Sunday, September 20, 2020

A Simple Public Safety Radio Scanner with the Raspberry Pi - Part 1 - Receiving Signals

All the bits needed to make a radio scanner

As I may have mentioned previously, along with a fondness of making sawdust, I am also a bit of a radio nut.

As I sit here typing out this post, I have my trusty HF Amateur Radio transceiver (an Icom 718 if you're curious) and my digital VHF scanner (a Grecom) keeping me abreast of what's going on, both locally and internationally.

My scanner in particular is quite busy since it is always checking the frequencies for a large number of public safety agencies in my area. While I certainly enjoy being in the know of what's going on in my local area, I do find that I may miss something that has happened closer to home because the scanner is busy telling me about something happening over in the next county.

This is particularly true about activity that involves my local fire department, which is about a kilometer away from my house. There have been a few times where I missed a call out and did not know that there was something going on until I saw the fire trucks rushing by my house.

I really wanted to have some way of scanning full time the four call out frequencies that the fire department uses in my area but still keep tabs on the other frequencies that I am scanning. It didn't really make a lot of sense to buy another scanner just to monitor a handful of frequencies.

However, I did have a few spare SDR (Software Defined Radio) dongles sitting around from my Glider and Balloon tracking projects. Could I use these for a dedicated scanner for my fire department?

Sunday, September 13, 2020

A Wee Life-hack - Making a Simple USB Battery Adapter

Who needs batteries?

Towards the end of summer, I always make a pilgrimage north to do a little bit of fishing. 

Since the place that I usually go has a decidedly poor coverage area for cell and internet signals, I find that those few days of fishing to be my time to fully disconnect from the world and recharge my body and spirit. 

The type of fish that I go for typically is the type that will go only for the freshest of bait - for some reason they are just not easily fooled by artificial lures. 

They especially seem to have a fondness for minnows, which, for those that aren't familiar with all things fishy, are a small fish that about an inch or two long - just the right size for the big ones that I am angling for to swallow in one bite. 

The issue is that the minnows up north know this too, and tend to be very timid about being captured for use as live bait. 

The minnows in the creek near my house however, don't seem to have this fear and are easily persuaded to enter my minnow trap with a few bits of bread. 

The challenge is how to transport my minnows so that they stay alive and well for the 2 hour trip to my fishing spot.  The key to transporting minnows is to make sure that they have plenty of oxygen in the container that I am hauling them in. 

Sunday, September 6, 2020

A Monthly Surprise in the Mail - Checking out a Kiwi Crate

A box of goodies

A few months back I developed a bit of a guilty pleasure in watching unboxing videos that seem to be everywhere on YouTube. 

The concept is that you get a box from an online store and you film yourself opening the box, removing and critiquing the items in the box. I actually tried my hand at doing one myself with my new table saw.  

Admittedly a very odd concept - but a very popular one, and strangely compelling to watch.  I suppose with fewer people going to physical stores, this has replaced "window shopping". 

I am especially drawn to watching unboxing videos which definitely are a spoof on the whole genre

In particular, the videos that I watched seemed to delve into something called "Crate Boxes". Crate boxes are usually part of a monthly subscription where you get a box full of goodies delivered to your front door each month. These crates are usually geared to a particular interest (movies, video games, etc.) and the contents of the crates usually follow a monthly theme. 

Most subscriptions are actually pretty reasonable for what you get - usually around 20 or 30 dollars a month. 

There are quite a few of these subscription crates out there. For example, my spouse subscribes to a crate that sends her goodies for her card making hobby. 

The other day, I saw a post in my Facebook feed about a crate subscription service called KiwiCo that offered something called a Kiwi Crate. 

KiwiCo focuses its crates towards providing STEM, STEAM, and Science kits, mainly for kids. 

While I haven't been a kid for a long long time, I noticed that they had various levels of crate subscriptions based on various age and interest levels. 

I was actually surprised to see that they did offer crates for "older" kids in the 14 to 104 age range with 2 crates - a Eureka Crate that was geared towards Science and Engineering projects and a Maker Crate that was aimed towards Arts and Design projects. 

Of course, I was more drawn towards the Eureka crate so I checked it out a little more. 

I was actually pretty impressed with what you got in a crate. A crate usually contains a very useful item, such as an electric pencil sharpener, or an articulated desk lamp the comes in a kit form. Again the items have a heavy STEM slant as they use the assembly of the item as part of a teaching exercise. 

I was actually pretty intrigued, so I subscribed for the Eureka crate, with my first crate arriving at my door a couple of weeks later. 

Sunday, August 30, 2020

The Necessary Evil - Shop Maintenance

Changing the saw blade

Last week I was ripping some stringers from a pallet for a new project that I was working on when my table saw made a bit of a clunk and shot out a couple of sparks - it would appear that I had forgotten to remove a nail from the stringer before I started cutting.

Obviously, the saw blade didn't really like that too much and proceeded to tell me this by making an absolute mess of the cut on the next board that I ripped.

Effectively I wrecked the blade and it needed to be replaced.

Changing a saw blade on a table saw is a fairly straight forward affair of loosening the nut that attached the blade to the spindle of the table saw's motor, except for a slight twist.

If you tried to just take a wrench to the nut, you will quickly find that the blade will just spin freely as you turn the nut. No matter how dull the blade is, it is still not a good idea to have something like that near fingers that are in close proximity, nor can you just hold onto the blade with one hand while wrenching with the other - a sure-fire way to get a nasty cut.

To do it properly, you need to wedge in a piece of scrap wood between the blade and the body of the table saw.  The blade digs into the wood, and not your hand as you loosen the nut.

Switching saw blades is just another part of regular shop maintenance,  that thing you need to do from time to time to ensure that your fingers stay attached and your projects look decent.


Sunday, August 23, 2020

"Instant Pot" Autopsy

One Pressure Cooker Ready for Inspection

With everyone staying home more due to the situation that has been happening in the world this year, there seems to be a bit of an explosion of people letting their inner chef out and trying their hand at making home-cooked meals.

This really became apparent when I noticed a definite shortage in the grocery stores on things like flour and yeast. There certainly seems like there is a lot of bread being baked recently.

Another thing that I have noticed, actually long before the pandemic hit, that that there has been a renewed interest in making meals with pressure cookers.

Unlike the pressure cookers of my Grandmother's time, which resembled something that would have been more at home in a science laboratory, the pressure cookers of today look downright sleek and high-tech with custom programs built-in for handling almost anything you would which to make.

Pressure cooking is the process of cooking food at high pressure, employing water, or a water-based cooking liquid. High-pressure limits boiling, and permits cooking temperatures well above 100 °C to be reached, meaning that foods cook much faster with pressure cooking than with other methods

The most common pressure cooker being sold these days is the "Instant Pot" but there are a lot of other cookers on the market that function in exactly the same way.

A few years ago I bought a no-name pressure cooker mainly to do some canning, but recently I also started to use it to make some nice and easy one-pot meals.

Recently I was cleaning the cooker when the relief valve (which is a safety device that is used to release pressure if the internal pressure of the cooker gets too high) fell out of the lid and fell down the drain in my sink.

This meant that my pressure cooker now had a small hole in the top of its lid - not an ideal situation for maintaining pressure.

As it seems to be the case in our disposable world today, a quick search online for replacement parts made it quite clear that it was more cost-effective to buy a new cooker than repair the old one.

After a quick trip to my local store, I was able to start cooking again, but in the meantime, I still had this old cooker.

Perhaps a little dissection was in order - just to see what secrets it held - and maybe to see if we can find some goodies too for future projects.