Thank you Ken
Regards
Mike K1PEV
Sent from my iPad
On Dec 8, 2012, at 12:25 PM, "Ken Brown" <ken.d.brown@hawaiiantel.net> wrote:
> There are not many parts in those filters. If you draw out the schematic by
> looking at the PCB traces you can reason out which parts could fail in a
> shorted mode, or in an open circuit mode, and cause complete loss of signal
> throughput. (If you do this exercise you will no doubt realize that some of
> the components could fail changing the filter characteristic, without making
> the signal throughput go away altogether.) One you have decided which
> components could cause total loss of signal, then consider the likely modes
> of failure based on what you know about the components. I would hazard to
> guess that them most common failure mode of crystals is open circuit, when
> one lead breaks off from the plate on the side of the quartz crystal. For
> disk ceramic capacitors ( that is all I have seen in the Ten-Tec filters) I
> would guess that short circuit would be the most common failure mode, but at
> the voltages and currents these things are subjected to in the IF of a radio,
> it seems u
nlikely they would ever fail.
>
> You could short circuit the series crystals one at a time to see if signal
> comes back. Of course you will not have the proper bandpass characteristic
> while doing this.
>
> The other possible cause is a failure of connections between components.This
> I would guess is more probable than component failure. Reflow all of the
> solder joints, and make sure the pins are clean. Then try again.
>
> 73 DE N6KB
>> Does anyone have any insight into problems (and solutions) that would cause
>> failure in a Ten Tec model 282 (or any other similar model) crystal filter?
>> When the unit is plugged into its slot (on a Corsair) we get no response.
>> Our next step is to test it on a network analyzer but I felt it would be
>> worthwhile to also get inputs from people on the reflector.
>>
>>
>
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