Hi, the KPA100 is alive. I startet to desolder D16 and D17 but D16
broke. D17 was OK. I soldered two new 1N5711 and now after some minor
adjustments the KPA100 is back!
best regards
Holger. DL9HDA
Am 2014-05-05 22:20, schrieb Don Wilhelm:
Holger,
That indicates that D11 is shorted. I
That is good news Holger.
73,
Don W3FPR
On 5/8/2014 3:53 PM, dl9...@dl9hda.de wrote:
Hi, the KPA100 is alive. I startet to desolder D16 and D17 but D16
broke. D17 was OK. I soldered two new 1N5711 and now after some minor
adjustments the KPA100 is back!
Holger,
Those resistance values indicate that D16 and D17 in the KPA100 are
faulty. The resistance in the forward direction should normally be much
lower. You can check to see if your ohmmeter is reading properly by
measuring a new or known good small signal diode.
I believe if you check
Dear Don,
thank you very much for your answer. I checked it with an wattmeter and
a dummy load. Nothing.
But I checked the voltages at the diodes especially D11, D12, D13 and
D14 in receive-mode:
D12 and D14 have the right voltages at the anodes and cathodes when I
switch from low-power
Holger,
That indicates that D11 is shorted. I would replace D11, D12 and D14
and remeasure.
Do not substitute - use only 1N4007s. While those are normally power
diodes, they work well for switching purposes too, and that is not true
of most other diode types.
73,
Don W3FPR
On 5/5/2014
Holger,
I didn't think of it before the last response, but be certain you are
using the correct Diode Voltage chart.
If you have a newer KPA100 or one that has been upgraded - with blue
toroid cores at RFC1 and L15, then you must use the newer voltage chart
(download the most recent KPA100
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