[Kenwood] TS830s Receive Problem - Need Some Help

[Pancake, John W CTR USAF 721 MSG/CEO-PWT]

Good Morning All - 

 

I'd like to ask for the group's advice in resolving a receive issue with my (previously OK working) 830s.  I'm scratchin' my head on this one, hi.   

 

I've been upgrading it with several of the improvements that Richard Measures, AG6K, suggested (#1, #3, #4, #7, #8, #11, #13, #16). I have done these in the past with other 830S with good results... until now. I have double-checked all my work and haven't found any mistakes. Antenna is verified as working properly.

 

PROBLEM #1: Receive sensitivity is terrible!  AF gain has to be cranked up ¾-to- full to hear anything on any band. 

 

PROBLEM #2: The S-meter needle has NO movement at all even with strong local signals from the antenna (AGC switch is ON). 

 

Using the internal calibrator as a signal, the AF gain volume is NORMAL but again, absolutely no S-meter movement as I sweep the VFO thru zero beat. AGC switch is ON. 

 

With the antenna connected, it acts like something is "swamping" the input signals. I say this because when I applied a good (1mv) signal from my RF signal generator to the ANT input,  it produced normal S-meter action and normal volume in the speaker at minimum settings of the AF gain control.

 

I did carefully solder the RIF coax cable end pins to ensure good electrical continuity. It helped bring up the audio a bit but it is still very low. AGC voltage measured correct. RF gain control works properly. The first ANT coil (L41) and Q5 (replaced with new) on the RF unit check good. L41/L13 peaked just fine using an AC millivoltmeter on the speaker terminals. 

 

Took some voltage readings at Q1 (rf amp) on the RF unit. Voltages at G1 , S and D appear to be reading LOW ???

 

terminal D (to L13) = 11.8vdc (schematic calls for 12.4vdc) ???
terminal G2 (to R12) = 2.7vdc (schematic calls for 2.7vdc)
terminal G1 (to R11) = - 0.6vdc (schematic calls for +1.1vdc) ???
terminal S (to R13) = 0.13vdc (schematic calls for 1.0vdc) ??? 

 

I'd greatly appreciate it if anyone has a suggestion or two as to why the S-meter is "asleep" and RX sensitivity and volume is so low but everything seems normal when the signal input is from my SSG... Thanks & 73, Bill, w0ng