Re: R2 repair

>   From: "johnrowe19" <[email protected]>
>Subject: aerial problem
>
>i have been an r2 user for some time. When in my car I connect it to 
>an external mag mount. This plugging and unplugging seems to have 
>loosened a soldered joint somewhere under the aerial causing 
>intermittent signal which by "wiggling" the aerial will be OK.
>
>I am happy to resolder but how do i take the device apart to get at 
>the source of the problem. Any help will be greatly appreciated.
>  
>
First, get a copy of the R2 service manual.  I found one at 
<http://www.rigpix.com/icom/icr2_service.pdf>.

Go to page 3-1 (PDF page 6), called Disassembly Instructions.  There are 
three diagrams.  Note that after "Removing the Rear Panel", the next 
step is "Removing the RF Unit", which is before "Removing the Logic 
Unit".  So you need to read the diagrams top-to-bottom, not left-to-right.

Remove the rear panel after removing the two screws in the battery 
compartment.  Now look at the "Removing the RF Unit" diagram.  The 
symbol F inside a circle shows 5 points that need to be unsoldered.  
Three of those points are very close together, and they are the antenna 
solder connections.  There are two solder points for antenna jack ground 
and one for the center pin.  You may be able to resolder these without 
further dismantling the radio.  The solder points are somewhat hidden by 
the plastic radio case, so you will need a fine soldering iron to get in 
to them, and you'll have to be careful not to melt the plastic case 
while you are working.

If soldering these points does not fix the problem, you'll likely need 
to remove the RF board to take a closer look.  Desoldering the 5 points 
is probably best done with solder wick.  Again, be careful not to melt 
the case for the 4 points near the top of the radio.

The instructions for removing the RF unit say that you need to remove 
the nuts D and E on the control shaft and antenna connector.  If I 
remember correctly (It's been years since I had my R2 apart), you do not 
need to remove these nuts just to remove the RF board, since the control 
and antenna jack remain in the radio with the logic board as the RF 
board comes out.  So this may be an error in the instructions.  On the 
other hand, if you want to remove the logic board, you *do* need to 
remove those nuts, and they can be a real problem.  They are installed 
with something like Loctite and take a fair bit of force to unscrew the 
first time.

 I managed to remove the one on the control shaft using a pair of 
needle-nose pliers with the tips fitted into the slots on the nut.  But 
to get the nut off the antenna jack, I ended up making my own spanner 
wrench.  I started with a slot screwdriver whose blade width was equal 
to the nut outer diameter.  Then I cut a large notch in the blade wide 
enough and long enough to clear the antenna jack body.  (I used a cutoff 
wheel in a Dremel tool to remove the metal).  This leaves two long 
points that fit into the slots on the antenna nut.  This worked 
beautifully for me.

    Dave



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