[aprssig] FREQ Object radio issues (b)

[Bob Bruninga]

Here are some more notes I have found on some known problems:

Use of the "xyz" in the OBJECT NAME: 

> FFF.FF0xy object is OK and QSY is OK
> FFF.FF5xy object is OK and QSY is OK
> FFF.FFxyz object will not QSY in early D710 models.  Now fixed.

> FFF.FFxyz objects of any format will not QSY the FTM-350 (confirm?)

Extra "0" on end of the +xxx or -xxx OFFSET format.  The THD72 will accept
extra characters after the required +xxx or -xxx.  These will all give the
proper offset:

> 440.000MHz tOFF +500 Bob's radio 
> 440.000MHz tOFF +5000 Bob's radio 
> 440.000MHz tOFF +5000Bob's radio
> 440.000MHz tOFF +5000000 Bob's radio
> 440.000MHz tOFF +500Bob's radio

BUT SHOULD N OT BE USED until confirmed all existing radios can tolerate it.
This was a proposed backwards-compatible future fix to making the offset
more human readable, because then we could recommend the use of +5000
instead of the +500.  But this CANNOT BE USED until we have surveyed all
radios to see if ALL radios can properly set the offset if the additional
"0" is included.  Or all radios are upgraded to do so

Here are some other known issues for the Compatibility table of position
Comments:

Leading space:   (required, required-not, don't care) - (Y, N, X)

Xmits space:     (Transmits leading space) - (Y, N)

Requires "MHz":  (Requires mixed case, allows any case)     - (Y, N)

Requires "MHz_": (Requires trailing space) - (Y, N)

Xmits MHz_:      (Transmits trailing space) - (Y, N)

Responds to +xxx and -xxx offsets - (Y, N)

Transmits offsets +xxx and -xxx   - (Y, N)

Allows extra trailing zero so that +600 works, where only +60 is IAW spec -
(Y, N)