Need KAT2 Help

[Tom KG3V]

Just finished assembling a KAT2 for my K2. When I started testing I found a  
problem. I only get "HI" on the display in the CALn step, where you are  
supposed to adjust for a reading of 000. Reducing power as low as I can go,  
I can get a "000" display, but as soon as I increase the power, I get "HI".  
I tried CALP and I did get readings that made some sense (a high value for  
FWD and low value for REF power) but the FWD was something like 22 watts,  
which seems too high.

I disassembled and reveiwed the SWR bridge section, counted turns on T1,  
removed the link on T1 and pulled up T1 to inspect the leads and soldering.  
Also verified all the component values and soldering in that area.

So my streak is over. Thought you just finished assembl, turned on power,  
and all this Elecraft stuff just worked! Guess it had to happen.

Any ideas/

Thanks/73,

Tom, KG3V
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[Don Wilhelm-4]

Tom,

You must obtain a low balance reading before you can do any *valid*
power or SWR calibration.
If you cannot null with the capacitor, there is something wrong -
normally that something is associated with T1 and the other wattmeter
components, but you say you have checked those.

OK, the next logical step is to find out for certain whether you have a
problem with the wattmeter or the L-C board.  Separate the Control board
from the L-C board and place a jumper from J4 pin 2 to J5 pin 15 (yes,
it is a long jumper - the second pin in from the far ends).  Now, with
only the Control Board (you must use the ANT1 connector) - connect a
dummy load  and again try to balance the wattmeter - if you find that
the capacitor now achieves a null, look for the problem (likely a relay)
on the L-C Board -but if you still cannot null the wattmeter, take
another look at T1 and its associated components.

73,
Don W3FPR

[hidden email] wrote:

> Just finished assembling a KAT2 for my K2. When I started testing I found a  
> problem. I only get "HI" on the display in the CALn step, where you are  
> supposed to adjust for a reading of 000. Reducing power as low as I can go,  
> I can get a "000" display, but as soon as I increase the power, I get "HI".  
> I tried CALP and I did get readings that made some sense (a high value for  
> FWD and low value for REF power) but the FWD was something like 22 watts,  
> which seems too high.
>
> I disassembled and reveiwed the SWR bridge section, counted turns on T1,  
> removed the link on T1 and pulled up T1 to inspect the leads and soldering.  
> Also verified all the component values and soldering in that area.
>
> So my streak is over. Thought you just finished assembl, turned on power,  
> and all this Elecraft stuff just worked! Guess it had to happen.
>
> Any ideas/
>
> Thanks/73,
>
> Tom, KG3V
>  
>

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[Tom KG3V]

Thanks to both of you for the sugestions. I actually got this to work, and  
I am not sure if it originally worked, or if my resoldering fixed a  
problem. I was able to obtain a voltage reading but only over about 20  
degrees of the rotation of C55. I had no idea it would be this touchy.  
Also, the lowest I can get is about 009-011 on the reading. If this sounds  
normal, I may be OK. If not, I may still want to do some more  
checking/debugging. The ATU does now appear to be working.

In general, I found the KAT2 instructions were not quite up to th elevel of  
excellance of the other K2 components I have assembled. A couple small  
things like telling you that R6 was nt yet installed at the end of board  
assembly would have helped. Also, I was told to remove some stuff that was  
not there, and told to add some stuff that was already there (of course the  
later made me happy).

As always, thanks for the help.

Tom, KG3V


On Sep 10, 2009 8:19pm, Don Wilhelm <[hidden email]> wrote:
> Tom,



> You must obtain a low balance reading before you can do any *valid* power  
> or SWR calibration.

> If you cannot null with the capacitor, there is something wrong -  
> normally that something is associated with T1 and the other wattmeter  
> components, but you say you have checked those.



> OK, the next logical step is to find out for certain whether you have a  
> problem with the wattmeter or the LC board. Separate the Control board  
> from the LC board and place a jumper from J4 pin 2 to J5 pin 15 (yes, it  
> is a long jumper - the second pin in from the far ends). Now, with only  
> the Control Board (you must use the ANT1 connector) - connect a dummy  
> load and again try to balance the wattmeter - if you find that the  
> capacitor now achieves a null, look for the problem (likely a relay) on  
> the LC Board -but if you still cannot null the wattmeter, take another  
> look at T1 and its associated components.



> 73,

> Don W3FPR



> [hidden email] wrote:


> Just finished assembling a KAT2 for my K2. When I started testing I found  
> a problem. I only get "HI" on the display in the CALn step, where you are  
> supposed to adjust for a reading of 000. Reducing power as low as I can  
> go, I can get a "000" display, but as soon as I increase the power, I  
> get "HI". I tried CALP and I did get readings that made some sense (a  
> high value for FWD and low value for REF power) but the FWD was something  
> like 22 watts, which seems too high.



