gypsym...@aol.com wrote:
k4...@mindspring.com writes:
Hi Garey,
The counter preset information is carried between the Digital
Board and the Translator Board on the pins on the left side of the
DR-7,
and they are susceptible to solder cracking with age, stress.
Will pull the DR7 again next checking all the pins and solder joints
on the board..
If I have not mentioned all of those pins were resoldered last spring.
Gary P. sent me a sheet for checking binary on the Translator board
with the band switch at 28.5.
He did not indicate pin 45 (it was literally zip as in .1) however
pin 43 was HI and he said LO. ??? I had not checked any information on
the above....so more research.
Pin 49 should be chassis ground. Pin 43 Hi is a problem. Does it EVER
go Lo on any other band?
Now for the bad . I realized that I had never reseated the power
supply board. Have now done so twice with deoxit on the second pull.
Pin 1 (regulated - 5) you said 3 to 4 was -3.241 >>>>OK
Pin 2 (regulated 25) you said 24...SxxKs at +21.61 >>>> Not good.
Should be 24 VDC +/- 0.5V Make sure the top half of the DC-DC
converter transformer is "TIGHT" against the bottom half. Even a
slight gap here will hurt. You should have 30V on the input to U2103
Pin 3 ground for above checks....also cross checked with just a case
ground.
Pin 10 (Reg +10v) +10.04 and the same off of the resistor at the top
of the board. >>>>> OK
Pin 11 (Reg +5) +5.02 >>>>> OK
Pin 12 ground for above, couldn't get to, and figured I didn't need to.
Now I know I have to pull the PS and rework too.
I did note that C2103 (on output pins)which was supposed to be a 10
mf @25V was a 470 mf <mailto:m...@25v> @ 25V. But that should not have
made that much difference, just a longer time rate, and it was there
prior.
>>>> OK this was a field change I believe.
Snow on ground, cold temps, wife upstairs napping with grandson due to
wake up....
What better day to work on a radio. >>>> :-)
73's Carl wd8nhk
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>
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