Any Hot Mods for the Uniden "Honest Abe"?

[Robb]

I picked up a Honest Abe for next to nothing. It is a real dog as far as modulating goes. It keys five watts and swings to 8 watts - that is all it can do. Pretty anemic - to say the least.

It's got the 858 PLL chip in it, so I know it has potential. But on a watt meter, it really blows chunks - modulates slowly and reluctantly. I'm a huge fan of President radios, and I want to give this radio to a neighbor so that he can get on the band. I tried clipping the diode, but it doesn't do much still - so I soldered it back. Turning the modulation pot on the board all the way up did next to nothing for it.

I understand this chassis is the same (?) as a Cobra 29 XLR, but I could be very wrong. I'm hoping for insights and some solid tips to make this a loud talker without using a linear, so I need to extract the potential from this little honey. Any good links or replacement/substitute parts suggestions would be greatly appreciated!
Thanks in advance.

 

[Robb]

Here I am again, wondering if anyone can direct me to some usable mods for this nice little radio.
Sure would appreciate it!

 

[Sickpuppy22]

Here ya go rob scroll down to the president section of this page,
NW CB RADIO

it say's adjust VR5 or cut D14 for modulation and then adjust L15 L12 L11 for Am power hope this helps you.

 

[Robb]

Thanks Sickpuppy.
I've tried those mods, and they don't work that well.
Thanks for the effort - I appreciate it.

What I am looking for, is a MOSFET final mod, and possibly a swing mod for it.
Maybe even a mod for the TX/RX frequency response improvement.
I'm sure that someone one this forum knows this radio well. I thought this radio was equivalent to the Cobra 29 XLR - and that all of the mods for the Cobra 29 XLR will work on the Honest Abe too.
We will see...

Here's a very good chart for Cobra radios that shows all of the tuning points:
http://www.radiomods.co.nz/cobravrlist.html

 

[unit_399]

ROB -

You're right, the Honest Abe uses the same board as the Cobra 29XLR which was a real kick-ass radio in its day. Trouble is Abe has a really weak driver and final set. You can upgrade to 29XLR driver and final (2SC2091/2092), but also need to change values of R42,R43, & C57. New values: R42 - 15 ohms, R43 - 3.3 ohms, C57 - 220 pf. This will make the radio a real talker. BTW I would suggest not cutting/removing D14. Just set VR5 for max modulation.

- 399

 

[Robb]

ROB -

You're right, the Honest Abe uses the same board as the Cobra 29XLR which was a real kick-ass radio in its day. Trouble is Abe has a really weak driver and final set. You can upgrade to 29XLR driver and final (2SC2091/2092), but also need to change values of R42,R43, & C57. New values: R42 - 15 ohms, R43 - 3.3 ohms, C57 - 220 pf. This will make the radio a real talker. BTW I would suggest not cutting/removing D14. Just set VR5 for max modulation.

- 399

Thanks!!
What about the 2SC2314 and 2SC1969 bipolar driver/final?
Won't they work?
It's got a 2SC2028 and a 2SC2029 in it right now

Is there a swing mod for it too?
Howabout a recieve mod?
Which transistor should be changed?
I've also got some Shottky diodes - too...
Thanks Again!!!
I have a boatload of 2SC2999E's as well for the recieve mod.

 

[ButtFuzz]

Same As 29XLR

3 Crystal AM Model, same innards as

Cobra 29XLR, 89 XLR, President Dwight D (old), Honest Abe, Teddy R, Zachary T (old), Robyn AM-500D, Teaberry "T" Bear, "T" Command, Titan "T"

Here's a 29 XLR Service Manual... Maybe some info in there you can use?




and here's the schematic...



Talk Powah, biatch...

MODELS: Cobra 29XLR, 89XLR
1. Change R87 (2.2 Meg) to a 1 Meg
2. Change R49 (47 Ohm) to a 27 Ohm
3. Change R42 (4.7 Ohm) to a 1 Ohm
4. Change R43 (2.2 Ohm) to a.47 Ohm
5. Re-Tune L15, L12, L11 for maximum Forward Power

 

[Muddy Waters]

3 Crystal AM Model, same innards as

Cobra 29XLR, 89 XLR, President Dwight D (old), Honest Abe, Teddy R, Zachary T (old), Robyn AM-500D, Teaberry "T" Bear, "T" Command, Titan "T"

Here's a 29 XLR Service Manual... Maybe some info in there you can use?


[
and here's the schematic...


Talk Powah, biatch...

MODELS: Cobra 29XLR, 89XLR
1. Change R87 (2.2 Meg) to a 1 Meg
2. Change R49 (47 Ohm) to a 27 Ohm
3. Change R42 (4.7 Ohm) to a 1 Ohm
4. Change R43 (2.2 Ohm) to a.47 Ohm
5. Re-Tune L15, L12, L11 for maximum Forward Power

Good information to have. I as well have a Honest Abe, thanks

 

[MisterFatty]

Toss a so-called SuperTalk in the radio, will help a bit, one of the few ways to get a doggy 858 chassis to talk without getting to deep into it...

 

[Robb]

Toss a so-called SuperTalk in the radio, will help a bit, one of the few ways to get a doggy 858 chassis to talk without getting to deep into it...

Nice tip...Is there a link/page that would show this info up a little bit clearer? It is too small to make out as it is as a thumbnail...
Thanks!

 

[MisterFatty]

if you click through it will enlarge.... but here you go....


Super-Talk

 

[Robb]

Alignment info for the Uniden Honest Abe/Cobra 29 XLR

This will align both radios

 

[Robb]

Diodes 4 & 5, 8 & 9, 22 & 23 are 1N60P's. I'm pretty sure that two are for AGC, two more are for the AM detector, and the last two are for the Noise Blanketer circuit. But w/o the schematic, it is hard to figure out what is what.

Would be be advisable to replace them all with Shottky diodes?
I think the NB and AM detector may benefit from this mod; but I am a bit leery about the AGC becoming too sensitive/fast.

Thoughts?

 

[Robb]

Never mind, I found the schematic for the 89XLR; same as Honest Abe and the 29XLR.
Thought I would make it available for the forum . . .

 

[SMILEX2692002]

I have came in contact with a President Zachary T with the same board as the Cobra 29 xlr and the President Honest Abe ect.
This is the older Zachary T with the 858 chip.
Any updates for increased modulation/power out with this board?
My radio shows 60% modulation with the amc turned all the way up.
I use a Silver eagle microphone.
The radio shows 4 watts dk and swings around 8-10 Pep.
Nice radio just lacking some modulation and power.