Front end FET of transverter blown with CW configured K2

[PA5MW]

OK, guess Murphy forced me to screw up twice this week :))
So another mistake I would like to share with you all.

Observation:
20dB lost in receiver performance at your transverter, no C1 adjustment
possible (Elecraft XV50 kit)

Cause:
Q3 PHEMT ATF34143 defective

How did I manage that:
K2 configured in CW , with no RX delay and Iambic keyer set in the menu.
The PTT line from your mic is also the 'dot' line for your internal keyer.
When pressing the mic's PTT in CW mode, the K2 starts sending dots in full
BK.
Your transverter will try to follow the quick TX/RX switching , but since
there is also little or no RX delay, the front end FET will go to heaven.
Normally you would not press the mic while in CW mode, but trying to locate
my other mistake (max ALC reading in SSB) I
Both my A and B version K2's do this.
Again human error here, but we're learning :))

'73 Mark, PA5MW




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[Don Wilhelm-3]

Mark,

Either you did not correctly describe the situation, but that transverter
must work in CW mode too, and yes, it makes no difference whether the CW dot
paddle or the PTT switch is presses when in CW mode, a string of dots should
emerge.

The XV50 transverter should be able to follow the T/R switching of the K2
with no problem and no damage to the transverter, unless you have some
strange connection on the antenna side of the transverter.

73,
Don W3FPR

> -----Original Message-----

>
> OK, guess Murphy forced me to screw up twice this week :))
> So another mistake I would like to share with you all.
>
> Observation:
> 20dB lost in receiver performance at your transverter, no C1 adjustment
> possible (Elecraft XV50 kit)
>
> Cause:
> Q3 PHEMT ATF34143 defective
>
> How did I manage that:
> K2 configured in CW , with no RX delay and Iambic keyer set in the menu.
> The PTT line from your mic is also the 'dot' line for your internal keyer.
> When pressing the mic's PTT in CW mode, the K2 starts sending dots in full
> BK.
> Your transverter will try to follow the quick TX/RX switching , but since
> there is also little or no RX delay, the front end FET will go to heaven.
> Normally you would not press the mic while in CW mode, but trying
> to locate
> my other mistake (max ALC reading in SSB) I
> Both my A and B version K2's do this.
> Again human error here, but we're learning :))
>
> '73 Mark, PA5MW
>

--
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[PA5MW]

Hello Don,

The transverter uses one relay contact (K1) to disconnect the antenna input
from the Q3 input transistor during TX. I understand there will be a small
delay before the full 20W output power is available on the RX/TX relay to
the antenna.
Still I doubt it is capable of doing full break-in (tx-rx delay menu set at
0) with dots at 20wpm and not suffer from any timing issue. The antenna was
correctly connected.
 But then again I can and will certainly not try to repeat this error.

73
Mark, PA5MW



----- Original Message -----
From: "W3FPR - Don Wilhelm" <[hidden email]>
To: "Mark_van_Wijk" <[hidden email]>; <[hidden email]>
Sent: Friday, July 15, 2005 22:05
Subject: RE: [Elecraft] Front end FET of transverter blown with CW
configured K2


> Mark,
>
> Either you did not correctly describe the situation, but that transverter
> must work in CW mode too, and yes, it makes no difference whether the CW
dot
> paddle or the PTT switch is presses when in CW mode, a string of dots
should

> emerge.
>
> The XV50 transverter should be able to follow the T/R switching of the K2
> with no problem and no damage to the transverter, unless you have some
> strange connection on the antenna side of the transverter.
>
> 73,
> Don W3FPR
>
> > -----Original Message-----
>
> >
> > OK, guess Murphy forced me to screw up twice this week :))
> > So another mistake I would like to share with you all.
> >
> > Observation:
> > 20dB lost in receiver performance at your transverter, no C1 adjustment
> > possible (Elecraft XV50 kit)
> >
> > Cause:
> > Q3 PHEMT ATF34143 defective
> >
> > How did I manage that:
> > K2 configured in CW , with no RX delay and Iambic keyer set in the menu.
> > The PTT line from your mic is also the 'dot' line for your internal

keyer.
> > When pressing the mic's PTT in CW mode, the K2 starts sending dots in
full
> > BK.
> > Your transverter will try to follow the quick TX/RX switching , but
since
> > there is also little or no RX delay, the front end FET will go to
heaven.

> > Normally you would not press the mic while in CW mode, but trying
> > to locate
> > my other mistake (max ALC reading in SSB) I
> > Both my A and B version K2's do this.
> > Again human error here, but we're learning :))
> >
> > '73 Mark, PA5MW
> >
> --
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.323 / Virus Database: 267.8.15/49 - Release Date: 7/14/2005
>
>
> __________ NOD32 1.1170 (20050715) Information __________
>
> This message was checked by NOD32 antivirus system.
> http://www.eset.com
>
>

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