Laptop interference, part 2

[steffen]

Here;s an update on my attempts to couple my receiver to my laptop.
Yesterday i had both fed from a single 12v battery, so no 220v mains. Connected a reasonable good (borrowed) wire antenna.
Result: a load of interference on the receiver even when i turn volume completely off, so it (also) gets into the LF part after the volume control.

Disconnected the laptop from the battery, so fed from its internal battery.
Result: crystalclear reception (well, almost).

Conclusion: interference enters through the power line.

he funny part is that despite the interference teh reception of RTTY (weather telex from Offenbach) is almost perfect and Northwood Weatherfax is not affected to much either. I am using JVComm32 v 1.22 for a decoder.

I will now focus my attacks on the powerline and report when worthwile result achieved.

Not this weekend though, the weather becomes perfect and the wife has this weekend off so onto the IJselmeer we go tonight.

Happy sailing, Steffen

 

[Bergman]

Well done Steffan

You seem to have cracked it.

Make sure that you focus on the lap-top. Stop it putting noise onto the power line. Probably originates in switched mode PSU.

 

[vyv_cox]

Happy to report that I have now sorted all my previous problems with receiving these weatherfaxes, by dumping the Xaxero system and buying Meteoscan. I went to the premises of the guy who writes the software (near Middelburg) and saw it working before buying. It's so simple when someone shows you how!

I am using a PCR1000 receiver and the standard telescopic aerial that comes with it. I run the laptop on the mains and find that playing about with the frequency choices usually sorts out the interference. I have not tried it with the inverter from battery power but I have noticed that this has a severe effect on MW and LW radio reception. Also, having the battery charger on, charging mobile phones, and a high solar panel output all cause interference. Overall, though, I now have a system that really works. Thanks to all for their assistance, especially HaraldS.

How was the Ijsselmeer? We passed through on Friday and Markermeer on Saturday, wind was quite light but very nice sailing.

 

[ParaHandy]

Hi there.........

Does the PCR 1000/meteo allow you to do a date driven fax reception where you tell it to listen and save at 0500, 0600 or whatever times? And does it allow you to switch frequency? If you gave it 3 frequencies, would the PCR look for the best?

My point is that in winter/spring just gone I would set my kit to pick up Northwood transmissions at various times. This it did automatically with JVFAX. However, you can't change the frequency once it's all set up unless you want to twiddle in between times which I didn't. I now find in summer that the reception conditions during the day are changing all the time which is a b*gger. Sometimes 2618.5 is better than 8040khz, other times 4610khz. My usual winter dead cert of 8040khz is no longer!

 

[vyv_cox]

It sounds as though the Meteoscan does much the same as your JVFAX. It records on time base but I have not found any facility for date-based. We had it set up to do fax from Northwood at 2100, followed by the 24, 48 and 72 hour faxes from Hamburg starting at 2115, then the RTTY for Baltic and North Sea overnight. I'm not aware of any facility to automatically switch frequencies. We were mostly using the Hamburg broadcasts in the evenings, enabling me to keep an eye on what was being received. I could change frequency manually if necessary, but mostly didn't bother. Reception varies enormously from minute to minute, with no obvious influence from the boat itself. I did find that the highest frequency available (11.? kHz) often gave the best results in daytime.

You can download a trial version at http://www.mscan.com/

 

[steffen]

Hi there Vyv,
Great sailing last weekend; Saterday we went to Lelystad in very light winds. Even the spi did not fill. Dropped anchor near Lelystad for the night.
Sunday we went close hauled to Enkhuizen and with the spi down to Monnickendam. Great.

Pity i didnt know you were around, we could have had a beer together.

As far as weatherfax etc.: all works now provided i do not use the battery for both radio and laptop though rtty and fax are relatively insensitive to the interference.
Found out yesterday that the local/distant button makes a hell of a difference; should be local to cancel all the worldwide signals. Works a treat with navtex, even got Nitton in my garage where i have the contraption set up. Unfortunately blew up the powersupply of my radio with a wrong touch of the 12V at the wrong place.

Happy sailing, Steffen

 

[steffen]

He Para,
You got a nerve have you to use my thread for your owm purpose. Get your own bl***y thread -

Happy sailing, Steffen

 

[vyv_cox]

We weren't far apart. Left Lemmer on Friday late morning, excellent beat across to Enkhuisen, then stopped at Edam overnight. Reasonable wind at first on Saturday but past Marken it died to virtually nothing. Through the Oranjesluis and to Ijmuiden by Saturday evening, all on the engine. Again, some wind Sunday at first, beam reach south but after an hour nothing. Boat is now at Scheveningen, when we arrived the temperature in the harbour was 34 in no wind. At 1900 last night the temperature in the boat was 35 but cooler outside in a light breeze.

 

[ParaHandy]

Oh dear....sod you, you can 'ave yr thread back -