Coping: The Prepper’s E.E. Lecture

Did I mention I will be on CoastToCoast with George Noory tonight? Something of a victory lap from my January market call, which has been very good, so far…

Lesson 1: Complex Design Gets Ure

I don’t think I ever told you why I got kicked out of Seattle University back in the day.

Mostly it was bad grades. I hated philosophy and putting my hands “in the same water of a running river, twice…” sounded suspiciously like BS. It still does.

Even worse was freshman engineering. I had been working as a professional broadcast engineer for three years, by then. And when presented with amesial force vector calcs, out came my serious – first on campus – hand-held calculator. Problem solved. Side order of decimal places.

Or, more properly, it would have been. Except father what’s-his-name insisted I use my nearly worn out K&E slide rule. “You need to be able to do the decimal points in your head!” I remember being yelled at.

I got better use for my brain that decimal points. You need to see the future in your head..and then go build it…” was my reply. Which is why I didn’t finish an undergrad degree until age 37 and a masters in 1997. Business not engineering. Schools without tools are for fools, I reckoned. A good call, too. RCA hired me as a microwave field engineer in Alaska, shortly thereafter which saved me four years of hopeless boredom and BS. I did real engineering work.

Thus, the first point of Prepper Engineering 101: Do what’s right and what works. We can worry about the paperwork later.

Lesson 2: Ground Faults

Peoplenomics Wednesday was terribly short (but still, our full complement of charts and market talk, since we’re never too lazy to make a buck).

The reason the power was off in my office was one of the rarest of electrical failures. A Ground Fault Interupter had gone toes up.

Back in my Alaska days, down-time was a curse. I was responsible for rerouting secure communications between this place and that. Should the outage last more than 5-minutes, even if I was sleeping in the BOQ on the other side of a remote site, the clock was 5-minutes. And the penalty for bad was on the order of $500 per channel per minute.

That doesn’t sound bad. Until you looked at how many channels I was managing (200) in which case a single minute of penalty got pretty spendy and this was 1968.

That was then. Speed mattered and it was all I did.

Wednesday, I was not able to restore “one channel of power” for about 20-minutes.

Having my eyes working at less than 50% had something to do with it. But there was also a flaw in my thinking. I simply assumed that because the GFI passed the self-test, it was good. Not necessarily, come to find out. Especially when the next item downline (toward my office) was a high capacity outlet for a 120V welder. It had become flaky, too.

The great result of all this is that I finally found out what had caused the apparent inverter/charger failure a month of three back. Here all this time, I thought it was the mouse nest in the conduit that is now stuffed with new wire and expando foam to keep vermin out.

While that might have had something to do with it, the GFI going Clinton (not working at the right moment) may have been why the inverter was shutting down…looking back on it, I’m embarrased I didn’t catch it sooner. Frequency-division multiplexing, believe it or not, can be much easier than grid-interactive power systems designed with two levels of fail-backs and fault detection.

As a design point going forward, we will no longer include a GFI between the first inverter and the downline UPS in the office. It’s a single point of failure issue where I simply “thunk myself into a box.”

Bad dog, George. Go to your corner.

Heavy Duty inline outlets will be installed today.

The take away here is simple: Start at Grand Coulee and work your way toward the toaster, one stretch of wire at a time. Assume self-tests are all ISIS- modified to screw with you.

Lesson 3. THE Best First Ham Radio Antenna

As you know, my friend Robin Landry who lives up in Shawnee, Oklahoma knows a great deal about electronics. No surprise, he was the “ears of the boat” in his Navy days, which is 40-years, or so under the keel.

Robin’s been nibbling at the Technician ham test training manual as time permits – he’s usually busy making money in the market.

As a little “incentive” I have a radio I’ll be giving him, too. A Yaesu 757 –GTCXii – which any ham will tell you is a great little HF rig. Great general coverage receiver, solid single sideband, and even a built-in keyer. We had one on our sailboat and never had a lick of trouble with it. This is a different one…our old one stayed with the boat.

