Care and Feeding an Icom PW1
W6DE
Page 7
Copyright 2017, All rights reserved.
Repairing your PW1:
Use the following information at your own risk. I make no warrantee as to correctness or completeness
of the following information. If you undertake any repairs and/or adjustments to your PW1 amplifier
based on this information, you do so at your own risk.
Not all problems have the same source. So while I’ve may have seen the same symptoms, it doesn’t
mean you have the same problem and the same fix.
First, do a Google search to find and then down-load the PW1 Service Manual.
If you have the technician skills you can repair a PW1 yourself. However, one extremely important and
needed skill is soldering. Soldering will require judgement about what size and type of tip on your
controlled temperature soldering iron to use. And, if you have to replace the MRF-150 finals you need
to know what type/size of soldering gun/iron to use. If you do not have significant electronics soldering
skills—this is not a project for you.
The daunting part is the disassembly. Take pictures of the unit before disassembly and at stages as you
disassemble the PW1. Take pictures of screw locations, cable routing and general layout. I’ve probably
got about 30 or so pictures and even then I missed a few screw locations. First time disassembly for
either the PA/RF side or the Tuner/Controller/Power supply side will take about 6 to 8 hours per side.
With experience it goes a lot faster.
A repair will take about a week or two as you figure out: what to do, what to fix, order parts and repair.
Be sure to work in a static free area. Don’t do the repair in a house where you are standing on a carpet,
a synthetic floor, or a plastic carpet protector. I have a shop with a concrete floor and a wood table to
work on; i.e., low static. Put cotton towels (NO synthetic material!) under the amp to help slide it
around. In the end, you will scratch whatever you have the PW1 sitting on—don’t use the dining room
table. Have a space with about an extra 12” to 18” around all sides of the amp while you work on it.
You’ll need another similar amount of space to safely place the assemblies/parts as you remove them
from the chassis.
Icom did a really good, sturdy, mechanical design on the PW1. A complete disassembly will have you
dealing with 40 to 50 small parts and fasteners. To keep from having left over parts, have several small
containers to separately place fasteners and small parts in as you disassemble the PW1 in stages. That
is: put all the fasteners in one container for the cabinet disassembly, then another container for the first
part of the left side (filter/combiner) then another container for the PA if you have to take that out too.
And so on. . . . You get the idea.
Any project is an excuse for another tool.
--Any PA work will require a good quality multimeter that can read milliamps to set the idle current—I
used the 300 ma scale on my multimeter.
--A clamp-on ammeter will be nice to compare the individual idle draw of all four power modules
without disconnecting the power leads. A suspected PA problem may require this to determine which
of the four PA boards is bad.
