UK.
The tubes were even cheaper from Meshna
I think they were $1/tube with sockets but without the circuit board, which
is the deal I went for since I was a cheapskate and did not realize that
the boards had th
How could you tell they were NOS? I have this religious belief that
everything on the surplus market consisted of NYSE pulls, as suggested by
the words "removed from operational equipment". Did your NOS actually come
in Burroughs boxes marked with the tube type, or were they just covered in
b
I really don't remember anything other than Burroughs brands on the 30+
tube I bought, but it has been 40+ years for most of them. I recently
repaired two clocks for non-Nixie failures, and between the 12 in those two
clocks and the 6 that I swapped in on general principles, I only remember
se
You probably learned a lot more about electronics by having and using that
scope, so I think it was the better investment.
On Friday, April 3, 2020 at 4:52:56 PM UTC-7, Robert G. Schaffrath wrote:
> ... though in hindsight, the tubes would have been the better
investment.
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My tubes were over driven by 2X-4X compared to the maximum values in the
B7971 data sheet: HV=-195V, cathode resistors=430ohms, MUX duty cycle =
12%. After running 24/7 for 40+ years, the tubes are very slightly dimmer
than the tubes I had kept as spares with a slight color shift. (You can
I would say whichever is cheaper, keeping in mind that nothing is cheaper
than free from the junque box. I used the floor sweepings (advertised as
npn 300V and 10W) from Poly Paks, and none of these have failed yet. I did
have one genuine Motorola MPSA92 fail after 40 years of service. Just
What do you have against the MJE340? Is it too large? Is it too much more
money (onesies retail in Silicon Valley is 34 cents versus 75 cents)? If I
had to go out and buy new parts in hobby quantities, I would get the MJE340
and not invest any more brain power, but if it was going to be used
So this is a matter of academic curiosity and not an effort to make your
device work. I think this is a neat thing to do. Based on your
observations, this suggests some experiments.
In a previous post, I speculated that both part numbers might use the same
chip. I now think this is les
On Thursday, April 23, 2020 at 3:10:36 PM UTC-7, gregebert wrote:
> I'm absolutely certain the MJE die is physically larger. For one thing,
it must conduct more thermal energy to the case.
I am inclined to agree, but if it were me, I would be willing to invest
$1.08 and a half hour in the expe
Is there a 1000X difference in the gain? Across all lots and all operating
conditions, I would have expected less than 10X.
On Thursday, April 23, 2020 at 3:56:44 PM UTC-7, gregebert wrote:
>
> Much of the additional leakage current is caused by the higher DC gain of
> the MJE device; the datas
Sure, but based on the similarities in the Central Semi data sheets, the
same die appears to be used interchangeably. So the factors I can imagine
is that they select and direct the leakier parts to the TO-220 package, or
that the TO-220 package makes a difference (like allowing a higher juncti
You might have to settle for one of the more modern transistorized curve
tracers. In the last century when 500-series scopes were going for
$20-$50, I remember talking to someone at one of the ham swaps. He said
that they were being bought up and cannibalized by the audiophools because
they w
It should be easy to convert the 575 back into a tube curve tracer since it
was a modified 570 with the filament transformer removed and the sockets
changed. If you can find a meterless Hickok tube tester, you have the
sockets, switches and filament transformer you would need to convert it
bac
I had one of these evaluation kits, and I recall that the displays were
socketed. If you have an oscilloscope, you should do some basic
debugging. I would start at the power supply (one of my nixie clocks used
a Signal Transformer of the same vintage that died due to an open
primary). If you
Also, as I think about it, there is a "keep alive" element, and you should
make sure it is energized at all times.
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I agree. I forgot that one of the first things you should do is apply HV
(like 150-200V) directly to the tubes,with a series dropping resistor of
47K-220K, and make sure it glows under these conditions. I realize that
this assumes you have access to an electronics lab...
On Saturday, April 25
As a matter of personal taste. I like to have a generous margin on BVceo,
like always larger than Vcc. To me, anything else is penny wise and pound
foolish, especially in hobby quantities. I always use transistors rated at
300V even if my Vcc is less than 200V.
Gregenert is probably right abo
With modern ROHS requirements, you will need to build it with lead-free
solder.
On Friday, May 1, 2020 at 5:27:11 AM UTC-7, Bill van Dijk wrote:
>
> Michail, I have an unbuilt Heathkit 5MHz model IO-4105 scope kit, in
> original box. Picked it up at a flea market a couple of years ago!
>
>
>
>
It was meant as a joke. I still use SnPb eutectic solder, and I think my
~1 kg is a lifetime supply I think I can blame this for my dumbness, since
I used to hold the solder in my teeth during construction and repair.
I have this religious belief, scientifically not proven, that Pb-free
solde
Based on my experience, you should expect at least another 300k hours even
if you "overdrive" them. That said, I don't remember anyone reporting a
natural death from old age and excessive usage.
On Wednesday, May 27, 2020 at 1:44:43 AM UTC-7, Terry Kennedy wrote:
>
>
> B7971s are amazingly rob
Over that voltage range, I would expect three branches on the IV. Did you
also track the firing voltages and extinction currents? Dark rooms vs
well-lit? Ambient temperature?
On Friday, May 15, 2020 at 8:57:08 AM UTC-7, gregebert wrote:
>
> Yes; for a given segment, there are tube-to-tube var
We kept ours in an Erlenmeyer flask, and I could never get my hand past the
bottleneck.
On Wednesday, May 27, 2020 at 1:06:26 AM UTC-7, Terry Kennedy wrote:
>
>
> I grew up in a time where in elementary school you got to dip your hand up
> to the wrist in a bottle of mercury,
>
--
You received
In addition to photons and cosmic rays, illuminating other elements can
also promote the firing (isn't that the reason for the "keep alive" on the
Panaplex?).
It has been a long time since I did it, but ISTR that you could stay on the
negative resistance branch by aggressively limiting the cu
That is a lot of mercury. I don't think we kept more than a pound. Also,
I don' tknow how you get the Hg completely out of the pan, since ISTR that
we would use the Hg to shine up nickels and pennies.
On Wednesday, May 27, 2020 at 7:46:33 AM UTC-7, Ira wrote:
>
> Get a pan off of the stove tha
Before you get too excited, that is probably Chinese yuan (aka renminbi),
so it would be closer to US$110.
On Tuesday, June 2, 2020 at 2:32:13 PM UTC-7, Terry Bowman wrote:
>
>
> If the colon tube is the ¥749 item that's slightly less than $7. That's
> downright cheap and at first glance they lo
On Monday, March 7, 2016 at 2:06:42 PM UTC-8, Jeff Walton wrote:
>
> I have a clock that uses Raytheon CK8754 tubes that has 35 years
> continuous use with no tube issues. That's over 300,000 hours. I hope
> that the B7971's last as long. I'll probably be gone by then..
>
> *Jeff *
>
I think
Back in the early 1970s, the cheap ones (~$1) all came with sockets with
cutooff wires. For about double the price, you could get the bracket with
the HV driver transistors. Clearly, these were used surplus from the
NYSE. It seems that they stayed cheap until the Nixie nostalgia hit the
hobb
Modern LEDs may be "better", but back in the old days, LEDs were no
characterized for reverse operation and were pretty poor rectifiers (I
forget whether it was leakage or low and unpredictable breakdown voltage,
or both). I would keep the series Si diodes.
There was a lot of discussion about
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