He’ll love it – after he gets the ticket.

But here lately, I’ve been noodling the follow-on: What the heck kind of antenna to recommend so we can kick things around on 80-meters at night (when he upgrades to General class I’ll send him the mic).

For the longest time, I’ve been using a CCD antenna – which stands for continuous current distribution. And the one I have was made by a fellow named Dave, I think it was, in Arizona.

Ah…here’s the website: www.ccdantennas.com.

You will notice that they are no longer building their CCD antennas… Dave apparently couldn’t get the right wire. I have one of his dual band (40 and 80) meter antennas and it works great.

But now that mine is getting long in the tooth, I am looking around for a new antenna which would work for Robin up in Oklahoma, and which I could put up here, since there are a few compromises to a CCD compared with a conventional dipole.

The CCD is twice the length of a normal dipole. So instead of 60-feet either side of center for the 80 meter band, the CCD is more like 120 feet each side.

There is also a fine (long) technical discussion about the gain trade-offs.

The CCD capacitors that are in the antenna every three feet, or so, change the phase relationship between current and voltage on the antenna. So it’s quiet (like a loop) but there’s no free lunch. In return, it might be argued that each of the capacitors (there’s something like 20 per side) results in a slight reduction of radiated power, though little impact on receive.

Bonus, though: The CCD works very well down close to the ground, while a dipole does not. With them, the higher the better.

(Someone put a hand up? Length of a half wave dipole is 468/ frequency in MHz. So for 3.75 MHz – the middle of the 80 meter band – the half wave dipole would be 124,8 feet or half that on either side of the center feed point. Am I going too fast for you? 62.4 feet of wire each way from the insulator in the middle which is the feed point.)

BUT we also know that inverted vee antennas, which are nothing more than dipoles with a high center that slope down to the ends at something like a 45 degree angle, are great for some applications, though we’ll skip the horizontal versus vertical polarized pattern development for another time. I coulf pour near-field plots all over the breakfast table if I don’t contain myself. Antenna design and stock charting are some of the finest brain uses I have found. One makes, the other spends, but that’s how balance is maintained in the Universe.

Where that leaves me is looking for a good ham antenna to recommend to Landry – and which I can buy for myself in the process.

Probably, one of the best dipoles for the money I’ve seen is the RadioWavzs Saturn 5-80 (specs) which is a fan dipole (several dipoles with a common feed point) so it will cover most of the major ham bands. $229 from the manufacturer or $170’ish from www.gigaparts.com, but notice that they have a long delivery time – there’s always a trade-off.

While I advocate young hams build their own antennas, sometimes after you’ve built every antenna in the book, you just want to save your energy for welding on the tower and other chores…so you just buy the damn antenna and move on.

For coaxial cable, Times LMR-400, or better. See www.thewireman.com and get their book, too. Must have for serious antennification. They will make up custom cables for you, too, so if like me, you just want to order 160-feet of LMR-400 coax, they will deliver it – and sealants and line and pulleys and whatever floats your antenna in the sky – so you can skip the messing around that is enjoyable, but a time sink. Get right to the install and tuning. I pay more and buy time for what I enjoy most.

The RadioWavz is likely the one I will recommend Robin take a hard look at.

BUT before you go out spending money on ham antennas, there’s something else to do first….

Lesson 4. Noise Hunting

I keep forgeting to tell Robin this, but I will email him this morning’s column…but this applies to you, too.

Get a cheap shortwave receiver (I recommend the Tecsun 660 or similar). Then tune around on the shortwave bands a bit in the evening.

If you can’t hear anything far away (radio Havana, for example) and all you hear is computer noise, then your first hobby will be hunting down the source of RFI – radio frequency interference.

