[Kenwood] Background Noise?

[Bob Snelgrove]

Thanks

Very helpful.

bob




At 10:32 AM 10/29/2003 -0500, you wrote:
>This is very common.  Since SSB has no carrier, there is no steady-state
signal 
>to pop over a squelch threshold like there is on FM (or AM for that
matter).  
>You'll notice the S-meter moves in response to voice peaks, unlike FM
where is 
>stays at a relatively fixed position during a transmission.  If you
applied a 
>squelch to a SSB signal, you might find that some of the softer spoken 
>syllables would get squelched because their peak level might be below the 
>squelch level.
>
>That being said, there are some (minority) HF rigs that include a squelch 
>feature that operates on SSB, but it is not that common.
>
>However, there are several things you can do to enhance your listening 
>enjoyment even without the squelch.  One of the best is to use the RF gain 
>control.  With it set to max like you've got it, you're turning the receiver 
>sensitivity all the way up and you'll hear all the atmospheric and
background 
>noise.  Try slowly turning the RF gain down, just until the background noise 
>diminishes.  Now, whenever a SSB signal comes on that is above the
background 
>noise level, it will be clearly heard and the background noise minimized.
This 
>is like a "soft" squelch and works very well.  You'll have to re-adjust
the RF 
>gain to adjust for the variable background noise level and propagation 
>conditions that occur hour-hour, day-day, etc.
>
>Another thing that helps is to make the AGC response slow.  I believe that
the 
>850 has a fast and slow setting for AGC.  Making it slow causes the AGC 
>controlled RX gain react more slowly between syllables of an SSB signal,
which 
>makes the noise between words, etc. much lower.
>
>You can also use the Attenuator and AIP functions to aide in reducing the RF 
>gain (like above).  The attenuator simply knocks down the signal level
before 
>getting into the receiver.  This works well when signals and background
noise 
>are strong.  It doesn't help when the background noise is low, because the 
>noise you hear is from the receiver, not the air.  
>
>On Kenwood rigs, the AIP can be confusing.  AIP stands for Advanced
Intercept 
>Point.  Quite simply, it refers to whether or not the front-end preamp is 
>engaged.  When the AIP is on (light is ON), then the preamp is BYPASSED -
that 
>is, the RF is taken into the RX in "advance" of the preamp.  In other words, 
>the RF is intercepted before the preamp.  When the AIP is off, the preamp is 
>in-line.  This is mainly useful under strong signal conditions.  Very strong 
>signals can create distortion and intermod products in the preamp, so the
AIP 
>is a way of removing the preamp and the distortion and interference that can 
>occur under very strong signal conditions.
>
>I hope this information helps.
>
>73 Alan W2AEW
>
>Quoting Bob Snelgrove <steelgtr@ix.netcom.com>:
>
>> Hi Gang
>> 
>> Got my 850 a few days ago and am enjoying it. This is my first real radio
>> and my previous experience is scanners.  I'm used to using the squelch on
>> the scanner to have silence until there is a signal. I can't seem to do
>> that on SSB. Is the background (whoosh) just something you have to learn to
>> get used to when no one is talking?
>> 
>> I am only using a discone scanner antenna for now but am very impressed how
>> well it's pulling in 40 meters.
>> 
>> I have the AIP "on" and both 2.7k filters on, RF gain all the way up.
>> 
>> Any suggestions much appreciated. A great rig!
>> 
>> 
>> thx
>> 
>> bob
>> 
>> 
>> - - -
>> 
>> Your moderator for this list is:
>> Larry Wilson KE1HZ kenwood-owner@mailman.qth.net
>> 
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