> I disassembled and reveiwed the SWR bridge section, counted turns on T1,  
> removed the link on T1 and pulled up T1 to inspect the leads and  
> soldering. Also verified all the component values and soldering in that  
> area.



> So my streak is over. Thought you just finished assembl, turned on power,  
> and all this Elecraft stuff just worked! Guess it had to happen.



> Any ideas/



> Thanks/73,



> Tom, KG3V




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[Don Wilhelm-4]

Tom,

Yes, the balance point is very 'touchy' - such is the situation anytime
you are trying to get a null (on any kind of equipment - the null range
is very small, and ideally is a single point).  On the KAT2, the normal
lowest reading on the display is in the 009 to 011 range as you have
found - from that I would say all is well.

Yes, the Elecraft K2 option manuals do not have as much detailed
supplemental information as the K2 manual because the builder would
normally have already experienced the details in the K2 manual.  That
was true initially, but now many K2 are being purchased used and the new
owner adds options without having that initial K2 building experience.
As far as removing stuff that was not there, the manual must be written
to cover any possible K2 configuration - thus, it is important  to
observe all  the  "If"  statements - if you do not have a particular
option installed, you will have nothing to remove.

73,
Don W3FPR

[hidden email] wrote:

> Thanks to both of you for the sugestions. I actually got this to work,
> and I am not sure if it originally worked, or if my resoldering fixed
> a problem. I was able to obtain a voltage reading but only over about
> 20 degrees of the rotation of C55. I had no idea it would be this
> touchy. Also, the lowest I can get is about 009-011 on the reading. If
> this sounds normal, I may be OK. If not, I may still want to do some
> more checking/debugging. The ATU does now appear to be working.
>
> In general, I found the KAT2 instructions were not quite up to th
> elevel of excellance of the other K2 components I have assembled. A
> couple small things like telling you that R6 was nt yet installed at
> the end of board assembly would have helped. Also, I was told to
> remove some stuff that was not there, and told to add some stuff that
> was already there (of course the later made me happy).
>
> As always, thanks for the help.
>
> Tom, KG3V
>

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[Tom KG3V]

Don,

Thanks again for the help. I think this is working and I will move ahead. I  
just need to install my new KNB2 and I should be ready to get the rig back  
in the operating position.

I do not have a major gripe with the KAT-2 directions, but it could use an  
update. I have a fair amount of building experience at this point, and I  
found myself in 2 or 3 uncertain situations. But the end result is fine, as  
with all my other Elecraft builds so far. I continue to be very impressed  
with the design of the K2 and accessories.

73,

Tom KG3V


On Sep 11, 2009 1:53pm, Don Wilhelm <[hidden email]> wrote:
> Tom,



> Yes, the balance point is very 'touchy' - such is the situation anytime  
> you are trying to get a null (on any kind of equipment - the null range  
> is very small, and ideally is a single point). On the KAT2, the normal  
> lowest reading on the display is in the 009 to 011 range as you have  
> found - from that I would say all is well.



> Yes, the Elecraft K2 option manuals do not have as much detailed  
> supplemental information as the K2 manual because the builder would  
> normally have already experienced the details in the K2 manual. That was  
> true initially, but now many K2 are being purchased used and the new  
> owner adds options without having that initial K2 building experience.

> As far as removing stuff that was not there, the manual must be written  
> to cover any possible K2 configuration - thus, it is important to observe  
> all the "If" statements - if you do not have a particular option  
> installed, you will have nothing to remove.



> 73,

> Don W3FPR



> [hidden email] wrote:


> Thanks to both of you for the sugestions. I actually got this to work,  
> and I am not sure if it originally worked, or if my resoldering fixed a  
> problem. I was able to obtain a voltage reading but only over about 20  
> degrees of the rotation of C55. I had no idea it would be this touchy.  
> Also, the lowest I can get is about 009-011 on the reading. If this  
> sounds normal, I may be OK. If not, I may still want to do some more  
> checking/debugging. The ATU does now appear to be working.



> In general, I found the KAT2 instructions were not quite up to th elevel  
> of excellance of the other K2 components I have assembled. A couple small  
> things like telling you that R6 was nt yet installed at the end of board  
> assembly would have helped. Also, I was told to remove some stuff that  
> was not there, and told to add some stuff that was already there (of  
> course the later made me happy).



> As always, thanks for the help.



> Tom, KG3V




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