Tuesday, February 24, 2009

Knoppix

A good place to start with Linux (I hope) is www.knoppix.net . I have started with the Dummies Book and, so far, successfully ran the program on my pc and laptop. Next in line are learning some of the commands and using the ton of software on my DVD that came with the book.

First things first, I guess. I am comfortable with the line command mode called CLI but learning the Linux commands may take a while. My first challenge will be to get Knoppix to recognize my wireless network on my laptop and on my desktop.

Should be interesting ....

Saturday, February 21, 2009

Daylight Savings Time - March 8!

In 2009, daylight time begins on March 8 and ends on November 1.

Short Wave Listening

Buy a copy of Monitoring Times every so often. Interesting articles, but also has a Shortwave Guide that shows you what is available every hour ... a real bargain!

Voice of Russia AM Radio Broadcast at 7.335. Very strong S7 signal around 10 pm CST. English News program at 11 pm (0500 Z)

Radio Havana Cuba English AM Broadcast News on 6.000 at 11 pm CST. Signal about S7 with QSB.

China Radio Int'l English AM Broadcast News on 6.190 at 11 pm CST. Sig abt s9!

Wednesday, February 18, 2009

40M To Get Better After Mar 29


7100-7200 kHz shortwave broadcasts to cease (Link)

For many years the portion of the band from 7100-7300 kilohertz has been allocated to short wave broadcasters outside the Americas and not available to radio amateurs outside ITU Region 2. At the World Radio Conference WRC-03 in 2003 it was agreed that the broadcast stations would move out of the section 7100–7200 kilohertz on 29 March 2009 and that portion would become a worldwide exclusive amateur allocation afterwards


From Shortwave Central blog ... AR

Sunday, February 15, 2009

IRLP to South Texas Repeater

This afternoon, I was able to chat with Don, K5OKB at his winter QTH near Harlingen, TX. After I let him know we had access to IRLP here in BA (Thanks Kevin!) then he sent me the repeater near him. I punched in the codes today and we had a nice QSO. He was a little "scratchy" coming back to me, but could be my mobile speaker(?). He said my audio was clear coming through at his end.

Don is the President of the Bartlesville ARC and he said he has been in regular contact with the other club officers via IRLP.

I am definitely impressed with the IRLP-enhanced mode of radio communication...AR

Friday, February 13, 2009

Thanks to Scott and Mac

Just wanted to thank Scott and Mac for their support on this blog ... it is appreciated! Since I am learning as I go, I hope it will be worthwhile. And I am open to any suggestions you may have ... AR

An SWR Meter is a Dangerous Thing!

The Feb 2009 issue of QST has an article titled "Keeping Current with Antenna Performance". This article gives a whole new perspective on using an RF Ammeter to determine if your system is resonant. This article states "An SWR meter is a dangerous thing in the wrong hands." It continues, "Many assumptions have to be made (not always valid ones) when one uses low SWR readings as an indication of maximum radiated antenna power".

That sort of catches your attention, doesn't it? It sure did mine. Now bear in mind, I am intrigued by this article but I'll need to do some pondering to absorb what is being said here. It seems simple enough and I'm trying to capture the main things that struck me in the article for this blog. Hopefully, you'll follow up and read the whole thing!

The author Eric Nichols, KL7AJ, points out "That is why in the broadcast industry the FCC has always required the direct power measurement technique for determining transmitted power. This is done by measuring radio frequency current at the antenna feed point, where the feed point resistance is known."

The key quote, for me anyway, is:
"For any given antenna -- that's an antenna with a fixed radiation resistance -- maximum current always results in maximum radiated power."

In the article, two homebrew devices are outlined to measure relative current and assist us with getting maximum current indication for our antenna / transmitter / feedline. (The RF ammeter must be placed somewhere along the feedline, i.e. after the tuner in the system.)

This article is too good to miss. More to come as I dig it out ... AR

SWR Readings

The following comment was from the http://tulsatechnet.blogspot.com . I responded to a question posted there. There is probably a better way to handle this, but I'm learning about blogging. The reason I am re-posting it here is for an introduction to the topic.

The following answers refer to using an SWR meter with "cross needles" to tune:

1. The SWR reading is where the needles cross.
2. The forward power is the amount of RF measured going to the antenna.

3. The reflected power is the amount of RF being sent back toward the meter - reflected.
4. Set the forward power as high as you can get it and the reflected power as low as you can get it. Normally, what increases forward power reduces the reflected power, so the needles should work together to achieve this. When reflected power is at "zero" the forward power should be your xmtr power.
5. I don't have an amp, but I never tune my xmtr at full power (100 watts). My suggestion would be to tune at low power (25 watts maybe) then retest at 100 watts. After that you can safely bring your amp into the mix.
6. Make some notes of the settings needed on your favorite frequencies and you can dial right in. With some experience, you will be able to tune up without a big hassle.

