Archive for September 2009

Antenna Rotator Problems

September 28, 2009

The big beam has been freewheeling for nearly a month. I finally cranked the thing down and took a look. Feedling is broken and the rotator sounds like it has marbles rolling around inside it.

The rotator is an Alliance HD-73. I had always thought it was much better than the CDE AR-22 but upon investigation the HD-73 can only handle a wind load of 10sq feet. Most ham rotators do 15sq feet or more.

Before the misshap I had trouble keeping the beam aligned to the rotator box indicator. At one time that problem was due to a missaligned gear that was driving the pot in the rotator. The HD-73 uses a potentiomemter inside the rotator to vary the voltage to a meter inside the control box. Well, this time the pot was just fine. The missalignment was due to the pipe mast slipping in the rotator coupling. So, I drilled a hole through the clamp and into the pipe. I threaded the hole in the pipe and screwed in a big bolt. Sucker would not slip anymore.

The HD-73 does not provide any sort of breaking to the mast other than the inertia of the geared motor mechanism. After the mast was not allowed to slip anymore, the force of t he wind stripped out the gears in the rotator. So much for avoiding slippage. I guess maybe the KT-34 was a little too much, or maybe the rotor was a little too light. There was no downward force on the rotor. A side saddle mount to the mast included a thrust bearing that bore the weight of the antenna.

So now that mast is tilted over and the beam removed, I can concentrate on repair.

I have a 50 foot tilt over. The tilting over part is drill stem pipe. The pipe is hinged at the 20 foot mark to a plate that is supported on the top of two sections of rohn tower. Been using that since the early 70’s of the last century.

Once I had the mast tilted over I tied it down so that if we did have storms there would not be any more damage. We did have storms but the only damage was due to my forgetting the mast was tied down before trying to raise it. I wondered why it took such a strain. Before I figured out what was going on, I ended up with a bent mast.

Tried to bend it back. No way that was going to work without risking pulling the tower sections out of the ground. So now I am having to engineed a way to remove the mast entirely so that I can cut the bent section out of the drill stem and weld it all back together after reinforcing the pipe above the 25 foot level.

The first 25 feet of pipe is 3 inch. The rest is 2.5 inch. It was 2.5 inch that bent.

Took a look at repairing the rotator. Found a fellow who does that. He also sells rotators. Wants close to 500 bucks for a new HD-73. Wants 60 bucks plus parts and shipping to repair a wrecked HD-73. That is shipping both ways and I figure one way was going to be around 20 bucks. So we are looking at 60+20+20+60(?) or more. Possibly close to 200 or better for repair.

Panasonic has a brand new rotator with twice the wind load capacity of the HD-73 for 300 bucks.

Unfotunately in this part of the country a wind load capacity of even 20 sq feet is inconsequential. We get storms with straight-line winds approaching. 90mph. God help you if you get brushed by a tornado. So it really does not matter that I ended up with a used AR-22. It will work. There is not downward force since the thrust bearing takes up the strain. And now I no longer pin the mast to the rotator so slippage is possible. What I really need is a very good braking mechanism to hold the pipe mast from turning in the wind. Of couse I know if I had that, It would just shell out the rotator when I froget to release the brake.

I have two old AR-22s. The AR-22s use two rows of ball bearings to support the rotating part against the non rotating part. But there are only six bearings on the top and six on the bottom. Those six are held spaced evenly around the perimeter by a band with spacers to keep the marbles in place.

The HD-73 had a full course of ball bearings top and bottom. I salvaged the balls out of the HD-73 and installed them in to one of the AR-22 rotators. The AR-22 with the extra balls will go on my auxilliary mast which will serve to hold a two meter beam and a multiband High frequency HF Moxon.

The remaining AR-22 will be used in the side saddle mount on the main tilt-over. It is going to be a 20 meter Moxon.

