[Elecraft] [K2] No Transmit Power

[Don Wilhelm]

  Brian,

Did you use coax for the lead from the RF Probe to your DMM?  Behavior 
like that indicates noise pickup after the detector diode - RF? Magnetic 
coupling?  It is really difficult to say what, you will have to examine 
your environment as well as your meter.

Yes, unless you can get the stray pickup (from whatever source) out of 
your DMM, you will have a difficult time doing any transmit signal tracing.

Hint - take your DMM into work with you and do a 1 to 1 comparison in 
the same environment with another meter.  If there is noise pickup on 
your meter at home, but not at your work location, having your DMM with 
you at work will reveal that condition.

73,
Don W3FPR

On 10/4/2010 10:18 PM, Brian Denley wrote:
> ?Don:
> I am still trying to get my K2 kit to transmit.  Since my last post, I have
> purchased a power meter and confirmed that virtually no power comes out of
> the antenna jack when the transceiver is keyed (the meter barely moves on
> the 20 watt scale).  I also purchased a new RF probe kit and so far have the
> same dismal result:  the lowest voltage I can measure (probing nothing) is
> 380 mV, and also 380mV when I attach the ground clip to the probe tip.
> Touching my finger to the probe tip gives no result as well.  This probe was
> built with new components from Elecraft, the diode is in the way the silk
> screen indicates (for the banded end). there is no other way to build it!
> The only idea I have is to take the probe into work and check it with a nice
> new Fluke meter with the idea that my 2 multimeters are just not suitable or
> have the wrong input impedance (needs to be ~10Megohms if I understand the
> probe circuit).  Without some way of measuring RF in the transmitter circuit
> I am just shooting in the dark.
>
> I attempted to check Q24 but it's solder joints are placed right under the
> small SMT board that is mounted on the backside of the RF board and
> difficult to reach unless I remove that board.
>
> Brian Denley
> http://home.comcast.net/~b.denley/index.html
>