[Elecraft] WA7U-KPA100

Sat Jun 22 13:07:03 2002

Thanks Dennis,

I just tried this again. I can't go to high power to adjust R26 and 27
because it keeps shutting down and the relays chatter.  I think I understand
what you are saying but not positive.  I have tried setting these pots with
5 watts, 20 watts, and also 30-40 watts but whenever I go above about 50
relays chatter and the output goes to zero.
----- Original Message -----
From: "NB1B" <[email protected]>
To: "Todd Gahagan" <[email protected]>
Sent: Saturday, June 22, 2002 10:17 AM
Subject: Re: [Elecraft] WA7U-KPA100

> I had the same type problem, except that I couldn't get more than 50 watts
> out on any band.  Even though your settings on R26 and R27 seem correct,
> they aren't.  I was placing the unit in tune, then adjusting them and
> watching the output, and it just wasn't increasing.
>
> Based on Gary's suggestion, I adjusted the pots, then put it in full power
> tune, then adjusted the pots, then put it in full power tune, and kept
> repeating this until I had the proper power out on the K2 display as on
the
> Bird, and the rig reliably showed the proper SWR.  If you do this, keep
the
> Hi Pwr Tune short- 1 or 2 seconds is all you need to read the Power out.
>
> Gary said that the ALC on the Xmit, coupled with the SWR detection
circuits,
> will aggressively shut down the power if the settings aren't correct.
>
> Good Luck.
>
> Dennis NB1B
>
> ----- Original Message -----
> From: "Todd Gahagan" <[email protected]>
> To: "Surrency, Gary" <[email protected]>
> Cc: <[email protected]>
> Sent: Saturday, June 22, 2002 11:51 AM
> Subject: [Elecraft] WA7U-KPA100
>
>
> >
> >
> > I seem to be having more than my share of problems with the amp project.
> > Everything checks out perfectly. Got the new firmware yesterday and it
is
> > installed.
> > Everything seems to be working just as it should until I get to the
> Transmit
> > Tests portion.  Anytime I go over about 60watts the PA shuts down and I
> get
> > the High Reflected status in the K2 LCD.  It then drops to an
intermittent
> > 35 watts power output.  I have checked all coax cables, Heathkit
Cantenna
> > dummy load, SWR bridge that I am using and can find no problems with
them.
> I
> > have rechecked the SWR bridge null 3 times.  I have also closely checked
> T4
> > and surrounding components. All of T4s lead are correctly placed and
> > resistance checks show that the leads soldered properly.  I did use
> prewound
> > toroids.  I would appreciate any ideas.  Thanks, Todd-WA7U
> >
> >
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