KPA500 no power out

[N7FN]

Can someone advise me on the following?

My KPA500 (S/N 2663) Amplifier stopped working in the middle of a CW QSO on
7MHz.
It has been working flawlessly for the past two months (since new).

At the time:
Driver is a K3 running 20w and KPA500 running 400 watts.
Antenna tuner is a KAT500.
Antenna is a GAP Challenger.
Frequency was 7.07 MHz.
While transmitting, the SWR on the KPA500 went high and a Fault flashed.
The KPA500 seemed to reset its self and I continued sending.
The sequence repeated a few seconds later except that the KPA500 had no
output power.
Further testing resulted in the following findings:

Reloaded the firmware.

K3, KPA500 and KAT500 was connected in accordance with Figure 1, Page 5, of
the Owners manual.
For the following tests, the output of the KPA500 was connected directly to
the SWR meter and the SWR meter was connected directly to the dummy load
eliminating the KAT500.

Frequency: 3.57 MHz, All works well.

Frequency: 7.07MHz, K3: (ON) 100w, KPA500: (Standby), SWR on KPA500: 1, SWR
on SWR meter between KAT500 and dummy load: 1.1:1
    K3 power reduced to 10w, Switch the KPA500 to Operate, KPA500 no lights
indicating SWR or Power.  K3: SWR and RF indicators jumping up and down.
Raspy tone heard in station monitor (TS-850).  The LCD shows: "7.0 MHZ" no
matter which switch around the display I push or how many times I push them
or how long I hold the switch.

Frequency 14.07 MHz, All works well.

The KPA500 (kit) is under warranty, anyone know what s going on here?  Did I
do something wrong?  Is it time to send it back to Elecraft?

Frank
N7FN





______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Arie Kleingeld PA3A-2]

Frank,

This looks like the problem I had with my KPA500 that turned out to be a
fault in the T/R switch. My troubles also started on 7MHz.
There's a modkit for that: E850607. I installed it myself.

This has been in the reflector before. Look e.g. for the thread on
KPA500 troubles of last October.

73
Arie


Op 5-11-2015 om 22:48 schreef [hidden email]:

> Can someone advise me on the following?
>
> My KPA500 (S/N 2663) Amplifier stopped working in the middle of a CW
> QSO on 7MHz.
> It has been working flawlessly for the past two months (since new).
>
> At the time:
> Driver is a K3 running 20w and KPA500 running 400 watts.
> Antenna tuner is a KAT500.
> Antenna is a GAP Challenger.
> Frequency was 7.07 MHz.
> While transmitting, the SWR on the KPA500 went high and a Fault flashed.
> The KPA500 seemed to reset its self and I continued sending.
> The sequence repeated a few seconds later except that the KPA500 had
> no output power.
> Further testing resulted in the following findings:
>
> Reloaded the firmware.
>
> K3, KPA500 and KAT500 was connected in accordance with Figure 1, Page
> 5, of the Owners manual.
> For the following tests, the output of the KPA500 was connected
> directly to the SWR meter and the SWR meter was connected directly to
> the dummy load eliminating the KAT500.
>
> Frequency: 3.57 MHz, All works well.
>
> Frequency: 7.07MHz, K3: (ON) 100w, KPA500: (Standby), SWR on KPA500:
> 1, SWR on SWR meter between KAT500 and dummy load: 1.1:1
>    K3 power reduced to 10w, Switch the KPA500 to Operate, KPA500 no
> lights indicating SWR or Power.  K3: SWR and RF indicators jumping up
> and down. Raspy tone heard in station monitor (TS-850).  The LCD
> shows: "7.0 MHZ" no matter which switch around the display I push or
> how many times I push them or how long I hold the switch.
>
> Frequency 14.07 MHz, All works well.
>
> The KPA500 (kit) is under warranty, anyone know what s going on here?  
> Did I do something wrong?  Is it time to send it back to Elecraft?
>
> Frank
> N7FN
>
>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[N2TK]

Does anyone know if there is a serial number cutoff where this mod is in
place?
I am assuming the LPF board wil be marked to tell which rev lewvel it is?
Tnx
N2TK, Tony

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Arie
Kleingeld PA3A
Sent: Friday, November 06, 2015 2:38 AM
To: [hidden email]
Subject: Re: [Elecraft] KPA500 no power out

Frank,

This looks like the problem I had with my KPA500 that turned out to be a
fault in the T/R switch. My troubles also started on 7MHz.
There's a modkit for that: E850607. I installed it myself.

