details?
my pleasure!
there are 12 pics not including my sig pic.
first will be #1 last will be #12.
pic 1 just shows an overview of the inside of the radio.
the board with the big IC chip on it is the mod board.
pic 2 shows the channel selector board, and the channel display board.
the display board is actually two boards, one premade for the channel LEDs, and the breadboard attached to it is for the mode LEDs.
this took a lot of custom fitting to get everything to fit where its supposed to.
the "CH 9" LED on the far right side of the mode LEDs (shown lit in my sig pic)
is now the hi/lo power indicator.
i can switch the deadkey from 2 watts to 4 watts, depending on what, if any, amp im running.
at the bottom of this pic you can also see part of the 10 turn pot i put in for the clarifier. the clarifier in this radio slides 17khz. 11khz up and 6 down.
this allows me to hit all the 5khz steps in between the CB channels that many international DXers use.
wanna hide from almost everyone right in the middle of the band? slide 5khz down! LOL
pic 3 shows the mod board (channel mod) and the freq counter board (mounted vertically)
it also shows the power supply board with the bridge rectifier mounted to the large heatsink. in stock form the bridge rec has its own small heatsink, which i always thought was inadequate.
i also mounted the TO-220 transistor (changed to a 2N6487) to this heatsink, as in stock form it is not heatsinked at all.
the main filter cap has been upped to a 10,000uFD.
pic 4 shows the radio on channel 100 which is 28.0050 and tuned down 5khz with the clarifier. Ill use this pic to note that the headphone jack is no longer a headphone jack and instead has been changed to an external audio input. this input goes right to the audio amp, so i can plug in studio type mics, mixing boards, guitar pedals/ guitars (my favorite) and whatever else i can think of.
we have all heard people play their CD's over the air with their mic held up to a speaker, and we all know how terrible that sounds. with this setup i have a direct line in with level controls on the mixer so when i play a CD over the air, it sounds like an AM radio station. (seriously, it is very cool to hear!)
pic 5 shows the wiring from the mod board to the PLL chip and also shows the big 11.3258 crystal. madisons do not slide very well because they came with the small style crystal which has a different load capacitance and therefore doesnt slide near as far. (about 7 or 8khz was all i could get)
there is no room for the big crystal on the top of the board so i mounted it to the bottom.
the little red trimmer cap you see is for the 10.240 reference crystal. this chassis never had a provision to adjust this, and mine was just a bit off, so i removed a fixed ceramic disc cap and added this so i could get it perfect. (yes, i am a weirdo LOL)
pic 6 (second post) shows the modulation light i added, which is driven from the little breadboarded circuit you see in pic 8.
the knob below the modulation light is the scan up/down control.
this is a rotary, momentary-off-momentary switch and was BY FAR the hardest part i have ever had to find. you'd think that these would be easy to come by, but i had the hardest time tracking one down.
i ended up finding it as Surplus Sales of Nebraska if that tells you anything.
turn the knob to the right, and it scans up. let go and it returns to off and stops scanning. turn to the left and it scans down. very nice feature when your radio has 192 channels.
why add this knob here and the modulation light?
the removal of the old analog clock left me with two different sized holes to fill. it worked out pretty perfect if i do say so myself! LOL
pic 7 shows the back of the freq counter display board. this board was originally all copper traces, but my friend who made the board didnt have the bit down far enough into the board and it left little copper shavings embedded into the cuts. this caused shorts and dimly lit digits, as well as many headaches figuring out why. after many failed attempts at cleaning out the traces, i peeled off all the copper i could and handwired it.
this pic also shows the wires going to the modulation light and the scan pot.
pic 8 shows the modulation light driver circuit i mentioned earlier.
pic 9 shows another circuit i breadboarded up which is a line out that goes to an 1/8" jack i added to the back of the radio. (no, i did not drill a hole for this, i carefully removed the FCC tag which reveals three more holes for jacks or switches.
this allows me to plug my CB into my stereo system so i can tweak the receive with my big 2 octave graphic EQ and listen through my reference monitors.
pic 10 shows a closeup of the freq counter board.
pic 11 shows a different view of the added boards, and also shows the LED meter lights.
they show up blue in the pic but they are white LEDs.
they give the meters a very cool "sea green" look.
pic 12 shows the channel guard board which helps cut down on channel bleedover. it works quite well.
well, thats about it. LOL
yes, it was a lot of work, but also a labor of love as i finally got to do things i had been dreaming about for years.
i replaced ALL the electrolytic caps and changed a few values as needed.
i did the 2999 receive mod along with the diodes.
i did some cap changes that give the receive a more HI-FI sound, as well as changing a few parts that widen the TX freq response.
i left the audio circuit basically stock in this radio, as i always loved the sound of these radios UNmodded with a D104 or a turner +3B which are the main mics i use on it.
thanks for the opportunity to brag on my radio.
i welcome any and all comments and questions.
LC
