Re: FTM-350 FREQ OBJ problem?


Lynn Deffenbaugh
 

On 5/8/2012 5:00 PM, James Ewen wrote:
Lynn, can you show me again where there's the FFF.FFFMHz definition for the rx frequency in the FREQUENCY OBJECT definition. I've got 3 versions of the freqspec document open and I can't find it...
There isn't. The only provision for a second frequency in a FREQUENCY OBJECT is in the following statement:

If both the object name and the
comment contain a frequency, then the name is considered the transmit
frequency for the object and the frequency in its comment text is
its crossband or non-standard split receive frequency.
According to how I read the following quote, NONE of the nice 1st/2nd 10 character stuff applies to frequency objects, you get the frequency in the object name and that's all! Because everything else REQUIRES an FFF.FF MHz or FFF.FFFMHz in the first 10 bytes which, by what I quoted above, would be the transmit frequency.

APRS FREQUENCY FORMATS:
-----------------------

There are two Frequency formats. The POSITION COMMENT format includes
the frequency as FFF.FFFMHz in the free field text of a normal
position or object report as noted above. The other is called the
OBJECT format because it puts the Frequency in the OBJECT NAME using
the format of FFF.FFxyz so that it shows up very clearly on the
radio's positions list. Of course, an object can also have a frequency
in its position comment as well. If both the object name and the
comment contain a frequency, then the name is considered the transmit
frequency for the object and the frequency in its comment text is
its crossband or non-standard split receive frequency.

As noted before, a 10x10x+ format is used for the POSITION COMMENT
format for best display on the existing variety of APRS radios. Here
are the standard 10-byte formats. Please note that spaces are
required where shown. In some cases a "_" may be shown for clarity
in this document, but in the actual format, a SPACE should be used:

1st 10-BYTES Frequency Description
---------- -----------------------------------------------------
FFF.FF MHz Freq to nearest 10 KHz
FFF.FFFMHz Freq to nearest 1 KHz

Examples:
146.52 MHz Enroute Alabama
147.105MHz AARC Radio Club
146.82 MHz T107 AARC Repeater (Tone of 107.2)
146.835MHz C107 R25m AARC (CTCSS of 107.3 and range of 25 mi)
146.805MHz D256 R25k Repeater (DCS code and range of 25 km)
146.40 MHz T067 +100 Repeater (67.8 tone and +1.00 MHz offset)
442.440MHz T107 -500 Repeater (107.2 tone and 5 MHz offset)
145.50 MHz t077 Simplex (Tone of 77.X Hz and NARROW band)

2nd 10-BYTES Optional Added fields (with leading space)
---------- -----------------------------------------------------
_Txxx RXXm Optional PL tone and nominal range in miles
_Cxxx RXXm Optional CTCSS tone and range in miles
_Dxxx RXXk Optional DCS code and nominal range in kilometers
_1750 RXXk Optional 1750 tone, range in km, wide modulation
_l750 RXXk Optional 1750 tone narrow modulation (lower case L)
_Toff RXXk Optional NO-PL, No DCS, no Tone, etc.
_Txxx +060 Optional Offset of +600 KHz (up to 9.90 MHz)
_Exxm Wxxm East range and West range if different (N,S,E,W)
_txxx RXXm Lower case first letter means NARROW modulation
_FFF.FFFrx Alternate receiver Frequency if not standard offset
THIS is why we need to unify the specification to ALLOW a frequency as the object name, but define ONE AND ONLY ONE set of parameters for the Position Comment that provides ALL of the required information.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

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