1.5 VDC Pseudocell

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Don

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Nov 8, 2020, 4:08:20 PM11/8/20
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This project shows how to build a 1.5 VDC pseudocell to take the place
of an AA sized battery. The mechanical aspect of this project offers the
greatest challenge. The electronic portion utilizes an easy to use LM317
adjustable voltage regulator to convert a 5 VDC source to 1.5 VDC.

(excerpt)

https://crcomp.net/pseudocell/index.php

(Thank you In Advance to readers who alert me to typos and whatnot.)

Danke,

--
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

jla...@highlandsniptechnology.com

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Nov 8, 2020, 4:19:52 PM11/8/20
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On Sun, 8 Nov 2020 21:08:18 -0000 (UTC), "Don" <g...@crcomp.net> wrote:

>This project shows how to build a 1.5 VDC pseudocell to take the place
>of an AA sized battery. The mechanical aspect of this project offers the
>greatest challenge. The electronic portion utilizes an easy to use LM317
>adjustable voltage regulator to convert a 5 VDC source to 1.5 VDC.
>
>(excerpt)
>
>https://crcomp.net/pseudocell/index.php
>
>(Thank you In Advance to readers who alert me to typos and whatnot.)
>
>Danke,

The 317 may not be stable without an output capacitor, aluminum or
tantalum.

Does the clock stepper motor use big current spikes every tick?

Really, can't you solder the wires?





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

Sjouke Burry

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Nov 8, 2020, 4:28:19 PM11/8/20
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On 08.11.20 22:08, Don wrote:
> This project shows how to build a 1.5 VDC pseudocell to take the place
> of an AA sized battery. The mechanical aspect of this project offers the
> greatest challenge. The electronic portion utilizes an easy to use LM317
> adjustable voltage regulator to convert a 5 VDC source to 1.5 VDC.
>
> (excerpt)
>
> https://crcomp.net/pseudocell/index.php
>
> (Thank you In Advance to readers who alert me to typos and whatnot.)
>
> Danke,
>
I think your clock would have been quite satisfied with
1.25 volts, that is about a halve empty battery.
A 20 uf elco at the output would be nice tnough.

Steve Wilson

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Nov 8, 2020, 5:04:57 PM11/8/20
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jla...@highlandsniptechnology.com wrote:

> On Sun, 8 Nov 2020 21:08:18 -0000 (UTC), "Don" <g...@crcomp.net> wrote:
>
>>This project shows how to build a 1.5 VDC pseudocell to take the place
>>of an AA sized battery. The mechanical aspect of this project offers
>>the greatest challenge. The electronic portion utilizes an easy to use
>>LM317 adjustable voltage regulator to convert a 5 VDC source to 1.5
>>VDC.
>>
>>(excerpt)
>>
>>https://crcomp.net/pseudocell/index.php
>>
>>(Thank you In Advance to readers who alert me to typos and whatnot.)
>>
>>Danke,
>
> The 317 may not be stable without an output capacitor, aluminum or
> tantalum.
>
> Does the clock stepper motor use big current spikes every tick?
>
> Really, can't you solder the wires?

The clock will drift. Eventually it will be so far off the correct time
to be useless.

Don lives in Casper, WY. He should have no problems picking up WWVB:

https://tf.nist.gov/stations/wwvbcoverage.htm

There are a large number of inexpensive WWVB wall clocks that are large
enough to read from a distance. These will keep time to better than a
second.

You can even get a kit to convert an ordinary clock to WWVB. Search
Amazon.

I use a HTAWI WWVB clock that is 16 inches in diameter. It is easy to
read from many feet away. It has 3 batteries and will switch
automatically when a cell runs down. I expect it to last 3 years or more
and keep perfect time.

--
Science teaches us to trust. - sw

Steve Wilson

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Nov 8, 2020, 5:13:20 PM11/8/20
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Here is a 20 inch La Crosse WWVB clock for $59.99

<https://www.amazon.com/Crosse-Technology-404-1220-Extra-
Atomic/dp/B006MOVP8E/>

Jeff Liebermann

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Nov 8, 2020, 5:56:19 PM11/8/20
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On Sun, 8 Nov 2020 21:08:18 -0000 (UTC), "Don" <g...@crcomp.net> wrote:

>This project shows how to build a 1.5 VDC pseudocell to take the place
>of an AA sized battery. The mechanical aspect of this project offers the
>greatest challenge. The electronic portion utilizes an easy to use LM317
>adjustable voltage regulator to convert a 5 VDC source to 1.5 VDC.
>
>(excerpt)
>
>https://crcomp.net/pseudocell/index.php

AA Dummy Cell:
<https://www.google.com/search?q=aa+dummy+cell&tbm=isch>
<https://www.ebay.com/sch/i.html?_nkw=AA+dummy+battery>
Add wires and you're done.

