Any form of increasing the mic gain internally (eg rf speech clipper) needs to
be carefully thought out. The microphone signal routing and earthing from the
the way to go. A tin can over the whole assembly may help. The biggest hurdle to
overcome in making changes to the KSB2 is interfacing with the existing firmware
which is far from straightforward.
> Intersting ideas. If you did enlarge the SSB board to get all the bits in,
>
> in which directions would you enlarge the exixting board?
> IMHO it would be essential to contain the "new" board in a 'tin' box in turn
> mounted on metal, which raises the question of access to test points etc on
> the RF board, but a solution might be available.
>
> If you are considering some form of RF Clipping processing, you will need a
> second 'IF Filter' anyway. Although some people have got away with it, it is
> not a good idea to clip a DSB signal as produced by the balanced modulator.
> A lot of weird gurgles can result.
>
> As far as basic SSB 3db bandwidth is concerned, my personal preference when
> using small ladder filters, less than 8 crystals, is for a bandwidth between
> 2.0 kHz and 2.2 kHz. Although wider filters can sound nice, usually the
> filter's lower sideband skirt suffers to some degree (upper skirt if
> crystals in shunt connection). The result can be anti-social. Having said
> that, it is possible to build ladder filters with bandwidths around 5kHz at
> 5MHz, but various circuit trickery is involved and the skirts are a bit
> wide.
>
> Good luck with the project.
>
> 73,
> Geoff GM4ESD
>
> ----- Original Message -----
> From: <
[hidden email]>
> To: <
[hidden email]>
> Sent: Tuesday, March 01, 2005 10:07 PM
> Subject: [Elecraft] An idea for the K2
>
>> For $89 the SSB board certainly gives you the most bang for the buck.
>> I see a 2.6khz up grade option is offered.
>>
>> I noticed a larger SSB board would fit. I am going to experiment on the
> SSB
>> board.
>> I am trying to get an RF speech proc. AM mod/demod . perhaps a socket to
>> take an auxillary group of xtals. for a 2nd 7 pole filter, Perhaps even
> passband
>> or IF shift.
>>
>
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