[Elecraft] xv222 shuts down

[Dave Glenn]

Hi Don, 
Thanks for the input. 

I checked the current and when I can get it to put out more than a couple
watts I get about a 4 amp draw which seems normal. 

What I am finding is most of the test voltages are within range but running
at the end of their adjustments. Such as the lna at 230 mv where the range
is 200 to 275 with 250 nominal. 

The only way I am able to get more than  2 watts out is to turn up R22 the
input rf gain control to the point where it jumps past the 10 volt max to
around 18 volts. I feel like it is going into oscillation or something isn't
biased correctly. 

Backing R22 down it jumps to 6 volts and the output drops to 2 watts. 

I have gone through the alignment process, peaking for output to TP5 and set
the input frequency to 222.500 as I am more interested in performance at the
bottom of the band. 

I do know that when I do get the 17 to 20 watts out the PA module does heat
up so that is likely why the resettable fuse is going. 

Not sure where to go next. 
73, Dave N6TEB

-----Original Message-----
From: Don Wilhelm [mailto:w3fpr at embarqmail.com] 
Sent: Saturday, June 01, 2013 3:14 PM
To: Dave Glenn
Cc: Elecraft at mailman.qth.net
Subject: Re: [Elecraft] xv222 shuts down

Dave,

Can you measure how much current is being drawn by the XV222?  It sounds
like the resettable fuse is being tripped.
That could be either due to a fault or due to excessive heating of the PA
module.
The max output should be reduced for FM operation.

In addition - the XV222 was designed for the low end of the band, not higher
up in the FM portion.  That means that the output Low Pass Filter may be
tuned for a cutoff frequency lower than where you were operating.  Should
that be the case, excessive current and lower output would be a result.

73,
Don W3FPR

On 6/1/2013 5:00 PM, Dave Glenn wrote:
> I have an xv 222 transverter that will shut down after transmitting for
> about a minute.
>
> Using FM for testing. The front panel just goes dark and I need to power
> cycle the k3 to get it back.
>
>   
>
> I am using a K3 to drive both 222 and 432 transverters.
>
>   
>
> Also, when going through the alignment process, R22 should be between .1
and
> 10 volts. When I adjust this the voltage will jump from about 7 to 18
volts.
>
>
> I discovered it had been running at this higher setting and getting about
18
> watts output. When I roll the voltage at TP5 down to the correct range I
get
> almost no output from the xvter.
>
>