If, before using the MFJ tuner, you transmitted into a high vswr,
you may have blown your final output transistors. A similar thing
happen to me running a Century/21 mobile.
73, de Joe, AA4NN
On Tue, 3 Aug 1999 23:11:30 EDT Kb4utv@aol.com writes:
>
>I have a Century 21 with a drive problem. It is hard to get the full
>60
>watts input without drawing to much current from the power supply. I
>get the
>hum in the side tone whenever this occurs. Also when it seems to be
>behaving
>itself, the power output will flucuate between 30 and 15 watts, never
>a
>steady output/input, but not a large current pull on the power supply.
> I
>checked antenna, coax, etc to be sure I wasn't getting a mismatch. Am
>using
>a MFJ Tuner. I think it might be associated with the power supply.
>The
>switching transistor on the rear panel, I believe it is a 2N3055, gets
>really
>hot. Could this transistor be the problem? Looking at the power
>supply
>diagram, I think this is what regulates the voltage for the drive
>operation.
>Am I on the right track? Any suggestions most helpful. 73's John
>KB4UTV
>
--
FAQ on WWW: http://www.contesting.com/tentecfaq.htm
Submissions: tentec@contesting.com
Administrative requests: tentec-REQUEST@contesting.com
Problems: owner-tentec@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|