Or, buy one that does exactly what you're suggesting:
<https://www.clockparts.com/aa-cell-uninterruptible-power-supply/>

I'm wondering about your "And its electromechanical action
drains batteries far too quickly". How quickly is far too quickly? Do
you have any current drain measurements? If not, a pointer to the
spec sheet on the clock mechanism would suffice. One of these AA high
torque motors?
<https://www.clockparts.com/aa-high-torque-movement/>
<https://www.esslinger.com/mini-quartz-high-torque-clock-movement-aa-with-hardware/>
Oh swell. No data sheets.

Notice that they have high torque movements that run on C cells. This
one claims to run 3 years on one C cell:
<https://www.esslinger.com/clock-movement-c-long-life-quartz-movement-high-torque/>

I'm thinking either something is wrong with the mechanism (friction,
wrong lube, insects in the gears, dirt, dust, etc). Perhaps your
expectations might be a bit much for the clock runtime from a AA cell,
maybe you're using cheap batteries, the clock may have a phantom load
draing the battery, or the clock motor drops out at too high a battery
voltage. Lots of things that might go wrong that a few measurements
might highlight.

It might be fun to try running it from a super-cap. Lots of peak
current and no self-discharge.

Good luck with the project.

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Steve Wilson

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Nov 8, 2020, 6:32:23 PM11/8/20
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The clock will drift. He needs WWVB. See my earlier post.

jla...@highlandsniptechnology.com

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Nov 8, 2020, 6:43:35 PM11/8/20
to
On Sun, 8 Nov 2020 21:08:18 -0000 (UTC), "Don" <g...@crcomp.net> wrote:

>This project shows how to build a 1.5 VDC pseudocell to take the place
>of an AA sized battery. The mechanical aspect of this project offers the
>greatest challenge. The electronic portion utilizes an easy to use LM317
>adjustable voltage regulator to convert a 5 VDC source to 1.5 VDC.
>
>(excerpt)
>
>https://crcomp.net/pseudocell/index.php
>
>(Thank you In Advance to readers who alert me to typos and whatnot.)
>
>Danke,

Why not hang a D-cell on the other side of the wall? That would give
you battery backup!

Steve Wilson

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Nov 8, 2020, 7:18:20 PM11/8/20
to
jla...@highlandsniptechnology.com wrote:

> On Sun, 8 Nov 2020 21:08:18 -0000 (UTC), "Don" <g...@crcomp.net> wrote:
>
>>This project shows how to build a 1.5 VDC pseudocell to take the place
>>of an AA sized battery. The mechanical aspect of this project offers
the
>>greatest challenge. The electronic portion utilizes an easy to use
LM317
>>adjustable voltage regulator to convert a 5 VDC source to 1.5 VDC.
>>
>>(excerpt)
>>
>>https://crcomp.net/pseudocell/index.php
>>
>>(Thank you In Advance to readers who alert me to typos and whatnot.)
>>
>>Danke,
>
> Why not hang a D-cell on the other side of the wall? That would give
> you battery backup

The clock will drift and pretty soon be useless. He needs WWVB to keep
time. The batteries can last up to 3 years. See my pervious post.

gfre...@aol.com

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Nov 8, 2020, 7:25:02 PM11/8/20
to
On Sun, 8 Nov 2020 21:08:18 -0000 (UTC), "Don" <g...@crcomp.net> wrote:

>This project shows how to build a 1.5 VDC pseudocell to take the place
>of an AA sized battery. The mechanical aspect of this project offers the
>greatest challenge. The electronic portion utilizes an easy to use LM317
>adjustable voltage regulator to convert a 5 VDC source to 1.5 VDC.
>
>(excerpt)
>
>https://crcomp.net/pseudocell/index.php
>
>(Thank you In Advance to readers who alert me to typos and whatnot.)
>
>Danke,

I made one of these but I found out for about $10 Amazon will sell you
one in either 1.5/3v/4.5v or 6v with appropriate dummy batteries to
fill the holder.

https://tinyurl.com/y35tbt56

Don

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Nov 8, 2020, 7:56:51 PM11/8/20
to
The project's complete and has been up running for a day now. The clock
itself is primarily aesthetic rather than scientific. In other words,
replacing it is not an option. As it drifts, it'll be easy enough to
adjust its hands with a long pole while standing on the floor without
dragging out the ten foot ladder.
Your followup makes me feel my solution is optimal. Those dummy
batteries you mention apparently allow higher voltage batteries to be
retro-fitted in a bank of batteries? But the wall clock only
accommodates a single 1.5 VDC AA battery.
The premade pseudo battery won't work because there's no nearby
outlet to plug it into. Besides, it also requires a larger, unsightly
hole, to pass either the wall wart or the AA pseudocell through.

