Tuesday, November 30, 2010

Lesson 14: General Class Exam Course G3C

Here is the 14th lesson in the General Class series.  This lesson covers the G3C questions and ionosphere propagation.  Nothing too earth shattering to remember in this lesson.  A few things to reflect on, though.

The order of the ionospheric layers which impact propagation, and which you need to know for the exam, from lowest to highest are the D, E, F1 and F2 layers.  The D layer only exists during daylight hours.  As the sun goes down, the D layer disappears.  This is important to know because the D layer will absorb most signals below 10 MHz.  This limits daytime propagation for the lower HF frequencies to ground wave propagation only.

The F2 layer is the highest layer of the ionosphere which impact signal propagation.  Because it is the highest layer, signal which are bounced off of it tend to reach the farthest distances on the earth's surface.

Hope you enjoy the lesson! 


Sunday, November 28, 2010

Lesson 13: General Class Exam Course G3B

Here is the 13th lesson in the General Class License series.  This lesson primarily deals with Maximum Usable Frequency (MUF), Lowest Usable Frequency (LUF), and ionospheric skip.  One of the thrills of the HF bands is that you regularly have the ability to send you signals all over the globe via bounces off various layers of the ionosphere.  This lesson provides some parameters to those skip conditions.

For the purposes of he exam, the MUF and LUF are describing the condition of the ionosphere and how capable it is to bending signals back to earth.  The MUF is the maximum usable frequency that will support communications between two points.  The LUF is the lowest usable frequency that will support communications between two points.  For the questions on the exam, the LUF and MUF are dealing with the HF bands as well as the 6m band.  The closer you are transmitting to the MUF without going over, the better your signal will propagate.  As you decrease in frequency below the MUF, the skip distance becomes less and less.  If you transmit below the LUF, your signal gets absorbed by the ionosphere.

Though the MUF and LUF may seem like opposites, it is possible for the LUF to be a higher frequency than the MUF.  When this happens, all long distance HF propagation is for the most part shut down.

The two numbers (or distances, rather) that you need to memorize are:

-The average distance on the earths surface for a signal skipped off the F2 layer of the ionosphere is 2,500 miles.
-The average distance on the earths surface for a signal skipped off the E layer of the ionosphere is 1,200 miles.

And that's about it.  Please feel free to leave any comments, suggestions, or questions you may have in the comments box below.  Thanks!


Friday, November 26, 2010

Lesson 12: General Class Exam Course G3A

This is lesson 12 and the G3A questions.  Here we are dealing with sunspots and geomagnetic disturbances as well as there impact on radio wave propagation.  Especially in dealing with HF frequencies, the solar cycle and the rest of the sun's behavior has a big impact on propagation, both good and bad.  It is part of the environment that you will need a fairly good understanding of if you are hoping work the HF frequencies.  The lesson is fairly straight forward, but there are a few things you will need to know.

-The average sunspot cycle is 11 years.
-The sun's rotation is 27 days long.  If you are having good propagation on 10m, then you might need to wait until the sun does a complete rotation before you find that sweet spot again.
-It takes 8 minutes for X-ray and ultraviolet radiation to reach the earth from the sun.
-It takes 20-40 hours for the impact of charged particles expelled by coronal Mass ejections to impact the earth's magnetic field.  These are carried in the solar winds.
-Sunspots are good for HF propagation especially above 20 MHz.
-Geomagnetic disturbances are bad for HF propagation, especially in regions closer to the poles where you can usually see the northern and southern lights.  This does not necessarily mean they are bad for VHF propagation.
-The K-index in a short term prediction of the stability of the earth's magnetic field.
-The A-index is a long term prediction of the stability of the earth's magnetic field.

Focus on the above and this lesson will be easy.


