Coping: Weekend Project Warrior Notes

I have a slightly sore set of stomach muscles this morning, now that we’re putting up the overhead insulation in the new audio/video production room.  One of these days I will go back to doing occasional YouTube and other media.  May come out with the .MP3 version of Peoplenomics, but we’ll just have to wait and see on that one.

For now I’m content with spring being here and being able to get a lot of outside projects back on track.

Putting up overhead insulation is a lot easier than it used to be.  Mainly because the right tool for the job is at hand. 

That last time I was putting in fiberglass insulation I was doing it with a manual stapler.  After a day of serious insulating I ended up with a terrible blister on might right hand in the valley between the thumb and forefinger.

Not being a complete idjit, I now own not only an electric staple gun, but also an air-powered one.  Turns out both have been a good investment.  For the insulation, we have a Stanley TRE550 Electric Staple/Brad Nail Gun which will set you back about $30.  Free shipping with Amazon Prime, too.

You might be asking “Why the air stapler if you have an electric one….are you that lazy you fat so-and-so?

No, not at all.  It’s just that with a little higher than book pressure, the air-powered stapler is better for heavier work – like upholstery.  If you already have the air compressor and hoses, the Surebonder 9600A, Heavy Duty Staple Gun with Case will only set you back $25.

Earlier this week, the Elaine and I took a 20-question quiz which is in the new issue of The Family Handyman (1-year) ($12).  The questions were all about the arcane arts of home repair like how to prevent corrosion when joining dissimilar metal pipes, for example..

Elaine came in as an “advanced” DIYer in the scoring and I came in as a “”DIY pro…”  but you wouldn’t know it to look at some of my work.  Not that it’s slap-dash.  It’s just that there’s only so much time and too many things to do in life.  I just seem to lose interest after flowing on more than 2 or three coats of varnish…that kind of thing.  Two more and projects would look like glass, but is that worth the time?  I mean we’re talking golden weekend time, after all.

Today we’ll finish up the insulation in the ceiling of the A/V room and then tomorrow the floor will go into the sun porch, which was insulated earlier in the week.  That and a new storm door and Elaine will be able to move the drum kit outside that’s presently occupying the guest room.

And that, in turn means we’re having a guest.  My friend (and coauthor) Howard Hill will be coming by for a visit Monday on his travels about.

Besides being a genius of collateralized mortgage analysis, what I don’t think I’ve ever mentioned about Howard is he actually grew up in the White House, because his dad was the sound engineer for both JFK and LBJ.  So, as you might expect, the two main topics on the agenda Monday will be figuring out where to put the speakers (just so) in the new room.  I’ll run the wiring for them (and some XLR’s for instrument recording) before I button up the walls.

I’ve managed to talk Howard out of a pair of Bose 901’s which will augment the subs I have for the front of the room.  And we can debate whether the 201’s will work for rear-fill, or whether the Interaudio SA-200’s (a bit smaller, brighter, but less bottom to them) would be a better choice.

Howard’s forgotten more about audio and high-end sound gear than most people have ever learned.  As a serious (and I mean serious like heart attack) audiophile, he’s got a couple of the pieces from the original Grateful Dead Wall of Sound, before they decided to stop packing around the really heavy gear like the big tube amps that sound so warm and smooth….

I’m working on Howard to write the definitive book on cheapskate audio.  There’s been so much good gear produced at the consumer level that all you really need is a few hundred bucks and some smarts to be able to “rock the house” (and break windows if that’s your deal) and an eBay account.

The problem is knowing which gear is good and he’s a kind of walking encyclopedia about such things.  And if a performing artist like, oh, say Dave Brubeck, ever needs you to mic a performance in a 35 MPH wind on the White House lawn, Howard’s dad can tell you where to put five mics to make the outside sound better than 99% of indoor venues. 

The difference between fanaticism and audiophile may blur at times, but this is one of those areas Homeland Security doesn’t seem to get worked up about….

Like anything else around here, we’re doing the A/V room on a budget and the sun room is all recycled windows.  A fair number of the 2-by-4s are new, along with the insulation.  But it’s all done on a shoestring.  No room around here for a 10% markup for architects (sorry).  Two more rooms on the house and not a single drawing made, so far.  We should be in a position in another couple of months to let you know whether that’s a good thing, or bad.

Meantime, the drum set ought to be out of the way before the weekend is out.  Nothing like tripping over a snare drum in the middle of the night to wake a fellow up.  Go ahead, ask how I know….

Next Hobby:  Ham Radio Q & A

Reader Jason sent in a question:

So at bar trivia tonight the question was what has more bandwidth at night. AM or FM.

Immediately, we groaned because we think they mean range, meaning AM, and that was the answer. However in a vain effort to salvage this, I want to say the effective bandwidth of AM is lower during the day because of the day star (sun) causing interference. 

Is it hopeless?

