Weather fax on netbook + portable sony radio

[ffiill]

I have now spent three months with my Eton g3 set up at home it the middle of the north west highlands surrounded by mountains.
The following feedback regarding reception /signal quality may be of use.
Generally speaking I have downloaded good quality weatherfax from the word go as well as good quality rtty and sound reception.
I am using a forty foot horizontal wire antenna-4 strand domestic commonly used to wire up ceiling spots.
Its strung from one end of my roof to other-chimney stack to chimney stack.
Fed to receiver by domestic satellite 75 ohm coax.
Receiver is attached to computer by coax sheilded audio cable.
I receive on USB.
I usually find receiving with radio plugged to mains via provided transformer charger causes too much interference so run on batteries.
Interference also comes from washing machine;dishwasher and our oil fired central heating.
I have only tried it on my boat using its whip antenna but get reasonable reception.
For the boat I will be using a similar antenna taken to the masthead by messenger line and fed by 75 ohm coax from deck through cabin.
I am already aware of some interference on the boat source yet to be determined.
Please note 75 ohm is no good for transmitting-just happens I have a full reel of the stuff.
I have a little home made T matched antenna tuner which I intend to try out.
For the uninitiated this basically through use of a tapped coil attached to the end of the wire allows you to lenghthen or shorten the wire to get best reception for given frequency.

 

[iainhu]

A very interesting post. Thank you.

A 40' antenna is quite an antenna. Makes my portable reel antenna look quite under-rated. Interesting though that you're trying a vertical antenna on the boat. I'd wondered about hoisting an antenna on a halyard.

Interesting that on-board you've found the built-in telescopic antenna to work reasonably well. That's encouraging. The benefit of the G3 is that you, laptop and it can move from boat to boat easily, but once intricate antenna are required it all becomes a little more complex, so knowing you've got reasonable results gives me more hope!

Thanks for the extra info.../Iain

 

[MASH]

Forgive me if this has been answered previously in this fascinating but very long thread...
I am keen to get the iPad HF Fax app running - has anyone had success with it?

I haven't yet bought an SSB receiver and have been trying to use one of the internet access receivers to get a fax signal to test the app before doing so but cannot get anything but background noise. Any ideas?

Is it feasible for someone to record a bit of the signal and mail it to me in an audio file so I can play it to my iPad to see if it works OK? I don't want to but a receiver only to find the app doesn't work properly!

 

[Conachair]

Forgive me if this has been answered previously in this fascinating but very long thread...
I am keen to get the iPad HF Fax app running - has anyone had success with it?

I haven't yet bought an SSB receiver and have been trying to use one of the internet access receivers to get a fax signal to test the app before doing so but cannot get anything but background noise. Any ideas?

Is it feasible for someone to record a bit of the signal and mail it to me in an audio file so I can play it to my iPad to see if it works OK? I don't want to but a receiver only to find the app doesn't work properly!

Not sure about ipads but have a hunt on youtube, there should be some sample audio on there.

good luck!

 

[iainhu]

Very nice audio of a signal at: http://www.youtube.com/watch?v=PwgUXKXbFQk Starts about 50 seconds in

 

[Sybarite]

Wow...

 

[BigART]

Forgive me if this has been answered previously in this fascinating but very long thread...
I am keen to get the iPad HF Fax app running - has anyone had success with it?

I can confirm that the app works well on an iPad, I just hold it near the speaker of our Icom M710 and in come the pictures. The Black Cat website recommends using a wire audio connection for best results but an audio connection works well enough for me as long as the saloon isn't too noisy (heavy weather, etc). I would post a couple of pictures but can't work out how to do it on an iPad.

There is also a Navtex app by Black Cat which works equally well with an audio connection.

Angus

 

[nigelmercier]

... I would post a couple of pictures but can't work out how to do it on an iPad...

Press the Home button and the Sleep/Wake/power button at the same time, it takes a screen shot and saves it.

 

[BigART]

Press the Home button and the Sleep/Wake/power button at the same time, it takes a screen shot and saves it.

I can work out how to do that but I can't seem to find a way to get the screenshot from the library onto the YBW album to use in a post. Any ideas?

 

[nigelmercier]

The bit from 4607KHz to 4610KHz is one Side Band and the bit from 4610KHz to 4613KHz is the other. What that means is that, with SSB, the average frequency of each side band (USB or LSB) is offset slightly from the original carrier frequency, hence you need to tune slightly above or below to receive the appropriate side band...

SSB starts off with two sidebands, and a carrier. One of the sidebands and the carrier are suppressed on transmission, to be regenerated in the receiver. To do this, the receiver should be tuned to the exact frequency of the original carrier, otherwise the sidebands will have a frequency offset. If the receiver is having to be tuned to a different frequency, there is something wrong.

I can't seem to find a way to get the screenshot from the [iPad] library onto the YBW album to use in a post.

You need to use the Advanced message window, then add an attachment.

 

[Conachair]

SSB starts off with two sidebands, and a carrier. One of the sidebands and the carrier are suppressed on transmission, to be regenerated in the receiver. To do this, the receiver should be tuned to the exact frequency of the original carrier, otherwise the sidebands will have a frequency offset. If the receiver is having to be tuned to a different frequency, there is something wrong..

The original carrier being 1.9Khz below the published frequency for weatherfax on USB. Apparently.

See tables below for abbreviated versions of radiofax broadcast schedules. Assigned frequencies shown, for carrier frequency subtract 1.9 kHz. Typically dedicated radiofax receivers use assigned frequencies, while receivers or transceivers, connected to external recorders or PC's, are operated in the upper sideband (USB) mode using carrier frequencies.

http://www.nws.noaa.gov/om/marine/radiofax.htm

 

[nigelmercier]

The original carrier being 1.9Khz below the published frequency for weatherfax on USB...

From your link:

Assigned frequencies shown, for carrier frequency subtract 1.9 kHz. Typically dedicated radiofax receivers use assigned frequencies, while receivers or transceivers, connected to external recorders or PC's, are operated in the upper sideband (USB) mode using carrier frequencies.

So that is where the discrepancy comes from, glad that is sorted.

 

[K-ron]

Hi people,
Although this thread is old, many thanks to all the contributors, I have had instant success using my sony portable radio with the inbuilt arial inside a shed using the black cat app on iPad. Amazing. I have picked up northwood and the German DWD. I now intend to use the back stay of my boat as an arial and link the radio to the iPad using USB camera connections and USB soundcard. Thank you.

 

[oldvarnish]

When my laptop failed on an ocean passage (I plugged it into the SSB to get fax charts) it took me a couple of days to remember I had the iPad app. Good innit? Was getting fax charts on the iPad from just north of the equator. And from New Orleans too.

Sorry that's not very clear. I was getting Atlantic fax charts from Northwood UK, and American ones from New Orleans