[OZAPRS] HF frequency drift reports ...?

Thu Jun 30 21:49:12 EST 2011

all fully accepted, tnx

>>> Setting frequency is difficult because too much reliance is placed on a
dial reading<<<
Exactly this is the problem in most cases...
73

-----Original Message-----
From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
Behalf Of Ray Wells
Sent: Donnerstag, 30. Juni 2011 12:42
To: ozaprs at aprs.net.au
Subject: Re: [OZAPRS] HF frequency drift reports ...?

Mike,

No bother at all and I accept your statement re frequency offset being a
contributor to a lack of success. Setting frequency is difficult because too
much reliance is placed on a dial reading rather than a "real" 
reading and some rig owners are reluctance to accept that "their" rig may
not be on the precise frequency indicated on the dial. As a long term (until
recently) user of crystal locked rigs such as the Codan, I have had no
option other than to initially set the crystal frequency with a Service
Monitor and then fine tune with a waterfall display. 
User/potential users should be guided in the use of a waterfall display that
gives an immediate (when signals are present) indication of frequency
setting. Perhaps the aprs web page should contain such information.

I do accept the improved technology of the smart modem but I can't accept
that older technology won't do the job most of the time.

Regards,
Ray vk2tv

On 30/06/11 20:31, OE3MZC Mike wrote:
> Ray,
> Accepted.
> I don't want to discourage anyone from using Hf-APRS - on the contrary.
>
> And to be fair- I just stepped into the discussion, because I saw 
> someone's MSG saying that he could not enter the network and was 
> asking for reasons (Power, antenna...) and in my experience it is 
> often the frequency that is not accurate, if you don't get relayed or
gated.
>
> It seems to me that the real reason is the price not technology.
> You are asking a sponsorship, I will see what I can do, but I have 
> already donated one unit to ZS and one to V51...
> and I am not earning bonus like bankers-hi
>
> Sorry to have bothered you
> 73
> Mike
>
> -----Original Message-----
> From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] 
> On Behalf Of Ray Wells
> Sent: Donnerstag, 30. Juni 2011 12:16
> To: Australian APRS Users
> Subject: Re: [OZAPRS] HF frequency drift reports ...?
>
> Mike,
>
> In my 13.5 years of running a BBS and in my last two years or so of 
> running a HF Igate I have found that for 99% of the time there is no 
> need for an expensive replacement for a standard, low cost TNC.
>
> Mobile stations managed to access my BBS with a standard rig/TNC and 
> my heard list on 30m aprs is normally filled with stations from all 
> over the world.
>
> I agree with Scott that, unless some kind person is prepared to donate 
> sufficient smart TNC's to cater for the entire Oz aprs network, let's 
> leave the hype alone for a while. All you are doing by promoting the 
> smart TNC is discouraging users and potential users who have standard 
> equipment that will work just fine nearly all of the time.
>
> My comments are based on practical application over a long period of 
> time, not some specification sheet.
>
> Ray vk2tv
>
>
> On 30/06/11 19:31, OE3MZC Mike wrote:
>> Hi Ray,
>> all,
>> I appreciate the discussion on this topic and accept your opinion.
>> It is fair to say, that you can use a modern synthesized rig for 
