RF Explorer - 15-2700MHz Spectrum Anakyzer $269

I added some more photos.

I'm having nightmares where everything I touch either rusts or falls apart.

No. I have a system that works. Cardboard boxes last just long enough to finish such a project. I throw everything I might need into various boxes in random order, and fill up the Subaru until no more will safely fit. The rest goes on the roof rack. The system works because the most recently used items end up on top of the pile, while the least recently used items end up on the bottom. See garbage collection algorithm for details.

The 3m dish only took about 30 minutes to align. On the 4m dish, both the elevation and azimuth would be trivial were it not for:

1. The home made LMB mount that is aparently off axis.
2. The collection of dead LMB's.
3. The small the signifcant difference in mounting frame size between the old and new 4m dishes.
4. The large amount of brute force required to rotate the rusty bolts.
5. The lack of fine grain granularity in elevation from the Come-Along adjuster.
6. The massive weight of the azimuth adjuster.
7. The lack of usable distant references due to the proximity of the shore line, and the offshore fog.
8. The surplus of great ideas.
9. The inability to test reception without taking a receiver offline.

The basic problem is that I've been assuming that the frame behind the dish is perpendicular to line towards the bird. Due to the home made LMB mount, this is apparently not the case. I will need to identify one of the satellites heard, calculate the error, and compensate the target values.

DBS dishes (DirecTV and Dish) are easy. Make sure the mounting j-pipe is exactly vertical. Set the elevation marked on the dish mount. Swing around the azimuth until the meter shows a signal. Tweak for peak. It takes me maybe 15 minutes at worst. However, this monster has no vertical pipe, no boresigt, no convenient elevation markers, and weighs 200+ kg. Such things do not scale gracefully.

See: Three of the dishes are all pointed at the same bird. Note the shadows. Compare with a similar photo showing the right 4m dish after the move, which is obviously not aimed correctly.

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

On a sunny day (Sat, 02 Nov 2013 13:56:33 -0700) it happened miso wrote in :

Well you can make things as complicated as you want,

It is just a rotor, but the mounting shaft, the part that moves, is like this:

/ |

So if the dish moves sideways it also tilts, exactly following the horizon.

• * * * * * . * sats . .

• * \|/ dish positioner

I made a better drawing here, the horizon is the dots.

That system, with the 'bended' shaft, is all you need to exactly point to geo stationary sats with only one motor.

Quite honestly I have no idea why people use those insane big dishes in the US. Either your sats are kaput, weaklings, or you are not looking at geo stationary ones. There is plenty of info on the web, and I am sure you know it because we have discussed this before.

Setting the Motec up using xdipo takes about 10 minutes, no need for any fancy tools. Only requirement is that you can point south.

Mine is SPECTRAN® HF-60100 V4

Mine is for hobby and for searching free WLAN channels.

How should I say this, for a trip to a mountain top, the price of equipment and job should go hand in hand. But even HP can fail or be inadequate, too heavy or simply be too expensive.

Spray paint the boxes different bright colors. This helps identification and may also ease roadside discussions with the local police.

I know some people that even use them for changing oil on their car during a trip; remove the tools, drain oil into box, latch the lid (gasketed) closed so it doesn't leak, recycle oil when back in civilization. (It's an elderly car, so they usually carry enough fresh oil with them to do this.)

For some reason, ammo boxes are slightly easier to find around Army ammunition plants. The farm and ranch stores around Tulsa would often have a pallet of the smaller ones, and a guy along US 69 had the big ones for sale, all presumably coming from the plant in McAlester.

Matt Roberds

Some of my ammo boxes are so tight that I can't open them after going from high altitude to low altitude. We get our money's worth with those boxes.

I use the 7.62mm UN boxes. Big enough for many instruments. If you standardize on a size, you can get a flat surface when you load up the cargo area.

I've seen some home brew electronics built into boxes.

The big dishes are C-band legacy as far as I know. Most modern housing covenants pretty much ban them for home use.

