KD4TO
Member
- Joined
- Apr 22, 2025
- Messages
- 13
If you had a plastic diffuser panel in front of them the light would likely be more uniform. Like these these dffuser panels.The LED's are connected to the power switch with a dropping resistor in series.
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.the LED's are not behind the display
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.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.
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.and a nice big color matching carrier-on indicator light mod.
It's Mod-32 in Bill Cheek's Vol. 2What 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.
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..😎It's Mod-32 in Bill Cheek's Vol. 2
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.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.
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…😁
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.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).
View attachment 184146.
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.By the mid 90's Bill Cheek no longer recommended crystal speed-up modifications.