>> Hf-APRS, of course, But your statement also confirms my findings: you 
>> need to be within plus/minus 40Hz- let's say 50Hz ok...
>> depending on signal/noise ratio, signal levels and other distortion 
>> from 230V/50Hz..
>> If you doing at home, you can use a soundcard with waterfall display 
>> or other means of tuning, no problem.
>>
>> If you do mobile out in bush things are much more complicated.
>> Assume you use a TinyTracker or Opentracker and a FT857 or similar.
>> The frequency in display will often be more than 100Hz offset from 
>> real channel and the only way of tuning is to use the ECHO- command 
>> in the digipath - which requires a laptop to change settings when 
>> driving
> again...
>> And considering drift caused by temperature changes in car you might 
>> add another variable to the equation.
>>
>> However it would be much easier for mobiles if more I-Gates would 
>> have 800Hz"wide band" receive capabilities...10times better.
>> I think there is not just the SCS DSP-TNC that can do this, but also 
>> some software for soundcard from G4hyg 
>> http://www.crosscountrywireless.net/aprs_messenger.htm
>> but I am not sure...
>>
>> Just for records: I am not related in any way to SCS, but using such 
>> a device for years on Gateway OE3YCB-4 and OE3XUR and comparison to 
>> old type Packet-Tncs is obvious.
>> http://www.scs-ptc.com/downloads/pscproject.2008-09-29.7249707140/rel
>> e
>> ases/1
>> .0/scs-datasheet-tracker-english.pdf
>> I have crossed Australia and Africa in 4WD using HF-APRS...so some 
>> level of experience ...not just "hot-air" -hi
>>
>> Vy 73 de Mike
>> VK3FPF/OE3MZC
>>
>> -----Original Message-----
>> From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au]
>> On Behalf Of Ray Wells
>> Sent: Donnerstag, 30. Juni 2011 10:35
>> To: vk2io at amsat.org; Australian APRS Users
>> Subject: Re: [OZAPRS] HF frequency drift reports ...?
>>
>> All,
>>
>> I believe my HF rig has done a dummy spit with regard to frequency.
>> I've not logged anything since Sunday - been too busy to do daily 
>> mheard
> checks.
>>
>> Overall this concern over frequency accuracy is nothing but hot air.
>> As someone who has used HF packet for near 14 years (mostly as a 
>> BBS), all I can say is that for most of the time the frequency 
>> accuracy of the average synthesised amateur rig is more than accurate 
>> enough to achieve excellent results.
>>
>> Whilst the benefits of an expensive modem that tracks frequency 
>> cannot be denied, such a unit is not necessary for good HF packet
performance.
>>
>> Historically I have used a waterfall display to "net" my radio and 
>> that method returns excellent results. Like others on this forum I 
>> seriously doubt the frequency that's being used by VK3MY - I have 
>> always observed it to be lower than other stations by about 40Hz. I 
>> net to the average and, despite VK3MY being about 40Hz low I logged 
>> 2100 packets from him in seven days. So much for the 10Hz frequency 
>> accuracy requirement suggested in this forum. I've found that +/- 
>> 20Hz is good enough and, if signals are clean, up to 50Hz error will
work.
>>
>> If I get a chance I'll switch from the FT747 back to the TS430 over 
>> the weekend.
>>
>> Ray vk2tv
>>
>>
>> On 30/06/11 14:01, Gerard Hill wrote:
>>> Hi Terry,
>>>
>>> I would not be too concerned. Frequency reports in the list do not 