This has been in the reflector before. Look e.g. for the thread on
KPA500 troubles of last October.

73
Arie


Op 5-11-2015 om 22:48 schreef [hidden email]:

> Can someone advise me on the following?
>
> My KPA500 (S/N 2663) Amplifier stopped working in the middle of a CW
> QSO on 7MHz.
> It has been working flawlessly for the past two months (since new).
>
> At the time:
> Driver is a K3 running 20w and KPA500 running 400 watts.
> Antenna tuner is a KAT500.
> Antenna is a GAP Challenger.
> Frequency was 7.07 MHz.
> While transmitting, the SWR on the KPA500 went high and a Fault flashed.
> The KPA500 seemed to reset its self and I continued sending.
> The sequence repeated a few seconds later except that the KPA500 had
> no output power.
> Further testing resulted in the following findings:
>
> Reloaded the firmware.
>
> K3, KPA500 and KAT500 was connected in accordance with Figure 1, Page
> 5, of the Owners manual.
> For the following tests, the output of the KPA500 was connected
> directly to the SWR meter and the SWR meter was connected directly to
> the dummy load eliminating the KAT500.
>
> Frequency: 3.57 MHz, All works well.
>
> Frequency: 7.07MHz, K3: (ON) 100w, KPA500: (Standby), SWR on KPA500:
> 1, SWR on SWR meter between KAT500 and dummy load: 1.1:1
>    K3 power reduced to 10w, Switch the KPA500 to Operate, KPA500 no
> lights indicating SWR or Power.  K3: SWR and RF indicators jumping up
> and down. Raspy tone heard in station monitor (TS-850).  The LCD
> shows: "7.0 MHZ" no matter which switch around the display I push or
> how many times I push them or how long I hold the switch.
>
> Frequency 14.07 MHz, All works well.
>
> The KPA500 (kit) is under warranty, anyone know what s going on here?  
> Did I do something wrong?  Is it time to send it back to Elecraft?
>
> Frank
> N7FN
>
>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net Please help support this email
> list: http://www.qsl.net/donate.html Message delivered to
> [hidden email]
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message
delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[w5zzt]

Well my T/R circuit just failed yesterday.  Mine is a 2016 model that was a
kit.  serial number 3032.

It's out of warranty so waiting for Elecraft to call me so I can send it in
to be fixed.  No smoke just quit and disconnected it before it blew the
finals of my radio.

Anyone had this repair done lately?  I just wondered what the cost is to
repair if anyone knows.

Harold
W5ZZT



--
Sent from: http://elecraft.365791.n2.nabble.com/
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Petr, OK1RP/M0SIS]

Dear Frank,

it should help you.

http://ok1rp.blogspot.com/2017/02/elecraft-kpa500-lpf-tr-switch-rework.html

Petr



-----
73 - Petr, OK1RP
"Apple & Elecraft freak"
B:http://ok1rp.blogspot.com
MeWe: https://bit.ly/2HGPoDx
MeWe: https://bit.ly/2FmwvDt
--
Sent from: http://elecraft.365791.n2.nabble.com/
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Petr, OK1RP/M0SIS]

Tony,

s/n not known but rev.D9 or earlier with SMD parts assmbled should be reworked... BUT no A/B
rev. as these are thru hole parts populated LPF/PA boards.

Simply if your LPF/PA board is thru hole yellow caps populated then it is
not rework kit for you (Elecraft parts kit: E850607) and if you have the SMD
parts assembled then check if it is rev. D9 or earlier.

The LPF/PA boards where this mod is applied already is marked rev. D10 or
higher.

Petr



-----
73 - Petr, OK1RP
"Apple & Elecraft freak"
B:http://ok1rp.blogspot.com
MeWe: https://bit.ly/2HGPoDx
MeWe: https://bit.ly/2FmwvDt
--
Sent from: http://elecraft.365791.n2.nabble.com/
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[e-mail]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [e-mail]

[Iain MacDonnell - N6ML-2]

On Tue, Oct 15, 2019 at 7:04 AM w5zzt <[hidden email]> wrote:
>
> Well my T/R circuit just failed yesterday.  Mine is a 2016 model that was a
> kit.  serial number 3032.
>
> It's out of warranty so waiting for Elecraft to call me so I can send it in
> to be fixed.  No smoke just quit and disconnected it before it blew the
> finals of my radio.

