"Thierry" wrote in message ...
Hi,

If you have an external wattmeter connected to your transmitter, can you
make a test at 100 Watts PEP and give me your true emitting power in watts ?

Speaking normally (without shouting) in their mike with normal compression
(10 over 25), some hams say that their wattmeter displays a power of about
50-60 watts (of course in CW they reach 100 W)
But some arrive to move the niddle to about 100 watts in SSB using their
barefoot RTX...

This could be all over the map, depending on the type of wattmeter
used. Very few wattmeters are good at giving an accurate reading of
voice peaks. The meter movements are too slow. If someone see's the
full 100w on SSB, they either have an excellent peak reading
wattmeter, or they are overdriving their radio. I'd say the majority
#2...:/

It seems that some RTX can reach the nominal power doing a hardware
modification at the mike itself to increase the 60 w displayed in SSB to
about 100W. According these hams there is no disadvantage to make this
change.

There is no advantage either, if the mike circuit is capable of fully
driving the radio. The circuit you have is surely capable. All you
will end up doing is adding distortion, and lowering the setting you
keep your mike gain.

The problem mainly occurs of the Kenwood TS-570D (all the serie in fact)
using a handy mic or even a desk model (the ones sold by Kenwood).
The same problem occurs with the Yaesu 1000 MP (tested at 100 W).

I've never heard of any such problem. You are just being fooled by the
meter. Didn't this type thing come up a few weeks ago?
You have average reading meters, and you have type of peak reading
meters. With NORMAL drive, and average speach, you will usually see
only 25-35 watts on an average meter when doing 100w out. This is
normal!!! Don't try to pump up the gain to get more reading. You will
just overdrive.
Then you have passive peak reading meters. They are always sluggish,
and never read the full actual output. Most will average about 80w
peaks, with actual 100w peaks. All they are doing is adding a small
electrolytic cap to the meters to give some "hang time".
Then you have active peak reading meters. These will be the most
accurate, but still can't be taken as gospel as voice patterns vary.
If you can adjust your mike gain and be within the normal ALC specs
for that radio, you have enough mike drive.
If you can whistle hard into the mike, and get nearly 100w on the
meter, you have enough mike drive.
Don't worry about what you read on SSB. If you are doing 100w CW, you
should be doing it on SSB. Heck, When I run 1300w out, I usually see
only about 400w on average meter voice peaks. Don't think my voice
peaks are really 1300w? Go out and grab the end of my antenna, and get
back to me after the paramedics wake you up. :/ The bottom line.
Very, very few wattmeters are worth a hoot at measuring SSB voice
peaks. You are worrying about an issue that doesn't really exist.
Well, unless the rare case you do have a radio problem, but I doubt
it. A friend of mine runs a 570, and he's made no mention of this
"problem". Misunderstanding wattmeter action is very common among
newer hams. Thats why many overdrive, when they really are not
intending to. They are fooled by those dang blasted meters. MK