Archive for October, 2019

5 results.

Garlic Prep

Oct18
by catz on October 18, 2019 at 08:00 and modified on October 22, 2019. at 14:18
Posted In: gardening, garlic

Two days after work or prepping for garlic planting. about 3 1/2 hours in total to crack open about 150 bulbs to get 847 cloves for planting in 142 rows of six each.
Working inside to do this part really helps in the field when planting. IT used to take us two full days in the garden, cracking and planting. Now we hope to be done outside in only a few hours.
This year we have at least 99 types, some of which are named the same but come from different sources.

acropolis greek
aglio Rosso Creole (2019)
armenian (2015)
artichoke formidable
barcelona red sp
bubbas chesnock
carpathian
chesnock red
chilean silver
chloe
crème de la rasa (2018)
czech broadleaf
dujanski
f3V
Fishlake F1
Fishlake F21
Fishlake F23
Fishlake F3
Fishlake F30
Fishlake F40
Fishlake F7
french
genki
georgia crystal
georgia fire
georgian (2018)
german red
german white
hungarian(2015)
inchelium
italian lorenz
italian purple (2019)
italian sicilian (2018)
japanese
japanese sikura
khabar
koji (2019) Perth
korean purple
kostyns red russian
kostyns red russian (2019)
lacota (2019)
lucian sicilian
magnificent
marino (2016)
mennonite
metechi
mexican Red Silver
music
music (2019)
musical/music
newfoundland (2019)
northern quebec
northern quebec (2019)
northern siberian
northumberland (2018)
omas
persian star (2015)
persian star (2018)
phillipino
polish jenn
port au george (2018)
purple glazer
purple stripe sicilian
railway Creek (2019)
red rezan
roja (2019)
rose de lautrec
rose de lautrec (2019)
rosewood (2015)
russian red
russian red (2019)
saltspring Select(2016)
seversky palisek
shouldice
siberian
sicilian gold (2019)
sicilian gold (2016)
silverskin40
slovak
solent wight
spanish antihelion (2015)
spanish roja
spicy korean
susan Delafield/Music (2016)
sweet candy (2015)
tibetan
transylvanian
ttv5
us polish
us republican
us romanian
vampire (2018)
wettergren (2016)
wettergren (2019)
wild garlic
wyld garlic
yugo (2018)
yugo red (2019)
zemo

Comments Off on Garlic Prep

True Field of View

Oct15
by catz on October 15, 2019 at 12:28 and modified on October 15, 2019. at 12:29
Posted In: astronomy

True Field of View

In the past, when imaging Jupiter. I did a full field image run, put the image up on the screen, found out the apparent diameter of Jupiter and physically measured the screen and Jupiter to determine TFOV.

This past weekend, Kim & I tried it out on a star. Using firecapture and the reticle turned on, we centered the star, stopped the tracking and timed how log it took to hit an edge. Luckily for us, it went on a diagonal and exited almost exactly at the corner in 12.69 seconds.

* drift test for FOV wth ASI290MC camera, no reducer, no barlow, on the Torus telescope D=400mm F10, FL=4000mm
12.69 seconds from centre to top right corner exit.
camera pixel resolution=1936×1096.

The centre reticle location is 1/2 of that, so 548×978
Using right angle geometry, the diagonal is 1121 pixels, full diagonal would be twice that or 2242 pixels
calculate drift 1/2 FOV is 12.69 seconds
full FOV is 25.38 seconds

360 degrees / 24 hours = 15 degrees/hour
15 degrees/hr / 60 minutes/hr = 0.25 degrees/minute (15 arcmin/minute)
15 arcmin/minute / 60 seconds/minute = 0.25 minutes/second (15 arcseconds/second)
So just count how long it takes in seconds for a star to move across an eyepiece’s FOV and multiply it by 15 to get the FOV in arcseconds.
TFOV(diagonal)=15*Time
TFOC(diagonal)=15*25.38=381 arcseconds = 6 minutes 20 seconds diagonal

ZWOASIM290MC FOV 1936×1096 pixels gives 329 x 186 arc seconds rectangle

Turns out this method is WRONG! (*Unless* you are using a star with a declination of 0)

Use this formula instead:

The True Field Of View (TFOV) is then:
TFOV = 15.04*T*Cos(delta)
where “delta” is the star’s declination, “Cos” is the Cosine function, and “T” is the measured drift time interval. If the time is measured in minutes, the true field will be in minutes of arc, and if the time is in seconds, the true field will be in seconds of arc. For example, if a star has a declination of 25.5 degrees (ie: 25 degrees 30 minutes), and a measured drift time of 2.75 minutes (ie: 2 minutes 45 seconds), the true field of view is then 37.3 arc minutes in diameter. For stars within 3 degrees of the celestial equator, the Cosine function can be approximated to 1, and the formula becomes:

We used a star near saturn (mag 0.52 38 arcseconds with rings)
HIP 93423 mag 6.2 dec -22deg 39min = 22.65 degrees
cosine 22.65 degrees is 0.923
TFOV=15.04*25.38seconds* 0.923= 352 arcseconds (less than original calculation of 381)

so ZWOASI290MC TFOV= diagonal 352 arcseconds, rectangle 303×172 arcseconds

Then someone mentioned you can do the same with just the focal length and the camera sensor chip size, which led to this
formula:

I found: sensor size (mm) * 135.3/focal length (inches) = arcminutes
mixing units seems to be just wrong, but perhaps the fudge factor of 135.3 accounts for that?

the camera sensor size is 5.6×3.2mm
focal length of 4000mm=157 inches
5.6*135.3/157= 4.8 arcminutes
3.2*135.3/157=2.8 arcminutes

drift solution:
ZWOASI290MC TFOV= diagonal 352 arcseconds, rectangle 303×172 arcseconds = 5×3 arcminutes

So the two answers are reasonably the same, within error limits.

