Royce 642 Clarifier Mod?

[151SilverDollar]

Is there any one good way to open the clarifier for +/-5khz slide for tx/rx? I have seen different mods and they are all different. Anyone have good experience with a clarifier mod for the 642 that was stable? Any pics to go along would be great. Channel mod was not a problem.

 

[sonoma]

have you looked at the clarifier mod in the secret cb books on cbtricks. volume 13 page 24 shows a clarifier mod. does not say how much it slides.

 

[151SilverDollar]

have you looked at the clarifier mod in the secret cb books on cbtricks. volume 13 page 24 shows a clarifier mod. does not say how much it slides.

I looked at the mod. I did the mod step by step and it did not change anything. It acutally locked my rx and it would not move. I saw that someone grounded the green wire to the top of a can. ExitThirteen said the clarifier was not like others when doing the mod. There must be more to it. I also noticed only 7.5v at Q18 emitter. I wonder if not having 8v is the problem. It would be great to unlock the clarifier. I also noticed the receive and transmit are somewhat off. Looks like the transmit is good and on frequency but the receive knob is at 10 o clock. Someone posted AM USB LSB adjustments but it moves both tx/rx together. I need to figure out how to match the TX/RX before I open the clarifier. If I don't it will be off all the time when I match the receive to whoever is talking. I will be low on transmit.

 

[ExitThirteen]

Here's what I have for the Royce 1-642.

Extra Channels:
Cut trace in between pin 11 of the PLL and the wire that goes to the channel selector, which should be purple. Wire in a SPST switch. Remove Q23. You'll get 27.425-27.595.

Clarifier: Cut the white wire that comes off the clarifier control at the PCB. Move this white wire to the emitter of Q18 (should be 7.5-8V at this spot).
Remove the green wire that comes off the clarifier control at the PCB and move it to PCB ground. I just solder this wire on top of one of the silver square "cans". Don't mess with the 10k pot method they talk about in the Secret CB book. Just move the white wire to the emitter of Q18.

Adjust CT1, CT2, and CT3 to center the clarifier. That's what I have done on mine, and it works great, no issues. However, they don't have a lot of slide, unless you change the varicap diode to a "superslide diode". I have 2 Khz slide up, and 2.5 KHZ slide down.

~Cheers~

 

[151SilverDollar]

Here's what I have for the Royce 1-642.

Extra Channels:
Cut trace in between pin 11 of the PLL and the wire that goes to the channel selector, which should be purple. Wire in a SPST switch. Remove Q23. You'll get 27.425-27.595.

Clarifier: Cut the white wire that comes off the clarifier control at the PCB. Move this white wire to the emitter of Q18 (should be 7.5-8V at this spot).
Remove the green wire that comes off the clarifier control at the PCB and move it to PCB ground. I just solder this wire on top of one of the silver square "cans". Don't mess with the 10k pot method they talk about in the Secret CB book. Just move the white wire to the emitter of Q18.

Adjust CT1, CT2, and CT3 to center the clarifier. That's what I have done on mine, and it works great, no issues. However, they don't have a lot of slide, unless you change the varicap diode to a "superslide diode". I have 2 Khz slide up, and 2.5 KHZ slide down.

~Cheers~

I will give it another shot and see what happens. If I can't get it to work I will try the mods on the 641 even though they are different. Thanks for the info. I may have not centered the frequency with the CT controls. This may have been the problem and it would not adjust. Thanks for the info. Where is the varicap diode located by number. Is there a change out for it for the super diode? Cool stuff.