Wednesday, November 24, 2010

Lesson 11: General Class Exam Course G2F

Welcome back!  Here is lesson 11 covering the G2F questions and Morse Code procedures.  CW is a fun way of communicating that is easier than you think to learn and really opens up a lot of possibilities in Ham Radio.  If you have the opportunity, I highly suggest you learn it.  This lesson is fairly straight forward, but there are some Q signals and prosigns you'll need to memorize.  They are:

Q signals:
     QRS   Send slower
     QRQ  Send faster
     QSL   I acknowledge receipt
     QRV  I am ready to receive messages

     AR    End of formal message
     KN   Listening for a specific station or stations
     CL    Closing station

A 'C' in an RST report means you have a chirpy or unstable signal.

That's all the hard stuff for lesson 11.  If you have any comments, suggestions, or questions please leave them in the comment box.  Until lesson 12...


Lesson 10: General Class Exam Course G2E

Here is lesson 10!  Lesson 10 covers the G2E questions dealing with data modes.  There is a bit that you may want to memorize.  There is a great deal on RTTY and data bits that most Hams may not be familiar with, especially if you're not computer savvy.  That information you need to know for the exam is as follows:

-The mode for AFSK RTTY is most often LSB
-RTTY uses a 5 bit code with additional start and stop bits
-RTTY frequency shift (FSK) in HF is 170 Hz

-Routing and handling information contained in data packets are found in the header

-Frequecies where data is most often used:
     20m 14.070-14.100 MHz
     80m 3570-3600 MHz
     20m PSK is most often used ~14.070 MHz

As always, please leave any comments, suggestion or questions you may have.  Thanks!


Monday, November 22, 2010

Lesson 9: General Class Exam Course G2D

Here is lesson 9.  Lesson 9 covers the G2D questions, specifically the Amateur Auxiliary.  The Amateur Auxiliary are Amateur volunteers who are enlisted by the FCC to help ensure Part 97 compliance.  There are a lot of them and you'd be surprised how fast they can find you if you're coloring outside the lines.  Most often non-compliance is a mistake and you'll get a friendly warning, but have no doubt that the auxiliary can forward you straight to the FCC.  So be good.

Please feel free to leave any comments, suggestions, or questions in the comments box.  Until next time...


Lesson 8: General Class Exam Course G2C

Hello once again!  Here is lesson 8 which covers the G2C questions dealing with emergency communications.  This questions in this section are fairly straight forward.  There is a common theme in the questions: when dealing with an emergency...anything goes (almost).  If you are handling a true emergency dealing with immediate threat to human life or property, there is a lot of slack in the Part 97 rules to allow you to deal with the emergency in an as effective manner as possible.  You also want to keep communications as simple and to the point as possible. 

Feel free to leave any comments, suggestions, or questions in the comments box! 


Sunday, November 21, 2010

Lesson 7: General Class Exam Course G2B

Here is lesson 7 in the General Class exam series covering the G2B questions.  This lesson can basically be summed up as a lesson in Amateur Radio courtesy.  The use of band plans is gone over in detail.  For those not familiar with using a band plan, it is essentially a voluntary agreement between Amateurs to use certain segments of the radio spectrum for certain purposes.  For instance, PSK use on specific frequencies, calling frequencies, low power frequencies, etc. are part of a band plan. 

The questions are fairly straight forward, but there are a few that you will need to memorize.  These questions deal with how far away (frequency-wise) you need to be from another station transmitting in various modes to avoid causing interference. 

CW                            150-500Hz
SSB approx.               3 kHz
170 Hz shift RTTY      250-500 Hz

That's it.  If you have any comments, suggestions, or questions please leave them in the comment box.


Tuesday, November 16, 2010

Lesson 6: General Class Exam Course G2A

Here is lesson 6! This lesson goes over the G2A questions dealing with phone communication and HF voice modes. No real difficult memorization in this one, but there are a few questions whose phrasing is a bit tricky and can throw you off the correct answer. As always, if you have any comments, suggestions, or questions, please feel free to leave them in the comment box!


Monday, November 8, 2010

Lesson 5: General Class Exam Course G1E

Here is the Lesson 5 which covers the G1E questions.  The G1E questions primarily deal with Repeaters and third party traffic.  There are several questions in this lesson which I feel are a little vague and may be a little too in the weeds for regular use.  Other than that, this is a pretty easy lesson.  If you have any questions, comments, or suggestions, please feel free to leave them in the comments box!