classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view


I have posted this once before but thought I might ask again if anyone
else has had this problem lately that did not deal with the filter
settings being set wrong.  My filter setting are correct I have doubled
checked them. I have a 2.7 stock filter with the offset at -.85, which
is what is written on the filter.  I have had this rig for about 3 years
now and never a problem on the transmitt.  It does not pass the 5 or 50
watt calibration.  When in transmitt is shows 0.0 watts out.  On the 5
or 50 watt calibration test , it show 1.4 watts out .    I have also
been in contact with Gary at Elecraft, but I guess that are gone today
and probably the rest of the week for Thanksgiving.  So I thought I
might ask here if anyone knows what else I can check for this problem.  
This is what Gary advised me to check and I have done so.
 From Gary-AB7MY at Elecraft:
*T**ry checking the TMP cables inside the rig are not loose, and also
wiggle the TXCO on the KREF3 board to see if it is not making good
* *
**Was there a storm nearby with lightning recently? If so, some damage
may have occurred to the PIN diodes in the rig.***( Yes but I had all
cables unplugged from rig except power from power supply and computer)
**See if the gate to ground resistance on Q2, Q4, Q5 of the LPA is quite
low, or much less than 1K to 2.5K which is the bias pot setting for
those transistors. Also you can touch the tabs of the 3 LPA transistors
when in transmit for 1-2 seconds to see if they are not getting warm as
expected. Do not transmit longer than that with the bottom panel
removed, and use care to not burn your finger.**
These are my findings so far.  on Q2   4.26k ohms,  on Q4  3 k ohms and
on Q5  3 k ohms.  The LPA transistors seem to warm up also,  as tested
above.  All cables and TXCO all seem to be fine also.

I was hoping that some of you tech guys might have idea of what I can
test next.  Looks like I will probably have to send it in, but would
like to find a fix, if I can.  Bad time of year to send it in with all
of the Holiday's coming up.

Any help would be great.

K3# 3906
Elecraft mailing list
Post: mailto:[hidden email]

This list hosted by:
Please help support this email list: