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The TS-830S service manual's alignment procedure, Step 9 ("VCO adj &
check") contains the PLL coil adjustments for the various bands. The procedure calls for a frequency counter and DVM. Here's my confusion/problem: the measurement point for the frequency counter is shown as: RF(PLL) - TP3(D40) I interpret this to mean EITHER: TP3 on the RF assy, OR D40 on the PLL assy But, perhaps I am mistaken ... I see a vast difference in the signal levels at these two test-points. The signal at PLL-D40 appears to be correct (i.e., when I align the tuning coils specified to produce a 4.00 VDC level on the DVM at PLL-TP1, I measure a 1.058 vrms signal at PLL-D40). But, the 2nd step in this section then calls for a check of the signal level at RF-TP3 to be 1V (+3/-2 db). But, the signal level at RF-TP3 is so weak as to be almost un-readable (I measure ~5.0 millivolts). Final info: I measured the signal level on the RF assy at the junction of L44 and L40, and it is approximately 95% of PLL-D40 total, so I know that: a) the VCO cable carying the signal is making good connection and not hi-Z, and b) L44 is NOT open, c) C61 is NOT shorted, and d) L40 is PROBABLY not hi-Z. Which all leaves me with a partial (or full) short at RF-TP3 (what _should_ the inductance value be of the primary of T3 on the RF unit be?), or am I simply not interpreting the alignment test-points and procedure correctly? BTW: the frequency at PLL-D40 is ~1500 Hz too high. Anybody have any ideas??? |
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