Uniden Grant (PC-409) AM audio mod (the right one)

[Rabbit Ears]

Hi folks!!

Re: Uniden President Grant (PC-409) AM audio mod.

FACT: Most audio mods for this radio are just CRAPOLA!! I use the conservative approach....based on FACTORY docs.

As you well know there are SEVERAL audio mods out there for the Uniden President Grant. I decided to base mine on the Cobra 146GTL's shunt-type (very easy to figure out) AMC circuit.

First you locate an outline of a VR on the right hand corner of your PC board by the power plug. You solder a 1K VR in that spot. Find TR26.... and remove R-130 1.5K ohm it is located in front of L2(towards you as you are facing the front of the radio) . Solder a wire to the base (the hole that R130 came out of) of TR 26 with a 1N4148 soldered to it (cathode towards the VR away from TR26's base).

Now connect it to the wiper of the VR you installed earlier.

The mod is done....now you have adjustable AMC (bigger audio).

NOTE: I only read about 65% modulation before my mod. Now it has been adjusted up to 95%. My pals were very impressed!!

Awww...shoot!! Now I've got TWO Washington (8719) base stations that are to be getting the SAME mod....from the FIXED AMC to Adjustable AMC. ;D ;D ;D

Dudes!!! Outa' sight!!

Read and heed...I DARE YOU. ;D ;D

More illustrations to follow....Got to take pics.

[Motormouth37]

I clipped the limiter on mine put it on a switch for when I am close to someone. Run a noise canceling mic with the gain around 1/4 and it sounds great.

[Rabbit Ears]

*Sigh...* May the "splatterboxes" enter the arena. .. the planet plagued with their continuous ANNOYANCES and garbled distortions!

I've already been through my "splatterbox" phase.....when I was twelve?? "But....*arrrrhh dee aye!!!* it wuz a fine time me bucko'...TIMMY!!

Smashed radio...and a bunch of buddies shaking their fists and pointing their fingers at my bruised face. Busted glass...my tubes...

Since then, I've been to college, tech schools, and training in the Navy. Now that I'm getting to a "twisted, eccentric, ripe middle-age" I've little tolerances for..."SPLATTERBOXES" *RANT...Rant!..rant!* *censored* *blip!*

[TheCBDoctor]

Hi Motormouth37

I have to agree that it is easier to just cut the clipper, but I can't condone it because the problem is at some point someone will turn that Mic gain up and the radio will splatter. The peak power you see isn't really there because the waveform is distorted. The tops are flattened.

It is okay to just cut the limiter and adjust the mic gain knowing that you are at 100% modulation. The problem is when you go to sell it the new owner is bound to turn the Mic gain up.

Here are some photos of what an over-modulated radio looks like. Just click on this link. If you click on each photo it will give you more info.

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If you want to be louder you can use a power Mic as long as the limiter is in place. Cutting the limiter out does make you louder, but the fact is you aren't getting out much further. The meter shows more power, but it is a false reading. The down side with a clipped limiter is the operators close by get bleed-over.

But hey, it is "The Out Law Band." If I wanted to talk about computers, radios, and how tall my grass grew last week I would have kept my Ham ticket.

I know some Ham operator will take offense about the remark I made. I had a Ham license when you actually had to know code and build a radio. Besides I don't need a license to talk on the Ham band.....I will just use Rabbit Ears' numbers.

Respectfully

[Rabbit Ears]

Just fussing with yet another Uniden Grant (PC-409)...Mannnn! Another PNP limiter clipped!!

Use my number??? *HEH!!* Make it loud and proud!!