President Adams Radio Information needed.

[NightRanger3151]

Does anyone have any info on the President Adams AM/SSB radio? I have one and would like the schematics and adjustment locations for it.

Right now I'm trying to figure out how to align the clarifier back to center. The clarifier on this radio need to be turned all the way to the right to work on AM and even then it's not quite enough. (Not sure about SSB yet).

I also noticed a diode had been cut from D32 and would like to know more about what that is too.

[Uncle Ray]

Hi mate , go to

cbtricks.com and download the Realistic trc449 diagram. Its pretty much the same.
PS , part numbers may differ BUT you'll work it out.

[zodiac]

NightRanger,
It may be a bit late but D32 in the MK2 Adams PC 346 is part of clarifier being unlocked and that may be reason your having trouble getting on frequency.
The full unlock.
Desolder one end of R117, D30 and lift them out of the holes or remove them both.
Remove the wire from next to C110 (Brown and White), this wire comes from the clarifier control. put it to a constant voltage, there is a 9v rail at the front of the radio to the right of R161. Looking from the track side of the board R161 is a 1w 56ohm resistor.
This voltage may be too high so you will need to add a resistor to bring it to the amount of shift you require.
Or use 5 volt if you find you cannot get the radio on frequency again.
I added another varactor diode in series with the original ones of the same value to all three varactors to bring the radio back on frequency again.
Unlocking the clarifier this way you don't need to remove D32.

If I remember right TC6 is for USB TX and RX and AM TX.
TC5 is LSB TX and RX and CT 4 is AM RX only.
Hope this helps you out if you haven't done it by now.

[DIRTY HARRY]

NightRanger,
It may be a bit late but D32 in the MK2 Adams PC 346 is part of clarifier being unlocked and that may be reason your having trouble getting on frequency.
The full unlock.
Desolder one end of R117, D30 and lift them out of the holes or remove them both.
Remove the wire from next to C110 (Brown and White), this wire comes from the clarifier control. put it to a constant voltage, there is a 9v rail at the front of the radio to the right of R161. Looking from the track side of the board R161 is a 1w 56ohm resistor.
This voltage may be too high so you will need to add a resistor to bring it to the amount of shift you require.
Or use 5 volt if you find you cannot get the radio on frequency again.
I added another varactor diode in series with the original ones of the same value to all three varactors to bring the radio back on frequency again.
Unlocking the clarifier this way you don't need to remove D32.

If I remember right TC6 is for USB TX and RX and AM TX.
TC5 is LSB TX and RX and CT 4 is AM RX only.
Hope this helps you out if you haven't done it by now.

Hi zodiac what is the maximum amount of slide either side of the 12'o clock position with this mod mate? cheers in advance,Shaun

[zodiac]

Shaun,
It's been a long time now but I think it's only about 3.1/2 KC's in total without having to change or add components.

[DIRTY HARRY]

Hi zodiac & cheers for getting back to me,o.k if thats only how far it slides then its not worth doing for me, was hoping it would slide 5kc either side, i was doing a google search & came by this...

Cool radio hack #2: A President Adams CB radio, 40 channel, 858 SSB chassis. The 858 PLL is capable of 400 channels. I replaced the 10.240Mhz crystal with a 5.120Mhz crystal, so I could get 5kc steps out of the PLL


do you think this would work for me to then be able to get on the zero's aswell as the normal channels? cheers again,Shaun

[zodiac]

But how do you get on the 5's, you'll only have the zero's.
You'd need to be able to switch from one to the other not just replace it.

[DIRTY HARRY]

But how do you get on the 5's, you'll only have the zero's.
You'd need to be able to switch from one to the other not just replace it.

Good point zodiac, so if i just exchanged the 10.240mhz crystal with a 5.120mhz one would it definetly just transmit on the zero's only? as im not well up on how crystals behave etc,cheers,Shaun

[Rick]

How about switching Pin 7.

[DIRTY HARRY]

How about switching Pin 7.

How would i do that to get it to work Rick? i aint seen that mod on the web.

[Rick]

This pin 7 is normally tied high.
The easy way to do this is to cut the track to pin 7 and solder a 4K7 resistor across the track you have cut, now solder a wire to the pin side of the resistor and solder a second wire to ground then solders the ends of the wires to a switch.
When the switch is switched off the radio will have 10 KHz channels and when switched on the radio will have 5 KHz channels.

I think you should start a new thread in CB Radio Modifications.
As this is a mod and not alignment question.

[DIRTY HARRY]

This pin 7 is normally tied high.
The easy way to do this is to cut the track to pin 7 and solder a 4K7 resistor across the track you have cut, now solder a wire to the pin side of the resistor and solder a second wire to ground then solders the ends of the wires to a switch.
When the switch is switched off the radio will have 10 KHz channels and when switched on the radio will have 5 KHz channels.

Tried it, & it gave me some of the zero's , but on lowband, the adams i have has been eprommed & no matter where i put the 3 way band switch it was stuck on lowband when i sent pin 7 to ground,not to worry i might give the crystal method a try.

[DIRTY HARRY]

I think you should start a new thread in CB Radio Modifications.
As this is a mod and not alignment question.

Yeah your most right to say that, just got carried away while we were on the subject of the Adams

[hamguy2]

hi i see your talking about the president adams cb radio i have 3 of them here 1 still in its box,the best way to put a slider or tx clarifier is when you put the wires on the regulator to give it its power to slide some wobble on ssb ,the best way is to do it i found is to install a seperate regulator on the heatsink nearby then run the wires off the regulator legs then you run them to the right sections then there no wobbles on the tx or rx. i think the regulator is a 7805 by memory if you do that you wont have any wobble troubles ,thanks hamguy2 nsw australia

[hamguy2]

that wouldnt be full power youd have to rewind all the rf coils for tuning and tx and rx coils ,the vco in the 858 are all over the board the most ive seen them do is from 26055 to 29105 and thats 1 watt on 29mhz and the rest of the radio was only about 8 watts ssb ,thanks david

[hamguy2]

hey night ranger, you havent got a spare or an old adams part radio you want to sell the plastic channel 9 button off i have an adams here it works etc but i need the orange plastic button that works the channel 9 button im prepared to buy 1 off someone if they want to sell it ,thanks david nsw australia .

[13EL121]

are the CH19/ CH9 not black ones? The scan & normal button are orange.

[hamguy2]

both do you have any full adams dead im also after a 40 channel selector out of 1 plus the ribbon cable canb you give me a list in what youve got ill buy it off you if u want to sell them thx david

[13EL121]

Hi David!
Sorry, i've no parts to sell. I have only one adams...
If i will find them i'll mail you!
73s, Ralf