[Icom] PW1 Antenna tuner repairs

Fri, 31 Jan 2003 21:41:25 -0500

Hi Adam,

I marked the insulated couplers on the caps indicating full mesh. Am
downloading the manual now. Will have the factory one in a week along with
the caps.

I do not know why the protection circuit did not take the tuner off line.
Probably operator error...  :( Repeated pressing of the tune button....

Thanks,

Bob, W3PT

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Adam Farson
Sent: Friday, January 31, 2003 8:59 PM
To: [email protected]
Subject: RE: [Icom] PW1 Antenna tuner repairs

Hi Bob,

Firstly, you can download the PW-1 service manual here:

http://www.qsl.net/icom/manuals.html

Scroll down to "Download IC-PW1 Documents"

When you replace the capacitors, I believe that you may need to recalibrate
the autotuner. This involves positioning the capacitor rotors at the correct
default angle on the servo-motor shafts. (This procedure is required in the
Yaesu Quadra amplifier, but may not be for the PW1).

This procedure is not mentioned in the IC-PW1 service manual. It may be a
good idea to contact the PW1 expert at Icom Service (1-800-USA-ICOM).

Hate to mention this here, but it comes as a profound shock to me that
unlike the Quadra, the PW1 does not have a reflectometer at the autotuner
output. I have had traps blow up whilst transmitting at 1kW PEP on 20m; the
reflectometer in the Quadra caught the resulting impedance anomaly and took
the amplifier off-line instantly.

Best 73,
Adam, VA7OJ/AB4OJ
North Vancouver, BC, Canada
http://www.qsl.net/ab4oj/
Icom FAQ Site:
http://www.qsl.net/icom/

-----Original Message-----
From: [email protected] [mailto:[email protected]]On
Behalf Of Bob Marzari
Sent: January 31, 2003 14:29
To: Icom
Subject: [Icom] PW1 Antenna tuner repairs

Hi,

I smoked the two variable caps in the tuner. The amp is located in basement
below me and I was hot and heavy into the 160M CW contest last weekend a had
an antenna problem. The problem caused the caps to arc over and ruined them.

I took the top cover off and with needle nose pliers managed to remove the 2
badly warped plates on one cap and one on the other. This allowed me to see
if any of the other support circuitry was damaged. It wasn't and it tunes
fine but of course that was into a 50 ohm load. It will sorely miss that
capacitance I removed when in the real world.

I do not have a manual, I ordered one today and two caps from Icom. Has
anyone replaced them on this reflector and has some tips?

Thanks,

Love my PW-1

Bob, W3PT

----
Your Moderator: Dick Flanagan W6OLD, [email protected]
Icom Users Net: Sundays, 1700Z, 14.315 MHz
Icom FAQ: http://www.qsl.net/icom/

----
Your Moderator: Dick Flanagan W6OLD, [email protected]
Icom Users Net: Sundays, 1700Z, 14.315 MHz
Icom FAQ: http://www.qsl.net/icom/