Jeff Liebermann

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Nov 8, 2020, 8:09:34 PM11/8/20
to
On Sun, 08 Nov 2020 22:04:54 GMT, Steve Wilson <sp...@me.com> wrote:

>The clock will drift. Eventually it will be so far off the correct time
>to be useless.
>
>Don lives in Casper, WY. He should have no problems picking up WWVB:
>
>https://tf.nist.gov/stations/wwvbcoverage.htm
>
>There are a large number of inexpensive WWVB wall clocks that are large
>enough to read from a distance. These will keep time to better than a
>second.

If Don wanted a clock that ran forever, he should have so stated.
Although the project notes at:
<https://crcomp.net/pseudocell/index.php>
lack any statement as to what he's trying to accomplish, I would
deduce that not replacing the AA battery at unspecified intervals is
the main problem. You just expanded the project by adding an accuracy
problem. Whether this is a problem worth solving is up to Don and his
client.

I didn't see any mention of replacing an LR44 batteries, so I'll
assume that the clock does NOT have an automagic DST (daylight savings
time) feature. There's also something called "auto-set" which is
intended for areas with WWVB interference or reception problems:
<https://www.clockparts.com/blog/atomic-clock-movement-versus-the-auto-set-movement/>
Unfortunately, it looks like the DST feature is run by a tiny LR44
battery, which will probably also need replacement. Therefore if the
clock requires resetting the time twice per year, I would assume that
accuracy is sufficient between DST resettings to not require a daily
WWVB resetting.

The hands on the clock seem to be a little longer than the top of the
ladder, or about 14 inches long. Such long hands on the clock might
require a high torque drive mechanism. Hard to tell without a size
measurement. I couldn't find one that does both WWVB and has high
torque. I'm sure they exist, but I can't seem to find one.

>You can even get a kit to convert an ordinary clock to WWVB. Search
>Amazon.

Are you suggesting a kit that replaces the existing movement with one
that has a WWVB receiver, or some kind of retrofit kit? I found quite
a few WWVB clock movements on Amazon. The only retrofit kits I could
find were complete replacements of the clock movement.

>I use a HTAWI WWVB clock that is 16 inches in diameter. It is easy to
>read from many feet away. It has 3 batteries and will switch
>automatically when a cell runs down. I expect it to last 3 years or more
>and keep perfect time.

Nice. I had a cheap ordinary wall clock in my office that ran on a
single AA cell for about 15 months. After about 2 years of use, it
started to slow down and drain the battery in as little as 4 months.
So, I tore it apart, cleaned out the accumulated dirt, re-assembled,
and it again ran for about 15 months per AA cell. The bushings that
ran the hands don't like dust. I gave it away when I retired last
month.

Don

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Nov 8, 2020, 8:28:06 PM11/8/20
to
In sci.electronics.design Jeff Liebermann <je...@cruzio.com> wrote:
> On Sun, 08 Nov 2020 22:04:54 GMT, Steve Wilson <sp...@me.com> wrote:
>
>>The clock will drift. Eventually it will be so far off the correct time
>>to be useless.
>>
>>Don lives in Casper, WY. He should have no problems picking up WWVB:
>>
>>https://tf.nist.gov/stations/wwvbcoverage.htm
>>
>>There are a large number of inexpensive WWVB wall clocks that are large
>>enough to read from a distance. These will keep time to better than a
>>second.
>
> If Don wanted a clock that ran forever, he should have so stated.
> Although the project notes at:
> <https://crcomp.net/pseudocell/index.php>
> lack any statement as to what he's trying to accomplish, I would
> deduce that not replacing the AA battery at unspecified intervals is
> the main problem.

You are absolutely correct. The webpage needs to make the main problem
and its solution more explicit.

