K4 bandpass filters?

[Jim Miller]

Eric mentions bandpass filters in his interview and the description of the K4D mentions a second set of those.

I wonder how those are configured?
Are they always active?
Do they permit general coverage operation?

Jim ab3cv
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[Bill Frantz]

In the K4HD model, there are two crystal filters, one for CW and
one for SSB. These radios are designed for strong nearby
signals, as might occur on a DXpedition, where there are several
stations operating on the same band.

I wonder if the "SSB" filter is wide enough for running
Fox/Hound FT8 in Fox mode. There you really want a bandwidth of
4K or so to copy all the callers.

On the other hand, you may want narrower when running SSB. It is
possible that the DSP filter can handle that situation since you
can plan the transmit frequencies to be at least 4KHz apart.

73 Bill AE6JV

On 5/19/19 at 4:10 PM, [hidden email] (Jim Miller) wrote:

>Eric mentions bandpass filters in his interview and the
>description of the K4D mentions a second set of those.
>I wonder how those are configured?
>Are they always active? Do they permit general coverage operation?
>
>Jim ab3cv

---------------------------------------------------------------------------
Bill Frantz        | Re IOT: "How many access control systems
does it take
www.pwpconsult.com | to change a light bulb?" - Dean Tribble

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[Nr4c]

The K4D has s second ADC and therefore must have the band pass filters identical to the existing ADC use for the main two receivers in the base K4.

Sent from my iPhone
...nr4c. bill

> On May 19, 2019, at 11:51 PM, Bill Frantz <[hidden email]> wrote:
>
> In the K4HD model, there are two crystal filters, one for CW and one for SSB. These radios are designed for strong nearby signals, as might occur on a DXpedition, where there are several stations operating on the same band.
>
> I wonder if the "SSB" filter is wide enough for running Fox/Hound FT8 in Fox mode. There you really want a bandwidth of 4K or so to copy all the callers.
>
> On the other hand, you may want narrower when running SSB. It is possible that the DSP filter can handle that situation since you can plan the transmit frequencies to be at least 4KHz apart.
>
> 73 Bill AE6JV
>
>> On 5/19/19 at 4:10 PM, [hidden email] (Jim Miller) wrote:
>>
>> Eric mentions bandpass filters in his interview and the description of the K4D mentions a second set of those.
>> I wonder how those are configured?
>> Are they always active? Do they permit general coverage operation?
>>
>> Jim ab3cv
>
> ---------------------------------------------------------------------------
> Bill Frantz        | Re IOT: "How many access control systems does it take
> www.pwpconsult.com | to change a light bulb?" - Dean Tribble
>
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> Elecraft mailing list
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> Please help support this email list: http://www.qsl.net/donate.html

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[wayne burdick]

>  Nr4c <[hidden email]> wrote:
>
> The K4D has s second ADC and therefore must have the band pass filters identical to the existing ADC use for the main two receivers in the base K4.

Indeed it does.

Wayne
N6KR


>
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[Jim Miller]

Hi Wayne

Could you respond to my other questions on bandpass filters?

Thanks

Jim ab3cv

On May 20, 2019, at 7:00 AM, Wayne Burdick <[hidden email]> wrote:


> Nr4c <[hidden email]> wrote:
>
> The K4D has s second ADC and therefore must have the band pass filters identical to the existing ADC use for the main two receivers in the base K4.

Indeed it does.

Wayne
N6KR


>
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