[Amps] Fwd: Linear Amplifier Tuning---PROPERLY!

[Jim Thomson]

Date: Sun, 25 Dec 2011 13:34:03 -0800 (PST)
From: Commander John <crazytvjohn at yahoo.com>
Subject: Re: [Amps] Fwd: Linear Amplifier Tuning---PROPERLY!

I fail to see how having spurious sidebands at -20, -30, -40?or whatever makes the??????????????
Signal wider.? The sidebands are still there regardless of final?suppression level.

###  You are confusing sidebands with IMD.   This is NOT FM.     It's  SSB.    IMD is caused by non linearity. 



 It is the receiving stations receiver having the rejection ability that reduces received?interference.?

### wrong again!    IF station XXX  using his ICOM  on TX....is  10 khz wide... then he's 10 khz wide.    If you are 3 khz away, you are now screwed, and there is no filter on the the planet that's gonna do any good.  He's   Txing on your  RX passband, so his TX  IMD is now overlapped with your RX passband. 




 Having adjacent sidebands that are stronger than necessary causes a receiving station to hear these sidebands at a harmful signal?strength further away from the transmitted frequency than if they had supression at a highter level

##  It's  adjacent IMD, not sidebands. 




A legal limit station would have much stronger IMD because it is stronger not wider.? It only is preceived as wider because they are stronger than from a 100 watt transmitter.? 
##  That all depends  on how loud his IMD is to start with.   But yes, if 2 x stations have the same IMD... but one is 10db louder than the other [say a bigger ant or amp].... then the station with the 10db syronger signal will also have IMD that's also 10db stronger.    Which is all the more reason to have a cleaner signal when u have a big amp, and big towers' ants etc.

##  No point in all these deluxe receiver's  with 100db dynamic range. It's of now use,and pointless on ssb.   Not until the  TX IMD gets improved on these ham xcvr's.   The Icom's  are 10 khz wide when u stuff white noise into them...and the yaesu 5000 in Class A  is only 3.5 khz wide  [both measured at the -45db point].   The bands are NOT crowded .  They are  just jammed  full of sub standard  xcvr's..which is most of them.. with junk TX portions.  If everybody got heir act together, you could easily double the number of ssb signals on a given band.   You could triple that if everybody had class A, or the eq. 

Jim   VE7RF 





john W9ZY