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Idea for next version of DRAWS


Saku Elovaara [OH1SA/OH2YA]
 

Dears

DRAWS board looking very nice, but also noticed that audio in/out to radios has no galvanic isolated audiolines (audio transformers)  like all other digi interfaces nowdays..

I will understant space of RPI hat format boards, but also think about security of electricity loops... Also I like to see trimmers for in and out leves, but this is also similar space problem.. But when looking board layout, possible space for audio transformers may ne just behind L and R connectors.. just populate even one of radio port, no space for 4 transformers, but maybe space for two.


73
Saku OH1SA


 

I will allow the engineer explain the electronic principles but the transformers are omitted by design.

The transformer modifies the passed audio spectrum and can distort certain modulation forms (such as GMSK) so as to make them unusable. 

Audio levels are digitally controlled under software by circuitry in the sound chip.

On Sun, Nov 25, 2018, 14:06 Saku Elovaara [OH1SA/OH2YA] <oh1sa@... wrote:
Dears

DRAWS board looking very nice, but also noticed that audio in/out to radios has no galvanic isolated audiolines (audio transformers)  like all other digi interfaces nowdays..

I will understant space of RPI hat format boards, but also think about security of electricity loops... Also I like to see trimmers for in and out leves, but this is also similar space problem.. But when looking board layout, possible space for audio transformers may ne just behind L and R connectors.. just populate even one of radio port, no space for 4 transformers, but maybe space for two.


73
Saku OH1SA


Robert Sears
 

With the ability to power the PI/DRAWS from the same power source as the radio the need for this type of isolation is really eliminated.

Robert/KF7VOP

On 11/25/2018 02:02 PM, Saku Elovaara [OH1SA/OH2YA] wrote:
Dears

DRAWS board looking very nice, but also noticed that audio in/out to radios has no galvanic isolated audiolines (audio transformers)  like all other digi interfaces nowdays..

I will understant space of RPI hat format boards, but also think about security of electricity loops... Also I like to see trimmers for in and out leves, but this is also similar space problem.. But when looking board layout, possible space for audio transformers may ne just behind L and R connectors.. just populate even one of radio port, no space for 4 transformers, but maybe space for two.


73
Saku OH1SA


Saku Elovaara [OH1SA/OH2YA]
 

Dear John

That reason, limitation for use some modulation form is very clear reason to use direct connection. I agree that. So if user still think use of audio transformers, it can use with in custom cables between board and radio, then it also usable with any applications in future is needed. Thanks!
73
Saku