# Weatherfax audio file for testing



## rockDAWG (Sep 6, 2006)

Anyone have a link for an audio file to test my iPhone App?

I have this 
HF Weather Fax Marine Radiofascimile Decoder App

TIA


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## RichH (Jul 10, 2000)

That's an iPAD app, are you sure it will work with an iPHONE?

There are quite a few ONLINE HF/SSB radios that can be controlled and set to the frequencies you want to listen to. 
Simply follow the internet radio's 'how to tune' and listen ... and set your iPhone near the computer speaker (best to use an amplified PC speaker). Your computer connected to one of these 'online' and controllable radio's will then 'substitute' as an HF/SSB radio.

Here's an example of one based in Virgina: http://www.chilton.com/scripts/radio/R8-receiver

Others (but choose the right frequency range and best/close location): The Listening Post - Links to Other Radios

Here's your NOAA WeFax schedules. Use Boston @ 9.110 MHz in *AM* mode. 
NWS Radiofax 
Most WeFAX is broadcast on *AM* mode, not LowerSideBand or UpperSideBand modes, so set the internet radio's controls to AM for proper connection.

If using an internet controlled radio via your PC choose/select an internet based receiver that is 'fairly close' (~500 mi) to the broadcast station

General NOAA listing for broadcast marine weather, etc. : National Weather Service Marine Forecasts


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## SVAuspicious (Oct 31, 2006)

The iDevice software works but is not much more than a toy. Since there is no way to connect directly to the radio you have to have the audio up which is irritating and best and keeps the off watch awake for hours at worst.

Wefax is transmitted as FSK. Most mariners receive it using SSB (usually USB) which is why the seminal reference rfax.pdf reminds you to offset the tuning frequency by 1900 Hz. If you use LSB you'll need software that can invert the tones.


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## smurphny (Feb 20, 2009)

Looks like a great app if it works. SSB analog speaker tones are usable to access Wfax. In fact, with a cheap HF radio and some software, you can get Wfax onto a computer. I haven't tried this and can't comment on its relative usefulness but would suspect it would be prone to interference and loss of signal. I wonder if they're filtering signals and repeating on 4g networks to get a reliable picture. It's easy to spend 3k on a good SSB/Pactor system. Can't imagine you'd be able to come anywhere close to the long distance reliability with an iphone...yet. I can pick up fax signals from afar on the SSB. This kind of radio circuitry can't possibly be in an iphone.


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## tombesore (May 24, 2011)

Here's a link to the current schedule of WeatherFax transmissions by the Coast Guard.

http://www.nws.noaa.gov/om/marine/rfax.pdf

Set your dial frequency to 1.9KHz below the stated frequencies and keep the radio on USB. You can get this signal from a simple Grundig handheld radio with a nice long wire antenna and feed the speaker output right into your iDevice.

Amazon.com: Grundig Globe Traveler G3 Portable AM/FM/Shortwave Radio, Black - (NG3B): [email protected]@[email protected]@http://ecx.images-amazon.com/images/I/[email protected]@[email protected]@21543OnFncL

If you don't have access to a radio, I am open to experimenting via Skype or Google+ with you if you'd like me to tune my receiver to these frequencies and feed you the audio remotely. It could be a cool group demonstration on a G+ Hangout.

I've experimented with these transmissions and it's really hit or miss depending on the time of day, frequency selection and daily noise level. It makes for an interesting experiment, but I prefer to get my weather by voice broadcast, satellite or even HF email. It's not so frustrating as when the signal starts to fade on your wefax picture!


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## RichH (Jul 10, 2000)

SVAuspicious said:


> Wefax is transmitted as FSK. Most mariners receive it using SSB (usually USB) which is why the seminal reference rfax.pdf reminds you to offset the tuning frequency by 1900 Hz. If you use LSB you'll need software that can invert the tones.


Oops sorry, dame bramage ... indeed most WeFax is broadcast on Upper Side Band (FSK).

