Grant PC999AB

[indaso2005]

Hello, I would appreciate help with a President Grant PC999AB without rx (noise only in FM) or tx.
I removed the mods I had and am restoring them, I can't identify the faults. Help.
- TR50 very hot in ssb
-VR11 does not adjust bias

Thanks

[ch25]

Check VCO first

[indaso2005]

Hi, thanks for the help.
Tests:
TR25: b=1.9 c=7.68 e=1.38
TR26: e=0 c=3.5 b=0.7


Thanks

[13EL121]

Old electrolytic Capacitors?

[indaso2005]

Hello, I have already replaced all the capacitors.
Thanks

[ch25]

Was it working before cap replace?

[indaso2005]

No, the same symptom.

[bitbang]

Hi,

TR50 normally runs hot in SSB RX/TX in any case wont stop RX from working
TR25: b=1.9 c=7.68 e=1.38 OK
TR26: e=0 c=3.5 b=0.7 also OK

I do not know what kind of test equipment you have, if only a multimeter then I would try and find out if the VCO is locked or not.
Check PLL pin 9 (VCC) has 8v on it then check pin 6 (LD), it should be around 8v if locked and around 0-1v if unlocked.

Schematic if you dont have it: https://cbtricks.org/radios/president/g ... dx_sch.jpg
Transistor voltages: https://cbtricks.org/radios/president/g ... tricks.gif

[indaso2005]

Good afternoon, thank you very much for your help with this problem.
I'll do the tests.
Thanks

[indaso2005]

Hello again, among other equipment I have an RF generator, oscilloscope, multimeter, frequency meter, etc.
Pin 9 - 8.27v
Pin 6 - 8.1V

thanks

[indaso2005]

Good evening, I took some measurements; TR31-0.0/0.0/0.7 TR32-0.5/0.7/0 TR33-7.69/8.09/7.9 TR35-8.3/8.2/7.6 TR36-0.68/0/0
TR37-8.35/0(8.0)/7.8 TR38-1.04/12.66/1.6 TR39-13.35/836/12.63 TR40-1.14/3.5/0.51

I need help, I'm getting desperate.
Thanks

[Mitch]

Have you got the service manual?
https://www.g7syw.com/files/uniden-expo ... manual.pdf

[indaso2005]

Yes I have.

[indaso2005]

Hello, does anyone have photos of the PB-005AA board connections??
Thanks

[indaso2005]

According to the alignment, TP9 and TP8 without bias, vr11 doesn't change anything, PLL problems in tuning the frequency, etc. etc.
I need help, I can't find the problems using the circuit.
I would appreciate it if anyone could help, I want to restore this old radio but it has a lot of problems.
Thanks