[Amps] Ampleon BLF189XR 1900W LDMOS transistor

[Jim Thomson]

Date: Thu, 20 Oct 2016 08:47:03 -0400
From: "Paul Christensen" <w9ac at arrl.net>
To: <amps at contesting.com>
Subject: Re: [Amps] Ampleon BLF189XR 1900W LDMOS transistor

>"It's about time the FCC imposed  2.8 KHz bandwidth limitation with a
requirement that *all* products outside the required bandwidth be suppressed
by at least 30 dB (preferably 40 dB) plus 10*log(PEP/100) above 100 W "

That would preclude use of most legacy gear we've been using for a long
time.  It would be an enviable goal for new product, however.  

Although I'm not a fan of bandwidth regulation, Canada created a
well-thought bandwidth plan that allows for variable bandwidth by band of
operation.  For example, their RBR-4 regulation (previously RIC-2) sets a
maximum bandwidth on 80m/40m of 6 kHz, independent of mode, followed by the
following restriction:  "The bandwidth of a signal shall be determined by
measuring the frequency band occupied by that signal at a level that is
26?dB below the maximum amplitude of that signal."  On the 30m, the maximum
bandwidth is 1 kHz.  

Today, we can achieve much better than -26 dBc.  However, if the U.S.
imposes a strict bandwidth on "all emission products" for voice, then
arguably, we need a coordinated effort with Canada and many other "strong
signal" countries to follow.  For example, here on the east coast, there are
times when Canadian and EU stations are stronger than many U.S. stations on
20m -- and greater in number.  During those conditions, a U.S. bandwidth
limit may only be of moderate help, especially when strong, non-U.S.
stations exceed a 2.8 kHz voice bandwidth.  

Paul, W9AC

##  Not gonna happen anytime soon.  Ill enjoy my 6 khz bw on all hf bands thank you very much.
Folks up here who operate AM, are also only allowed 6 khz BW.   Thats why they have the 6 khz rule. 
On AM, that means CXR and both usb and lsb.   You need a bare minimum of 3 khz audio, so the total
RF BW now becomes 6 khz.... IE:  3 up and 3 down.    If 6 khz AM is ok, then so is 6 khz SSB. 

##  Worry more about 10,000  brain dead contesters on the weekends.   If you use  2.8 khz or less
BW  on ssb, then you are back to using phonetics all the time.   Since I started using essb back in 2001, 
I have never used phonetics, even on noisy low bands.   You require more PO when using narrow  2.8 khz
ssb.   I have already run these various tests  hundreds of times.  Intelligibility drops way off with narrow ssb bw. 

## We are only allowed  750w po on CW mode, so we are down 3 db from our friends to the south of us.
But its all semantics anyway, since trying to enforce a BW rule is  next to impossible.   Esp when the typ
ham  bozo  adds his  RX BW  to my TX BW, to try and obtain total BW.   

Jim  VE7RF