(Ok Thanks Jim thanks! I sent it with windows mail).
I have two 425 with these in them.
Just an FYI.. I was able to trace out the transistor circuit. They put
the adjusting pot for the RF power output meter on the display board, as
well as the adjusting pot for the BAR GRAPH meter. Both of them on the
bar graph meter board. There is a single NPN transistor voltage
amplifier to drive both meters.
R13, on the SWR board, has been removed and bypassed, and R12 changed to
330K ohm.
Also, the high voltage metering resistors have been changed from 1
megohm (3 of them) to 820K ohms, X3. Only one of these late model units
had the 820K ohm resistors, and one had the original 1 Meg resistors,
the other the 820K resistors. The 1 meg resistors had changed higher, so
the meter could not be adjusted properly. I had some 449K resistors from
a WD7S board, and put 6 of them in, in place of the 1 meg. Still could
not get the HV meter to come up high enough. So i removed 1 of the 499K,
and now have full adjustment.
Something to add/change on your Titan 425 schematic. Even if its by some
notes Jim.
*I love that schematic Jim! So much easier to troubleshoot and
understand whats what.*
Thanks
73
Jim W7RY
On 3/15/2020 1:16 PM, Jim Brown wrote:
This often occurs when someone sends an html formatted post to a
reflector that only takes plain text. I know that other contesting.com
reflectors reject html And since I value your posts, I wanted to let
you know.
I have several 425 manuals. I'll look through them.
73, Jim K9YC
On 3/15/2020 10:46 AM, Jim wrote:
Why would this be blank?
Thanks
73
Jim W7RY
On 3/14/2020 1:55 PM, Jim W7RY (Shack) wrote:
Does anyone have a schematic or board layout for the Titan 425
display board 81220* Rev B*.
This board has 2 pots and a transistor. All of my manuals show just
one pot and no transistors.
Thanks!
73
Jim W7RY
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