Yikes!  Bandwidth is NOT dependent on time of day, year, or when the Moon is in the Seventh House, or any of that stuff.  It’s just how wide a signal is.  So we need to be exact when we use the term bandwidth and band.  Confusing them is like confusing horses and horsepower.

The AM and FM radio bands are pieces of the radio spectrum.

Since we’re been talking home handyman stuff this morning, I have a measuring tape.

We’re going to stretch it out 108 inches, like so.

Anything more than about 60-inches will propagate (get around) line-of-sight only (most of the time, rate exceptions like sporadic E, ducted propagation, and other radio-frequency trivia you don’t need right now.)

So FM is Line of Sight being in the 88-108 megahertz range, and we’re using our measuring stick like a 9-foot long tuning dial, right?

Now, at night, the radio waves down in the 1/2-inch to 30-inch range do act differently.  The 1//2” to 3” range is the Medium Wave (MW) band and the 3” to 30” area is called the High Frequency (HF) part of the band.

This is because the Maximum Useable Frequency (MUF) is different in the day than night.

Whatzzat?  There’s a layer of the ionosphere called the F2 layer that is responsible for most of the bouncing of radio waves.

During the day, the highest frequency that will bounce may be 28 MHz (think of it as 28”) which would be 28-inches on our big long dial.  (CB is at 27 inches).

This is why the good DX (distance) communications on these high bands is in the daytime.

At night, the MUF (maximum useable frequency) drops.  And you get “bank shots off the sky, 200 KM up in the F2 only up to maybe 10-MHz (10-inches on our big radio dial).

At night, as the MUF drops, it begins to bounce down to the bottom of the MW/AM broadcast band.  And it’s why many AM radio stations use non-directional antennas at night.  But at sunset you will hear a series of clanks and the signal may go up, or down, in strength as the station uses two (or more) towers to put out a directional signal.

The FCC has a complex set of rules on directional antennas and there are some very good (and highly specialized) engineering firms like Hatfield & Dawson up in Seattle.  I met Ben back when I was trying to be a classical music DJ at KLSN up on Roosevelt Way in Seattle and Ben was chief engineer for the what at the time would be the “alternative” station.  Hatfield (senior) and I worked on a couple of directional systems including KURB way back whenever that was….

Extra Class Ham Note:  When you’re designing a phasing system for a multiple power array, don’t forget that if you’re working AM that the L/C tuning circuit for the antenna will be asymmetric.  This is why good AM radio station arrays (H&D client types) make sure that their matching systems are flat out some good distance on either side of the carrier frequency.  Depending on the phasor, there can be a noticeable change in apparently loudness depending on the asymmetry of the frequency response of the matching circuit. 

Now, hold up your hands if you’ve ever used a Nems-Clarke field strength meter setting up three towers or more….Ooops!   I digress…

The bandwidth question of the signals if a different one.  In a nutshell, an AM station modulation results in bandwidth that is directly proportionate to the Input audio frequency.

When you whistle into an “amplitude modulated” AM transmitter, on say 1200 KHz, assuming you have perfect pitch at 1 KHz, your whistle will generate “sidebands” at 1199 KHz and 1201 KHz.   When the whistle is at 10 KHz (your lips will bleed, but have fun trying to get this high) the sidebands will be 1t 1190 KHz and 1210 KHz.  Just before your lips or lungs explode.

And just before the FCC shows up with a monitoring band, because they like AM stations to roll off above 5 KHZ so that the bandwidth of the AM signal is 10 KHz – 5KHz ABOVE AND 5KHz  BELOW

Animation of audio, AM and FM signalsAs long as we’re whistling, this morning, and talking about bandwidth, let’s whistle into our FM transmitter.  This means frequency modulation.

In frequency modulation, the frequency of the signal goes back and forth between an upper and lower limit.  The bandwidth of a commercial FM signal is proportionate to volume of the input. 

So your 1000 Hz whistle uses the same bandwidth as a 10 KHz (hurt yourself) whistle.

But if you whistle very softly, the bandwidth may be 5 KHz and loudly it spreads out to 100 KHz (50 KHz on either side of center).

In ham radio, the old standard was (going from memory here) between 5 and 15 KHz but narrowband FM has come to the commercial services and theirs is a lot of discussion about whether narrowband FM should be applied to ham radio.  See this discussion, for example.

My buddy Gaye up at www.backdoorsurvival.com has been slammed with real work, so I’m not sure if she & survival hubby will get over to take their Tech licenses tomorrow, but I’m encouraging to at least skim the rules and follow common sense.

Some people have this terrible guilt complex about doing all their work.,,,and doing it perfectly.  But the flip side is there’s only so much time to life and if you’re going to get it all it, there’s some times when you just have to say “Screw it…I’m going to take a fun break.”

Don’t send her any emails today, though.  Instead, save them up for Monday.  Make those short too.  Something like:    “Well?”

Write when you break even, AND when you get all your spring projects done…

George   george@ure.net

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