Wednesday, October 20, 2010

Lesson 3: General Class Exam Course G1C

Here is lesson 3!  The G1C questions primarily go over power limitations, bandwidths, and baud rates.  There is a bit of memorization which goes into this lesson, but there are some things to keep in mind that will help you remember the numbers a little easier.

Here are the things you need to straight up memorize:

The maximum bandwidth for RTTY and data using unspecified code on 2m and 6m is 20 kHz.

The maximum bandwidth for USB communication on 60m is 2.8 kHz.

For the purposes of the exam, Ham operators on all HF/LF bands (10m - 160m) can use up to 1500W PEP output for transmissions.  There are two exceptions: 30m and 60m.  For the 30m question, you need to know that the 30m band extends from 10.1 to 10.150 MHz and you can only transmit up to 200W PEP output.  For any other question just providing the frequency, the answer is going to be 1500W.  For 60m you can only transmit up to 50W PEP output relative to a half-wave dipole.

For the questions on signal rate (baud) there is a bit of trick.  For all the baud questions on the exam, the same four possible answers are given: 300 baud, 1200 baud, 19.6 kilobaud, and 56 kilobaud.  56 kilobaud (the fastest possible answer) is an incorrect answer for all the baud questions so you can knock it out right away.  The way the rest break down is: HF bands below 10m (12m - 160m) use the slowest signal rate (300 baud); 10m is in the middle at 1200 baud; and the VHF bands (2m and 6m) are the fastest of the three categories at 19.6 kilobaud.   The higher the frequency, the faster the baud rate.  If you can remember that breakdown, you will get those right!

Please feel free to leave any comments, suggestions or questions in the comment box.

Until lesson 4...

73,
Andy
KE4GKP

3 comments:

  1. Your answer to G1C09 is incorrect, at least according to qrz.com and the Official Question Pool. 56 kilobaud is apparently allowed on 1.25m and 70cm bands:

    G1C09 (A) [97.305(c) and 97.307(f)(5)]
    What is the maximum symbol rate permitted for RTTY or data emission transmitted on the 1.25 meter and 70 centimeter bands
    A. 56 kilobaud
    B. 19.6 kilobaud
    C. 1200 baud
    D. 300 baud

    ReplyDelete
  2. Greg,
    You are correct. The General Class videos have not been updated with the July 1st changes so this question is a little outdated. I'm currently working on the updates which should be posted soon. Thanks and 73!

    -Andy

    ReplyDelete
  3. Thanks for doing these videos -- but just a warning for those viewing this lesson -- many of the questions are now using different bands so the answers are different...so basically, until these are updated, this particular lesson might not help as much as far as memorizing answers. Be sure to compare with the current question pool! There are only 11 questions in the question pool for this section now as well. This is NOT to criticize, since I'm very thankful that these are here, but just to inform other viewers of the changes.

    ReplyDelete