[aprssig] RINO Position decoding (new subj)

[Stephen H. Smith]

bruninga at usna.edu wrote:
>>>> "Wes johnston" <wes at kd4rdb.com> 03/08/06 8:56 PM >>>
>>>>         
>> I think the problem with the rinos is not the transmitter... 
>> the probeml is twofold with receiver... squelch too tight, 
>> and desense caused by close prox to GPS unit hash.
>>     
>
>   
Does the squelch setting affect data receive at all?   I would have 
assumed the data decode was taken directly off the discriminator, before 
the squelch.  


> And #3 which is the receivers are 7 dB worse than
> typical HAM front ends (my measurements on 3
> of them)...
>
> So putting a LNA in front of the APRS receiving
> RINO should get at least that 7 dB back while also
> picking up maybe 6 dB of external Antenna gain.
>
>
>   
Which will probably grossly overload the mediocre RX front end with 
GMRS/FRS activity from all  the other channels, not to mention the 
numerous high-power paging systems that seem to plague every urban area 
on 460 UHF, if you stick the radio up in the air with an external gain 
antenna.    

I think the approach of mating the post-discriminator data-decoding 
smarts from a Rhino carcass to the discriminator of a "real" radio would 
be much more llkely to work.   You could use the discriminator-out pin 
("9600 Baud Data")of the Mini-DIN6 data connector of a D700 on 
UHF.....)    Or a TM-708 which is the same radio minus the TNC and APRS 
firmware.





Stephen H. Smith    wa8lmf (at) aol.com
EchoLink Node:      14400    [Think bottom of the 2M band]
Home Page:          http://wa8lmf.com

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