It is not too hard to get rid of, but you may end up making an investment in RFI beads. These are doughnuts of iron powder (ferriter) that clamp on AC power cords to things like noisy computers (power supply going out?), monitors (notoriously noisy, try some beads on the video cable which may help). Even respectable things – like our big MPPT charge controllers on the grid-tied solar. Why these? Well, MMPT controllers are a kind of buck-boost converter that will take what comes off the panels, high or low, and correct the voltage to feed the battery banks.

Except, hold it: No free lunch – one of the fatal truisms of electronics.

MMPT controllers can generate a fair bit of switching noise. So I went crazy on power filtering here a while back, the best I could get for a noise floor on a sunny day with the charge controllers running was about -110 dbm (our Rohde & Schwarz SYM-01 signal generator is in calibration, so we trust it to be so, jahwohl).

Since throwing in ferrite beads, we are now able to get down to -129 dbm on the 20 meter band and a bit less on 15 meters.

Here again, however, we offer the same advice to all: Test the radio environment to find all the snakes before you fork out a ton of money on equipment.

Can ham radio get expensive? Oh, not as bad as a horror-story divorce, but…

I would love to have a new Icom 7800, but as a practical matter, our Kenwood 590S is very sensitive down past my noise floor, so other than bragging rights…what’s the point? I mean they are $13,000 and change.

Same thing with antennas.

You can spend umpteen zillions on antennas. I know people with huge wide-spaced beam antennas on monster towers. 200 feet and 12 elements and…But I have as much fun with 60 feet of tower and three elements. Besides that leaves the other $10K to invest eye drops, ham radio parts, studio doo-dads, tools for the shop, airplane maintenance, or to play with in the market.

The definitive place to find out how good a particular piece of ham gear is might be www.eham.net where you can find reviews on almost anything, including the radio I’ll be giving Robin. Same thing with that RadioWavz antenna, I’m looking at. Read review, take a grain of salt and only then open the wallet.

When you start crusing the Amateur Radio section of eBay, eHam is like a buyer’s guide. Just remember, YMMV.

Lesson 5. A Real Engineering Problem

I can here the already licensed hams screaming “Where’s the beef?” So for them.,..

HR-10 receiver revamp.

This is a radio my life-long bud from Gig Harbor built as a kid back in 1964,

I picked one up for him off eBay to tinker with down here (which he really enjoyed – that and the Rohde…).

But the receiver is prone to changing frequency of both the local oscillator and the BFO as the RF gain is moved.

Solution: Rip out the 6X4 rectifier, install silicon diodes, new filter cap from www.hayseedhamfest.com (which I can’t say enough good things about – they had a replacement cap and discretes for by Hallicrafters SX-117 off the shelf), and then install an OA2 +150 V regulator tube in its place to stabilize the HV supply.

Refer to the following schematic:

image

Class Problem: Connect the OA2 at the indicated location.  Junction of R43, R44 and C56.  Drawing scrawled by hopeless idiot. 

Question 1: New resistance value of the 1300 ohm 10W dropping resistor (R44) to achieve 150 volts instead of 125 is what value and wattage?  Show power calculations and margin of safety if you use the 10 watt cop=out.

Question 2: Change the value of the dropping resistor (R43) that goes to the last filter cap section to what value? (Hint, it only supplies power to the audio amp).

Question 3:  George figures a 1K replacement for R44 and changes out R43 to 56K after an all-night bender.  How much, and what type, of smoke will be released?

Homework due by noon today.

Looking ahead:

My buddy Gaye over at www.backdoorsurvival.com has an article coming up on why you should learn Morse code. Hmmm…how would I know that?

Remember, if you have a technician class license, you can run CW (Morse) on 80, 40, and 15-meters. You too can become a digital human.

(Whew! Longwinded…)

Weird Dreams, Anyone?

Well, it must be the full moon..which is when I seem to have the best vivid dreams.

This latest one is worth keeping an eye out for in the headlines.

I was a worker in some kind of large mine – many side shafts off the main tunnel. The scene was brightly lit and all white.

We were taking turns working – about 10 minutes at a time because of dust that was quite chalky.