Steve Wilson

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Nov 8, 2020, 10:42:48 PM11/8/20
to
Jeff Liebermann <je...@cruzio.com> wrote:

> On Sun, 08 Nov 2020 22:04:54 GMT, Steve Wilson <sp...@me.com> wrote:
>
>>The clock will drift. Eventually it will be so far off the correct
>>time to be useless.
>>
>>Don lives in Casper, WY. He should have no problems picking up WWVB:
>>
>>https://tf.nist.gov/stations/wwvbcoverage.htm
>>
>>There are a large number of inexpensive WWVB wall clocks that are
>>large enough to read from a distance. These will keep time to better
>>than a second.

> If Don wanted a clock that ran forever, he should have so stated.

He implied so by generating a battery replacement and running wires in
the wall.

> Although the project notes at:
> <https://crcomp.net/pseudocell/index.php>
> lack any statement as to what he's trying to accomplish, I would
> deduce that not replacing the AA battery at unspecified intervals is
> the main problem. You just expanded the project by adding an accuracy
> problem. Whether this is a problem worth solving is up to Don and his
> client.

He is doing this for himself.

WWVB clocks solve the accuracy problem.

> I didn't see any mention of replacing an LR44 batteries, so I'll
> assume that the clock does NOT have an automagic DST (daylight savings
> time) feature. There's also something called "auto-set" which is
> intended for areas with WWVB interference or reception problems:
> <https://www.clockparts.com/blog/atomic-clock-movement-versus-the-auto-
> set-movement/> Unfortunately, it looks like the DST feature is run by
> a tiny LR44 battery, which will probably also need replacement.
> Therefore if the clock requires resetting the time twice per year, I
> would assume that accuracy is sufficient between DST resettings to not
> require a daily WWVB resetting.

The drift is temperature sensitive and usually runs about 15 seconds per
month. Eventually it will get so bad the time reading is worthless.

WWVB solves this problem.

>>You can even get a kit to convert an ordinary clock to WWVB. Search
>>Amazon.
>
> Are you suggesting a kit that replaces the existing movement with one
> that has a WWVB receiver, or some kind of retrofit kit? I found quite
> a few WWVB clock movements on Amazon. The only retrofit kits I could
> find were complete replacements of the clock movement.

Yes, that's how they work.

>>I use a HTAWI WWVB clock that is 16 inches in diameter. It is easy to
>>read from many feet away. It has 3 batteries and will switch
>>automatically when a cell runs down. I expect it to last 3 years or
>>more and keep perfect time.

I used to use a HTAWI, but now I notice I have changed to La Crosse.

They all keep perfect time, even up here near Toronto. You should have no
problem in California.

> Nice. I had a cheap ordinary wall clock in my office that ran on a
> single AA cell for about 15 months. After about 2 years of use, it
> started to slow down and drain the battery in as little as 4 months.
> So, I tore it apart, cleaned out the accumulated dirt, re-assembled,
> and it again ran for about 15 months per AA cell. The bushings that
> ran the hands don't like dust. I gave it away when I retired last
> month.

I have been using WWVB clocks for many years. They still work perfectly.

The WWVB clock movement is pretty tightly sealed. I have never had one
damaged by dust. Taking the movement apart will destroy it.

Congratulations on your retirement.

I retired about 8 years ago. It is a completely different world. No tight
schedules to meet, no customers to argue with, much more relaxing. You
can do your own thing, at your own pace.

I never could understand people who retire, then die. I guess they didn't
have any hobbies that could keep them busy.

piglet

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Nov 9, 2020, 3:36:41 AM11/9/20
to
On 08/11/2020 9:08 pm, Don wrote:
> This project shows how to build a 1.5 VDC pseudocell to take the place
> of an AA sized battery. The mechanical aspect of this project offers the
> greatest challenge. The electronic portion utilizes an easy to use LM317
> adjustable voltage regulator to convert a 5 VDC source to 1.5 VDC.
>
> (excerpt)
>
> https://crcomp.net/pseudocell/index.php
>
> (Thank you In Advance to readers who alert me to typos and whatnot.)
>
> Danke,
>

Your circuit design description states that R3 provides the minimum 10mA
load current. Yet the value of R3 is 15k which only draws 0.1mA which
when added to the R1/R2 divider current of 1.13mA means the minimum load
on the LM317 is only 1.2mA far short of the stated 10mA

You don't even need R3 - just change R1 to 120R and R2 to 24R.

