[IRCA] Palstar R30CC mod

["Craig Healy" <bubba@xxxxxxxxxxxxxxxxxxxx>]

I made a modification to the Palstar R30CC today.  With a loop antenna, or a
short whip, it needs more gain.  Normally I use the DX Engineering RPA-1
which works very well.  However, the extra box is a bit of a nuisance.

Inside the Palstar is a 10 AA battery holder which I've never used.  For
portable operation I use a 12v 7ah lead acid cell as is used in UPSs and
alarm systems.  $25 at Radio Shack.  It will run the Palstar and RPA-1 combo
for many hours and is rechargeable.

The internal battery holder was removed, and one of my RPA-1 units was
modified to fit inside.

The two mounting ears were cut off, and four screws used to put the preamp
on the removable metal plate formerly used for the battery holder.  It was
put to the volume control side to clear the internal speaker.

Both preamp coax connectors were removed, and some RG-58 soldered to the
pads to which they were connected.  The input from the antenna was soldered
right to the connector on the back.  The output to the radio was soldered to
the two-pin push on connector used to connect to the main board of the
radio.  A smaller coax such as RG-174 would have been a bit easier, but the
RG-58 was fine.

A switch was put on the back panel right above the pushbutton for the dial
light.  That was the preamp can be used, or not.  Power was routed from a
black wire which is the output of the on/off switch on the volume control.
No need to have the preamp on if the radio isn't.

I put it all back together, and it worked just fine.  Didn't notice any
performance difference, but it's more convenient to use now.

I did disconnect the 455KHz output to the back panel jack to see if that was
causing any spurs.  Didn't seem to, and will be connected next time the
cover is off.

Next mod is to make an LED lighting array for the frequency readout and
S-Meter.  One of the bulbs was out, and another broke while I was removing a
shield.  There is ten volts fed to the bulbs, so I'll calculate the LED
requirements from that.

I also am going to modify the circuit board so the fuse on the back works
for the external power.  As manufactured, it only works on the battery pack.
(!)

One other mod I did was to replace the tuning knob with one that has a
little crank handle.  Easier to use.

And, since it's used in the truck, a dab of silicone seal will be put on any
screws or nuts inside that might vibrate loose.  It did that once and
shorted out a power lead internally.  Not pretty.

I may look at replacing the wide IF filter with a 4KHz version, if I can
find one.

All in all, the Palstar is a nice little rig.  Certain beats the heck out of
any radio I've had in the truck before.

Craig Healy
Providence, RI

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