How CCrane Skywave tunes VHF Air AM and NOAA NFM transmissions?


h. garcia
 

Hello everyone, happy Friday!

I was having some wandering thoughts on about certain receivers can tune bands not supported by the SiLabs Si473x IC.

Eton/Gruding Elite and XHData D808 - based on the schematics one the russian radioforum - used a clever approach: they used a TA7358 to bring the VHF Air band to an IF within Si473x front-end. The AM demodulation is done by Si4735 itself.

However, I can't find details on the CCrane Skywave SSB and it's NOAA VHF Narrow FM capability. Did CCrane included a second SiLabs C with WX band to enable reception and alerting?

Cheers!

pu3hag huelbe


Ron Zuccalo
 

Hello. Yes 2 different chips in the.sky w
 Ssb. Aseperate one for the air band noaa and band widths. Confirmed.

On Fri, May 7, 2021, 2:08 AM h. garcia <pu3hag.l@...> wrote:
Hello everyone, happy Friday!

I was having some wandering thoughts on about certain receivers can tune bands not supported by the SiLabs Si473x IC.

Eton/Gruding Elite and XHData D808 - based on the schematics one the russian radioforum - used a clever approach: they used a TA7358 to bring the VHF Air band to an IF within Si473x front-end. The AM demodulation is done by Si4735 itself.

However, I can't find details on the CCrane Skywave SSB and it's NOAA VHF Narrow FM capability. Did CCrane included a second SiLabs C with WX band to enable reception and alerting?

Cheers!

pu3hag huelbe


h. garcia
 

Hello all,

Guess I found evidence Skywave SSB uses a Si4735-D60.

I payed a visit to the excellent PU2LCR Ricardo Caratti's Si47xx Arduino Library Project at Github. The documentation  refers a few times to the  "AN332 REV 0.8 UNIVERSAL PROGRAMMING GUIDE
AMENDMENT FOR SI4735-D60 SSB AND NBFM PATCHES". It's the PDF attached.

Have you ever noticed when you switch to SSB, Si473x-based receivers mute the speaker for a while and show an animated icon? That's the microprocessor live patching the SiLabs chip with new DSP code. On pages 4 and 33 of the PDF, you can see the commands and parameters available once the SSB or NBFM patch gets loaded.





h. garcia
 

Thank you!


Jock Elliott
 

Interesting!


Paul Blundell
 

Thanks. That is great information.


On Fri, 7 May 2021, 17:50 h. garcia, <pu3hag.l@...> wrote:
Hello all,

Guess I found evidence Skywave SSB uses a Si4735-D60.

I payed a visit to the excellent PU2LCR Ricardo Caratti's Si47xx Arduino Library Project at Github. The documentation  refers a few times to the  "AN332 REV 0.8 UNIVERSAL PROGRAMMING GUIDE
AMENDMENT FOR SI4735-D60 SSB AND NBFM PATCHES". It's the PDF attached.

Have you ever noticed when you switch to SSB, Si473x-based receivers mute the speaker for a while and show an animated icon? That's the microprocessor live patching the SiLabs chip with new DSP code. On pages 4 and 33 of the PDF, you can see the commands and parameters available once the SSB or NBFM patch gets loaded.