[1000mp] Receiver Attenuator - defective

[Mike Gilmer]

There are two attenuator circuits in the MP - a 6dB and a 12dB (the 18dB
position uses both).

R1039 (47ohm, 1/10 W) on the RF unit (according to my service manual) is the
culprit (it's the series resistor in the 6dB pad switched by RL1003).

Now the fun part: The resistor is on the RF unit, which is located under the
poweramp's heatsink/fan, which in turn is under the top cover.  It's near
relays RL1002 and RL1003 on the underside of the board.

Mine popped last year - better that than the front-end!

Mike N2MG



PY2XB wrote:
> I have the same problem reported in the emails below. Per diagrams
probably
> resistor 1151 (47 ohms) opened. Anyone could give some tips on where these
> resistors are located, what a type of resistors and what to expect when
> replacing them.

> HA1AG wrote:

> > You have blown a few resisitors in your ATT switch. It's quite
troublesome
> > during the contest and they are easy to replace. They act as a sort of
fuse
> > so to say.

> > GW4BLE wrote:
> > >
> > > When switching in the 6dB or 18dB attenuator on my 1000MP
> > > signals disappear
> > > completely,  the 12dB position appears OK.   Same on all bands.
> > > Rest of the receiver runs as-normal.
> > > Any ideas?
> > > Maybe blown something running SO2R in last weekends' CQWW ?