KD4TO
Member
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- Apr 22, 2025
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- 13
RS Pro-2004/2005/2006 display issues..?
- Thread starter KC0CCB
- Start date
If you had a plastic diffuser panel in front of them the light would likely be more uniform. Like these these dffuser panels.
About 16 yrs ago when the EL panels were still sold on eBay, I bought about a half dozen each for my 2004 & 2006. I also did the light switch mod to my 2004 and keep the light off most of the time.
Did the LED strip not fit in the old EL slot? Also I really like the idea of converting to LED and doing away with EL.
Paco-Jerte
You Member, Member!
maybe ice blue LED's would be best for the eyes? my honest opinion.
KD4TO
Member
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I couldn't find a way to fit the LED's where the old EL was, not much clearance and it didn't illuminate the display well. I'm hoping the LED's will last a long time.
N1SQB
Member
Pro-2004 is the best for a backlight display change, among other things. I did mine a few months ago, added an extra 100 channels and a nice big color matching carrier-on indicator light mod. Dimmer switch is the main culprit for premature display light wear. The switch on mine now functions on/off only. Yup love my 2004
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What did you tap for the COI ? I tried to figure it out 34 yrs ago but couldn't. I did a host of other mods though, including even the crystal speed mod.
It's Mod-32 in Bill Cheek's Vol. 2
N1SQB
Member
That article is good for the tap point for the COI. However, Bob Parnass did an article where you use less parts and do not use so many lights, just one. I can’t find the article. I actually made a diagram years ago to help others on here. I can’t seem to find it. I have been having fun with this scanner lately. Today I built an external signal strength meter project. I repurposed an old Yaesu external meter, and put an on/off switch with a 10k pot to calibrate it. I’m toying with the idea of doing a center tune mod too..😎
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I just wanted to add a point, 34 yrs ago in 1991 I figured out an easier way to do the crystal speed mod on the 2004 than how Bill described. My method as follows: After you remove CX501 (a ceramic clock oscillator, that looks like a small blue M& M, by wiggling it back & forth) from the CPU PCB, then wrap your 10 MHz crystal with electrical tape. Now remove the CPU PCB from the 2004 and flip it over and now solder the crystal to the the old solder pads of CX501 on the bottom of the CPU PCB. ... This makes doing the crystal speed mod so much easier. In fact I always considered Bill's crystal speed mode method to be flawed. If you remember when Bill soldered in his speed up crystal to the top of the board he admitted that it was able to short out on another component and blow his IC9 (the transistor that runs the battery backup circuit). And Bill said that it was "much less fun than a barrel of monkeys" replacing it, since it was on a another board in a hard to get to place. ... Also in my opinion, since CX501 was nearly against the metal rail and in the corner of the CPU PCB, it is nearly impossible to put your speed up crystal where CX501 was on the top side of the board. My speed up crystal has been soldered to the bottom of the board and wrapped in electrical tape (like I described above) for 34 yrs now and has never caused any probs there. ... I would also add that the default scan speeds of the 2004 are dreadfully slow and the crystal speed mod really kicks them into gear because it is a 2.63 MHz OC of the CPU and is 27.03 channels a second which is just faster than the 2006 which is 26 chan/sec. which is considered Hyperscan on the 2006. Also, doing the 400 channel mod makes doing the crystal speed mod even more of a necessity.
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N1SQB
Member
That’s the one mod I hesitated to do on my 2004, for the reasons you mentioned. I mostly use it now for civil and military air monitoring so speed is no longer a necessity. I never thought about doing it your way.
Just the same, I’m gonna leave mine as is. The center tune +/- 5 kHz mod is next, just for fun. I’ve done the signal strength meter mod obviously, and the keyboard beep disable, plus the COI light and the extra 100 channels, with a backlight replace and dimmer switch resistor removal. Yup, I’ve been busy…😁
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By the mid 90's Bill Cheek no longer recommended crystal speed-up modifications. Aside from his concerns, it is possible to speed the clock up so much that the phase locked loop can't keep up with frequency changes so transmissions are missed. The Scan below is the most comprehensive post from Bill Cheek on this issue. Two years later he reiterated his non-support for speed-up mods in even stronger language (WSR V7 N2 page6).
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N1SQB
Member
Thank you for posting this. It’s something I have hesitated to do as I stated before. With modern scanners, there’s no need to worry about fast speeds. Back in the day, when these were popular and state of the art, it may have been something to consider. I now have this 2004 around for searching and monitoring of the civil and military air bands. For that, speed is not a factor. I just finished up my center tune mod…😁 Here’s what the inside looks like so far.
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I can attest that 10 MHz is safe for the 2004 and 14 MHz is safe for the 2006. Thirty four yrs in my 2004 and 30 yrs in my 2006 proves that. Bill said that 10 MHz was the max limit in the 2004, but then he got crazy and suggested 18 MHZ max in the 2006, which runs at 12 MHz stock. BTW, 7.37 MHz is stock on the 2004.
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A single radio running at elevated speed for years does not prove safety in the large population of radios. What is clear is that the higher speed will raise the CPU temperature which will raise its failure rate. Some will fail before others and the ambient temperature of the room will have an effect. If the radio is run from 12VDC instead of the internal power transformer that will help lower the temperature inside the radio cabinet.
Bill Cheek found that the speed-up crystal caused his CE-232 scanner/computer interface to stop working and that was one of his major objections.
