Re: sending images/binary files on #macos

Bob Cameron

Hi Judi

Realising this may not be the info you are after.

Within the fldigi suite the methods to send binary/nonplaintext are;

flarq - An executable that is part of the standard fldigi build
flmsg - binary/image mode
flwrap, send as text, flwrap (unwrap)

In my experience the biggest problem is that these files are often quite large and unless the link is perfect, some retry/resend method is needed. Although I haven't used flwrap for ages I seem to remember it checksums for validity, but has no correction method beyond a complete resend.

If your requirement is direct station to station (not broadcast), flarq may be a better choice. The sending end needs an operator, but the receiving end could be unattended. (keeping in mind that TX/RX handshaking does go on) It checks that blocks are received and resends only what is needed. flsmsg (I haven't used) is like a layer above flarq that I understand works in a similar way.

flamp to an unattended receiver solves the data loss problem by transmitting the whole file over and over. I use to send 12KByte jpgs over HF with 8PSK500F that needed 3-4 resends. This full repeat is often a large limiting factor. If however the receiving station (or stations) are attended then those individual blocks missed can be resent. This is not as fully automated as flarq though.

Both flamp and flarq convert the binary file as needed on the fly. flwrap doesn't need to be run manually. Just chose the file to send direct from flamp/flarq.

Hope you find this useful.


On 01/12/18 07:43, J. Clark wrote:
I used flwrap 1.3.5 to create a wrap file from an image that I'd like to send. 
Looks like flamp was the program to use but it's now 3 years old, nothing available for current macOS (High Sierra/Mojave). Anyone have a recommendation for a workaround? How do others send digital files from a Mac?

Judi Clark | KK6ZCU

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