K2 - Day Twenty Four... sort of

I have lost track of how many days I have spent 30-60 minutes here or there trying
to track down a low power/Hi Current issue.

It turns out that I had two issues:

1. Low power... about 4-6w instead of 14-15w. After looking at and touch every component
in the PA Bias and PA circuits it looks like there was something wrong with T4. I
am not sure what... but the problem has been resolved.

2. High Current... looks like L16 and/or L17 in the Low Pass Filter was the problem.
I removed them and rewound them.

I spent about 6 hours working on the radio today. (About 4 hours of testing... about
2 hours of construction/repairs.)

I am happy to have a working radio. I hope to be able to spend a little time tomorrow
tweaking up the 10m/12m power levels and then button up the radio.

I am ready to move on to the ATU and SSB module kits next.  :-)

Faster

My ISP did some tower work last Friday to resolve some of the performance and outage
issues that my area has been experiencing.



For some reason things are sluggish this AM even though the speed test looks ok.

Sheer Pin

Here is a better photo of what the sheer pin looks like.

Sheer Pins

I was not sure why my new 50" snow blower as pushing more snow than it was blowing
yesterday. As it turns out the two sheer pins let go.  The only thing moving
snow was the second stage auger.

I had some spares so it was not a big deal to fix it in my heated garage. I think
that I will stop by the hardware store today and pick up some spares. --It is supposed
to snow again tonight.

Scotty... I need more power!

My ISP seems to have an issue for some reason.

Icom 208H - Skip Channel

Among the many amateur radios that I have in shack is an Icom 208H. It has been sitting
here largely unused. With winter approaching I figure that will be in my shack or
near my work bench quite a bit more. I decided to spend the money and get the proper
software to be able to program my radio via my PC. I ended uploading in repeaters
and simplex frequencies for the Twin Cities metro, central Minnesota, and as far north
a Brainerd and Pequot Lakes. I also loaded in the railroad frequencies.

I have been pretty impressed the receive coverage so far.

One issue that I have run into when the radio is scanning is an occasional repeater
that is hung up. I can never remember how to configure the memory to skip the
channel.

Now it the note is posted in my blog where I can find it.  :-)

K2 - Day TwentyThree

I am trying to track down why my power output is low. I have a couple of hours into
this today... my vacation day (use it or lose it)

----Snip from the email that I sent to the
Elecraft Reflector----


K2 gurus:

I got a note from Gary (support) and Don (w3fpr) with some ideas.

--I checked the low pass filters and the number of turns.

--I validated that T4 is oriented the right direction --No burnt relays

--8R/8T are ~8vdc (R-7.87/T-7.815)

--8R on transmit goes to 0.245vdc

--I clipped W1 to test for PA feedback (no change)


--I removed the bottom panels and cleaned up a couple of joints as a CYA


--Removed and rewound LP for 80m


--Checked & resolder the connections of toroids for 20/30, 15/17, & 40


--Repeaked (on receive) all of the band pass filters with a signal generator


--Repeaked (on transmit) all of the band pass filters

I made some progress: (Original Test... and after some rework)

--Freq-----1 Test----1 Msg----2 Test----2 Msg

 3.750mhz  2.5w     
Hi Cur   2.3w      Hi Cur

 7.100mhz  6.1w     
Hi Cur   6.6w      Hi Cur

10.100mhz  0.3w     
Hi Cur   4.9w      Hi Cur

14.100mhz  0.3w     
Hi Cur   5.7w

18.100mhz  9.5w              
7.3w


21.100mhz  4.1w        
      5.0w

24.900mhz  0.5w             
 4.9w

28.200mhz  6.0w             
 6.3w

As you can see I am now getting ~5w on all bands except for 80m. I suspect
that the toroid cleanup might have been part of the answer for 20/30 and tweaking
the band pass brought 10/12 into better alignment.

On the three bands that I get a high current message it appears at the
peak power out and does go away if the power is reduced. Any chance that I am only
seeing power out of Q7 or Q8 instead of both of them?

>

K2 - Day Twenty One & Twenty Two

Thursday was day 21. I spent the afternoon trying to trouble shoot
an RF issue. I built the RF probe and poked around the radio while I was on the phone
with Scott @ Elecraft HQ. It is hard to poke around some of the RF amp sections because
the bottom cover/heat-sink is in the way.

-------------

Saturday was day 22. I went over to N0FP's QTH. He has an O-Scope.
Between two of us we went thru the schematic and compared notes with the O-scope readings.
We were seeing RF thru the entire chain where we were expecting it.... just not enough
RF.



Using the scope we able to measure the DC and the RF. His scope was fast enough that
we were able to see a lot of detail in the RF. Even though T3 tested out properly
it looked like the likely problem. I rewound it and put it back into the circuit.
I also borrowed some small heat-sinks that would fit on the PA transistors so that
we could test the radio without the rear cover.

I am now seeing the proper amount of RF coming out of the rig. I need to take one
more pass thru tuning up the Band Pass Filters. Once that is done I need to test the
output of each band to make sure that all looks good.



At this point it looks like the circuits are playing as expected. Next phase is to
hook up the speaker and close up the case then the basic build is complete.

I have the SSB and ATU option kits to put together next.

Too big to fail is a sign that they are too damn big!

I think that it
is clear that I have become a cranky old curmudgeon.

 

-------

cur-mudg-eon

 

–noun


a bad-tempered, difficult, cantankerous person.

 

Origin:


1570–80; unexplained; perh. cur- repr.

-------

 

This bail out crap
is idiotic. Companies should strive to have viable business models, provide
leadership, and be able to pick themselves up on their own. Since when did we start
rewarding failure? Maybe some of these companies with poor leadership and/or business
practices should go out of business... let evolution play out instead of creating
another bubble.

 

I never thought
that I would start quoting Ronald Reagan... but I am starting think that he was right.
Look at the bail-out and then consider: "Government
is not a solution to our problem, government is the problem."

 

Too big
to fail is a sign that they are too damn big!

 

Argghhhhhh!

GM - WTF

WTF

Ok.... this pushes me over the edge. GM is now spamming my
inbox with their attempt to get some of the bail-out cash. What a bunch of free-loaders.
They think that they should be bailed out just because they have run their company
into the ground.

I don't see anyone handing me bail-out money or offering me an easy way out.

GM here are a couple of common sense ideas for running your business:

• 
  Provide some real leadership, vision, and consider innovating again.
  


• 
  Maybe come up with a couple of vehicles that people are interested in buying.


• 
  Dump some of the crap from your product line that is no longer viable.


• 
  Stop comparing yourself to your competition.


• 
  Lead by example and stop looking in the damn mirror.

What a lame attempt to skim for money. Now they are trying to put the spin on their
crappy business model.