Here's the 'mother of all WeFax' websites on the net, including discussions on smart phones, tablets, etc. etc. History

Using a simple audio patch cord between the radio (simple portable 'Short Wave' with AM/USB/LSB/CW or HF/SSB) and a PC and using simple/fairly inexpensive programs will get you WeFax out at sea. I use a simple audio patch from my SSB (or portable SW receiver) into a Mac using "multi-mode" as the software for WeFax and marine TTY - MultiMode - CW RTTY SSTV FAX MORSE PSK31 ACARS SITOR AMTOR ALE DTMF FFT ASCII Decoding Software for the Macintosh


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## SVAuspicious (Oct 31, 2006)

RichH said:


> Oops sorry, dame bramage ... indeed most WeFax is broadcast on Upper Side Band (FSK).


I seem to be on a bit of a tear on vocabulary. Please forgive me. Skip the next paragraph if you don't care about what makes your radio work.

Frequency shift keying (FSK) is generated by a transmitter switching between two very close frequencies, usually 170 or 200 Hz apart, that are called 'mark' and 'space.' It was initially used for radio teletype (RTTY). Some genius (literally) applied to to image transmission and reception by setting standards for keying rates. It was intended to be received in a radio by injecting a signal at the frequency between mark and space and filtering the products with low pass and high pass filters to recover the mark and space. Another genius realized that this was analogous to SSB reception and that a couple of very narrow filters could recover the mark and space. Using an SSB mode (usually upper sideband, USB) means tuning off a bit (1900 Hz) in order to put the mark and space tones in the bandpass of the filters.

But you guys already knew that. *grin* It's pretty cool stuff, actually very simple and robust. Engineering elegance. I wish I knew the names of the geniuses because they deserve to be recognized.



RichH said:


> Using a simple audio patch cord between the radio (simple portable 'Short Wave' with AM/USB/LSB/CW or HF/SSB) and a PC and using simple/fairly inexpensive programs will get you WeFax out at sea. I use a simple audio patch from my SSB (or portable SW receiver) into a Mac using "multi-mode" as the software for WeFax and marine TTY - MultiMode - CW RTTY SSTV FAX MORSE PSK31 ACARS SITOR AMTOR ALE DTMF FFT ASCII Decoding Software for the Macintosh


Right. A couple of points. One is that the mic input on MOST laptops is mono and the behavior of stereo plugs in mono jacks isn't always what is expected. Similarly, the way that mono signals (like SSB) are routed to stereo jacks as found on many shortwave radios is not consistent. I strongly suggest a 1/8" male mono plug to 1/8" male mono plug patch cord and a 1/8" female mono jack to 1/8" male stereo plug adapter. Put the adapter in the shortwave radio and hook up the patch cord.

There are a number of software options for Windows: JVCOMM32, Multipsk, and Digipan among others. I usually use JVCOMM32 on delivery. It is simpler and easier to set up. I do use Multipsk on Auspicious as it gives me the ability to transmit radiofax as well as receive.


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## tombesore (May 24, 2011)

You inspired me to do my own little test this morning. I found that I was receiving solid signals (S9+20db) from the 4Kilowatt NMG New Orleans Coast Guard transmitters during their morning run of WEFAX transmissions. The image below was received through a modern HF amateur radio transceiver and fed into the Multimode for Mac program. The frequency was 8502 kHz USB.

As you can see, the image is fair at best, even with a very solid S9 signal and modern reception gear. This is typical of the images I've been able to pull in. The pics are fair at best and most of the time I can barely make out the notations.

Has anyone else had better luck pulling in higher quality pictures over HF? Let's see what you got!

By the way, I also set my iPad next to the speaker with that BlackCat Wefax program running and, while the same image did appear on the iPad, it was far worse quality!


