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I need some help from the reflector guru's in buildng a plain old KAT-100 in the original case.
My problem is that I cannot trace the input power (Nominally 14 VDC) from the coaxial power connect beyond the junction of the 12VDC terminal of the 7805 regular and R13. There is 0 VDC at this intersection. This should be easy to find, and I have reflowed all the solder joints in the area. Here are the voltages:
Location Voltage DC
J1 center pin to grd. 14.26
Diode D4 Anode (i.e., line end) 14.25
R12 to Q1 Base 14.23
R12 to Q1 Emitter 14.24
U8 in terminal (marked 12 VDC) 0.00
R13 to PR1 0.00
P3 Hot to Grd 13.34
My guess is that ZTX789A Q1 is a bad part or that U8 has an internal short to ground and pulls everything to zero voltage (nothing is hot however). I have spare 7805's but I do not know if replacement is a good idea without determining the root cause.
Any consel would be appreciated.
De WA3SGZ Les
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