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Reviews Categories | Filters, RF: bandpass, duplexer, lowpass, highpass, RFI/EMI | CALF KC9ON Help

Reviews Summary for CALF KC9ON
Reviews: 2 Average rating: 5.0/5 MSRP: $55.00 plus shipping
Description: Audio filter for CW work. Comes as a kit.
Product is in production.
More info: http://
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K0FTC Rating: 5/5 Mar 31, 2017 09:36 Send this review to a friend
Excellent AF Filter  Time owned: 0 to 3 months
I got this filter to use with a KD1JV transceiver being built for me by someone skilled at surface mount and will follow up with a review when I get that radio. However in the meantime I've played with this filter with my KX2 (it uses the same size power connector as the KX2- so easy to power with a splitter from the same power source for the KX2) and TS-590, both radios having great DSP filtering. This filter extends your options to manipulate what you are hearing by the AF filtering of the CALF and while using the IF DSP filters/shift capabilities of the transceiver. I think it really helps to clarify the signal and helps with QRN and static crashes caused by this stormy spring weather. I personally think the signal is less harsh listening with the CALF than the narrow filtering of the transceiver alone. The CALF also has its own input and output volume controls and that has helped with my poor hearing, especially with the KX2, which is pretty low volume for my ears. It also allows an extension of headphones further away from the radio and putting the volume control closer to my operating position. I bought the built model, and John (KC9ON) sent me a graph of the filtering that each of six filter choices provides. (There are a wide variety of options from un-built kit with no case, to a fully assemble with case choice.) John also included cabling and adapters from my stereo outputs to match up with the mono ports on this device. My built model has been done exceptionally well. KC9ON, is very responsive to questions via email, and shipped this unit quickly with documentation. I missed not having more filtering with my KD1JV MTRs on occasion and I am really looking forward to using it with the KD1JV SODA when I get it.
W2OSR Rating: 5/5 Mar 23, 2017 11:24 Send this review to a friend
Good filter for CW  Time owned: 0 to 3 months
Works very well with my LNR Mountain Topper to reduce the background hiss. The kit is not for a first time kit builder. Excellent instructions for assembly. Some of the screws supplied could be a bit longer. No noticeable ringing at the narrowest filter position.

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