[ICOM] Icom PW1 Failures - How To

[Troy L Davis]

This subject is of great interest to me because I have never been able to 
get my PW-1 to auto tune its internal tuner when the PW-1 was not powered 
on.  I operate almost exclusively these days on PSK 31 with only about 20 
watts so the PW 1 is just sitting there doing nothing but showing the green 
lights.  If I try to tune the PW-1 with it's power off, nothing happens.. 
it does nothing.. If I add some drive from the 756PRO III it still does 
nothing when the tuner is pressed at the power levels I am running.. My 
hunch is that it requires more drive to auto tune on or off that I am 
willing to put through the 756 running audio / digital modes.. if I turn 
the PW-1 on, adjust the 756PRO  III power knob to max, (it's normal 
position for SSB, CW, etc..  and press the PW-1 tuner it of course turns on 
the 756 and gets it's necessary drive signal plus the CIV band signal and 
all works fine..
You may be asking well, so how do I do tune it.. simple I put the 756 on 
line, turn the AMP on, Tune and then turn the amp off and only run the 
756.. but frankly, I have thought all along that was a rather Micky Mouse 
approach..
any other suggestions would be greatly appreciated.. I just did the entire 
install , recalibrate the ALC, and checked all the functions and they work 
as expected except for the tune while turned off as described on page 14 of 
the manual..

73 , Troy , W4AJJ

At 03:15 PM 6/8/2005, you wrote:
Hi Harry,

To quote the PW1 user manual, p. 2:

When the linear amplifier is OFF, the [AMP/PROTECT]
does not light and the exciter's signal is applied to one of
the output connectors or the IC-PW1's antenna tuner.

Ibid., p. 14, top:

This antenna tuner is also used when the linear amplifier
is turned OFF.

The Yaesu Quadra can also be configured with ATU on-line
At 07:33 AM 6/9/2005, you wrote:
>Hi Adam and group,
>
>Not certain I agree that the antenna tuner in the PW1 functions when the
>main switch is off at the PW1.
>My ATU internal to the PW1, later serial #, does not work unless the power
>is on to the PW-1.
>I checked this with Icom, even if 12 volts is applied to the PW1 from the
>765 exciter and the PW1 LEDs for the antenna and exciter input are
>illuminated, the ATU will not work.
>It will only work when the main power switch is on for the PW1.
>The ATU will function with the amplifier section off, but not the main power
>switch.
>
>As far as determining antenna resonance, its really rather simple, MFJ-259.
>The antenna is a 160 meter dipole fed with balanced line.
>I am using a Heathkit 2060 tuner and the MFJ to confirm feedpoint impedance
>and SWR.
>
>The Icom manual for the PW1 does state on page 16, item 7 "Use the exciters
>antenna tuner to tune the line between the IC-PW1/EURO and exciter, if you
>have an antenna tuner connected to the exciter."
>
>I can't believe that the operation of a internal tuner of the exciter can or
>should cause a fault in the SWR measuring circuit of the PW1, yet is has
>happened to me and others.
>Sorry, that seems like a design issue.
>Can someone check the schematic and explain the failure of R7 on the
>Splitter board any other way?
>
>73 Bruce W1UJR
>
>-----Original Message-----
>From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
>Behalf Of Adam Farson
>Sent: Wednesday, June 08, 2005 9:44 PM
>To: 'ICOM Reflector'
>Subject: RE: [ICOM] Icom PW-1 Failures - How To
>
>Hi Harry,
>
>Here is some further clarification courtesy Matt, KK5DR:
>
>...The ATU can be operated without the PA section enabled. It can also be
>operated without the PW1 even being powered up. DC power to operate the ATU
>and antenna selector is provided by the exciter through the ACC cable.
>
>These features [Antenna selector & ATU operation with PW1 powered down] are
>only provided on later versions of the PW1, S/N 1165 or higher.
>
>The ATU requires at least 60 watts of drive to complete a tune cycle.
>
>Cheers for now, 73,
>Adam VA7OJ/AB4OJ
>
>
>-----Original Message-----
>From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
>Behalf Of we1x at comcast.net
>Sent: 08 June 2005 15:17
>To: ICOM Reflector
>Subject: RE: [ICOM] Icom PW-1 Failures - How To
>
>Went back and tried it..I stand corrected.
>
>thanks Adam.
>
>Harry WE1X
>
>-------------- Original message --------------
>
> > Hi Harry,
> >
> > To quote the PW1 user manual, p. 2:
> >
> > When the linear amplifier is OFF, the [AMP/PROTECT] does not light and
> > the exciter's signal is applied to one of the output connectors or the
> > IC-PW1's antenna tuner.
> >
> > Ibid., p. 14, top:
> >
> > This antenna tuner is also used when the linear amplifier is turned
> > OFF.
> >
> > The Yaesu Quadra can also be configured with ATU on-line and PA stage
> > off-line: [OPERATE] key off, [TUNER] key on.
> >
> > The ATU insertion loss is approx. 0.5 dB.
> >
> > Cheers for now, 73,
> > Adam VA7OJ/AB4OJ
> >
> >
>
>
>Scanned by WinProxy
>http://www.Ositis.com/
>----
>Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net Icom Users
>Net: Sundays, 1700Z, 14.316 MHz Icom FAQ: http://www.qsl.net/icom/
>
>
>
>----
>Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
>Icom Users Net: Sundays, 1700Z, 14.316 MHz
>Icom FAQ: http://www.qsl.net/icom/