RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > Scanners, Receivers and Related Equipment Forums > Radio Shack Scanners


Radio Shack Scanners - A forum for the discussion of all Radio Shack scanning radios and receivers.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #41 (permalink)  
Old Yesterday, 1:37 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Oct 2017
Location: Whitehall, Mi
Posts: 28
Default Unknown PRO-2006 mods

Quote:
Originally Posted by pro92b View Post
IC9 regulates the battery voltage down to 5 volts for the memory chip. Testing battery current with the radio unplugged will effectively tell us what the current into IC9 is. For now lets keep to non-invasive testing and not unsolder anything. I'll be signing off for the evening at this point.
10-4.

For some reason I think of transistors as rectifiers (I think that is the term) and not IC's (more than one transistor). Mental block due to naming convention on my part as there is overlap where a transistor is a basic IC, duh. Thanks for the IC9 details. I was thinking there should be an output voltage at one point also and didn't think more into design function since I was just plugging and chugging away measuring correctly. Definitely makes sense critically thinking.

Charged 9V Battery for PRO-2006, reads 8.37V directly after taking off charger.
Using the method you noted and demonstrated in the photo I get either way radio on/off:
1 uA with radio plugged in to AC outlet (at first then goes to zero)
54 mA with radio not plugged in to AC outlet (at first then drops)

IC5 voltages (V) with 9V battery present, radio turned on.
pin 8 - 0.003
pin 9 - 3.78
pin 10 - 2.21


IC5 voltages (V) with battery absent, radio turned on
pin 8 - 6.93
pin 9 - 0.07
pin 10 - 2.22

IC9 voltages (V), battery was not present
Radio off but plugged in, input=8.48, output=4.85
Radio on and plugged in, input=8.37, output=4.85

IC9 voltages (V)
Radio unplugged and battery present, input=6.94, output=4.78

9V Battery reads reads 8.35V directly after testing.

Thanks for all the support!
Reply With Quote
Sponsored links
  #42 (permalink)  
Old Yesterday, 9:36 AM
Member
   
Join Date: Jun 2002
Posts: 1,598
Default

The readings for IC5 are correct so it is functioning properly and does not need to be replaced.

The IC9 current readings are not quite as expected. With the radio plugged in the reading should be 2uA and it should not drop. Check to be sure the meter is set to measure DC current and not AC current. The current is determined by resistors R232 and R235 and it should be steady at about 2uA.

The 54mA reading is about 1000 times higher than normal which implies a fault in the circuit. The report of this reading dropping as well suggests that the meter might be set on AC current. At any rate if the current is around 50mA, that certainly will drain the battery in less than a day.

IC9 powers the CPU and memory chips and it is possible that the high current drain is from a problem on the logic board. To isolate the load, unplug CN3, the large connector on the main board at the front of the radio. With the radio unplugged from the wall, measure battery current with CN3 unplugged. If you still read 50mA then IC9 should be replaced along with capacitors C234 and C235. If the current reading drops back into the microamps with CN3 unplugged, the fault is on the logic board. Unfortunately the CPU is a custom chip and the memory is long obsolete so the logic board isn't repairable. It would need to be replaced if you can find a donor radio or maybe buy a logic board from G&G.
Reply With Quote
  #43 (permalink)  
Old Yesterday, 1:02 PM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Oct 2017
Location: Whitehall, Mi
Posts: 28
Default Unknown PRO-2006 mods

Quote:
Originally Posted by pro92b View Post
The IC9 current readings are not quite as expected. With the radio plugged in the reading should be 2uA and it should not drop. Check to be sure the meter is set to measure DC current and not AC current. The current is determined by resistors R232 and R235 and it should be steady at about 2uA.

The 54mA reading is about 1000 times higher than normal which implies a fault in the circuit. The report of this reading dropping as well suggests that the meter might be set on AC current. At any rate if the current is around 50mA, that certainly will drain the battery in less than a day.

IC9 powers the CPU and memory chips and it is possible that the high current drain is from a problem on the logic board. To isolate the load, unplug CN3, the large connector on the main board at the front of the radio. With the radio unplugged from the wall, measure battery current with CN3 unplugged. If you still read 50mA then IC9 should be replaced along with capacitors C234 and C235. If the current reading drops back into the microamps with CN3 unplugged, the fault is on the logic board. Unfortunately the CPU is a custom chip and the memory is long obsolete so the logic board isn't repairable. It would need to be replaced if you can find a donor radio or maybe buy a logic board from G&G.
10-4

I used the A settings where there is a solid line above 3 dashed lines. I notice on the one multimeter however, that current setting range isn't surrounded by a green line and is red. The A~ is surrounded by green on the meter I used and I just checked to see and is flashing "AC" when I switch to A~. There is no reading when power on, powered off there is a 0.3 that flashes and goes to zero.

