[Elecraft] Help with defective KFL3A-400 needed

[Don Wilhelm]

Marcus,

You might want to query the folks at Inrad - they build the 8 pole filters.

You would need to replace all the crystals with a matched set, so it may 
be better to buy a new filter.

73,
Don W3FPR

On 12/30/2016 8:18 AM, Marcus Busch [DL1EKC] wrote:
> Hello everybody,
>
> I have a friend's KFL3A-400 on my bench which shows a 20 dB passband attenuation with
> high ripple. The fault was originally detected by a 3 S units signal drop in the K3
> compared to its other crystal filters. The filter was working perfectly until
> recently.
>
> I disassembled and measured all crystals and they seem to be OK, with the exception
> of crystal no. 6 showing a higher ESR. But is this an issue?
>
> The input and output transfomers seem to be OK as well, although checked only for DC
> conductance and isolation. All solder joints have been checked.
>