would like to help

Online discussion forum for BCRA's Cave Radio & Electronics Group

Moderator: David Gibson

Tim
Posts: 3
Joined: Wed 13 Mar 2019 10:07

would like to help

Post by Tim » Wed 13 Mar 2019 21:53

How about a real digital radio?
Maybe it could eliminate the static noise always present on this 87kHz analog models.
I do agree with the minimum commands the better but also the simple the design it could be easier for others to replicate.
Would like to be involved in the next generation of radios.
Tim

David Cooke
Site Admin
Posts: 298
Joined: Thu 29 Dec 2005 23:22
Location: Axbridge, Somerset, UK

Re: would like to help

Post by David Cooke » Fri 15 Mar 2019 11:20

Hi Tim,

Welcome to the forum.

Are you aware of the Nicola 3 Cave Radio System which is a digital radio? See https://www.facebook.com/AssociationNicola/
Dave Cooke
BCA IT Working Party, BCA Web Services, National Cave Registry Co-ordinator, CSCC Webmaster

Tim
Posts: 3
Joined: Wed 13 Mar 2019 10:07

Re: would like to help

Post by Tim » Wed 20 Mar 2019 00:02

Hello David,

Thanks for the reply.
The Nicola 3 is not a real digital radio but a mix of an analog with some digital to generate the frequency for transmit.
My idea is to creat a radio to operate like digital televison.
The audio received signal is much more clean.

Tim

IACooper
Posts: 2
Joined: Tue 02 Oct 2018 08:05

Re: would like to help

Post by IACooper » Mon 25 Mar 2019 16:22

Rob Gill did some experiments using FreeDV codec for digital speech using the uHeyPhone at last year's Spring field meet. The results weren't exactly stunning, but it was only one series of quick experiments with the various stages hooked together on the day and little prior setting up or testing. It was concluded it would require more effort to get working, and that was using a laptop PC to do all the codec number crunching stuff.

I'm aware of a few people working on software defined radios (such as Nicola3) which use analogue SSB for the RF link but modulate/demodulate that in the digital domain (I now have an SDR receiver on the uHeyPhone as well). I don't know of anyone working on a codec and transceiver dedicated to digital speech over cave radio though, you may need to start the project off yourself to see if others are keen to hop on board to join you as well.

Tim
Posts: 3
Joined: Wed 13 Mar 2019 10:07

Re: would like to help

Post by Tim » Wed 27 Mar 2019 12:11

Hello IACooper,

Thanks for the valuable information.
Would like to know more about that experience with the heyphone using the pc.
The sm1000 seems to replace the pc for the codec so probably is possible to implement it on a cave radio also.
Will try to reach Rob, maybe I could collaborate with him on a new development.

All the best,
Tim

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