But even HP can fail or be inadequate, too heavy or simply be too expensive.

You should be doing wifi site surveys with Kismet.

The lack of ventilation also seems to condense moisture inside. There's not much, but usually enough to rust or rot everything inside. Desiccant works, but is a maintenance problem. I've also added air valves to pressurize the box, but found that they eventually leak air.

So, I've switched to overpriced plastic ammo boxes (MTM dry box) for my first aid kit, bug out kit, APRS tracker, emergency ham radio kit, and junk boxes:

Ok, let's do the math. If I take about half the junk I threw into the back of my Subaru Forester, and repack them neatly into 7.62mm ammo boxes, I would need about at least 10 boxes at about 5 lbs each. That's 50 lbs of excess weight to drag around. No thanks. The plastic boxes are much lighter and somewhat bigger. Cardboard boxes are lighter, bigger, and much cheaper.

I wonder if they checked the ammo box speaker for resonances. Without internal damping, it's going to vibrate at some frequency.

Yep. I built a transmitter hunt radio (fox and hound) inside one in the 1960's. The lead acid battery was a problem. If I charged it with the lid closed, some of the corrosive electrolyte would vaporize and condense on the electronics. I eventually added a battery vent manifold with access to outside air, but by then, the radio had become totally unreliable from corrosion. My experience with marine radios also taught me that there are things to worry about before building something into a sealed enclosure.

Emergency comm radio, battery, and storage in ammo boxes:

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

Most of my HP test equipment is 30-40 years old, and working just fine. I wish I could say the same for some of my more recent purchases.

Kismet will not show non-802.11 sources. For example, it will not show interference caused by microwave ovens, 2.4 GHz FHSS (freq hopping spread spectrum) radios, 2.4GHz video cameras, cordless phones, Bluegoof, baby monitors, ZigBee 802.15.4, microwave fruit driers, 2.4GHz ham radio, RF lighting, etc. It's also difficult to do direction finding with Kismet.

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

Ah, but if the ride is rough, the ammo box will protect the gear better. Not as good as as those "rotomolded" transit boxes, but cheaper.

Incidentally a sealed battery should not be a corrosion problem. You find them in NEMA installations.

Now a sealed box without desiccant can be an issue.

Absolutely true. You need kismet plus a spectrum analyzer to be complete.

You can kind of direction find with kismet if you lock on a WAP and note where it can be received.

No, just recalling the fate of an HP 8662A I bought on eBay a few years ago as a counterexample to your novel "UPS never screws up" conjecture. It sh owed up with a hole going all the way through one corner of the package. T he same thing could've happened to the dishes.

Sorry, not sure what you mean here.

-- john

Well, that's the advertised theory. VRLA (valve regulated lead acid) batteries, also known as "sealed" batteries, have been around since the mid 1970's. They weren't available for my initial construction, but I've used them later. However, I was suspicious of the claims and decided to run a test. This was for a solar powered repeater in a NEMA something box. I put the battery inside a plastic bag and let it charge. I didn't care about hydrogen outgassing, but was worried about vaporized electrolyte. Sure enough, there was some condensed "fog" on the inside of the bag. I replaced the bag and added some baking soda into the bottom of the bag. If there was any acid in the bag, the baking soda should foam and inflate the bag. There was quite a bit of inflation, but nothing spectacular. I few measurements later, I found that the battery was being charged fairly close to the

100% charge limit. When I backed it down to about 85% of full charge, the outgassing ceased. Bottom line is that VRLA batteries only outgass when overcharged or charged close to 100%.

I think you can get away with it if you don't overcharge or just put the battery in a plastic bag.

I've built a few weather stations and wi-fi repeaters/AP's inside various NEMA enclosures. If there's a battery, it's either external, or there is a separate ventilated partition inside the NEMA enclosure.

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

Lefties always know more about *any* subject than you do, particularly if that subject includes your life. In this case, "miso" knows how you packed the package better than you *AND* knows how it was handled.