Update on KX1 1804

[Bernie Gardner]

Last week I reported a little problem in the power output of this radio.   I
took Don's advice and checked all relevant components (all seemed ok) and
then managed to get the correct relationship between 20 and 40 meter outputs
by adjusting both L1 and L2 as he suggested.  The power still seemed low, but
I used for a few days.  Last Saturday I installed the 30-80 upgrade.  That
went ok (but one of the more intense Elecraft experiences!)  Everything seems
ok now except the power is still low.  I even made a few contacts Sunday in
Field day using  a wire in a tree in the backyard and the KX1 on it's
internal batteries.  It really is a great thing and I look forward to taking
it with me on future trips.  

The only problem is that the power out with a 13.4V supply, as measured with
the DL1 dummy load, varies from 2.6W on 30m to 1.9W on 20m, so it is clearly
below specs.  These values are within less than 10% of values from an analog
Daiwa power meter, so I think they are close to correct.  So the question is,
should I change the two resistors?  Is the extra watt on external or 1/2W on
internal power worth the risk of overdriving the output transistor?

Bernie
W1AZ
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[KENT TRIMBLE]

Yup, do it.  You won't regret it, nor will you blow the PA.

With internal Lithium batteries (the non-chargable kind), I ran 33 feet
of hook-up wire from a picnic table to a 30 foot push-up mast, and in
the middle of 20-meter Saturday afternoon FD bedlam worked Utah,
Colorado, Maine, Vermont, Texas, and Tennessee with 1.2 watts.

I would also recommend the little speakers recently talked about on the
reflector that you can get at Walgreen's in a blister pack -- two for
$10.  They're the cat's meow.  By the way, rumor has it that some guy
gobbled up a bunch of those blister packs from every Walgreen he passed
on his way to Dayton and then peddled them to the unsuspecting for $20 a
speaker.  Makes a mother proud!

73,

Kent  K9ZTV



Bernie Gardner wrote:

>Last week I reported a little problem in the power output of this radio.   I
>took Don's advice and checked all relevant components (all seemed ok) and
>then managed to get the correct relationship between 20 and 40 meter outputs
>by adjusting both L1 and L2 as he suggested.  The power still seemed low, but
>I used for a few days.  Last Saturday I installed the 30-80 upgrade.  That
>went ok (but one of the more intense Elecraft experiences!)  Everything seems
>ok now except the power is still low.  I even made a few contacts Sunday in
>Field day using  a wire in a tree in the backyard and the KX1 on it's
>internal batteries.  It really is a great thing and I look forward to taking
>it with me on future trips.  
>
>The only problem is that the power out with a 13.4V supply, as measured with
>the DL1 dummy load, varies from 2.6W on 30m to 1.9W on 20m, so it is clearly
>below specs.  These values are within less than 10% of values from an analog
>Daiwa power meter, so I think they are close to correct.  So the question is,
>should I change the two resistors?  Is the extra watt on external or 1/2W on
>internal power worth the risk of overdriving the output transistor?
>
>Bernie
>W1AZ
>  
>

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Wilhelm-3]

Bernie,

First be certain you have adjusted R4 for full clockwise rotation - and
if you still have low power, yes, make the 2 resistor changes for the
KX1 power mod.

73,
Don W3FPR

Bernie Gardner wrote:

>
> The only problem is that the power out with a 13.4V supply, as measured with
> the DL1 dummy load, varies from 2.6W on 30m to 1.9W on 20m, so it is clearly
> below specs.  These values are within less than 10% of values from an analog
> Daiwa power meter, so I think they are close to correct.  So the question is,
> should I change the two resistors?  Is the extra watt on external or 1/2W on
> internal power worth the risk of overdriving the output transistor?
>
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com