Comments Off on True Field of View

Garlic planting prep 2019

Oct15
by catz on October 15, 2019 at 12:20 and modified on October 15, 2019. at 12:24
Posted In: gardening, garlic


Its that time of year… time to plant the garlic cloves before the ground freezes.
So this past weekend, we cleared out the VegBed4 of tomatos plants, stakes, basil, flowers and more.
It is about 28’x29′ or about 800 ft^2 give or take.
Added to that was 16 bags of composted manure, 15kg each, about 240kg total.
The big tiller fired up and we went through the entire bed in about 15 minutes.
There is still a lot of grass around the fencing, so we won’t be planting in it… there was actually about a 21′ line available North-South.
So we pegged two posts and ran a string between the two and then went through and made sample dibbles 8″ apart to see how many dibbles we could get in 21′.
The answer turned out to be 32 dibbles of 6 holes each.
Then we went in the East West direction to see how many sub-beds could be fit in the garden, with a 1′ gap between each for a walking path.
That turned out to be about 4 sub-beds in the 21′ long length and about 3 more sub-beds in about 16′, guesstimating maybe 25 dibbles in those sorted rows.

So we should have:
(32*4) + (25*3) = 128+75 or about 200 dibbles of 6 holes each, giving us a maximum planting of approx 1200 cloves.

We have cover cloth for use in the spring to try and slow down the leak moth issues, and we are also investing in some irrigation tape, to regularly water them in the spring and summer up to the end of June. This leaves July for them to dry up in time for harvest near the end of July.

So.. for the next few evening we prepare… predetermining what types and how many of each to plant (in increments of 6), get signage premade (cause if you don’t sign it when you plant it, you may never get around to it!), bagging those and also preparing 1″x2″x18″ stakes to staple the signage onto.
Hopefully on planting day, it will be warm, clear, not raining and not take more than 3 or 4 hours.

From 2018:
So the old signage comes off the short stake and gets reattached to the new 2 and 2/3′ long stakes. In addition, with multiple rows of the same type, we need to create some new markers so that *each and every row* has signage.
New for 2019:
Stakes that tall are too tall… you often get caught on sticks as you go through the bed… so we are cutting down stakes from 2.7′ to maybe 1.5′

Comments Off on Garlic planting prep 2019

Transit of Mercury 2019 Nov 11

Oct07
by catz on October 7, 2019 at 15:52 and modified on October 7, 2019. at 15:55
Posted In: astronomy

2019nov11

The transit of Mercury across the face of the Sun is fast approaching!
Time to start thinking and preparing for the event. This graphics shows that the entire transit will be visible for us in eastern ontario canada.

From wikipedia:
Transits of Mercury occur in May or November. The last four transits occurred on November 15, 1999; May 7, 2003; November 8, 2006; and May 9, 2016. The next will occur on November 11, 2019, and then on November 13, 2032. A typical transit lasts several hours.
Start 12:35 UTC
Mid 15:20 UTC
End 18:04 UTC
Total transit time = 18:04-12:35 = 5 hours 29 minutes.
Daylight Saving Time switches on Sunday 2019 November 03!
We are 5 hours behind UTC so for us the transit starts at 07:35 EST and ends at 13:03 EST.

our plans are to:
1) video the entire event with a camcorder with a solar filter
2) take still images every few minutes with a DSLR camera and a 300mm lens with a solar filter.
3) take still images with an astro camera on a telescope with a solar filter.

The path takes it very close to being across the middle of the sun as well.. providing for a longer transit time.

Comments Off on Transit of Mercury 2019 Nov 11

complex!

Oct07
by catz on October 7, 2019 at 15:19 and modified on October 7, 2019. at 15:20
Posted In: tech

charger

This is a 2-3 year old ryobi 40v lithium battery charger. It has stopped working. I wondered how complex it could be inside… a transformer, a bridge rectifier and maybe a capacitor or two to smooth out rough edges. First I had to find a &@#$)@# torx screwdriver as they don’t seem to want people to look inside.

This is what I found:

inside charger


From the 110vac on the right the circuit starts with a transformer at the bottom, a bridge rectifier and then a 220uF capacitor.. exactly what I was expecting.
Then there was all that other stuff! Wow. Another transformer, some non-power handling diodes, lots of capacitors and a couple of ICs! A friend suggested the rest of the components are a switching power supply. And the other thing to note is the three output leads (red, black and white) to the battery.

A replacement charger is in the $140-200 range so cobbling together something that will charge would be very nice!

Comments Off on complex!