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## tombesore (May 24, 2011)

rockDAWG,

Here's a link to a sample audio file. It's a 24 Hour Surface Forecast WEFAX image transmitted by the US Coast Guard transmitters NMG on 8502kHz this morning around 7:30am central time. With this seemingly strong audio, my decode was readable but only marginal quality.

https://archive.org/download/WEFAXFile1/WEFAX File 1.wav


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## RichH (Jul 10, 2000)

tombesore said:


> You inspired me to do my own little test this morning. I found that I was receiving solid signals (S9+20db) from the 4Kilowatt NMG New Orleans Coast Guard transmitters during their morning run of WEFAX transmissions. The image below was received through a modern HF amateur radio transceiver and fed into the Multimode for Mac program. The frequency was 8502 kHz USB.
> 
> As you can see, the image is fair at best, even with a very solid S9 signal and modern reception gear. This is typical of the images I've been able to pull in. The pics are fair at best and most of the time I can barely make out the notations.
> 
> ...


with Multimode (Cocoa) adjust your radio squelch and output volume (horizontal 'slider' on the top right of the Multimode window) to clarify and adjust such pics., using the 'slider' and your radios fine tune frequency control to maximize the received 'peak' wave forms overlayed and centered to one of the 'red' reference lines in that 'box' at the top right in the multimode window. 
Also be sure that youre set up for "line" instead lf 'grey"; "LINE" function is for line charts, "grey" is for satellite pics.

Also be aware that the current sunspot activity is nearing its maximum .... lots of good propagation but can have lots of distortion 'background noise' which can distort your reception.


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## SVAuspicious (Oct 31, 2006)

tombesore said:


> You inspired me to do my own little test this morning. I found that I was receiving solid signals (S9+20db) from the 4Kilowatt NMG New Orleans Coast Guard transmitters during their morning run of WEFAX transmissions. The image below was received through a modern HF amateur radio transceiver and fed into the Multimode for Mac program. The frequency was 8502 kHz USB.


Hi Tom,

That's pretty fuzzy. I rarely see anything that bad. Icom 802/AT140/SCS PTC-IIpro/Airmail-GetFax I was getting near-Internet quality pictures from Boston well East of Azores. Up and down the US East Coast I get Boston and New Orleans really well.

I've had similarly good results using a Kaito 1103 and JVCOMM32 with a big hunk of copper wire hauled up as high as possible. The antenna makes a big difference.

Did you collect your signal aboard the ferry at your club? Could there be interference from being at the dock or even from internal systems? On delivery I've had a number of noisy boats that required shutting systems down to get a good fax image -- obviously a pain if you're shutting down refrigeration for a six hour wefax cycle.


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## tombesore (May 24, 2011)

As for that fuzzy signal, I am wondering if I had the greyscale option selected instead of b/w. The signal was strong and noise is minimal. The antenna is a 140' long Windom stretched between the ship's mast.

I'll give it a try again and hope for better results .... also using the tuning tweaks suggested earlier in this thread. Thanks for the suggestions.


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## smurphny (Feb 20, 2009)

tombesore said:


> You inspired me to do my own little test this morning. I found that I was receiving solid signals (S9+20db) from the 4Kilowatt NMG New Orleans Coast Guard transmitters during their morning run of WEFAX transmissions. The image below was received through a modern HF amateur radio transceiver and fed into the Multimode for Mac program. The frequency was 8502 kHz USB.
> 
> As you can see, the image is fair at best, even with a very solid S9 signal and modern reception gear. This is typical of the images I've been able to pull in. The pics are fair at best and most of the time I can barely make out the notations.
> 
> ...


That's fairly distorted. I sometimes get similar results if I forget to turn off equipment like the converter. It looks like interference. Have you tried ferrite beads on cables? What kind of counterpoise?


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## RichH (Jul 10, 2000)

tombesore said:


> As for that fuzzy signal, I am wondering if I had the greyscale option selected instead of b/w. The signal was strong and noise is minimal. The antenna is a 140' long Windom stretched between the ship's mast.
> 
> I'll give it a try again and hope for better results .... also using the tuning tweaks suggested earlier in this thread. Thanks for the suggestions.


Try aligning your antenna to straight vertical as much as possible ... horizontally polarized antennas are subject to pick up a lot of 'noise' from automotive type spark ignition engines and are highly insensitive to signal coming in at the 'ends' ... better to be 90° from the broadcast origin; vertical antennas seem at times to better dampen out such automotive induced background noise and are more omnidirectional.