What does "just quit and disconnected" mean?

My KPA500's T/R also died recently, and also damaged my K3. The
initial symptom was that the KPA500 would throw a fault 09 (high
reflected power) immediately on attempt to transmit on any band. While
attempting to diagnose this remotely, at one point I turned the K3's
output level below 12W (so just using the LPA, not the KPA3). After
that, the K3's TX was dead - "long story short", the final FETs in the
LPA were fried. Seems like something in the KPA500's T/R allowed big
RF to get fed back to the K3 - apparently the KPA3 finals could take
it, but the LPA ones couldn't. I've since replaced the two FETs, and
my K3 is back to life. When I brought the KPA500 home, the symptom
changed. On attempting to transmit, if I provided any RF drive, the
asterisk on the display would disappear - so it seemed to be unkeying
itself. It seemed like RF may be leaking into the keying circuit. In
an email exchange with support, some voltage readings suggested a
diode problem. I replaced the D7 thru D10. That made the voltages look
better, but the symptom of the amp unkeying itself persisted. Support
said that no one has heard of that happening before. Since I don't
have a supply of parts at hand, and have limited diagnostic skill, I
sent it to Watsonville Hospital. It's now waiting in the queue
(supposedly 10-15 days).

> Anyone had this repair done lately?  I just wondered what the cost is to
> repair if anyone knows.

Minimum $95 (one hour), plus parts and any additional labour. Waiting
to find out....

73/GL,

    ~iain / N6ML
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Lyn WØLEN]

As I have previously posted, my KPA500 (factory built, purchased new a few
months ago) failed after a couple weeks of use in the same manner.

I sent it to Elecraft, and they repaired it at no cost to me (of course)
except the nearly $100 it cost me to ship it to them, insured.

There were a number of parts replaced ... including one resistor that was
missing.

And yes, it also took out the transceiver (IC7300, not in warranty) which
Icom took care of very quickly and at reasonable cost.

73
Lyn, WØLEN


-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of iain macdonnell -
N6ML
Sent: Tuesday, October 15, 2019 11:14 AM
To: w5zzt
Cc: Elecraft Reflector
Subject: Re: [Elecraft] KPA500 no power out

On Tue, Oct 15, 2019 at 7:04 AM w5zzt <[hidden email]> wrote:
>
> Well my T/R circuit just failed yesterday.  Mine is a 2016 model that was
a
> kit.  serial number 3032.
>
> It's out of warranty so waiting for Elecraft to call me so I can send it
in
> to be fixed.  No smoke just quit and disconnected it before it blew the
> finals of my radio.

What does "just quit and disconnected" mean?

My KPA500's T/R also died recently, and also damaged my K3. The
initial symptom was that the KPA500 would throw a fault 09 (high
reflected power) immediately on attempt to transmit on any band. While
attempting to diagnose this remotely, at one point I turned the K3's
output level below 12W (so just using the LPA, not the KPA3). After
that, the K3's TX was dead - "long story short", the final FETs in the
LPA were fried. Seems like something in the KPA500's T/R allowed big
RF to get fed back to the K3 - apparently the KPA3 finals could take
it, but the LPA ones couldn't. I've since replaced the two FETs, and
my K3 is back to life. When I brought the KPA500 home, the symptom
changed. On attempting to transmit, if I provided any RF drive, the
asterisk on the display would disappear - so it seemed to be unkeying
itself. It seemed like RF may be leaking into the keying circuit. In
an email exchange with support, some voltage readings suggested a
diode problem. I replaced the D7 thru D10. That made the voltages look
better, but the symptom of the amp unkeying itself persisted. Support
said that no one has heard of that happening before. Since I don't
have a supply of parts at hand, and have limited diagnostic skill, I
sent it to Watsonville Hospital. It's now waiting in the queue
(supposedly 10-15 days).

> Anyone had this repair done lately?  I just wondered what the cost is to
> repair if anyone knows.

Minimum $95 (one hour), plus parts and any additional labour. Waiting
to find out....

73/GL,

    ~iain / N6ML
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]