Welcome, here you will find some information about a older scanner that is in
use every day all over the world. You will also find some modifications that
will make the scanner even better.
This may be one of the best scanners ever made
and you can add the
OptoScan 456 by Optoelectronics (or
OptoScan light) for a full feature Computer Control interface that allows
control of the Pro-2006 with CI-V and tape recorder interface and will allow
CTCSS/DCS/DTMF decoding. You can use Probe software (see my information on this
site about Probe) with this setup. You can click on any of the pictures
below to enlarge them and then use your back button to return to this page.
The Pro 2006 is one of the easiest scanners to
modify for discriminator output. Just a couple supplies are needed to complete
the mod. You open the
case up and connect to "TP2" on the PC board. It resembles a resistor standing
on end. You need to solder the positive leg of the 1uf capacitor or 1K ohm
resistor to the exposed
wire of the discriminator tap. The other leg needs to be soldered to the center
conductor of the shielded audio cable. You can connect the ground to a metal can
Pro-2006 Discriminator Tap Modification
There are only 2 screws on the top to take the Pro-2006 apart, use caution not to pull the wire to the top mounted speaker loose. You can lay the top aside connected or unplug the speaker from the board once you get the top open.
it is very easy. You can find the layout for the mod and in the pictures below. Just click on any picture to get a larger
view then use your back button to return here.
The pictures below are of my modification to the Pro-2006 for a Discriminator. The Pro-2006 have the TK-10420 chip and can be tapped at
TP2 or pin 9 of the chip. You can use a 1uf capacitor or a 1K ohm resistor from TP2 to your coax feed. You can find a close ground on the shield of the T7 can.
The best place to mount your jack (you can use a 1/8 mono or sub-mini 3/32mono jack. ) is on the back of the scanner.
Pro-2006 IF Bandwidth Modification
While on the topic of the Pro-2006 here is a neat little modification to change
the IF selectivity to receive Wefax or other signals that require a wider
bandwidth. Something around 30 - 50 Khz should work fine. You want to look at
IC2, pins 3 and 5. These connect to the Ceramic filter CF4. Here is information
from the late Bill Cheek on the modification. I have found this mod can work but
is a 'hit and miss' so I have started looking for a better way to do this.
Short of a 30 kHz replacement filter, I'd suggest soldering a pinline socket to each of the two NFM chip/filter pins, and then plug in a range of ceramic disk capacitors until you find
one that works best. You can easily remove the capacitor with no ill effects to return to normal operation. Values to try include: 47-pF. 100-pF, 470-pF .001-uF .01-uF.
The idea is to leak just enough of the desired signal around the IF filter. Too much, and adjacent channel interference looms as a show stopper. Too little, and you're back to Square One.
I started this project when I was thinking about watching some wefax satellite again (I use to be into it heavy with dedicated equipment but the internet made it so easy to find satellite I left it all go but I have been interested in playing with some of the new software for sound cards and just looking at some of the satellites again). Searching all over the internet and printed information about the best thing I could find was a few ideas to jump across the IF filter with a capacitor to 'leak some additional signal' (see my Pro-2006 modification page for this information). This really was not a good answer (in my mind) it was hit and miss and I could not switch back to normal bandwidth for general scanning. I had this idea and phase 1 is to see if it really will work and phase 2 is to put it into action.
The idea is to remove the ceramic filter, build a board to hold more than one filter, find a way to switch and find power to run it. Leads must be kept very short and noise can not be added.
This idea can apply to a number of scanners but I used my Pro-2006 to work with. There are two phases to this project, the first to see if the idea
will work and then implementation. You could use a combo of a 6kHz, 15kHz, 30khz and 50kHz filter (either any two or add a relay and use all four (4) with a
proper switch). You can also just 'plug' filters in with a simple modification noted below. The project is useful but also give something to think about with your scanner.
Pro-2006 IF selectivity bandwidth Modification - Phase 2
I will just update as I go along here. I found that I had to switch both the input and the output to avoid interaction of the filters. The revised drawing is below that works. You could expand it to
another relay and switch that would allow four (4) filters to be switched in.
Another option that will let you plug in filters as you need them and is very simple to do. You just put board pins (you can get them from Digi-key Part Number A208-ND).
The filter will fit into these. The row of 4 you don't even have to take the pins out of the plastic, they fit the board fine. The fifth pin you will have to break out of
the plastic strip. In my pictures below my fiter is getting very 'used' from my experimenting and I have a new one on order but the old one works just the plastic is getting
beat up. This will let you plug in filters, capacitors or coils here to work with. That's the project. If you have comments or questions e-mail me.
The pictures below are of my Pro-2006 IF selectivity bandwidth Modification. The Pro-2006 has the TK-10420 NFM Discriminator chip (IC2). It uses a 15kHz ceramic filter (CF4) across pins 3 and 5 of IC2.
I hope this gives you some ideas. I am not responsible for any damage so don't do the modifications if you feel you can't. At the bottom of this page is some information on bandwidth needed for a
number of modes.
Two other worth while modifications
You need to remove the boards (at least take the bottom one loose) for this but it is worth while. The squelch on some scanners doesn't work too well because of too much 'hysteresis'. Hysteresis prevents weak signals from 'jumping' the squelch open and closed and that can be annoying. A circuit with hysteresis requires a stronger signal to open the squelch than it does to keep it open.
Scanners will too much hysteresis (Like the Pro-2006) make it hard to receive the weaker signals with too much hysteresis. Bob Parnass published a fix that really works well, he replaced the 33K resistor in the Pro-2006 (R152 on the linear PCB main board) with a 100K resistor and it really does a good job of improving the squelch. R152 is a surface mount resistor and can be
removed and a standard one put in it's place. Be really easy with this one, you can mess up fast because things are so small (I won't tell you how I know but I do! LOL. If you don't feel good about it don't try it. No, I am not responsible for any damage!
I did the first modification with a stock resister but that just wasn't right so I went back and replaced it with a surface mount resister, looks better :)
The other modification that is worth while is to remove C208 (top mounted 0uF) from the circuit. If you use the scanner to listen to any WFM (FM Broadcast) removing C208 will help to correct a faulty de-emphasis and WFM will sound a lot crisper.
Range 25-520 & 760-1300 MHz
Modes AM, FM & WFM
Priority 1 channel
Scan 26 channels/second
Search 26 steps/second
Audio 1.3W nominal
Power 120V AC 12V DC
Size 8"(W) x 3"(H) x 8"(D)
Weight 4.9 lbs
Interfaces BNC, DC, speaker