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## jackdale (Dec 1, 2008)

SVAuspicious said:


> I've had similarly good results using a Kaito 1103 and JVCOMM32 with a big hunk of copper wire hauled up as high as possible. The antenna makes a big difference.


Tell me about that "big hunk of copper wire".

I am thinking about a similar setup to use on my trips around Vancouver Island. Few of the boats have SSB.

Jack


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## Minnewaska (Feb 21, 2010)

I don't understand why no one has made a patch cable and software that will connect an iPad directly to a Pacor modem. Getting weather over SSB is ridiculously complicated for the 21st century.


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## smurphny (Feb 20, 2009)

Minnewaska said:


> I don't understand why no one has made a patch cable and software that will connect an iPad directly to a Pacor modem. Getting weather over SSB is ridiculously complicated for the 21st century.


It does seem pretty archaic but I guess the population that uses hf is not big enough to spur tech geeks to do much research and invention. With satellite communication now available (for those who can afford it), I think HF will eventually be replaced. Once more companies get more satellites up there, maybe there will be some real competition to reduce the price of satellite links. Once every-day mobile devices go to satellite signals instead of land towers it should bring the cost down and supply reliable and clear signals to boats anywhere on the planet.


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## RichH (Jul 10, 2000)

..... might be something for Sirius-XM radio to consider, huh?


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## rockDAWG (Sep 6, 2006)

tombesore said:


> rockDAWG,
> 
> Here's a link to a sample audio file. It's a 24 Hour Surface Forecast WEFAX image transmitted by the US Coast Guard transmitters NMG on 8502kHz this morning around 7:30am central time. With this seemingly strong audio, my decode was readable but only marginal quality.
> 
> https://archive.org/download/WEFAXFile1/WEFAX File 1.wav


Hey Tombesore,

Thanks for taking time to capture the sound file for me. I play it with iPAD just out of the computer speaker or headphone. THe weather chart is very distorted. In other words, it works. But need to obtain a better quality sound input for iPAD.


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## rockDAWG (Sep 6, 2006)

Minnewaska said:


> I don't understand why no one has made a patch cable and software that will connect an iPad directly to a Pacor modem. Getting weather over SSB is ridiculously complicated for the 21st century.


Exactly, 10x
Actually, Black Cat has address this.










iPad / iPhone / iPod Touch Microphone Adapter Wiring Diagram

The also posted another source - ready made solution. So I will look into it to see if it will work.

iPhone 1/8 inch line-level audio input adapter - 3.5mm 4 conductor TRRS Male to 3.5mm TRS Microphone Input Jack with built-in Attenuator


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## Minnewaska (Feb 21, 2010)

rockDAWG said:


> Exactly, 10x
> Actually, Black Cat has address this.
> 
> image deleted
> ...


I don't really understand this. That iphone port is for headsets, meaning an output. How can it be used to accept input from an external source?

I thought someone may make a cable to connect to the rectangular port that is used for communication in both directions and charging.


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## Minnewaska (Feb 21, 2010)

smurphny said:


> It does seem pretty archaic but I guess the population that uses hf is not big enough to spur tech geeks to do much research and invention......


That's probably it, but Pacor still seems to be in business. If I were them, I would think making the use of their device simpler, would sell more. Not to mention its free weather. No 3G subscription or wifi needed, so it would be useful to coastal cruisers too.


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## Minnewaska (Feb 21, 2010)

RichH said:


> ..... might be something for Sirius-XM radio to consider, huh?


They already have it. We have XM weather download into our aircraft. It's about $60 per month. Marine version available too, but also has a subscription and hardware cost. I believe late model chartplotters are designed to overlay the input.


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## rockDAWG (Sep 6, 2006)

Minnewaska said:


> I don't really understand this. That iphone port is for headsets, meaning an output. How can it be used to accept input from an external source?
> 
> I thought someone may make a cable to connect to the rectangular port that is used for communication in both directions and charging.


To my understand you need the Camera Connection adapter for iPAD.

In their site, it says:
========
With the Camera Connection Kit, you can plug a USB sound input device into the iPad, and use a patch cable between it and the radio's audio output. This is by far the best solution. 
==========


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## ottos (Aug 12, 2008)

Minnewaska said:


> I don't really understand this. That iphone port is for headsets, meaning an output. How can it be used to accept input from an external source?


