http://elecraft.85.s1.nabble.com/K3-killing-RX-key-clicks-tp4093607p4116875.html
>
> While on 160m a few nights ago I heard loud key clicks and tracked it down
> to a ham just 1 mile away who was chasing a DX station. When he
> transmitted,
> my K3 was rendered totally deft from any signal within 10 Khz of him! My
> 200hz roofing filter, ATTN, preamp off and RFG down had no effect. I guess
> even the K3 has it's limits.
> Steve
> N4LQ
>
[hidden email]
> ----- Original Message -----
> From: "David Gilbert" <
[hidden email]>
> To: "Ron D'Eau Claire" <
[hidden email]>
> Cc: "'Elecraft Reflector'" <
[hidden email]>
> Sent: Tuesday, December 01, 2009 1:29 PM
> Subject: Re: [Elecraft] K3: killing RX key clicks
>
>
>>
>> I'll accept all of that, but it still doesn't change the fact that there
>> are some rigs out there that generate bad key clicks for no reason other
>> than the fact that their users either don't realize it or don't care
>> enough to fix them.
>>
>> When I first received my Icom 756Pro (now my backup rig) several years
>> ago I discovered that the default rise/fall times (adjustable in one of
>> the menus) was set to 2 msec (!). That's unconscionable, but I'll bet
>> the majority of Icom users never bothered to check it. Many of the
>> Yaesu rigs generate horrible key clicks unless their users have
>> performed a simple hardware modification on them (see the info at
>> W8JI.com).
>>
>> I operated about 36 hours in the contest this last weekend and made over
>> a thousand contacts using the 8-pole 250Hz roofing filter. Many times
>> I'd be running a frequency within 200 Hz of a S9+30db station without
>> even knowing he was there. Other times I'd hear key clicks (loud enough
>> to cover the dits in callsigns I was trying to copy) from stations I
>> couldn't even find while tuning with the subreceiver! One large M/M
>> operation had great sounding signals on all bands except 15m, where the
>> key clicks were objectionable two KHz away even when their signal was
>> S5-S7. At least in that case they have promised to find the problem and
>> fix it.
>>
>> Actually, there is a third reason why some stations have bad key
>> clicks. They admit they do it on purpose in a contest because it gives
>> them more elbow room.
>>
>> In my experience with the K3 in several major contests since I bought it
>> last January, the very great majority of bad signals I've heard on the
>> air have been due to the TX on the other end, not the RX on my end.
>>
>> 73,
>> Dave AB7E
>>
>>
>>
>> Ron D'Eau Claire wrote:
>>> Key clicks can be generated by several different mechanisms within the
>>> receiver itself. Paradoxically, it's easier to produce false clicks with
>>> a
>>> high performance receiver than it is with a lesser receiver.
>>>
>>> These have nothing to do with the transmitted signal.
>>>
>>> The first line of "defense" is to turn off the Preamp and turn on the
>>> Attenuator to reduce the overall strength of the signals. Next is to set
>>> the
>>> AGC to "Slow" to ensure a strong signal isn't within the roofing filter
>>> bandpass and triggering the AGC while the variable DSP filter is set
>>> narrow
>>> so the beat note isn't heard. In some cases using the RF gain to control
>>> the
>>> level helps a great deal. Another approach is to use a narrower roofing
>>> filter or to shift your bandpass so the edge of the roofing filter is
>>> very
>>> close to the desired signal on the side toward the interfering station
>>> and
>>> as far from the interfering station as possible. Shifting the bandpass
>>> may
>>> require you open up your DSP bandwidth to continue to hear the desired
>>> signal or shifting the DSP filter position within the roofing filter
>>> bandpass.
>>>
>>> And, remember, "clicks" are an essential component of a CW signal. They
>>> are
>>> the sidebands created by modulating (keying) the signal. Very careful
>>> shaping of the keying envelope, such as used in the K2 and K3, can
>>> minimize
>>> clicks while maintaining an easily readable signal, but the only way to
>>> completely eliminate clicks is to not key the signal at all. With a
>>> really
>>> high-performance you can snuggle up very close to a signal, as many here
>>> have noted. When you do that, you're much more likely to hear the
>>> essential
>>> clicks required for good keying.
>>>
>>> Ron AC7AC
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home:
http://mailman.qth.net/mailman/listinfo/elecraft>>> Help:
http://mailman.qth.net/mmfaq.htm>>> Post: mailto:
[hidden email]
>>>
>>> This list hosted by:
http://www.qsl.net>>> Please help support this email list:
http://www.qsl.net/donate.html>> ______________________________________________________________
>> Elecraft mailing list
>> Home:
http://mailman.qth.net/mailman/listinfo/elecraft>> Help:
http://mailman.qth.net/mmfaq.htm>> Post: mailto:
[hidden email]
>>
>> This list hosted by:
http://www.qsl.net>> Please help support this email list:
http://www.qsl.net/donate.html>
>
> --------------------------------------------------------------------------------
>
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.709 / Virus Database: 270.14.88/2538 - Release Date: 12/01/09
> 02:59:00
>
> ______________________________________________________________
> Elecraft mailing list
> Home:
http://mailman.qth.net/mailman/listinfo/elecraft> Help:
http://mailman.qth.net/mmfaq.htm> Post: mailto:
[hidden email]
>
> This list hosted by:
http://www.qsl.net> Please help support this email list:
http://www.qsl.net/donate.html>
>