Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: VO1NA on 477kHz last night

To: <[email protected]>
Subject: Re: LF: VO1NA on 477kHz last night
From: "Graham" <[email protected]>
Date: Tue, 2 Dec 2014 17:29:12 -0000
Importance: Normal
In-reply-to: <[email protected]>
References: <[email protected]> <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
suffering from static interference

Not as such  Roelof

By using Manchester coding , each of the 250 ish bits are self sycn , so its not possible to 'loose lock' this coupled with non-linear routines in the dsp give a good level of compression / resistance to static and being only 1 frequency , Doppler has minimal effect as well
The decode process is similar to a Jig saw , once all possible
bits of a TX sequence [ or 40 + % of them ] have been observed , then
the decoder re-assembles the tx along the time line , being a 'data
mode' what is recovered is the original pay-load , but , due to
using algorithms to compress the call sign , false decodes , will
have the same format as a call , but not a valid one ,
I noticed last night, high background noise , and Joe's signal
dropped at one point , that may of been a Ae change ?
73-G.

--------------------------------------------------
From: "Roelof Bakker" <[email protected]>
Sent: Tuesday, December 02, 2014 11:11 AM
To: <[email protected]>
Subject: Re: LF: VO1NA on 477kHz last night

Hello Joe,

I am running a PERSEUS overnight spectrum recording from 200 - 600 kHz each night. So, it is no problem to run OP8 on 477 kHz whilst these recordings are running.
Looking at last night's recording for T/A signals, propagation has been
better.
There was also a fair amount of static.
However, I don't know if OP8 is suffering from static interference or not.
This is what I found:

02-12-2014 05:54    477 VO1NA de PA0RDT Op8 -31 dB F:11% in Middelburg
02-12-2014 05:24    477 VO1NA de PA0RDT Op8 -25 dB F:12% in Middelburg
02-12-2014 04:54    477 VO1NA de PA0RDT Op8 -29 dB F:11% in Middelburg
02-12-2014 04:24    477 VO1NA de PA0RDT Op8 -28 dB F:16% in Middelburg
02-12-2014 02:24    477 VO1NA de PA0RDT Op8 -31 dB F:16% in Middelburg
02-12-2014 01:54    477 VO1NA de PA0RDT Op8 -31 dB F:15% in Middelburg
02-12-2014 00:54    477 VO1NA de PA0RDT Op8 -27 dB F:17% in Middelburg
02-12-2014 00:24    477 VO1NA de PA0RDT Op8 -33 dB F:9% in Middelburg
01-12-2014 23:54    477 VO1NA de PA0RDT Op8 -29 dB F:15% in Middelburg

Best regards,
Roelof
=====================================================================
From: Roelof Bakker, pa0rdt
Location: Middelburg, Zealand SW Netherlands, 51 30 02 N, 03 36 02 E
Locator: JO11tm
Receiver: PERSEUS, MODE USB, bandwidth 2.4 kHz
Aerial: pa0rdt-mini-whip, 5 metre up in a hawthorn tree.
======================================================================





<Prev in Thread] Current Thread [Next in Thread>