>>> seem to expire, so they'll stay there until reset. I think the list 
>>> was reset or is not being transmitted at the moment because the 
>>> beacon has
>> stopped.
>>>
>>> Sending the report is a good idea - thanks VK6UZ! Its an automated 
>>> system though so you need to do your own verification. For example, 
>>> I am sure that VK2TV-4 is not 143 Hz low. Other entries in the list 
>>> are, as far as I can tell, reasonably accurate with a slight 
>>> tendency to report too low a frequency.
>>>
>>> Oh and Dave, I miss VNG too. Used to use 7.5 MHz reference a lot.
>>>
>>> Cheers ... Gerard, VK2IO
>>>
>>> On 30/06/2011 1:23 PM, Terry Neumann wrote:
>>>>
>>>> It doesn't take a lot to confuse me these days. OK I'll admit it. I 
>>>> am confused by the list of stations Mike has copied below.
>>>>
>>>> I've checked for myself and that's more or less what the site is 
>>>> delivering in real time at this moment.
>>>>
>>>> My station is one of those listed with today's date. It hasn't been 
>>>> on HF APRS since I returned from our Flinders Ranges trip over a 
>>>> couple of weeks ago:
>>>>
>>>> http://aprs.fi/?call=vk5atn-15&mt=m&z=11&timerange=86400
>>>> <http://aprs.fi/?call=vk5atn-15&mt=m&z=11&timerange=86400>   gives
>>>> the true picture. It's in the shed with the HF rig off and the 20 
>>>> metre whip on the bar. (I just checked)
>>>>
>>>> So why is it appearing in the lists for today? And all of those 
>>>> going back over the past day or so?
>>>>
>>>> Simple answers only please - type slowly .......
>>>>
>>>> Puzzled 73
>>>> Terry
>>>>
>>>>
>>>> Date: Wed, 29 Jun 2011 13:37:07 +0200
>>>>> From: "Mike Zwingl oe3mzc"<oe3mzc at oevsv.at>
>>>>> Subject: [OZAPRS] QRG drift HF APRS
>>>>> To: "Australian APRS Users"<ozaprs at aprs.net.au> 
>>>>> Message-ID:<00ed01cc3650$e08f6800$cda8a8c0 at WORKSTATION>
>>>>> Content-Type: text/plain; charset="iso-8859-1"
>>>>>
>>>>> see how all stations on 10Mhz are drifting offset in QRG:
>>>>> http://aprs.fi/?c=raw&call=vk6uz-4
>>>>> It is not the absolute but the relative value to each other that 
>>>>> makes the problem in decoding hf-aprs sigs.
>>>>> (values after callsigns is given in Hz)
>>>>>
>>>>> 2011-06-29 11:24:57 UTC:
>>>>> VK6UZ-4>APU25N,TCPIP*,qAC,T2AUST:=3211.17S/11604.17E&HF-IGATE
>>>>> 10147.6USB Perth
>>>>> 2011-06-29 11:29:01 UTC: VK6UZ-4>APRS,TCPIP*,qAC,T2AUST:>dF (Hz):
>>>>> WIDE1 +100, VK2GKA-15 +50, VK7BW-15 +50, VK8ZAB-4 +25
>>>>> 2011-06-29 11:29:02 UTC: VK6UZ-4>APRS,TCPIP*,qAC,T2AUST:>dF (Hz):
>>>>> VK4UN-4 +62, VK5ATN-15 +65, VK5LY-15 +43, VK4KWI-15 +75
>>>>> 2011-06-29 11:29:02 UTC: VK6UZ-4>APRS,TCPIP*,qAC,T2AUST:>dF (Hz):
>>>>> VK2AJ-15 +50, KF7EU-6 +25, ZS6SS-3 +62, VK2TV-4 +143
>>>>> 2011-06-29 11:29:02 UTC: VK6UZ-4>APRS,TCPIP*,qAC,T2AUST:>dF (Hz):
>>>>> VK3DHI-15 +68, VP8DEU +43, VK2DQC-15 +81, VK4DMI-4 +96
>>>>> 2011-06-29 11:29:02 UTC: VK6UZ-4>APRS,TCPIP*,qAC,T2AUST:>dF (Hz):
>>>>> VK4HW-15 +46, VK4VP-15 +25, DL8RCB-3 +100, IW2GOB-10 +100
>>>>> 2011-06-29 11:29:02 UTC: VK6UZ-4>APRS,TCPIP*,qAC,T2AUST:>dF (Hz):
>>>>> VK4KMR-15 +46, F5LDS-4 +112, VK2SX-15 +50, LA4FPA-15 +87
>>>>> 2011-06-29 11:29:02 UTC: VK6UZ-4>APRS,TCPIP*,qAC,T2AUST:>dF (Hz):
>>>>> VK7DIK-4 +40, VK3MY-4 +65, VK3BZQ-9 +37, VK5LY-4 +43
>>>>> 2011-06-29 11:29:02 UTC: VK6UZ-4>APRS,TCPIP*,qAC,T2AUST:>dF (Hz):
>>>>> VK4UN-15 +43, VK8LM +50, VK5LY-6 +50, VK3BDG-9 -18
>>>>>
>>>>
>>>>
>>>>
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