[DARARepeater] Thursday Night Group

[George]

Techfest next weekend - FEB 16 & 17

HF - UHF Antenna Analyzer UPDATE  

Projects

** License Exam Questions of the week

The Thursday Night Group will meet

Thursday, FEB 7 at 7:00 pm at the DARA Clubhouse.

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Things this week:  

 

1.        Techfest next weekend - FEB 16 & 17

TechFest 2019 at Sinclair. http://www.ascdayton.org/TechFest/   FEB 16 & 17.
Plan on helping with the kids building radios!!

2.        HF - UHF Antenna Analyzer UPDATE  

Phil is working on the software to match the new board

3.        ** License Exam Questions of the week

One question is drawn from each of the three question pools. Steve, AE8AT,
is providing these questions.  Thanks Steve

 

Answers are at the end of this email.

 

We received a question regarding the strange mix of letters and numbers that
begin each question.  Every exam question has a unique combination of
letter-number-letter-number.  The first letter is a T, G, or E to identify
the question pool: Technician, General, or Extra.  Next is a single number
representing the category, for example, category zero is safety in all three
exam pools.  The first letter-number pair is called the "sub-element".   The
second letter is a "group" containing related questions.  Example,
sub-element G8 is Signals and Emissions, with group C of that sub-element
being Digital Emission Modes.  The questions are numbered sequentially:
G8C01, G8C02, and so forth always with a 2-digit number at the end.  The
question identity is included in case of a typo or some "help" from
autocorrect obscures either the question or the answer.  

 

T7A01 Which term describes the ability of a receiver to detect the presence
of a signal?

A. Linearity

B. Sensitivity

C. Selectivity

D. Total Harmonic Distortion

 

G4A04 What reading on the plate current meter of a vacuum tube RF power
amplifier indicates correct adjustment of

the plate tuning control?

A. A pronounced peak

B. A pronounced dip

C. No change will be observed

D. A slow, rhythmic oscillation

 

E4C06 A CW receiver with the AGC off has an equivalent input noise power
density of -174 dBm/Hz.  What would be the level of an unmodulated carrier
input to this receiver that would yield an audio output SNR of 0 dB in a 400
Hz noise bandwidth?

A. -174 dBm

B. -164 dBm

C. -155 dBm

D. -148 dBm

4.        Projects

Bring something to work on.   What you building?

For more information about B-Road Thursday Evening Group Projects.

Go to W8BI homepage ( <http://www.w8bi.org> http://www.w8bi.org) under
Education, Thursday Group.

Or

Go to ( <https://sites.google.com/site/darathursdaynite/>
https://sites.google.com/site/darathursdaynite)

There is a lot of information on this web site with additional content.

Hope to see you on Thursday evening's.

Everyone is invited!!! 

 

 

Answers:

T7A01 = B.

G4A04 = B.

E4C06 = D.  The answer is 10 * log(400) - 174 = -148 dBm.  If a 3000 Hz wide
filter (typical to voice modes) were used instead, an unmodulated carrier
input strength of -139dBm would be needed.  A much stronger signal! 

 

Quiz 26

 

 

 

 



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