[Icom] Icom Pro II and PW-1 (Do I have a problem here!)

Thu, 27 Jun 2002 10:52:06 -0500

Adam, thanks for your response, and I think I understand it all.  Have
proven that what you say in the first paragraph of your reply is true.  If
follow the book method using just pro and pw1 meters, it makes no difference
where I set the exciter output so long as it is at least 100W which is what
the pw1 requires for 1KW out. The ALC set point is a rather thick heavy
black line which allows a little bit of play in precisely where  the ALC is
set, which results in the pw1 watt meter showing 1000-1100 watts out with
pro output at full open.  Once set this way though, the pw1 watt meter
indicates 90 watts out for 100W in with the amp switched off (exciter just
running thru the amp). Would think amp would show at least 100W?  Seems to
suggest that the pw1 watt meter is always reading a little lower than either
the Pro II watt meter or the Bird.

Also, tried the second method you mentioned.  When so set, the pw1 indicates
1KW out, but the bird only says 850W out.  If set the alc to make the Bird
read 1KW out, the alc goes into the red somewhat.  Although it does not
explain the above mention discrepancy between the pw1 meter and the Pro II
meter with amp off,  I am now beginning to wonder about the Birds accuracy.
Or, perhaps the 1000W slug is not up to par.

I will, of course, play it safe until can prove the Bird's accuracy or
otherwise explain the differences.  Just do not like these kinds of
mysteries.  Suspect I will acquire another Bird meter from my friend and see
what happens using his.

Know you acquired a Pro II, and as you may recall I sought you advise before
acquiring mine which although I have listened have yet to transmit.  You
basically said if could buy it right, get it.  At HamCom, I paid $2700 cash
bottom line, no tax, no shipping, etc. Tax alone would have been about $300
dollars, so did not feel at all bad about paying $100 over the $2600 you
recommended.  Now just face the decision of which excess transceiver to
dispose of, the Pro or a KW950SDX. Either way, going used prices will force
a beating.

Have not checked you web site lately.  Do you now plan to setup a Pro II
page too? Thanks again for you advise and help.  You are one of just a
couple of guys who make belonging to the Icom reflector both educational and
a pleasure.
----- Original Message -----
From: "Adam Farson" <[email protected]>
To: <[email protected]>
Sent: Thursday, June 27, 2002 6:19 AM
Subject: RE: [Icom] Icom Pro II and PW-1 (Do I have a problem here!)

| Hi Bill,
|
| The ALC in the PW-1 will hold the exciter output at the level required to
| drive the amplifier to the preset power output. If the PW-1 requires 80W
of
| drive to produce 1kW output. turning the transceiver's RF POWER control up
| to full output will make no difference, as tithe ALC line is regulating
the
| drive level.
|
| As the ALC is the amplifier's first line of defence, it is absolutely
| mandatory to set it up correctly. Assuming that your Bird power meter is
| accurate to within 5%,another method is to adjust the ALC for a reading of
1
| kW (into a dummy load!)
|
| Best 73,
| Adam, VA7OJ/AB4OJ
| North Vancouver, BC, Canada
| http://www.qsl.net/ab4oj/
| Note new e-mail address:
| mailto:[email protected]
|
|
| -----Original Message-----
| From: [email protected] [mailto:[email protected]]On
| Behalf Of Bill Tarkington
| Sent: June 26, 2002 21:07
| To: [email protected]
| Subject: [Icom] Icom Pro II and PW-1 (Do I have a problem here!)
|
|
| Having recently purchased a Pro II, I followed the owner manual
instructions
| for both the amp and radio to set the ALC level on the amp so as not to
| overdrive it and risk FET damage.  Once all proper connections are made,
| book says to adjust the exciter (Pro II) output to 100W, then turn ALC
| adjustment screw clockwise slowly while key down on either CW/RTTY and at
| same time reading the ALC scale on the PW-1 control head until meter
needle
| is dead on the ALC adjust mark. Once adjusted thusly, key down at 100W
from
| the exciter and check PW-1 power meter to insure 1KW output.  Did all this
| and all looked to be okay.  HOWEVER, I noted that the RF power knob on the
| ProII was not fully clockwise (wide open).  Advancing it to full open
seemed
| to indicate the Pro  II was putting a little something in excess of 100W
per
| its power meter.  Bottom line is, I do not know what meters to trust here.
| Out of curiosity, got out the Bird 43 Watt meter with 1000W slug therein
and
| did some checking. First used the Bird meter with 100W slug to set
barefoot
| output on the ProII at precisely 100W and left it there(  little less than
| full open). Further testing with the Bird in and out of the circuit with
the
| PW-1 output seems to indicated the Pro's watt meter is pretty accurate,
but
| the power meter on the PW-1 is reading low.  If do the ALC adjustment
using
| the PW-1 power and alc meters per book,Bird says full amp output is 860W,
| not 1KW the PW-1 watt meter indicates. If do the ALC adjustment using just
| the Bird meters readings while ignoring the PW-1, the ALC goes into the
red
| some little way, and the output per the Bird is about 1250W.  All this
| leaves me wondering which watt meter to trust to obtain the full 1KW
output
| of the amp. If use the Bird and guess wrong, will 1250W out with ALC being
a
| little in the red likely cause me some amp damage?  The safe thing to do,
of
| course, is go with the PW-1.. BUT, I want them to agree more or less with
| one another or understand why not.  Incidentally, if it matters, all tests
| were done into a  1500W dummy load.  Am I missing something here?
Comments
| please. Bill, K3YC
|
| ----
| Your Moderator: Dick Flanagan W6OLD, [email protected]
| Icom FAQ: http://www.qsl.net/icom/
|
|
| ----
| Your Moderator: Dick Flanagan W6OLD, [email protected]
| Icom FAQ: http://www.qsl.net/icom/