Mark,
Most of the Paragon troubles are caused by poor solder connections. The
cure is to resolder all connections on the PLL board. You may have to do
this on both boards.
There is a test point at the junction of Q1 collector and Q3 collector
on the major loop board. Using a voltmeter at this point you can check
the PLL voltage. The PLL is broken into 4 bands as follows:
1) 22 to 30 MHz
2) 14 to 22 MHz
3) 7 to 14 MHz
4) .1 to 7 MHz
THe VCO coils are in a row with band 1 (22-30) on the left. You can
adjust the coils. The voltage on the test point should vary from about
2.7 V at the low end of each band to about 7.6 V at the high end.
Also, if your Paragon has a potentiometer soldered to U3, adjust the
potentiometer for 3.2 V at its wiper or center contact.
Good luck and 73,
Bob WB2VUF
elstar/mt wrote:
>
> Hi
> Paragon 585 PLL seems to be problematic for service.
> It´s hard to get real idea of Loop data and reason of
> error signal. Scope pictures and information of external
> generator data to MC14158 should help.
> All helping tips are welcome , please.
>
> Mark OH3LX.
>
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