Don't forget about the microphone part of the headset...that seems to be what they're utilizing.


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## smurphny (Feb 20, 2009)

Minnewaska said:


> That's probably it, but Pacor still seems to be in business. If I were them, I would think making the use of their device simpler, would sell more. Not to mention its free weather. No 3G subscription or wifi needed, so it would be useful to coastal cruisers too.


There are some land-based packet modems but Pactor, in Germany, seems to be the only one making them focused on the boating population. At around $1400 bucks, they really are out of the mass market price range. I don't even like to think about how much money I spent on the SSB system. Hopefully it will last for a while and not become obsolete too quickly.


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## Minnewaska (Feb 21, 2010)

ottos said:


> Don't forget about the microphone part of the headset...that seems to be what they're utilizing.


Of course. (Smacks palm on forehead)

Now that I think about it, the attachment to the Pactor modem should be Bluetooth. Dial in the freq on the SSB, fire up the modem and the ipad should connect itself. The rest should be a single tap on the screen. This has to be possible.


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## SVAuspicious (Oct 31, 2006)

jackdale said:


> Tell me about that "big hunk of copper wire".
> 
> I am thinking about a similar setup to use on my trips around Vancouver Island. Few of the boats have SSB.


My big hunk of copper wire carried on delivery is the end of a spool I bought in the mid-70s from Lafayette Radio Electronics. It was sold as "antenna wire."

Any 12 gauge (+/-) wire will work. Insulated is probably better for our application. I'd get something tinned for a permanent installation but for a go-bag it doesn't make much difference.

I run it up as high as I can and try to get 50 or 60 feet out straight(ish).

For the Kaito 1103 you connect the wire to the tip of a 1/8" male mono plug, insulating it from the ring. Just plug it into the external antenna connector. Watch the audio connectors -- most laptops have a mono mic input and the headphone jacks on shortwave radios including the Kaito are often stereo.

I use JVCOMM32 for weather fax demodulation and display.


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## smurphny (Feb 20, 2009)

I use a split lead antenna. It has the advantages of being able to roll it up and stow it when the boat is in storage and also eliminates the need to splice so many failure points into your backstay such as in a standard insulated stay antenna. GAM / McKim Split Lead Antenna | GAM Electronics For portability, this might be a good option.


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## SVAuspicious (Oct 31, 2006)

smurphny said:


> I use a split lead antenna. It has the advantages of being able to roll it up and stow it when the boat is in storage and also eliminates the need to splice so many failure points into your backstay such as in a standard insulated stay antenna. GAM / McKim Split Lead Antenna | GAM Electronics For portability, this might be a good option.


For whatever it is worth I am not a fan of that product. It works on some boats and is a dismal failure on others. The lack of predictability makes me unhappy.


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## rockDAWG (Sep 6, 2006)

SVAuspicious said:


> My big hunk of copper wire carried on delivery is the end of a spool I bought in the mid-70s from Lafayette Radio Electronics. It was sold as "antenna wire."
> 
> Any 12 gauge (+/-) wire will work. Insulated is probably better for our application.


I assume this is a single strand electrical copper wire we can get from HD. 12 G 50 ft is still pretty heavy and stiff for traveling.

Sangean makes a relatively compact antenna, not sure how that compared. ?? But the reviews look good on amazon.


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## smurphny (Feb 20, 2009)

Minnewaska said:


> They already have it. We have XM weather download into our aircraft. It's about $60 per month. Marine version available too, but also has a subscription and hardware cost. I believe late model chartplotters are designed to overlay the input.


My little Garmin 376C came with a satellite antenna and has access to XM Weather. The cost to subscribe to the service is ridiculous.


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## Minnewaska (Feb 21, 2010)

smurphny said:


> My little Garmin 376C came with a satellite antenna and has access to XM Weather. The cost to subscribe to the service is ridiculous.


I think, if you bundle it with radio, it gets a little better, but I hate paying for radio too.

