[OZAPRS] HF frequency drift reports ...?

[Ray Wells]

TS430 now back in service, haven't checked waterfall display yet but 
packets being decoded.

Ray, vk2tv

On 30/06/11 18:35, Ray Wells wrote:
> 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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