Courier Centurion 40D Restore

[357]

ok pink wire to regulator, 0.62A RX 2.6A TX SSB (wimpy test probes)
Voltage still not steady.
Next stop RT301 then the new 10A regulator I put in there.

OK the voltage is steady, but with the radio off, its 14.8V, with the radio on in RX its 13.8, TX it goes up a tad, 13.82-84.
Temps seems ok

RX <--------------------------> OFF

 

[357]

It still flickers, sometimes it blinks off/on.
Its got to be that 2sd555....

Just about to pull the trigger on a switcher

 

[unit_399]

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

I would NEVER run the supply above 14.8 vdc. 20 vdc will give the 16volt caps a lot of grief. Check the voltage at the cathode of D301. Should be about 6 vdc. Make sure that D301 is a 6.1v zener. BTW ... what kinda wattage is it putting out when it gets hot ??
Also ... bypassing the ceramics can't hurt.

- 399

 

[loosecannon]

357, here is the switching supply i bought:
http://rover.ebay.com/rover/1/711-5...0001&campid=5336136228&icep_item=161857689063

you only have to change the value of one resistor to get the voltage up to 13.8.
can't remember which one right now, but if you buy one i will look and find out.

I used a bit of ferrite on the input and output wires, but that's it.
no noise in the receive at all.

also, i had a similar problem with a 139XLR power supply, and it turned out to be the VR.
you might try replacing it.
LC

 

[357]

I would NEVER run the supply above 14.8 vdc. 20 vdc will give the 16volt caps a lot of grief. Check the voltage at the cathode of D301. Should be about 6 vdc. Make sure that D301 is a 6.1v zener. BTW ... what kinda wattage is it putting out when it gets hot ??
Also ... bypassing the ceramics can't hurt.

- 399

Yep diodes are good.
6.1v and 17.2.
I dont run the radio on the internal at all right now, especially testing.

357, here is the switching supply i bought:
http://rover.ebay.com/rover/1/711-5...0001&campid=5336136228&icep_item=161857689063

you only have to change the value of one resistor to get the voltage up to 13.8.
can't remember which one right now, but if you buy one i will look and find out.

I used a bit of ferrite on the input and output wires, but that's it.
no noise in the receive at all.

also, i had a similar problem with a 139XLR power supply, and it turned out to be the VR.
you might try replacing it.
LC

hmm the vr


I wish I could find a voltage chart for the regulator circuit.
I put the 2sd188 back in, noticed less voltage drop when applying load.
gotta find a 200ohm vr

 

[357]

rt301 6.8 center 8.4 and 4.5.
rectifier 20vac in 25.7 out.

 

[357]

anyone has one of these from a parts radio for sale, let me know.
Mine is obviously possessed
I the mean-time, I'll try one of these

 

[357]

I wish I could find a voltage chart for the regulator circuit.

Hmm the TR302 is only getting 6V on the base.
The 470 checks out, the bz162 is 17v...cap is new, tested twice, c945 changed no diff.
Tested another rectifier, no diff.
The VR seems good, voltage on all legs.

 

[357]

Jeesh I thought I had problems..

 

[357]

I found the problem...C311
power supply now stable.

 

[David Goodman]

This is really nice 357.

you are really going all out on this one!
you know when you start cracking meters open, you are doing the full detailed restore.

some things to remember not to forget:

1. clean and oil all the little clock gears, being VERY careful not to get any cleaner or oil on the number plates.
2. give all the VR's on the PC board a quick spray with contact cleaner, and work them back and forth to clean them. (if you are worried about changing the setting, just take a reading before and after)
3. since im betting that you can't find a quality speaker that will fit, i believe there are some techniques that the antique radio guys use to re-condition the speaker cone.
It would be worth looking into, as i can't quite remember which one was best, but i believe one method was mixing elmers glue with water and brushing it on the cone.
apparently it makes a big difference if your speaker paper is really dried out.

you probably are already on top of these things, but i thought i'd add them to the thread.

are you modding the radio as part of this restoration or keeping it all stock?
LC

Hello. I decided to get back into CB’s and began looking for an older base station to start. I found a Centurion 40D. This is crazy, but the unit was brand new in the original box. I am going to set this unit up soon. I know it is hard to believe it is brand new but seriously, that is no joke. I was shocked when I saw it in person. I pulled it out of the plastic and plugged it in. Please forgive as I was an enthusiast 40 years ago. I plugged in the unit and the LED’s for the channels did not light up. Also the meters do not light. I will put up our antenna this weekend. However, should I be alarmed that the LED’s and meter are not lit? I know nothing and I am begging help here with my Centurion 40D. Thank you in advance to anyone who replies.

Regards,
Davids

 

[David Goodman]

Hello. I decided to get back into CB’s and began looking for an older base station to start. I found a Centurion 40D. This is crazy, but the unit was brand new in the original box. I am going to set this unit up soon. I know it is hard to believe it is brand new but seriously, that is no joke. I was shocked when I saw it in person. I pulled it out of the plastic and plugged it in. Please forgive as I was an enthusiast 40 years ago. I plugged in the unit and the LED’s for the channels did not light up. Also the meters do not light. I will put up our antenna this weekend. However, should I be alarmed that the LED’s and meter are not lit? I know nothing and I am begging help here with my Centurion 40D. Thank you in advance to anyone who replies.

Regards,
Davids

Hello again. Alright, so I forgot that these have an AC/DC option. All lights are on. The the unit was made when I was 9 years old and I am 50 now. It was turned on for the first time today. Pretty cool.

 

[Riverman]

Sounds like something I'd do, David.
How about a pic with it all lit up? Those are beautiful radios. Never had one, but wanted one.