I have to eat and pick up mail as I am working offsite. Plus I have to leave because the timed ozone is about to turn on. I'll do like you noted when I get back and report.
Reply With Quote
  #44 (permalink)  
Old Yesterday, 9:18 PM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Oct 2017
Location: Whitehall, Mi
Posts: 28
Default Unknown PRO-2006 mods

Quote:
Originally Posted by pro92b View Post
The readings for IC5 are correct so it is functioning properly and does not need to be replaced.

The IC9 current readings are not quite as expected. With the radio plugged in the reading should be 2uA and it should not drop. Check to be sure the meter is set to measure DC current and not AC current. The current is determined by resistors R232 and R235 and it should be steady at about 2uA.

The 54mA reading is about 1000 times higher than normal which implies a fault in the circuit. The report of this reading dropping as well suggests that the meter might be set on AC current. At any rate if the current is around 50mA, that certainly will drain the battery in less than a day.

IC9 powers the CPU and memory chips and it is possible that the high current drain is from a problem on the logic board. To isolate the load, unplug CN3, the large connector on the main board at the front of the radio. With the radio unplugged from the wall, measure battery current with CN3 unplugged. If you still read 50mA then IC9 should be replaced along with capacitors C234 and C235. If the current reading drops back into the microamps with CN3 unplugged, the fault is on the logic board. Unfortunately the CPU is a custom chip and the memory is long obsolete so the logic board isn't repairable. It would need to be replaced if you can find a donor radio or maybe buy a logic board from G&G.
Reads 0.003mA or 3uA though drops and stays stable on 2uA.

I do see pin 4 of CN3 goes to the diode on the LM339N. The corresponding pin 4 blue wire on the logic board connector goes to the switch in the back with a wire on the other pole of the switch going to the correspoing pole on the other switch and the other pole of that switch going back to a diode on the LM339N board.

I touched the blue wire back to stock configuration though didn't break the line existing and same 54mA reading.

Not repairable? :-) I just read an HaD article (though I am not that person) who repaired an IC.
https://hackaday.com/2017/10/15/get-...l-chip-repair/
That is amazing to me and some real intense skill. I never read anything like that.

Is there anything known on the logic board that goes bad by chance you know of?

Thanks a lot for all your support and attention to detail on this project.

On another note... I did receive all #1 through #3 of the Modification Handbooks. The library didn't have the Ultimate book in yet. I also received a telescoping antenna that can screw in place.

I have to drill out the plastic a little more to get the antenna to fit.

Hopefully, I can pick up some stations now since I can set frequency, modulation and bandwidth.
Reply With Quote
  #45 (permalink)  
Old Yesterday, 10:18 PM
Member
   
Join Date: Jun 2002
Posts: 1,598
Default

Not sure I followed everything in your last post. Disconnecting CN3 returned the battery current to 2uA if I understand correctly. That implies the high current drain is on the logic board or a board added as a modification if it connects to CN3. Your radio has so many modifications done to it that I don't know if any of the mods has a bearing on the high current problem. It looks like IC9 is good though.

I don't see an LM339 in the PRO-2006 service manual. Are you talking about circuitry on an added board as part of a modification? There was something published about a data and tone squelch circuit that might be part of the mods in your radio. I attached what I have about the add-on board.

Are you saying that CN3 pin 4 causes 54mA battery current if it is connected even if other CN3 pins are disconnected? I am not clear on that. If the LM339 board is part of the problem, it can be removed and the radio returned to stock condition.

The hackaday article just shows repair of damaged pins on an integrated circuit. This is mechanical damage only and the chip had no electrical damage. I wouldn't expect that situation to apply to your PRO-2006.
Attached Files
File Type: txt DataSquelch.txt (15.9 KB, 6 views)
Reply With Quote
Sponsored links
  #46 (permalink)  
Old Today, 3:45 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Oct 2017
Location: Whitehall, Mi
Posts: 28
Default Unknown PRO-2006 mods

Quote:
Originally Posted by pro92b View Post
Not sure I followed everything in your last post. Disconnecting CN3 returned the battery current to 2uA if I understand correctly. That implies the high current drain is on the logic board or a board added as a modification if it connects to CN3. Your radio has so many modifications done to it that I don't know if any of the mods has a bearing on the high current problem. It looks like IC9 is good though.
Yes, correct, 2uA. I am thinking the added modification perforated board that has the LM339N chip with 4 diodes, 4 resistors, a capacitor and six wires connected from what I see.

Quote:
Originally Posted by pro92b View Post
I don't see an LM339 in the PRO-2006 service manual. Are you talking about circuitry on an added board as part of a modification? There was something published about a data and tone squelch circuit that might be part of the mods in your radio. I attached what I have about the add-on board.
Yes, added board circuitry. I still haven't read the #1 through #3 Scanner Modification Books by Bill Cheek.
I just realized the "Ultimate Scanner" is book #3. So I do have all three books.

Thanks for the attachment.

Quote:
Originally Posted by pro92b View Post
Are you saying that CN3 pin 4 causes 54mA battery current if it is connected even if other CN3 pins are disconnected? I am not clear on that. If the LM339 board is part of the problem, it can be removed and the radio returned to stock condition.
I left CN3 connected and unplugged the pin 4 wire with a single wire male and female connector going to the diode on the perforated mod board.

