Admiral 20B1 Combo restoration

[SwizzyMan]

OK I think my agc circuit is a bit off and this may be my sync issue. At the junction of the .5 uf agc filter and the 47k agc dropping resistor the voltage when a signal source is connected should be -5 volts but I read -4.17 volts instead. The problem is that I replaced that resistor and that capacitor. Also I am using only one lead of the antenna connection since the other one broke off yesterday but I had the same issue before the lead broke. What do I do? replace all the agc resistors? I know that the tubes involved in this circuit are in fact good.