piglet

Don

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Nov 9, 2020, 9:06:39 AM11/9/20
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Excellent! (As always, BTW.)
Looks like my worst fear was realized as sloppy discipline allowed
a decimal point to slip down from mils to micros. Your hint about how
to eliminate R3 is much appreciated too.
My approach to technology previously untapped by me is to approach
it with caution. And a R2 of hundreds of ohms somehow seemed safe, until
you helped me see things clearly in my mind's eye.
Anyhow, the perfboard will be quickly rebuilt with correct
components. It's mounted on an easily accessed backboard and plugged
into a strip connected to the UPS used for the phone system. The last
bit doesn't matter much, given how a long pole will be used to correct
the clock's drift.

piglet

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Nov 9, 2020, 9:22:52 AM11/9/20
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Thanks Don, you are very welcome.

piglet

Science teaches us to verify.

Steve Wilson

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Nov 9, 2020, 10:35:31 AM11/9/20
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A long pole risks damaging the clock hands.

A WWVB clock will correct the drift and automatically switch for daylight
savings. Batteries can last 3 years.

>> Danke,
>>
>
> Thanks Don, you are very welcome.
>
> piglet
>
> Science teaches us to verify.

I like your sig. Much better than doubting.

Claude Bernard is an interesting figure and is held as the first
scientist.

Actually I think that title should go to Michael Faraday and others from
his era.

Quote

"Michael Faraday (born Sept. 22, 1791) was a British physicist and
chemist who is best known for his discoveries of electromagnetic
induction and of the laws of electrolysis. His biggest breakthrough in
electricity was his invention of the electric motor."

https://www.thoughtco.com/michael-faraday-inventor-4059933

https://www.sciencehistory.org/historical-profile/michael-faraday

Tesla was credited with invention of the electric motor, but he was a
century too late.

Robert Roland

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Nov 9, 2020, 3:02:43 PM11/9/20
to
On Sun, 08 Nov 2020 14:56:12 -0800, Jeff Liebermann <je...@cruzio.com>
wrote:

>Or, buy one that does exactly what you're suggesting:

Sure, but you're taking all the fun out of it.
--
RoRo

Don

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Nov 10, 2020, 12:11:42 AM11/10/20
to
There's a few problems with the suggested off-the-shelf solution. [1]

The most project fun happened last, after piglet (and another at
eevblog) suggested 120R for R1 and 24R for R2. (piglet, with my last
sentence, it suddenly became obvious to me why you use R to denote ohms.
LOL.)
Although 120R and 24R certainly work, you may still ask, "Are they
optimal?" ROTFL. Let's have some fun and see!
First, you set up a system of simultaneous linear equations (details
shown at my updated link: https://crcomp.net/pseudocell/index.php ):

R1 R2

1 -5 0
1 1 150

Then you "plug and chug" the system through octave:

octave:1> A = [ 1 -5;
> 1 1 ]
A =

1 -5
1 1

octave:2> b = [ 0;
> 150 ]
b =

0
150

octave:3> r = A\b
r =

125
25

Close enough for government work, no? Now, was that fun or what?

Note.

[1] First, there's no nearby electrical outlet to plug it into. Second,
it requires a larger, even more unsightly, hole in the wall, to
accommodate either a wall wart or pseudocell. The attic's unheated
and must be sealed afterward, so the project then creeps into
spackle and paint matching.

piglet

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Nov 10, 2020, 7:36:23 AM11/10/20
to
+1 on Faraday. Had the great pleasure to visit the Royal Institution in
London where Faraday worked.

Robert Roland

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Nov 11, 2020, 1:56:55 PM11/11/20
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On Tue, 10 Nov 2020 05:11:39 -0000 (UTC), "Don" <g...@crcomp.net> wrote:

> it requires a larger, even more unsightly, hole in the wall, to
> accommodate either a wall wart or pseudocell.

In a pinch, you could snip the wire and splice it after you put it
through the hole.
--
RoRo

Don

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Nov 11, 2020, 2:43:22 PM11/11/20
to
In sci.electronics.design Robert Roland <fa...@ddress.no> wrote:
A larger hole must be drilled in order to push the off-the-shelf
solution's flexible cable through it. Stiff wire was pushed through,
instead of pulled through with a snake, to keep the hole as small as
possible.
The solution's cable length is also about 94 feet too short.
Perhaps you can spice it to the stiff wire. But it's difficult for me to
fully apprise the situation from an image. And unpleasant surprises,
after a sometimes long wait for arrival, are anthematic to me.
It's also difficult for me to pay $28.99 for parts freely available
in my bone pile.
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