Both AR-22 rotators and their control boxes needed work. Both these rotators are four wire with really cheap screw connections in the base of the rotators. To prevent the screws coming loose with use, I decided to remove the screws entirely and solder the roator wire connections into the holes left by the screws.

As predictable the AC capacitors in both control boxes had aged ungracefully and need replacement. The replacement calls for a 120 to 150 mfd 50 volt AC capacitor. I did not have one of those. I did have a couple of 120mfds at 50 volt DC which when hooked back to beack. Minus to minus with the plus leads going to the old capacitor connections after the old capacitor is removed. That worked.

Caution, don’t install larger caps or caps of much smaller value. That will not work. I initially installed two 560mfd caps figuring that if 120mfd is good, 560 would be more good. Trouble was it was no good. I finally got the thing to work well by connecting a 120mfd and a 200mfd back to back.

Another thing that allows better preformance is clean and well lubringcated gear mechanisms inside the rotator. After cleaning and lubricating, both rotators functioned much better.

Off Site Backups

September 25, 2009

If your data has value, I mean real value, if it is worth something significant, if it would cost your serious money to restore it, or if it is not at all restorable, then (and only then) is off site backup justified.

Even when off site backup is justified, you need to re-examine the advisability of entrusting something SO valuable to people you don’t know or the pitfalls of sending something of value over the internet, round trip.

I find it somewhat dumb to send my important data to someone and pay them for the priviledge. Ever hear of identity theft?

I am not implying that off site backup services cannot be trusted but why do you want to trust someone you don’t know?

You would be better off giving your data to your neighbor for safe keeping.

If you don’t have any friends or neighbors you can always clone your hard drive and keep it ‘off site’ in a safe deposit box at a local bank.

Yes off site storage is needed if your data has serious value. For most of us it would be sufficient just to keep a cloned copy of the hard drive in a safe place in our home. Of couse, if your home were destroyed in a fire you would loose the original and backup hard drives together.

Doing your own off site backup is not as convenient as backing up off site electronically with the help of a backing up service but doing it yourself is most likely cheaper and far more secure.

When you can purchase a 400gig hard drive for under fifty dollars, you really can’t complain about backup costs.

Updates

September 25, 2009

If programmers knew how tiresome frequent updates were there would not be so many. Or would there.

Frequent updates indicate that the job of writing the software is an ongoing excercise. That nothing about it is ready for use. It needs constant fiddling to keep it running. That is not software. That is bull shit.

Before software is released it needs to be tested particularly if the creator expects to be paid.

An initial release of a software package needs to be judged on how many updates it receives in the first year of use. Each update will allow purchasers of the software a ten percent refund on the purchase price. At that rate some software producers would be out of business because they would have gone deep into debt just have their software still ‘out there’ annoying people.

I can understand an update a month or even a week especially on new software, but stuff that has been out there a while or nearly daily updates on new software are clear indications that these folk have lost it. They show they do not know what they are doing and we need to avoid using their junky product before it gets us into trouble.

I no longer use any form of windows or dos to access the internet. All forms and versions of these softwares have long since outworn their welcome. I still use them because I have applications that will not run under wine on Linux and others that will not run on Linux, using wine or anything else but I have turned off the automatic update feature, disabled the ethernet connection used under windows and even unplug the ethernet cable when using windows. This is my way of securing windows from unauthorized use. It eliminates any succeptability to security breaches and shields me from the constant barage of updates and validity checks.

Best of all it allows me to run without firewall or resource wasting virus checking software.

Nearly all my internet browsing is now done with a live CD running Puppy Linux.

Computer Summary

September 25, 2009

A summary of work done on the computers during September.

SATA card and driver: It is finally official now. The Siliconix SATA card will not work under XP without causing problems with explorer. The solution is not to use the SATA drives under XP. Do not install the Siliconix driver. The card is okay in the PCI slot, just don;t load the driver.

We can use the SATA drives under Debian or we can run the SATA drives extenally using the external USB cable interface that handles SATA, IDE 3.5, and IDE 2.5. It is a cheap cable interface with its own switching supply for the hard drive.

