Hello group,
The K3 problem was quickly solved by Leo Duursma, PA0LMD.
An RF choke (RFC30) was open.
Thus, the diodes D25 did not get the required switching voltage.
Thanks to all that helped with evaluating the problem.
73,
Per-Tore
DL/LA7NO
Hi Per-Tore,
Can you identify which transistor (or other device) on the LPA module is
getting hot in transmit mode?
The drain terminals of MOSFET PA transistors Q4 and Q5 receive +12V
regardless of TX or RX mode, but the gate bias voltages are applied only in
TX mode. Unless there's a problem
Measured voltages over the PIN-diodes D26 & D27.
In Rx: 0,72 VDC. over both.
In Tx, the voltages varied a bit around 0,4-0,6 VDC.
While in TX, even with power set to 0,0W, one of the transistors in the LPA
is getting quite hot.
Cools down when switching over to Rx.
P-T
On Fri, 14 Aug 2020 at
Hi,
Still working on finding a solution to the below problem.
Elecraft support said:
"Since you are hearing signals, on frequency is presumed, only attenuated
~30 dB,
The SYNTH circuit is not the first place I would look."
Any suggestion wrt where to look first?
I guess it must be somewhere
Hi,
Checked all TMP connectors - no change.
P-T
-
73,
Per-Tore / LA7NO
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Help:
That is why just looking for loose TMP connectors may not be sufficient.
While you are inside the K3, give all the TMP connectors a slight twist
which should clear some of the corrosion.
73,
Don W3FPR
On 7/27/2020 6:25 PM, Wes wrote:
I've had TMP connectors badly corroded in my K3. See:
I've had TMP connectors badly corroded in my K3. See:
https://groups.io/g/Elecraft-K3/album?id=37256
Wes N7WS
On 7/27/2020 12:04 PM, Mike K8CN wrote:
Aye, Wes, indeed you did! I wasn't thinking of LO drive levels when I first
read your post, but was thinking of common signal paths for TX
Aye, Wes, indeed you did! I wasn't thinking of LO drive levels when I first
read your post, but was thinking of common signal paths for TX and RX
through the T/R switch and no deeper into the signal processing chain.
Let's hope your and Martin's suggestion proves to be the true cause of
I thought I said that.
On 7/27/2020 10:34 AM, Mike K8CN wrote:
I agree with Martin's simpler hypothesis. The sudden change of behavior in
both TX and RX modes could well result from insufficient LO drive to either
the 1st or 2nd mixers. Check that possibility before launching into
detailed
I agree with Martin's simpler hypothesis. The sudden change of behavior in
both TX and RX modes could well result from insufficient LO drive to either
the 1st or 2nd mixers. Check that possibility before launching into
detailed testing of the PIN diode T/R switch. It may be as simple as a
loose
Hi Per-Tore,
I don't know if there's an easy way to check the PIN diodes in the T/R
switch, especially since the SMD components of the switch are mostly on the
underside of the RF board. Here's where I would start:
1) Find spots on the RF board (top side) where you can measure the control
Apologies, I just saw the serial number 7818, quite a bit newer so
maybe not a failed capacitor, yet :)
Martin, H0ZED
On 27/7/63 23:32, Martin Sole wrote:
Hi,
What Serial number?
I have found on my own and a friends K3, both very low S/N around 300,
that the KREF3 board has been the
Hi,
What Serial number?
I have found on my own and a friends K3, both very low S/N around 300,
that the KREF3 board has been the culprit for this exact problem.
First check the all the TMP cables to and from the KREF3 board and the
synths. If all look good you should examine the K3REF board.
Thanks, Mike.
I guess this is the MA4P PIN diodes D26 & D27.
Is there an easy way to check those?
P-T
-
73,
Per-Tore / LA7NO
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You might check the PIN diode T/R switch. The high attenuation in RX mode
and no output power even when the 100 W PA is bypassed suggest that one or
more of the PIN diodes in the T/R switch have failed "open."
Mike, K8CN
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Yes, all bands are the same.
Received signals are normal in all respects, except signal strength.
P-T
-
73,
Per-Tore / LA7NO
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All Bands?
If receiving a strong station, is it on frequency?
73
George AI4VZ
-Original Message-
From: LA7NO
Sent: Monday, July 27, 2020 8:50 AM
To: elecraft@mailman.qth.net
Subject: [Elecraft] Elecraft K3 problem
Hello,
The K3 suddenly stopped working.
One day all OK, the next
Yes, as I said, same problem on both Ant1 & Ant2.
-
73,
Per-Tore / LA7NO
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Help:
Would not that make the rx dead?
I can hear strong signals.
But the tx is giving no output.
-
73,
Per-Tore / LA7NO
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Did you check the antenna selection?
--
73,
-John NI0K
https://www.qrz.com/db/NI0K
LA7NO wrote on 7/27/2020 7:50 AM:
Hello,
The K3 suddenly stopped working.
One day all OK, the next day serious problems.
Serial no.: 07818.
It has ATU and 100 W PA installed, and also a P3 connected.
Both K3
May be a LO problem. Check all of the TMP cables.
Wes N7WS
On 7/27/2020 5:50 AM, LA7NO wrote:
Hello,
The K3 suddenly stopped working.
One day all OK, the next day serious problems.
Serial no.: 07818.
It has ATU and 100 W PA installed, and also a P3 connected.
Both K3 and P3 were earlier
Hello,
The K3 suddenly stopped working.
One day all OK, the next day serious problems.
Serial no.: 07818.
It has ATU and 100 W PA installed, and also a P3 connected.
Both K3 and P3 were earlier well calibrated.
Supply: 14,5 VDC.
Symptoms:
- Rx seriously reduced sensitivity, only strong signals
Hello Glenn!
I found an old Thread from you in the Elecraft reflector. On the 28th of March
2009 you wrote that your K3 failed to load the FPF at the address x0040!!! I
have the same problem now with my K3!!!
Did you get it back to life? If yes, what´s the solution??
Hope to hear from you!!!
I've come across a problem trying to install the new K3 utility onto my
computer that's running an up to date version of Windows XP Pro.
I downloaded it to a file and then ran it. My firewall, the free version of
ZoneAlarm, blocked K3UtilitySetup_1_3_10_11.tmp(4656) reporting that it
Subject: [Elecraft] Elecraft K3 Problem with new K3 Utility
I've come across a problem trying to install the new K3 utility onto my
computer that's running an up to date version of Windows XP Pro.
I downloaded it to a file and then ran it. My firewall, the free version of
ZoneAlarm, blocked
...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of David Lankshear
Sent: Thursday, October 14, 2010 1:32 PM
To: elecraft@mailman.qth.net
Subject: [Elecraft] Elecraft K3 Problem with new K3 Utility
I've come across a problem trying to install the new K3 utility onto my
computer that's
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