To me, the fun part is designing and scratch building equipment several
orders of magnitude past this MFJ Box. I took my Amateur Radio exams when
one was required to draw schematics and write answers to essay questions and
actual use equations... that was during my freshman year in high school, and
about a month later I passed my 1st Class Commercial with Ship-Radar and
Radiotelegraph Endorsements. Actually, do to circumstances of 'life', when
I have let my tickets lapse, I've probably retested for Commercial and
Amateur Extra 4 or 5 times each over the years. And... I had to walk 30
miles (one way) to Chicago to the FCC Field Office... up hill, both
directions.

The context of the MFJ control box, to me, is the same as my kitchen AM
radio. If it doesn't work, I want to fix it, expeditiously, and be on my
way. There really isn't 'detailed' theory to deal with in the MFJ Box or my
AM Radio that was not covered in my high school Physics Class many many
years ago... of course today, it my seem complicated to many. Those
multiple choice questions are a real killer... you need to read over the
pre-published answers. Is that 'reverse engineering'?

There is nothing secret or revolutionary about the MFJ control box. After
using the box for 10 seconds it is manifestly apparent how the circuitry
functions. I do not have the time to waste tracing PC board foil, removing
and bridging components to find there values, let alone dealing with parts
that don't have a trade-standard part number. If that is exciting to you...
I guess everyone has their own particular level of abilities.

Plodding along, hit or miss, hoping to stumble across the defective
component(s) is the type of endeavor I'll leave to others.

Why in the world would I appeal to anyone for pictures when I have the
actual device sitting on my work bench? The components that had an physical
anomaly associated with their defective condition have been replaced.

A picture is worth a thousand words if it is a schematic... and worth much
more than that if it is valid set of equations.

If I need some "Already been done." electronic' stimulation I can page
through my Patents, EE Degree Thesis, books and papers, equipment I have
designed and constructed, and patents granted and denied.

My preference is for new projects under way... finding another original
project... or, for that matter... just sit down at the key and spend an
evening on the CW sub-bands. I'll leave the reverse-engineering to others
that are much more easily satisfied with that type of thing. My appliances,
however, I want a schematic and parts list... and be on the road again as
quickly as possible.

Hey... thanks for your comments... but I'm ONLY looking for a SCHEMATIC...
not a lecture or assumptions concerning my technical knowledge.

Emil







"328X1" wrote in message
...

Hello.com;695887 Wrote:
Lightning damage to an MFJ-1786 control box. Looking for a schematic.
Thanks.

Can't get a response from MFJ.

Merry Christmas all,

w9nm
at
sbcglobal
dot
net

I have always heard part of the 'fun' of Amateur Radio, is self
instruction. Since the MFJ-1786 Manual is readibly downloaded from
several source; and the fact it goes into very detailed 'theory of
operation', you probably don't really need a schematic drawing. Rather
than a schematic, I'd suggest appealing to users, for someone to take
good [and multiple] digital photos, then you can use them as a
'pictorial', and compare to your unit. Someone said 'a picture is worth
a thousand words' ; and they can help, if you actually do a reverse
engineering, and produce a schematic.




--
328X1