Hallo Orion users,
2 weeks ago I`ve got an Orion1. It was announced to be full ok.
But as I switched it on , I saw the display was a little dark in the
upper left corner
and was flickering during transmission.
After a discussion with the former owner i was looking for the reason.
After studying the schematics and some measurements I found the reason .
The +5volts- voltage on the power distribution board A9 is unstable.
During transmission and by changing the power voltage e.g. the
5V-voltage alternates between 5 and 4,4 volts.
At first I tried to get an new board . But it was not on stock at Ten Tec.
Then I found this forum here and could learn what has happend before
with some failures around the unstable 5 volts.
But changing the recommended board-capacitors brought no better results..
Then I saw a difference between the board schematic and the circuitry on
my A9 board:
On my board the upper PNP -transistor was not the original type TO220P
NTE 378.
Ten Tec had used -how long?- another type BD246C .
Because this one is a TO3P Type and not fittable onto the bord , it was
mounted very carefully-like production people do it-
via 8cm long wires beside the A9 board on the al -case.
I am very sure this outsourced transistor has worked in my Orion since
it has left the production.
( Serial Nr. 10C 10584 in 2005)
I ordered- over night- the the original NTE 378 from a semiconductor
dristributor, placed it next morning
within 15 minutes directly onto the board and it worked perfectly.
see http://www.qrz.com/db/DJ8LX
The +5volts are stable under all conditions .
Now I am very happy with my Orion.
best 73
Heinz , DJ8LX
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|