The Hitachi SATA drive remains installed in the computer and is the auxilliary storage for Debian. Mainly video files, movies.

The best media viewer is VLC. It works under XP and there is also a version for Debian.

We do have instructions on how to use dd to make an XP clone drive. We also have a drive duplicating utility for XP, Acronis. Acronis is easier to use but will only run under XP. That seems appropriate since it is the XP drive we wish to clone.

In the past we have swapped out drives for the cloning process. That is we install a second drive as a slave and run Acronis from the first master drive to clone it to the salve, then remove the slave, check it to make sure it works and is bootable, then put it away in a safe place.

Now we have a second drive installed as the second IDE controllers slave drive. We clone to it and leave it in the machine. We could boot off it using Grub. Which we do to make sure it is a good clone. But the main way we will be using it is as a source to a good XP system which can be used as a source to clone to the first primary drive when that drive should end up being trashed for whatever reason. The Acronis software will take any drive as source and clone to any drive as target.

The mpeg editing software we need is avidemux. Avidemux is available for XP, Debian, and OS-X. I have tried it on OS-X and it did not work. I tried it on XP. It worked, sort of. At least it seemed to work but I could not figure out how to use it.

The version for Debian has a broken package so it cannot be installed easily, but the bigger problem is figuring out how to use it. Looks like we are going to have to stay with XP and VideReDo for now.

While we are on the subject of non-working software, note that GnomeBaker cd/dvd writer created two dvds that did not read after they were created. Don’t use GnomeBaker. Remove it from the Debian system and check out all the other software that was loaded. Junk those programs that are redundant or do not work right.

The onboard (motherboard) USB ports do not work in high speed. Although Gigabyte provides high speed drivers, they do not work. So we added a secondary high speed USB PCI board and it does work. It has three ports. The internal port supports a four port hub that runs USB 2.0. The other two USB 2.0 ports come out the back. One goes to the USB-TV device. The other goes to the Venus T4U external drive box.

External USB stuff now works as it should with the new card. USB support for the internal ports has been deactivated in the bios.

Here, then, is the lineup for drives:

Internal to the Gigabyte computer:
First Master Drive hda1 (hd 0,0) XP 10gig IDE
First Slave Drive hdb1 (hd 1,0) Debian 90gig of a 300gig IDE
hdb2 (hd 1,1) Debian swap
hdb3 (hd 1,2) 90 gig NTFS windowsaux
hdb4 (hd 1,3) 90 gig free space
Second Master Drive hdc1 (hd 2,0) CD/DVD
Second Slave Drive hdd1 (hd 3,0) XP clone 10 gig IDE
First SATA Drive hsda1 ( ) Video storage 230 gig SATA

Externally we have the following:

WD passport drive USB 120gig mainly used as auxilliary on the iBook.

JACK drive USB (used to be firewire too but now does not work that way) 30gig uses an internal fan. noisey.

VENUS T4U drive enlosure USB. Room for four drives. Presenty has two 80gig drives intalled. One is the old iBOOk3. The other is the old FIREWIRE. Both drives have data that probably should be removed.

ThermalTake USB single 40 gig.

VOX 300gig USB, Firewire, and NSA. Has the storageS backup and the storageN backup.

External cable USB interface. This cable will interface to SATA, IDE 3.5 and IDE 2.5 drives. Has its own switching supply for powering the drives. Has a SATA power adapter to four pin molex.

Have gone back to the tray system of removable hard drives. Repaired the trays and housings. Have trays installed as Primary First Drives in Ham (supports the magic jack in the radio room), in Tower (an old 233mhz/98meg ram tower machine), and in Media (the XP/Debian Gigabyte 7XAP).

Also have a Dell machine and an iBook in the bedroom. Also have two Dells in the front room one of which is Mary’s work machine. The other is Michaels old P4 which needs work.

