[chirp_users] Displaying odd repeater splits

Tom Hayward tom at tomh.us
Wed Mar 2 11:51:28 PST 2016

On Wed, Mar 2, 2016 at 11:09 AM, gerard <gmkayaker at gmail.com> wrote:
> Hi,
> I'm am a long-time user of VHF radios starting with a VX-150 some 15 years ago
> and switching to Baofeng UV-5R when they were relatively new. I have been using
> Chirp to program my UV-5R since I first got the radio. One thing that I find
> annoying about how Chirp works with repeater splits is that it shows it as a +
> or a -. Most people I deal with in Canada give me frequency pairs. And I haven't
> found an easy way to get Chirp to show me the actual frequency (as opposed to
> the +/-.)  When I enter a frequency as a "split", it immediately gets converted
> to "+/-" and there seems to be no way to get Chirp to show it as a "split". This
> makes it really hard to confirm that I have the correct frequency entered; I
> need to do frequency math in my head or paper which increases the likelihood of
> errors.

This is a shortcoming of the UV5R. It cannot differentiate from offset
and independent tx/rx records--the radio stores them identically.
Chirp assumes that most users are hams and prefer the +/- offset view,
so that's how Chirp displays offsets less than 70 MHz. (This is the
conversion you're talking about.)

> It would be great if Chirp had a setting that allowed me to say "Always show
> splits using the format entered" or "Always show splits in: " and let me choose
> between +/- and "split".

Most ham radios (Yaesu, Icom, Kenwood) differentiate offset and
odd-split records. With these radios, Chirp displays the frequency or
offset as entered.

For the UV5R, this would require storing the "format entered"
somewhere. The UV5R memory provides nowhere to store this, so that
means we would need some sort of proprietary Chirp file to store this
information. The .img files are just a simple dump of the radio
memory, not proprietary, and don't offer a place to store auxiliary
data like this. This would only be beneficial when editing said
proprietary file--after doing a "Download from Radio" you'd be back to
just what was stored in the UV5R. Not really an optimal solution.

I've proposed an alternative scheme: on radios that don't know the
difference between an offset and an odd split, display as offsets in
the ham band and as tx/rx frequency outside the ham band. This would
work great for me as I program a number of Part 90 certified radios
for mixed Part 90 and ham use. In my area, ham repeater channels are
usually communicated by offset and commercial channels by their tx/rx
frequencies. However, this scheme presents some challenges too. The
hand bands differ by locale and not everyone has the same preference
as myself.

Your other idea, '"Always show splits in: " and let me choose between
+/- and "split"' has its own challenges. Besides the UI work to add
this preference selection (which most Chirp developers tend to avoid
due to its complexity), I think it would require updating all radio
drivers to support the new scheme--a monumental task. Also, it would
defeat the feature of most ham radios that properly differentiate
between offsets and odd-split records.

The way Chirp does it now was chosen intentionally to please the
largest number of users. Unfortunately we can't please everyone. We're
always open to discuss new ideas--that's what this mailing list is for
(or the chirp_devel list for the implementation details). Hopefully
this background on the treatment of offsets and radios that don't
support them is helpful fodder for discussion.


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