Bill Cheek found that the speed-up crystal caused his CE-232 scanner/computer interface to stop working and that was one of his major objections.
I found this thread:
forums.radioreference.com
I'm not sure if what you're looking for is on page 2.
Here is a copy of the original mod instructions by Bob Parnass.
Though it mentions the Pro-2004 primarily, the mod works on the Pro-2006.
A carrier operated light
With a room full of functioning scanners, it's difficult to determine quickly
which radio is "talking." I use separate external speakers on each radio, and
the spatial separation helps.
In addition to "hearing" which radio is active, I like to "see" which radio is
active, and carrier operated lights are effective at providing such visual
cues. The idea is to illuminate a lamp when a signal opens the squelch. A
small yellow light emitting diode (LED, another Bell Labs invention) is well
suited to this purpose. The following modification works well on all PRO-2004
modes.
To add a COR light to the PRO-2004, make use of the "scan control" pin (pin
13) on IC2, the TK10420 IC. Pin 13 has voltage present only when a signal is
detected. This chip contains the IF, detector, limiter, and squelch circuits
for NBFM.
If you tremble with an electric drill in your hands, read no further. The LED
can be mounted in a small hole drilled through the plastic front panel, just
to the right of the headphone jack.
Electronically, the circuit is simple. The voltage at pin 13 is not enough to
drive the LED directly, so a general purpose NPN transistor (e.g., a 2N2222)
can be used as a solid state switch.
- Pin 13 of IC2 is connected to the transistor base through a 10,000 ohm
resistor.
- The emitter is grounded.
- The collector is connected through a 1000 ohm resistor to one end of an LED.
This resistor limits the LED current to about 13 milliamps.
- The other end of the LED is connected to one contact on the rear of the
PRO-2004's on/off, volume control. This furnishes about 14 VDC unregulated
to the circuit. The back of the on/off switch has two contacts. Use the one
with the brown wire connected to it, as this contact is only "live" when the
scanner is turned on.
I mounted the 2 resistors and transistor on a small PC board, which I fastened
to the PRO-2004 chassis using a metal standoff.
The above mod was created and originaly posted by Bob Parnass.
Another Light Mod
Heres a video link to my youtube video on a light mod that I did for the Radio Shack PRO 2045, YouTube - PRO 2045 Lights.wmv My back lights went out on one of the two radios, so I decided to experiment with this. Turned out to be an exceptional improvement over the stock lights. As some of...
I'm not sure if what you're looking for is on page 2.
Here is a copy of the original mod instructions by Bob Parnass.
Though it mentions the Pro-2004 primarily, the mod works on the Pro-2006.
A carrier operated light
With a room full of functioning scanners, it's difficult to determine quickly
which radio is "talking." I use separate external speakers on each radio, and
the spatial separation helps.
In addition to "hearing" which radio is active, I like to "see" which radio is
active, and carrier operated lights are effective at providing such visual
cues. The idea is to illuminate a lamp when a signal opens the squelch. A
small yellow light emitting diode (LED, another Bell Labs invention) is well
suited to this purpose. The following modification works well on all PRO-2004
modes.
To add a COR light to the PRO-2004, make use of the "scan control" pin (pin
13) on IC2, the TK10420 IC. Pin 13 has voltage present only when a signal is
detected. This chip contains the IF, detector, limiter, and squelch circuits
for NBFM.
If you tremble with an electric drill in your hands, read no further. The LED
can be mounted in a small hole drilled through the plastic front panel, just
to the right of the headphone jack.
Electronically, the circuit is simple. The voltage at pin 13 is not enough to
drive the LED directly, so a general purpose NPN transistor (e.g., a 2N2222)
can be used as a solid state switch.
- Pin 13 of IC2 is connected to the transistor base through a 10,000 ohm
resistor.
- The emitter is grounded.
- The collector is connected through a 1000 ohm resistor to one end of an LED.
This resistor limits the LED current to about 13 milliamps.
- The other end of the LED is connected to one contact on the rear of the
PRO-2004's on/off, volume control. This furnishes about 14 VDC unregulated
to the circuit. The back of the on/off switch has two contacts. Use the one
with the brown wire connected to it, as this contact is only "live" when the
scanner is turned on.
I mounted the 2 resistors and transistor on a small PC board, which I fastened
to the PRO-2004 chassis using a metal standoff.
The above mod was created and originaly posted by Bob Parnass.
Had to go through this to make sure I hadn't posted in it earlier:
I have four PRO-2006s. Two were bought as hosts for the OS-456 Lite boards I obtained from Optoelectronics years ago and I managed to snag two more which had the Full boards installed.
All four need the backlights repaired. Need to find a source.
Will probably use these for air-band scanning, run in pairs (one Full and one Lite) controlled via Spectrum Commander IX. Also managed to get hold of better monolithic filters for the FM Wide selectivity option so a couple will get that mod too.
I have four PRO-2006s. Two were bought as hosts for the OS-456 Lite boards I obtained from Optoelectronics years ago and I managed to snag two more which had the Full boards installed.
All four need the backlights repaired. Need to find a source.
Will probably use these for air-band scanning, run in pairs (one Full and one Lite) controlled via Spectrum Commander IX. Also managed to get hold of better monolithic filters for the FM Wide selectivity option so a couple will get that mod too.