All machines can use any of the USB external drives. The Gigabyte and the iBook can also use firewire but that is not an advantage since firewire is the old 400 and USB 2.0 runs at 480..

Note that the only external drive capability that supports SATA is the cheap cable interface. Only the Dell in the bedroom supports SATA internally. Well, so does the Gigabyte in the front room but then only for Debian, not for XP.

At last count that brings us up to six active computers. We have desktop cases for six more and hardware to support most of them but they are all very old machines of the pentium I, II, and III variety. Hardly worth the effort to implement or restore.

Besides, we have only four additional monitors to support these other computers.

Posix Magic

September 23, 2009

Turns out it is very useful to know how to use the dd command in Linux.

The ‘dd’ command is a low level command line utility that allows reading and writing memory to screen, files, and other memory. It is useful in duplicating disks (partitions) by directly reading from one and writing to another. It can make backups of entire partitions by creating image files of the source partition. It applies to hard drives as well as floppy disks as well as any other storage media including tape drives and USB memory sticks.

Being a very powerful command line utility, dd can destroy a computer system in seconds if used improperly. There are no cautions included in this utility. Careful use is necessary and a full understanding of the command is a must.

More about dd at:

http://www.linuxquestions.org/linux/answers/Applications_GUI_Multimedia/How_To_Do_Eveything_With_DD

Linuxquestions.org has other useful answers. Answers to questions you might not even have thought to ask.

Debian boot disk problem

September 20, 2009

I knew it would happen if I screwed around with it long enough I would break it.

Messed up the boot disk. I have Debian 5.0 installed on the second hard drive in a 90 gig partition. Still have over 200gig left on that second drive that has no other paritions or software on it.

The first drive has XP.

I have been booting Debian off floppy because it is far more likely that I will have to re-install XP than have to mess with Debian. Since an XP re-install takes out the MBR, it makes no sense to put the Grub loader in the MBR where an XP re-installl can overwrite it. So, we depend on the boot disk to get to Debian.

Very simple, really. Boot order is floppy, cd, harddisk. If the floppy is inserted, Debian boots. Actually, Grub boots and the default is Debian. XP can be selected from the Grub loader too.

If we know in advance that XP is desired, all we need to do is pop the floppy out of the drive and reboot. That takes the system to the MBR of the first drive and XP boots normally like it would without all this nonsense.

This may not be the best way to do this but it works and I have gotten used to it.

While trying to make sure that I had a good spare Grub boot floppy, I ended up destroying the only copy I had.

There is all kinds of help on the web and specifically on Debian help sections explaining how to make a grub floppy, how to duplicate a grub floppy, how to use dd to do everything, how to use non-Debian CDs as rescue disks, everything leading to complicated proceedures and tricks when all that is needed is the original Debian 5.0 install CD.

Load the CD and boot from it. On the opening screen will be an option to choose ‘advanced’. Choose it and proceed as though installing Debian all over again. A very small and basic Debian system will be loaded to memory. When it gets to the partitioning option it will ask which partition contains the system you want to recover. Select that partition, then select re-install Grub.

When the Grub install screen comes up you can select where to install the Grub boot loader. I chose (fd0). Once that was done, I was taken back to the restore screen, selected install Grub again, and installed it to a spare floppy.

The entire process took all of two minutes. Mission accomplished and I am still wondering why none of the help on the web or Debian help sites recommended doing it this way. Perhaps they assumed you had already tried it the easy way without sucess. Perhaps they need help too.

California Bonds

September 18, 2009

The ads on the radio have been often and unrelenting. California is offering bonds to the tune of over 8 billion dollars!

Hey, maybe I should offer bonds of up to 1 biilion dollars.

Same difference, same backing, same investment opportunity.

California is paying its employees with IOUs. Its credit rating is non-existant. These are not junk bonds they are offering, these are toilet bonds!

I cannot believe that an organization that is essentially bankrupt is spending money it does not have on ads that will not deliver results.