[Kenwood] Kenwood TS850 - improved audio quality and reducedoutput

[Rob]

He just means the built in watt meter that comes with the rig.  Every  
time someone posts a complaint about not getting full output from a  
rig (not only here but in any ham forum), some wise guy always says  
something about being some fraction of a dB less so don't worry about  
it.   I always want to ask, "If you spent $250,000 on a Harris DX50  
broadcast rig and it put out 10% less than spec'd carrier output (45  
Kw instead of 50), would you just walk away and tell yourself it  
doesn't matter?   I bet you'd be on the phone to Harris screaming for  
a new transmitter.   Why should this be any different?  A ham paid  
good money for a rig that's supposed to put out 100 w.  He's entitled  
to get what he paid for.   He's not interested in some kind of "it  
doesn't matter" talk.  It matters to him and I bet it would matter to  
any of you guys if it were you who got the sub-par performing rig.     
Also, there are cases in which it matters such as when driving a pair  
of 3-500s and the amp's input Z is something other than 50 j0 so then  
the exciter starts to fold back some, and you need all of that 100 w.  
capability (and maybe more) to get the amp to anywhere near full output.

Having said that, a few cautionary notes.  First, it is very important  
to be measuring the PA output with an accurate meter.   Secondly, the  
last thing you should do is go into the rig and fool around with the  
pots that control the rig's output power.   That's a tempting quick  
fix, but you can easily wind up with a sick sounding transmitter  
that's putting out garbage 10 KHz up and down the band.   There is a  
real possibility that there is something else causing your problem.

I had an 850 once and I currently own an 870.  These two kenwoods have  
something in common:  the ALC circuits are easily affected by RF  
getting back into the rig via pickup on such conductors as the ground  
strap, mic and key cables, etc.   ALC on ham rigs is kind of crude,  
plus it's response is not usually flat across the audio input  
frequency spectrum because most rig's mic input circuits boost some  
audio frequencies.  If you have your rig in a strong tx field, say for  
example you drive an amp and have the antenna not too far away, the RF  
may be doing a false ALC trigger.  The first thing I'd try doing is  
connecting a hand mic to the mic jack, and running the rig into a  
dummy load with all unnecessary cables, including the ground strap,  
disconnected, and see how the rig performs.  If you can get it to put  
out 100 w., then you don't need to do anything with the internal trim- 
pots.   your next step should be to connect everything back and watch  
what happens.  Probably once you put the rig back on your antenna,  
your problem will return.   I'd start putting ferrite mix 31 chokes on  
all your cables including the coax feedline, and put an isolation  
transformer like an iBox between the audio gear and the mic input.

Speaking of the audio gear, there's nothing wrong with running all  
that, _provided_ you have a way to accurately listen to your signal  
off-air with a second receiver to verify the signal isn't distorted,  
or the tx audio does not have a muffled or excessively bass sound.  I  
also recommend you take a look at your tx wave with an oscilloscope.   
This will tell you whether or not you are flat-topping and also, it is  
a great way to check your peak power.  The little vacuum flourescent  
watt bar meter in the front panel probably isn't fast enough; in fact  
(now that I think about it), I'd get an old Tektronix oscilloscope and  
use that to measure your PEP before doing anything else as you may  
find the rig is putting out 100 w. after all -- the front panel meter  
just wasn't fast enough to catch the power peaks.  You can get a Tek  
model 465 on Ebay for as little as $50 (U.S.).   That is a great scope  
and just about all you need for average ham activities.  Just  
remember, if you ever want a rig to put out more than 100 w., get  
another rig -- keep ur hands off the power pots!  :  )

GL and 73,

rob / k5uj