Don't jump to conclusions just because one is nearby.
Are you pulling current on tx?
If so how much?
It's possible the low level driver went out.
Can you hear yourself in another receiver?
Mike wb8vge
Sent from my iPad
On Oct 14, 2013, at 5:28 PM, Paul Harker <paul.r.harker@gmail.com> wrote:
> I am a new member of the amateur radio community, and my first HF rig is an
> Omni C. I was attempting to tune an antenna with a MFJ949E, with the mode
> select switch (SSB-R / SSB-N / CW / LOCK) switch in the LOCK position, and
> DRIVE set just high enough to allow tuning.
>
> Suddenly the antenna tuner needles dropped to zero, and it appears I no
> longer have RF output. The Model 255 power supply did not shut down, and
> the receiver is still functioning. I am assuming that I managed to blow the
> MRF458 output transistors due to doing _something_ wrong. Maybe just a
> matter of fiddling too long and letting things get too hot. I don't know.
>
> Measuring the MRF458 with a meter suggests they might be bad, but it isn't
> a case of a dead short, and in the past I've found that power transistors
> can be deceiving when doing an in-circuit test.
>
> So... I looked for any sign of a fusible link or other protective circuit
> in the Omni schematics and didn't see any, but I thought I'd ask the
> experts before pressing "sumbit" on a transistor order.
>
> And any hints tips corrections to keep me from repeating my bungle would
> also be appreciated.
>
> Much thanks,
>
> Paul
> AC8OI
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|