President Grant Updates

[HA3GX]

Hi everyone!

I'm hoping for a bit of your expertise. Over 10 years ago, I bought a brand "new", original President Grant CB radio. It's fully functional, but I'd like to have it professionally restored by a specialist here in my country.

Since I'll be having all the capacitors replaced and getting it re-tuned on proper equipment, I figured it would be a good opportunity to give it a thorough "facelift." Given that at least 40 years have passed since this model was released, I know there have been countless improvements and optimizations for these radios.

My goal isn’t to replace every transistor for maximum output power (I know I could easily achieve that with aftermarket amplifiers). Instead, I'm looking to leverage your experience for more refined enhancements. Specifically, which transistors would be worth replacing to reduce noise? What type and brand of capacitors would you recommend for each stage? And would there be any advantage in upgrading the adjustment potentiometers—and if so, what type should I go for?

I'm willing to invest 100–200 euros if it means I won’t have to worry about this radio for the next few decades, except for routine care. I’m not interested in adding extra channels, but if you have any suggestions for practical improvements (since it’s already going to be opened up and worked on), I'd really appreciate your insights.

Thanks in advance for your help!

 

[9C1Driver]

The best bet for that radio would be to have it re-capped with quality components. There is a member here that goes by Klondike Mike, he sells complete radio cap kits for probably any radio out there.
After the re-cap a complete factory alignment is in order and then let that radio be what it is. I would stay away from any exotic mods or power upgrades, it's just not worth it to ruin such a classic radio.
There are some very sharp techs here on this forum that have probably worked on dozens of those over the years. They might have suggestions on 2-3 component values that should be changed/upgraded for better performance. There might even be a part or two that is no longer made.
Good luck with your radio, i'm sure it will give you many years of service when done.

 

[MKwrench]

Does it look like this one? If so I can make a list of my favorite modifications. I picked many of them up here in this forum. There are so many, try searching PC409, Grant XL, 148 GTL. The boards are slightly different, but function simularly.

 

[999]

Does it look like this one? If so I can make a list of my favorite modifications. I picked many of them up here in this forum. There are so many, try searching PC409, Grant XL, 148 GTL. The boards are slightly different, but function simularly.
View attachment 71001

If he's not in the US he most likely has the "export" version with the PC-999 board (or a variant of it) that has 3 bands, FM, and a roger beep.

 

[MKwrench]

Here is a quick and easy clairifier unlock that leaves everything centered and doesen't add an uncontrolable amount of range:
Lift one leg of D52, Lift the "long" leg of R44, Solder and shrinkwrap a wire from the lifted (top) leg of R44 to Pin 1 of the Voltage regulator.
Done.
Now the RX and TX will be fixed together, this helps with "temperature drift" or talking to someone who's off freequency a bit.

My other favorite "unplugs the nose" of the AM audio:
Replace R114 (27K I think) with a 10K resistor and nearby C46 (222) with a 224 capacitor then, upgrading C118 to between a 470uf to 1000uf filters mic. audio and repairs odd squeeling sounds.

There are some mods near the Balance modulator chip to open up SSB audio too, but I haven't tried them.
If you plan on using an amplifier there are lots of NPC variations too, my favorite is:
Remove c174, then add a 1000uf from the negative hole of c174 to the rear leg of the AM regulator.
Search radios that have the 8719 PLL for channel mods too.

 

[MKwrench]

If he's not in the US he most likely has the "export" version with the PC-999 board (or a variant of it) that has 3 bands, FM, and a roger beep.

I didnt think of that, I just replied before I saw this.