Unlocking Full 40 Channels & 4W Power for CB Uniden PRO440 (Similar to President Herbert)

Already the second day in turn, I browse the net in search of info on how to unblock full 40ch in AM and power up to 4W. I could not find on the forum answers to these questions for this CB model, maybe one of my colleagues has processed such a copy, I will add that from the look of the front plate is very similar to President Herbert

Does this device have an autotransformer in the modulator circuit? Because if you do not, then you can not achieve 4W in AM using simple means.

I can visually judge that the autotransformer is, unfortunately, more accurate navigating the radio without a schematic is difficult, on any site where is mentioned about the company uniden, there is no copy, maybe there is a counterpart in another company and you could scheme "borrow", if someone recognizes the equivalent of another company, I attach a photo, I will add it with radyjko on synthesis SM5124

One Stabo is similar to this, I do not remember the sign.

I have checked all that I have found, and nothing radio further 12ch AM ... I tried to find some switch by channeling the blockade, I read that it helps to connect it to the mass ... but without the scheme can make more of a mess than it is so I'm still in the exit point ....

As a standard on radios with mechanical channels you have to find a foot from the channel switch, on which the state changes to the opposite one when switching from 3 to 4 channel and 15 to 16 channel. Then, depending on the solution used, you cut off the path to that leg and attach it permanently to the state in which you have broadcasting and receiving over the entire forty years. In addition, you still have to tune the radio in zero, or coil or even a 4.7?H choke - 6.8?H in series with the quartz from the synthesis. Good luck.

I have already tuned the radio to "0" along with the quartz 18pF capacitor, the rest of the trimmer, there is still a problem with channels in AM and power, thanks to more specific tips, I will try to put them into practice But I'm still waiting for any info, maybe somebody I already played with this model

The matter looks a little mysterious ... In total, there are 3 mugs on which the state changes from "0" to "1" ... I tried to cut through the paths and give the pins opposite states but nothing of this fun did not work out, I wonder what still, I managed to bring to life the "RX" indicator which outside of 12 in AM did not shine, but it ended ...

Did you try to connect to all at once? If it does not help, check the two male transistors near the end I had once something, but I do not remember how it was unidena and it was quite a long time.

SM5124A, remove the fourth leg from the plate and stick to the mass (give the low state) and we have a full 40-piece. At this PLL, nothing is blocked by an encoder (channel switch).
At least this is the result of application SM5124A. I have not tuned the radio for a long time but I did it in other radios based on this synthesis, eg Stabo XM512.

Unless you are unlucky and another German patent but I doubt it

Quote:

With this PLL nothing is blocked by an encoder (channel switch).

In none (at least in those that I unlocked) popular CB radio is not blocked by PLL directly with the encoder. There is just a leg in the encoder that changes to the opposite state when switching from 3 to 4 and from 15 to 16 channels. How this signal is further used to block the AM depends on the constructor of the given radio.

Unfortunately, shorting the 4 knives of the SM5124A system did not give anything, no change whatsoever, I no longer know how to unlock this miracle ...

Nothing was missing ?? Ie. what does not switch to other channels ?? in AM does not it put up a carrier ?? because if it does not put a carrier, then it's coded by the encoder voltage on the WCz. I will try to give the method 100% at night as I will have a moment and check because I have Pres. Jimmy and it's the same construction.


Misleading sorcery SM5112A gives the state of the nap during the blockade. on 4 pin (check during filming) and it is controlled by the VCO blocking transceiver at the moment of supplying the fuel. Connect the resistor to the ground (after it is a diode) which was pinned to the 4 SM pin ... Now you have to check on which encoder leg (not connected with SM51 ... change L status to H mass) If you have not done on this radio the new it is also possible to try to mass only pin 34 at the front panel or in other versions 39 (their state should change at the time of blocking) If it is not some exotic radio series it will be in the middle as in Stabo XM512 .. . but as I wrote, I will check in the evening and make sure

he describes in a shortcut how a radio from the very beginning behaves ... even after closing the 4-n synthesis sockets. You can change channels from 1-40 both AM and FM without any problems, and the difference in AM below the 4th channel and above the 15th is based on the TX indicator on the radio, but no power is emitted (no bearing), there is also no hearing, if it's something I can help put pictures of both sides of the motherboard

@ gregorio27, So it does not really match what you wrote, but in turn:
- Only pins on which state changes when passing from channels 3na4 and 15na16 are pins 10,11,14.

Quote:

Connect the resistor to the ground (after it is a diode) which was pinned to the 4 pin SM

... so there is no resistor you wrote about, it is the diode itself, but as I wrote, nothing changes on this pin, so it probably does not make sense to connect it to the mass ...

So, go this way - radyjko has a patent in the form of a mechanical lock on the encoder. Pin 10 - 17 on SM5124a is connected to the encoder and number display. So, take a look at the other outputs on the encoder that are not connected to these pins, when switching to blocked channels. I do not have access to this model right now, but it should have pins connected to 2 or 3 jumpers on the board (if the sockets do not fail ) on the back of the encoder.
Uh-huh. It may still be so (sometimes it is misleading) that on these pins (jumpers) there will be no voltage only will be unplugged from the mass when entering the blocked channels, so you need to dry In then the leg changing the connection permanently massage ...

greet you with a photo of the middle @ can remember where you need to