Courier Centurion 40D Restore

[BBB]

My 40D apparently did come from a smoker, but I doubt it made it that brown, haha. I'd have to open it up again and see what numbers are on the main board. Maybe it was swapped out at some time. What site 399? Thanks.

 

[357]

My 40D apparently did come from a smoker, but I doubt it made it that brown, haha. I'd have to open it up again and see what numbers are on the main board. Maybe it was swapped out at some time. What site 399? Thanks.

​

UNIT 399 <site

Ya that's weird, those 858 boards are quite the mystery.
They have so many variations, I wish a Uniden insider made a movie or documentary about it.
It'd be nice to get some more pics of your board BBB.
From about 75 to 78 Uniden used this mainboard in a few radios.
Even the TRC 57 has the family resemblance.

It seems they used it with the cobra 138, 139 and 449,458,457 but they rotated the board with the finals from the side to the back and integrated the PLL section.

Otherwise its very similar.

​

 

[357]

You mean the mylar?

So the board marking is wrong....looking at coupling circuits, the schematic is right.

+ in / - out

more soldering.

Also that regulator is a 2SD188.
Anyone know what the next beefier one is? Maybe a TIP2955 would be better?

I've been toying with this head-scratcher and I came to the conclusion that the + on the board is correct.
I used a tantalum cap and one way the squelch acts up and gets a scratchy sound, if I reverse it and put the + to match the board, it works fine.
I see on BBB's board it uses a tantalum also.
I'd be interested to see the markings on that.

 

[357]

I've been trying to nail-down a kinda "crunchy" sound in the receive audio.
I found if I put my finger on pins 3 and 4 it eliminates the high tone "crunch".
I was wondering what this green insulated wire was from ground to ground over the pins.
I think they are using this to give some capacitance or something.
I rearranged it closer to the pins and it helped quite a bit.
I also added a 10uf cap from pin 3 to the "isolated" ground...helps a bit more.
yes the soldering looks like crap cause I'm still experimenting, I'll clean it up later.

 

[357]

Here's a Midland and a Pace, both use the + in - out routine.




Here's the "Courier" schematic marking the wrong polarity in and out.




Here's the actual caps installed the right way matching the actual markings on the board.
Clearly you can see the 1uf is heading to pin 6, whereas the schemtic has the - side going into pin 6.

 

[357]

I guess this radio's recieve is normal.
I found some videos that sound like mine, it has a kinda high tone crunchy sounding audio.

 

[357]

I've been trying to nail-down a kinda "crunchy" sound in the receive audio.
I found if I put my finger on pins 3 and 4 it eliminates the high tone "crunch".
I was wondering what this green insulated wire was from ground to ground over the pins.
I think they are using this to give some capacitance or something.
I rearranged it closer to the pins and it helped quite a bit.
I also added a 10uf cap from pin 3 to the "isolated" ground...helps a bit more.
yes the soldering looks like crap cause I'm still experimenting, I'll clean it up later.


View attachment 17674

See here, crunchy gone
http://www.worldwidedx.com/threads/how-to-properly-tune-l4-on-uniden-858.197762/#post-545987

After playing with C63, I'm guessing it is an attenuation situation.
the .1uf I had in there was letting in too much signal and was overdriving the receive.
Its so quiet now with the 4.7uf, maybe too quiet.
I think I mistook a 1uf for a .1uf.

I might switch it out for a 1uf or 2.2uf but its actually super wicked on SSB, theres very little noise floor and all the stations come in great.

Not sure what to think now.

I did notice the midland 79_893 uses a 2.2uf so its something to think about.
I'm just happy I found out why it was sounding below par on SSB.
I was ready to start tearing out detectors and RX amps.

 

[357]

Yup ... I should have said mylar. The regulator pass transistor 2SD188 is rated at 10 amps collector current, 200 Watt dissipation. Subs to an NTE 87. It should be more than the radio will ever require.

- 399

I find the power supply is still getting ridiculously hot.
I get 24vdc out of the bridge, that ok?
I'm trying to think what part would cause the power supply to run hot?

Is the TF-086 just wimpy? I see the 2000 used a TF-164
The cobra 142 looks a bit wider too.

 

[BBB]

What is the final filtered DC output? 12-14 VDC would be appropriate for a stock supply when transmitting. There is usually a potentiometer on the power supply board that can be tweaked up a bit if needed.

Put a true RMS AC meter on the filtered DC output and check to see how much (if any) AC ripple is present. Less than 1/4 volt should be okay. I think you said you already replaced the power supply filter caps right?

I tend to use my external 15 volt 100 amp power supply when the CB base stations come with the standard 3 pin power jack option. Fuse the power supply wires accordingly. You will loose the clock function (or synchronous motor) when not hooked up to the AC line but there is no question if the radio has enough supply power with 10 amp or greater PS running at 14.5 VDC. Sometimes audio problems, weak output, low modulation and flickering light issues go away magically.

