[aprssig] 6 meter APRS

[Chris Moulding]

I've seen similar situations over here. I run a 30m receive Igate as 
part of a 2m digi and Igate MB7UBN.

My local noise level is also high (around S6-7) mainly due to power line 
adaptors. Some days I don't decode any
packets but still easily make contacts around Europe with 30 Watts of PSK.

I've tried "PSK31 Server" and seen the Propnet site. It's good but 
limited by the use of the TCP/IP interface.

I want to make an add-on that doesn't use the TCP/IP interface so that 
UI-View could still be used as an Igate. It's
possible that the add-on could be used in an existing UI-View Igate 
running a HF and VHF packet TNC.

If it improves the reliability of the HF link then it could make HF APRS 
a useful option without excessive ACK's and digis.

73s,

Chris, G4HYG

Chris Moulding
Cross Country Wireless (2009) Ltd
7 Thirlmere Grove, Bolton, Lancs, BL4 0QB, UK
Tel/fax: +44(0)1204 410626
Mobile:  +44(0)7752 391908
Website: http://www.crosscountrywireless.net
Company number 6780346 registered in England and Wales  



Stephen H. Smith wrote:
> Chris Moulding wrote:
>> Thanks for your comments, Steve.
>>
>> My other main amateur radio interest beside APRS is the use of 
>> digi-modes on 30m and I agree with
>> your comments on symbol rates especially after using modes like 
>> OLIVIA where you can have 100%
>> copy on a signal you cannot hear.
>>
>>
>>
>> My motivation to design a PSK/QPSK TNC add-on program comes after 
>> trying for months to get a
>> 300 bd packet TNC design to work. It will decode a clean signal 
>> perfectly but feed it with an off-air
>> HF APRS signal with noise and signal corruption very few packets were 
>> decoded. An alternative
>> using PSK or QPSK would be far better for HF operation especially at 
>> this stage of the sunspot cycle.
>>
>> 73s,
>>
>> Chris, G4HYG
>>
>
> I agree.  It's even worse with connected packet or APRS' kludge of "an 
> ack in an unconnected packet" for APRS messages.
> I monitor 30M HF APRS here in southern California (Pasadena) 24/7 with 
> the 300 baud HF side of a KAM TNC. The results are on my UIview 
> webserver at:
>
>    <http://wa8lmf.dyndns.org:14439>
>
> Note that due to 1) My horribly high local noise level from a leaking 
> digital cable TV trunk and 2) the current non-existent sun spot 
> count,    it may be hours or days at a time before you see anything on 
> the map.
>
> I have watched a couple of stations, one in northern Cal (San 
> Francisco Bay area) and one in Texas try to carry on a live chat using 
> APRS messages numerous times.   Almost every time, each transmission 
> goes through 4-10 retries, and the ack will go though 3-5 retries 
> because either the message never gets to the other end, or the ack 
> never gets back.   The net effect on the available bandwidth on 30M 
> APRS in the western half of the US is disastrous. To add insult to 
> injury, one of these stations tries to use ECHO,ECHO in their path so 
> the endless retries wind up, in many cases, cluttering up the eastern 
> US as well.
>
> I've monitored the same thing with connected packet BBS systems on 20 
> meters:  Every connect attempt retries at least 3-5 times, then every 
> packet, and every ACK for every packet, during the conversation 
> retries 3-4-5 times.
>
> Don't know if you are aware of it , but years ago, G4IDE (author of 
> UIview) also created a PSK31 plugin for UIview.  This "PSK31 Server" 
> used the TCP/IP interface to UIview (i.e. emulated an Internet server 
> -- any TCP/IP using application or Telnet client can also use it).
> I actually used it from my mobile successfully on 20 meters several 
> times for coast-to-coast tracking.   This "PSK31 Server" app is used 
> today by Propnet and is archived on their website.
>
> ------------------------------------------------------------------------
>
> -- 
>
> Stephen H. Smith    wa8lmf (at) aol.com
> EchoLink Node:      WA8LMF  or 14400    [Think bottom of the 2M band]
> Skype:        WA8LMF
> Home Page:          http://wa8lmf.net
>
> JavAPRS Filter Port 14580 Guide
>  http://wa8lmf.net/aprs/JAVaprsFilters.htm
>
> "APRS 101"  Explanation of APRS Path Selection & Digipeating
>  http://wa8lmf.net/DigiPaths
>
> Updated "Rev H" APRS            http://wa8lmf.net/aprs
> Symbols Set for UI-View,
> UIpoint and APRSplus:
>
>
>
> .
> _______________________________________________
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> aprssig at tapr.org
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>
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