73, Gene(AE5FT)


Thursday, February 12, 2009

ARRL Membership?

NEW! QST Archive for Members Only - ARRL Members can access the QST magazine archive online, from December 1915 through December 2005. Archive results are intended for personal use only, and may not be freely distributed or copied.
=============================================
I copied the above from the ARRL website. Talk about a Benefit! This information alone is worth joining the ARRL. But you also get a monthly QST magazine subscription plus your membership in the organization. I think its a good deal.

Lots of people will rag on the ARRL for what they do or what they don't do. Well, I don't agree with some of the things they support either. But I left amateur radio about 30 plus years ago and then came back to it. I found out the ARRL had been there all that time watching out for hams and their best interests. Ham radio could have gone away and I would not have known it. So maybe I just appreciate the fact they looked after this hobby while I was busy doing other things.

When I came back, I found the ARRL was still sending code practice four times a day for five days a week. I started listening to their broadcast to regain my lost CW skills. It was still there! They had kept things going and I guess I appreciate that.

Amateur Radio operators are a tough sell. I doubt any one group can appeal to some of us. It is a wonder the ARRL is still around. But it and Amateur Radio are still going. So put whatever "wrongs" you see behind you and support this organization. I still think this is a good deal - for everyone....AR

Wednesday, February 11, 2009

First QSO on IRLP

Just had my first IRLP contact this evening. I tried the two Bartlesville links but no one was listening or was not brave enough to answer. I'll try those again sometime soon.

I linked (IRLPed?) with the OKC machine node #3761 and gave a shout. I must admit I was a little surprised when Mike, KE5EQD answered me. He was on his way to work and said he monitored the machine frequently. This is sponsored by the Aeronautical Aviation Center ARS (W5PAA) but he thought the repeater itself was near the Baptist Hospital. Someone more familiar with OKC might know where that is.

I am having a little trouble with terminology on this new (to me) mode as to what to call things - node, link, repeater, reflector or what. I'm sure I'll learn it all as I go. Kevin can probably help clear some of this up.

While I realize you can talk world-wide on this connection, I wanted to start a little closer to home so I would have some idea of who, what, when and where I was talking.

Pretty amazing! ... AR

Tuesday, February 10, 2009

IRLP Link by KD5RHF

Kevin's IRLP link works great! So far, I have only tried the reflector 9991, but it worked as advertised. Once I entered the DTMF code 9991, I received the confirmation message from RHF's node #3487. The 9991 reflector repeats what it has received. I then transmitted "AE5FT Testing" and after a short pause, the reflector repeated what I had said. I tried a couple of other short messages and then entered DTMF code 73. The link confirmed it was de-linked. I realize this is an humble beginning, but I'll get up my nerve and try out one of the other reflectors on the IRLP website at http://status.irlp.net/ .

According to my search on this web site, Kevin's is the only IRLP link in the Tulsa area. Good job, Kevin!

I'll be adding to this post as my IRLP confidence grows .... AR

Monday, February 09, 2009

Atomic Clocks Aren't

The wonderful "always correct" clocks (and watches) we enjoy today are actually radio wave receivers tuned into station WWV, the standard time reference for the United States. The radio wave broadcasts are based on atomic time standards, but our clocks are not atomic - just radio receivers.

Tune your HF rig or SWL receiver to 5. MHz or 10. MHz and you will hear the WWV broadcast. It is very interesting to hear the beacon and watch your "atomic" clock be in sync with each other.

Canada has the CHU broadcast which just recently changed frequency. For seventy years the Canadian time standard was on 7.335 MHz but as of Jan 1, 2009, the National Research Council of Canada shifted their 40 meter signal to 7.850 MHz. The CHU also broadcasts on 3.330 MHz and 14.670 MHz.

After my original post (above) I started wondering how these clocks had a good enough antenna inside a very small appliance to pick up these signals. Well it turns out there's a whole different broadcast station that is picked up by our clocks ....

Here's a quote from http://tf.nist.gov/stations/radioclocks.htm

In the United States, the signals received by radio controlled clocks originate from NIST Radio Station WWVB, which is located near Fort Collins, Colorado. WWVB broadcasts on a frequency of 60 kHz. Your radio controlled clock actually has a miniature radio receiver inside, which is permanently tuned to receive the 60 kHz signal.