 

[357]

What is the final filtered DC output? 12-14 VDC would be appropriate for a stock supply when transmitting. There is usually a potentiometer on the power supply board that can be tweaked up a bit if needed.

Put a true RMS AC meter on the filtered DC output and check to see how much (if any) AC ripple is present. Less than 1/4 volt should be okay. I think you said you already replaced the power supply filter caps right?

I tend to use my external 15 volt 100 amp power supply when the CB base stations come with the standard 3 pin power jack option. Fuse the power supply wires accordingly. You will loose the clock function (or synchronous motor) when not hooked up to the AC line but there is no question if the radio has enough supply power with 10 amp or greater PS running at 14.5 VDC. Sometimes audio problems, weak output, low modulation and flickering light issues go away magically.

Ya I guess thats what I'll do.
I got a samlex 1212 that can run it.

Somethings up with the power supply, the lights are flickering and right now its at 15.2 volts.
I think the BZ162 is dying cause its putting out 17.6v
Either that or the 1096 or 945.

Running external till I figure it out.

 

[357]

replaced tr301 and tr302.
Seems to be stable now, got the voltage down to 13.8
I'm still gonna use the external anyway cause the internal one gives off too much heat and it gets the radio drifting.

 

[357]

replaced tr301 and tr302.
Seems to be stable now, got the voltage down to 13.8
I'm still gonna use the external anyway cause the internal one gives off too much heat and it gets the radio drifting.

Nope still flickers.
I'll try cleaning the VR but I suspect a resistor.
R304 has only 6v on one side and comparing it with my other radio with the same board, it should be 14

 

[357]

I pulled the reg. board, lifted and checked every resistor component, all good.
wtf?

 

[unit_399]

I find the power supply is still getting ridiculously hot. I get 24vdc out of the bridge, that ok? I'm trying to think what part would cause the power supply to run hot?
Is the TF-086 just wimpy? I see the 2000 used a TF-164
The cobra 142 looks a bit wider too. View attachment 17721

24vdc out of the bridge is exactly on spec. The unit draws about 0.6amp in both AM and SSB receive (normal volume). With the rig set at 4W AM, and 12W ssb, it draws 2.4 A Am xmit w/mod, 3.3A SSB w/mod. The stock 40D transformer is rated at 19 vac @ 4.2 amps, so it should be stout enough. FYI, the 142 transformer is rated 17.2 vac @ 3.8A. The 2000 is 19.4 @ 4.8A. The best is the transformer used in the 139XLR which is rated at 20.0vac @ 5.4 A

Is the unit getting hot in xmit or in recv?? Or all the time. I checked my 139XLR after about 15 minutes on the air, and it was pretty warm, but not so hot I couldn't keep my fingers on the regulator.

Disconnect the pink wire going to the emitter of the regulator pass transistor (TR303), connect a milliammeter in series, and check the current draw in receive. It should be about 0.6A. You can check it in xmit using the specs above, just make sure your meter will handle that much current. Good luck & 73s.

- 399

 

[357]

24vdc out of the bridge is exactly on spec. The unit draws about 0.6amp in both AM and SSB receive (normal volume). With the rig set at 4W AM, and 12W ssb, it draws 2.4 A Am xmit w/mod, 3.3A SSB w/mod. The stock 40D transformer is rated at 19 vac @ 4.2 amps, so it should be stout enough. FYI, the 142 transformer is rated 17.2 vac @ 3.8A. The 2000 is 19.4 @ 4.8A. The best is the transformer used in the 139XLR which is rated at 20.0vac @ 5.4 A

Is the unit getting hot in xmit or in recv?? Or all the time. I checked my 139XLR after about 15 minutes on the air, and it was pretty warm, but not so hot I couldn't keep my fingers on the regulator.

Disconnect the pink wire going to the emitter of the regulator pass transistor (TR303), connect a milliammeter in series, and check the current draw in receive. It should be about 0.6A. You can check it in xmit using the specs above, just make sure your meter will handle that much current. Good luck & 73s.

- 399

Thanks for the advice.
I will check the amps, last time it was about 0.5 in receive and 3.4 in TX.
I did some voltage checks and it was idling high at 14.8 the 14.2 when I put on RX but just before I pulled the board it wouldn't adjust down below 14.3 and maxed to 20V via RT301.
It gets hot during TX, after 15mins the reg. is not passing the 5 second thumb test.
I have a trc57 here and its almost identical boards and parts and its rock solid and cool.

Somethings up with that board, I'm gonna put it back in and do some more checks like you mentioned.

I'm wondering about that isolated ground...maybe I should short those ceramics to ground?