Order Tray | Contact Us | Home | SIG Lists

[aprssig] FREQ Object Formats (FINAL COMMENT)

Bob Bruninga bruninga at usna.edu
Tue May 8 13:37:31 UTC 2012

➢ Yes.  It has always been that way.  Either include 
> NO OFFSET INFORMATION and the radio will  use its 
> standard offset (if it exists on that band and in
> that radio) or include the offset IN ACCORDANCE WITH 
> THE SPEC, either +xxx or -xxx in 10's of KHz.
> It just cannot be any simpler.

> You're saying that the radio will know that a frequency 
> is a repeater pair and assume what the split is. 

I am NOT saying that whatsoever.  

I am saying that the operator of a DIGI that is going to put out a Frequency Object KNOWS if it is a standard OFFSET and whether standard offsets are used in his area.  Then HE CHOOSES to either omit the offset, and let the radio do it or he should put in the offset in accordance with the spec.  It is not the radio deciding what to do, it is the DIGI SYSOP.

And we KNOW for a fact that ALL of the QSY/TUNE APRS radios sold in the USA DO automatically use the correct standard offset on 2 Meters, and we KNOW that the kenwoods will NOT do it on UHF.  Therefore I thought it was obvious even to the most casual observer that:

1) in the USA, for standard offset repeaters then NO OFFSET IS NEEDED.
2) In the USA, for UHF the offset should be included (in the SPEC format).

It just cannot be any simpler than that.  

3) For those still having problems in understanding, if your repeater is NON-STANDARD, or is on UHF, or is in any other country or region, or anywhere where there is no standard offset, then you MUST include the offset if you want things to work.

> That's just way to much of a guessing game. 

No guessing about it. Pure facts on how the radios work, and the spec covers all situations, if people would just do it right.  90% of the OBJECTS on the air seem to ignore it and just randomly pick and choose the data in their comments and then complain when it does not work...  When they are the problem and not everything else that they point to.

> What if we have a problem where a repeater goes down, 
> the repeater is kaput, and we are operating SIMPLEX 
> on the repeater output.  According to the spec, since no 
> offset is explicitly defined, the radio is expected to  
> do the offset thing, even though my radio is actually 
> operating simplex on the repeater output. 

Every radio sold in the USA that I have ever used, when tuned to a repeater channel will automatically set the offset (unless disabled by the owner).  If you want to operate SIMPLEX on that frequency then the operator has ALWAYS had to change the auto-shift to simplex.  Why would  we expect an APRS radio to not operate the way almost every other radio does.

> Vague, very very vague. The spec should assume NO offset 
> if one isn't offered,

Because that violates the principle-of-least-astonishment.  No other radios sold in the USA operate that way (unless the operator overrules the defaults), so why would we expect APRS radios to be different?

> specify it exactly if it is needed to contact the station via voice. 

Which is EXACTLY what I am saying and is fully covered in the spec.  If you want to transmit an offset, there is nothing preventing anyone from doing so.  An offset of +000 or -000 will force simplex just like it will in any other radio.

Bob, WB4aPR

More information about the aprssig mailing list