President richard troubleshooting

[iceman303]

Hello friends. I recently bought a President richard. It's working well, good transmit power ( 4w am, 20w ssb ), and receives well, but it has some faults. Alc and Amc do not work. I can turn the alc vr down and the power is still at max. It makes no difference when turned. This also happens with the amc, when turned down, modulation is still full, and I see it stays the same on the oscilloscope. Modulation looks a bit assymetric on the scope. Am power vr works, I can vary the power normally. Maybe the amc/alc amp ( or maybe att ) is not working. Any help about this is appreciated. Maybe I should check those transistors voltages, and the signal path to the amp or att? Also, I will add 2 higher bands, and a lower band, via a diode matrix. Any suggestions of what I should do. Should I adjust pll voltage, or any pots? Do I need to add a capacitor to allow correct operation on these bands? The radio seems original, I have not seen any evidence of any repairs. I have an multimeter, an oscilloscope, a signal generator, and frequency counter.
Any help is very appreciated. Many thanks in advance.

Joao

[cb4ever104]

Firstly 20W SSB is too much . Turn it down .

If your ALC and AMC VRs aren't working then check the states of TR34 and TR32 . 32 seems to go faulty quite often .

I usually only add the HIHI and LOLO . I've attached the diode configuration (Thx to Nick for this) , and also this "Just infront of the PLL there is a very small sized electrolytic which if i remember right is about 0.22uf, Just remove it, It prevents any "trumpeting" on the bottom end of lo.lo.

Don't forget to link PLL pin 9 to the blank 4008 pin too otherwise only around 13 channels on hi.hi will work. [Remove the jumper from PLL pin 9 to ground first]

I have never done the HIHIHI , and I haven't worked out the N codes , but they're probably on-line somewhere .

Regarding the capacitance . If you look at the schematic you will see that the SFT line that goes to R149 is normally grounded on the HI band , and has 8V fed to it on the MID and LOW . I normally replace the 3 way with a 5 way and keep this configuration on one of the switch poles , but also ground it on HIHI and 8V on LOLO . You might have to adjust the VCO a bit after adding the bands .

DSC00989.JPG

[14CS06]

Hello

Service manual Président richard

http://78roger.free.fr/president/manuel ... ichard.pdf

@+
Claude

[iceman303]

Hello again friends. Thanks for your replies. Paul, thanks for the help. I will check tr32 and tr34. I will follow those steps when adding the extra channels. Thank you Claude for the service manual. I will post results when I check the radio.

[cb4ever104]

Hello again friends. Thanks for your replies. Paul, thanks for the help. I will check tr32 and tr34. I will follow those steps when adding the extra channels. Thank you Claude for the service manual. I will post results when I check the radio.

and

Firstly 20W SSB is too much . Turn it down .

Once you fix the ALC VR obviously

[iceman303]

I opened the radio to check the transistors, and tr32 was missing. I put a 2sc945 in there. When testing, modulation was low, only 1 watt on ssb, and low modulation on am, and the alc and amc vr do not have any effect. I guess someone removed tr32 because of this fault. Voltages on tr34 are all ok, both rx and tx. Voltages on tr32 are all ok, but the service manual states 0v for the collector on tx, and I get around 50 to 60mv, that rises with modulation on all modes. ( maybe that's how it's supposed to function ). It seems as if tr32 is attenuating the modulation, regardless of adjusment. I wonder what is causing this attenuation. I will do some testing and try to figure out what's wrong with the circuit. Any help is very appreciated. Thanks.

[iceman303]

After some checking and testing, I solved the problem. Since all voltages were ok, I tried to check why the modulation was low. I checked a few things, and thought it might be a problem with the vr's keeping the modulation down. There was a 100 ohm resistor soldered across the alc vr. ( I had seen it before ) So, I removed the resistor, and the radio is now working properly. I have adjusted am power to 4 watts, around 98% modulation, and ssb to 12 watts pep. I will try to install the extra bands, I just need to get the switch. I will post results later. Thanks.

Joao

[Otter]

Just as a point of interest, and I can't check because I'm not at home for a while, I think there is the PB-010AB President Richard which is a SS360FM with a sticker on the front and there's one with a Ranger board and a black front.

[14CS06]

Hello

There was a 100 ohm resistor soldered across the alc vr.

http://78roger.free.fr/president/richard.htm

http://78roger.free.fr/president/modif/richard.jpg

@+
Claude

[cb4ever104]

maybe that's how it's supposed to function It seems as if tr32 is attenuating the modulation

That's how that circuit works . The more TR32 gets driven , the more the main audio line gets attenuated .

[Stronty]

A previous thread with some info on variants of the Richard can be found here> RICHARD VARIANTS AND MORE
Good luck with getting it sorted, great radio independent of variant really.

[Mudslinger]

Just as a point of interest, and I can't check because I'm not at home for a while, I think there is the PB-010AB President Richard which is a SS360FM with a sticker on the front and there's one with a Ranger board and a black front.

There are 4 versions. Black and silver unidem, Silver with PB-010AB, Black with PB-010AC

Then there are Black and Silver Ranger versions. The Ranger ones are pretty rare, especially the silver.

[Otter]

Ah, yes. The one I don't own is the silver Ranger one. I have the other 3 variants.

[iceman303]

Mine is the Black - Uniden - PB010 A/C with s-meter socket version. The s-meter has a crack on the face and does not work properly, so I bought a new one, and will install it later. I like this radio because I like the design and performance, it reminds me of a cobra 148 gtl. My first cb was a fm maxon with am addded to it, and after that I bought a cobra 148 gtl, that had some low, and high channels added, and also separate -5kc on rx and tx. Later, I also bought a ss3900 black, that I also used for a few years. I sold them both a few years later. I bought this radio, mostly to enjoy some dx on 11m. Thanks everybody for all the help and information.

Joao

[iceman303]

I've added the extra bands to the radio. I added one lower band, and two higher bands. The radio receives and transmits ok, but on the highest band ( 28.325 to 28.765 ), modulation changes pitch a bit, ( moving in frequency ). I also notice when changing channels on that band, if there is some station or carrier, you can hear the pitch change and then settle. I tried lowering the pll voltage, and it helped, it's not as noticeable. Any help is appreciated. Thanks in advance.