On the other side of a collapsed part of the tunnel were 10-20 men and they were digging for diamonds. They all had this crazy look in the eye.

Does it have any precognitive value? Who the hell knows. But it’s an entry in the dream journal that’s worth noticing…

Write when you get rich (or work 100 countries on 160 meters which may be a lot harder)

George@ure.net

Comments

Coping: The Prepper’s E.E. Lecture — 12 Comments

  1. This might interest you.

    ‘Sound City’ Reviewed: Much More Than A Film About A Mixing Board

    http://kroq.cbslocal.com/2013/02/05/sound-city-reviewed-much-more-than-a-film-about-a-mixing-board/

    It’s about a custom neve mixing board in a studio that recorded a lot of famous bands Fleetwood Mac being one. Dave Grohl of Nirvana fame bought it and made a movie about the board and all the stars that recorded on it. I saw an interview with Dave Grohl and he made it sound interesting.

  2. Read where they say you should not learn Morse Code visually. So is learning only by audio, similar to learning a foreign language, the only way even if one is a visual learner? If that is true learn to Copy before Xmitting? Suggestions?
    This is asked by a 70 year old who wants to learn something new. Thank you!

    {mm}

  3. THE SMOKE THEORY OF ELECTRONICS:
    Every electronic component is packed full of smoke when manufactured. If you do something that lets the smoke get out, the component stops working.

  4. George,
    I use a MFJ-1778 G5RV antenna for my HF radio. I have no complaints using this type of antenna and have talked all over the world. It covers 10-160 meters and is 102ft total length. IMO this would be an excellent first antenna for your friend for when he ventures into HF.

  5. 1974 University Physics class. Not allowed ‘lookup tables’, we were required to do trig functions on a sliderule, OR…(we had a progressive teacher) one of the new H-P 35 LED calculators that did trig functions and no one could afford. I had a fulltime job and money, so I drove 100 miles to the nearest big city to get my H-P 35 and never needed to learn to use slipsticks. I was the envy of my class the first semester, before the TI-151 came out second semester at half the price! H-P 35 was a classic, with reverse polish notation for calculating ‘stacks’ of complex equations. I sold it to a collector on ebay a few years back.

    • How much did you sell it for? I have 4 that I found in my Dad’s things after he passed WITH the manuals.

  6. MISSING INFO! How much current does the following stage draw from this power supply?? Hard to do the ‘smoke calcs’ when you don’t know what it is supposed to draw.

    • This is where I will reveal the engineering process.
      If you have the voltage measurement and the resistances (see r44 and r43) ou can infer current rather accurately.
      Once you have current (I) you can solve for P (power) and then apply power and current to figure resistance.
      Now that you’re a happily retired you can get a good antenna up on 20 and I share more problems to solve, lol.
      Seeing the way to solve it took me a minute. And since I didn’t have a big collection of 10 W power resistors, I used this as an excurse to get a whole kit of NTE 10 waters in their RK-07 kit from amazon… but I had 2 10 watt 2K’s so these will parallel and we’ll change the small resistor up and see if it smokes.

  7. George,
    I just bought a Buckmaster OCF Dipole. It works great! 90 ft on one leg and 45 ft on the other. Center height is 45 ft in an inverted eve installation. Worth a look

  8. My uncle, a very humble man with a 3rd grade education worked as a carpenter in the coal mines. He got a call from Port of Seattle, I believe, when he was in his 80’s to come help them with heavy timber work on the docks. All their engineers were trying to figure out what it would take to fix those old piers, my uncle figured it out for them on a lunch sack and went home. I think he was very pleased with himself.

  9. I’m not active in Ham Radio anymore but still have my rig (Yaesu FT901). I used to use a 60 ft (+-) sloper antenna for working DX on 80 meters. Feed point was about 30 foot up on my tower with the lower end about 10 foot off the ground. I could move the tip to which ever path I wanted to work. Mostly to the east for Europe and Africa, but also some Japanese and Russian stations too.