I then placed the pin 4 wire from the CN3 connector on the board side in contact with the logic board connector pin 4 wire (though that side of the wire is soldered to the switch on the back of the case and I didn't disconnect).

Quote:
Originally Posted by pro92b View Post
The hackaday article just shows repair of damaged pins on an integrated circuit. This is mechanical damage only and the chip had no electrical damage. I wouldn't expect that situation to apply to your PRO-2006.
I see. Would be great if the mod board removal corrected the issue.

73!
Reply With Quote
  #47 (permalink)  
Old Today, 4:09 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Oct 2017
Location: Whitehall, Mi
Posts: 28
Default Unknown PRO-2006 mods

Quote:
Originally Posted by pro92b View Post
I attached what I have about the add-on board.
I did just verify that two of the wires from the board are going to the trim pot attached on top of the case.

After realizing I need to practice my soldering skills on SMD components and other IC's... I found the comment in the .txt file humorous "1" x 1" though smaller is ok if you are good at micro circuits."

Especially, the term "micro" circuits?

The modifications seems like a great modification and seems more "mini" to me now days. OK, blah blah...
:-)

73!
Reply With Quote
  #48 (permalink)  
Old Today, 4:35 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Oct 2017
Location: Whitehall, Mi
Posts: 28
Default Unknown PRO-2006 mods

Quote:
Originally Posted by Ubbe View Post
There's no Probe like application for that interface. You can see in the link you provided that it is a simple remote keyboard function. It doesn't sound as anything you should pursue to have that PC interface working. The discriminator tap are for low speed stuff. As mentioned I/Q needs you to tap out the IF signal, 10.8MHz or whatever it is, and feed into a SDR dongle.
I'm guessing that I may still be able to tap into the I/Q data from the PRO-2006 as RFI-EMI-GUY suggested and you note run into an SDR dongle?

I'm still reading in regards to those details and have to better understand the baseband output from the IF specification for the PRO-2006 and the baseband input IF into a SDR dongle to meet the SDR dongle specification requirements. Maybe I can do with a $10 dongle, though the higher quality ones are around $20 now?

For equipment to test the baseband IF, I will have and, have the following:

I won a Heathkit GD-1B for $38 with all the coils last night and a MFJ-203 that I didn't expect to have the offer accepted for $50. I should be able to clean, paint maybe replace components and I was thinking add a 9V power supply or at least wall wart adapter and resell the GD-1B if not both and return that investment. I also wanted to try making some other coils for lower frequency testing as I see that was an option for the GD-1B. I'll test the MFJ-203 and probably resell as I am not sure I need though for the price seemed like a good deal. These can be used to test frequency still

I have a VICTOR VC3165 Frequency Counter. I could use that to test for frequency, though need to make a coupling coil. I think this is with maybe a certain gauge household wire and a number of turns a specific diameter attach to a male BNC connector with solder connection. I need to verify the specification requirements for the frequencies to test as this can be made for the GD-1B and maybe MFJ-203 also,

I have the TDS-520B that I haven't used yet that wound up working so far though doesn't have the FFT option turned on yet. I still have to install the NI PCI to GPIB adapter and NI 488.2 software, see if I can access the log file to see what is there and memory to make the required changes to turn on the option. This can be my best piece of equipment even though the case is in rough condition and the front cover is broken off. I was thinking I could have the front cover 3D printed for less than the cost to buy new. This is a great piece of equipment and my first oscilloscope I've owned.

I have to read more to make the frequency measurements and not damage anything still before I make contact with any devices. I can't believe how expensive the probes were and I took months to find one I could afford for the 500Mhz that spec'ed out for the scope. About 1/3 the cost of the scope.

If the PRO-2006 is 50Ohm, then I could make direct contact with the board with the 50Ohm probe correct? Otherwise, I will have to make a coupling coil to make the measurement?

I was also thinking I could use the RFExplorer or SDR and try that way also with an antenna or maybe make a 75Ohm coupling coil since the RTL-SDR's are 75Ohm. The HackRF I need to verify as I thought that is 50Ohm as is the RFExplorer.

At first I was thinking the baseband IF data could go into the computer software directly and the filter was performed by the computer hardware and software. I think now that the passband data has to go into the computer software and the software controls the bandpass filters on the SDR or device chip filter hardware.

I'm going to read some more.

Thanks for the feedback everyone.
Reply With Quote
  #49 (permalink)  
Old Today, 3:31 PM
Member
   
Join Date: Jun 2002
Posts: 1,598
Default

Looking at Bill Cheek's third book, "The Ultimate Scanner", I see that the data tone squelch board in your PRO-2006 is described in detail starting on page 121. Maybe this modification was a great idea 25 years ago when it came out, but with a variety of trunk tracking scanners available now it has outlived its usefulness. I would remove it and see if the battery drain returns to normal. If not, then the problem is on the logic board as long as the wiring to CN3 isn't diverted elsewhere.
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 3:42 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2015 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions