Converting Uniden instant 9 switch to 19 instead.

[LeapFrog]

68Elite and 78LTW. I won't own a SMT radio if I can help it. And I think these are the last ones made with through hole components. Also would like to do this to a 78Elite which i think is the same as the LTW just backlit face.

On the radio that you want to do the channel switch mod for, you gotta take the covers off and let us know the numbers(or text) on the PLL, then we might be able to offer up some suggestions. My 25/29 68/78 collection is lacking, I don't a Vietnam radio, yet. Taiwan R.O.C. are decent radios, I prefer them.

 

[Cruiseomatic]

Lol, I know where the PLL is. Let me crack one open and I'll look real quick since I have one here next to me.

 

[LeapFrog]

Lol, I know where the PLL is. Let me crack one open and I'll look real quick since I have one here next to me.

Right on

 

[Cruiseomatic]

Hope this helps.

 

[LeapFrog]

Hope this helps.

PLL Uniden 835ACE
D2816CP Is this the correct text, sorry it's a 'lil blurry, and my eyes aren't the best.

 

[Cruiseomatic]

Oh damn it is. Was clear when I uploaded it.
And you are correct, Thats what it says. Sorry about the serial tag being upside-down, Lol.

 

[sp5it]

Look at Uniden pro 640 schematic and do the same for quick 19

 

[Cruiseomatic]

Will do. Fighting a serious issue with a radio and a tech currently.

 

[LeapFrog]

This info might help.

uPD2814/uPD2816/HD42853/KM5624

Models include:- uPD2810Cobra 66GTL, Craig L150, President James K/AR-11/Old Hickory, Midland 77-856, Realistic TRC469/TRC420/TRC420A/TRC421/TRC422/TRC432/TRC441

uPD2816Cobra 29GTL/29LTD/63GTL/87GTL/89GTL/1000GTL, President Thomas J / JFK/Dwight D(new)/Zachary T(new), Superstar 120, SBE LCB-8, Teaberry Stalker XII/ Stalker V, Uniden PTC104 Trucker.

uPD2816 SSBMidland 6001(79-006)/ 7001(79-007)

These chips use 6 bit BCD/ROM programming.

sp5it is on the right track as far as I can tell, the
uPD2824 is the next pll down on that link, for the Pro 640.

your PLL is listed for the models in the first line of that quote, its not much, but a start. (That is, if the PLL is the same one in your radio, i think the UPD before the numbers isn't required, the D2816CP is likely a UPD2816 or some variant, data sheets, if found would tell more.)

If you can find an "instant 19" switch (some radios had 'em) in a sister radio, you could copy the way they did it.

Or if you find a modification for a radio that is similar (or uses the same PLL) you could blindly try it. AT YOUR OWN RISK
I tried one a long time ago, I clipped a diode in a Cobra 29, I clipped the wrong one, nothing bad happened, I just had to replace the diode.

If you cannot find the Factory Service Manual pdf online, the best idea I have is to get a Sam's Photofact for your radio, (if they made one).
Then at least you'd have a schematic, and some direction or clue.
(P.S. i don't know if it matters, but the Uniden 640 schematic is online, also a FSM )

All the best.
-LeapFrog

 

[Cruiseomatic]

Supposedly, The 29 and 25 are identical to the 68 and 78 series. And even claiming to use the same PLL according to that site. But how would I find out what sister radio these have that has instant 19 without staring through schematics for hours and hours....

 

[sonoma]

just go to cbtricks and the cobra 29 schematic is the 1st one on the 29 page. it shows the 19 and 29 switch. I have already looked at it saw it there.

 

[Cruiseomatic]

After pulling a 25 LTD classic apart, They manipulate the selector switch to do it and leave the PLL alone. So in theory, You could make any channel instant on. Still playing with it and reading the schematics.
Sometimes just experimenting with stuff yields the best answers. Schematics can only tell you so much. I have a 142 GTL I'm restoring and looking to do this aswell to save wear on the selector switch. But it just developed a no RX/TX issue suddenly. Just twitches the meters when first powered on. Also trying to find the other half of the Cobra WX board to install it in the 142.