The 60 kHz signal is located in a part of the radio spectrum called LF, which stands for low frequency. This is an appropriate name, because the FM radio and TV broadcasts that we are accustomed to listening to use frequencies thousands of times higher. The lowest frequency received by any of the other radios in your house is probably 530 kHz, the bottom of the AM broadcast band. Even that frequency is nearly 10 times higher than the WWVB signal.

At 60 kHz, there isn’t enough room on the signal (bandwidth) to carry a voice or any type of audio information. Instead, all that is sent is a code, which consists of a series of binary digits, or bits, which have only two possible values (0 or 1). These bits are generated at WWVB by raising and lowering the power of the signal. They are sent at a very slow rate of 1 bit per second, and it takes a full minute to send a complete time code, or a message that tells the clock the current date and time. When you turn a radio controlled clock on, it will probably miss the first time code, so it usually takes more than one minute to set itself (sometimes 5 minutes or longer) depending on the signal quality and the receiver design.

Once your radio controlled clock has decoded the signal from WWVB, it will synchronize its own clock to the message received by radio. Before it does so, it applies a time zone correction, based on the time zone setting that you supplied. The time broadcast by WWVB is Coordinated Universal Time (UTC), or the time kept at the Prime Meridian that passes through Greenwich, England. While a few users like their clocks to display UTC (ham radio operators, for example), most prefer to display local time. This means that the time in your area is corrected by the number of hours shown in the table [ -6 hrs for CST].

Once your radio controlled clock has synchronized, it won’t decode the signal from WWVB again for a while. Some clocks only decode the signal once per day, others do it more often (like every 4 hours or every 6 hours). Those that decode the signal just once per day usually do it at night, since the signal from WWVB is much stronger once the sun goes down. In between synchronizations, the clocks keep time using their quartz crystal oscillators. A typical quartz crystal found in a radio controlled clock can probably keep time to within 1 second for a few days or longer. Therefore, you shouldn’t notice any error when you look at your clock display, since it will appear to be on the right second, even though it has probably gained or lost a fraction of a second since the last synchronization.

These [coverage] maps [on the above website] are based on a field strength of 100 microvolts per meter, which in theory should be a large enough signal for most receivers to work with. In fact, some receivers have much better sensitivity (20 or 30 microvolts per meter). However, simply having a large signal doesn't mean that the receiver will work. What really matters is the signal-to-noise ratio, or the size of the signal compared to the size of the electrical noise near the same frequency. Raising the noise level is just as harmful as reducing the signal level. For example, if the radio controlled clock is near a source of interference (like a computer monitor) the noise level will increase, and the clock might not be able to synchronize. If the radio controlled clock is in a building with a metal roof, much of the signal will be blocked. Therefore, the signal level will be reduced, and the clock might not be able to synchronize.

End Quote

The antenna dilemma becomes more intriguing, tho. But, since everything works, the LF of 60 kHz seems to work very well at low power with the internal antennas in the clocks across North America. Meanwhile, I'm listening to WWV using a 40 meter dipole up about 20 feet! ... AR


What the "de"?

I've given a lot of thought to naming this blog and I've gone back and forth on a couple of things. I started out with "Amateur Radio" then "Ramblings" just sort of seemed appropriate as a catch-all category. After that I thought, well, it is close to ARRL, so I'll make it "Lessons".

I liked the ARRL (apologies to the real ARRL) but I thought Lessons was too formal because that meant each post would teach someone something. I decided that was too much pressure, so I changed it to "Lectures". A lecture meant I could say what was on my mind without guaranteeing any one they would learn anything .... Amateur Radio Rambling Lectures is what stuck.

It didn't seem complete, though, so after some thought, I added "de AE5FT". Okay, that's it. The blog has a name and maybe a personality will develop as it grows.

But, maybe not every one knows what "de" means. It could be "duh" or "doh", I guess, for the Homer Simpson groupies. The "de" means FROM and is a common practice used in CW QSOs. Whenever a participant in a CW QSO signs over to the other station they give the other station's call followed by "DE" - dah dit dit pause dit - then their own call sign followed by "K" - dah dit dah - meaning OVER. At that point the other station takes over and makes their comments.

That's the very short history of the ARRL de AE5FT blog name.... AR

And thanks to KD5NJR for his suggestion on the blog name ... I've adopted the colon into the name!