It makes more sense in the aircraft, as we're covering more distance in 15 minutes than we literally sail in an entire day. Getting specific terminal weather that's further away than we can receive a radio signal has been an outstanding safety upgrade. Used to have to dial into ground based verbal reports. Now I just look on a screen and see all the weather at every station along my entire flight path.


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## smurphny (Feb 20, 2009)

With the antenna connected, I can get free generic text weather but nothing else. 

Auspicious, I wonder what the problem was with the installations that did not work well. I have had no problems. When I installed the SSB, bought the parts from Dockside Radio. They are a great resource of information about what you need to make an SSB work. My radio is an ICOM 700pro/ICOM tuner. which seem to work well with this antenna. My primary reason for choosing this type antenna was to get rid of all those failure points at insulators in the backstay when I replaced it.


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## SVAuspicious (Oct 31, 2006)

smurphny said:


> My little Garmin 376C came with a satellite antenna and has access to XM Weather. The cost to subscribe to the service is ridiculous.


XM weather is Grib based, is it not? That means no fronts, although NWS is working hard on that. In the meantime missing fronts is a problem.



smurphny said:


> Auspicious, I wonder what the problem was with the installations that did not work well. I have had no problems. When I installed the SSB, bought the parts from Dockside Radio. They are a great resource of information about what you need to make an SSB work. My radio is an ICOM 700pro/ICOM tuner. which seem to work well with this antenna. My primary reason for choosing this type antenna was to get rid of all those failure points at insulators in the backstay when I replaced it.


This is about the GAM antenna, right? My issue is that it works fine on some boats and not at all on others. I'm glad it works for you. I wouldn't put money on it working on another Alberg 35 based on my experience with it.

I like direct fed antennas like insulated backstays, alternate backstay antennas like the Rope Antenna, and other rig-based elements. I like them because I want my customers to be assured that what they leave with will work and continue to work. I can't make that commitment with a GAM antenna.


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## Minnewaska (Feb 21, 2010)

SVAuspicious said:


> XM weather is Grib based, is it not? That means no fronts, although NWS is working hard on that. In the meantime missing fronts is a problem.


I don't use the marine version, so I'm not sure about Grib. The aviation version does not show fronts, but it does show composite radar. Combined with onboard radar, its an incredible tool. The satellite images can be as much as 6 or 7 minutes delayed when a lot is going on (ie a lot of data to download). Near meaningless in a sailboat, I suppose.

When coastal cruising, within a few miles of shore, we now use the NOAA weather radar app and the Intellicast weather app on the iPad/iPhone. Free.


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## smurphny (Feb 20, 2009)

SVAuspicious said:


> XM weather is Grib based, is it not? That means no fronts, although NWS is working hard on that. In the meantime missing fronts is a problem.
> 
> This is about the GAM antenna, right? My issue is that it works fine on some boats and not at all on others. I'm glad it works for you. I wouldn't put money on it working on another Alberg 35 based on my experience with it.
> 
> I like direct fed antennas like insulated backstays, alternate backstay antennas like the Rope Antenna, and other rig-based elements. I like them because I want my customers to be assured that what they leave with will work and continue to work. I can't make that commitment with a GAM antenna.


It is the GAM antenna. Maybe I'll hoist up the old insulated backstay and see if there's any difference. If I can get even better Wfax images, maybe the insulators go back in. Thanks for that info. The XM images are very nice, as noted by Minnewaska. They do not look like grib images. I think their minimum service that would be appropriate for sailing is about $30/mo. If it was more reasonable I would subscribe in a minute because the real-time satellite images would be VERY useful. One other note is that it does not seem to be worldwide but only US and Can. Even with a good Wfax image, it is still delayed data.


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## SVAuspicious (Oct 31, 2006)

Minnewaska said:


> I don't use the marine version, so I'm not sure about Grib. The aviation version does not show fronts, but it does show composite radar. Combined with onboard radar, its an incredible tool. The satellite images can be as much as 6 or 7 minutes delayed when a lot is going on (ie a lot of data to download).


I did some research and was unable to find any clear information about the data sources for XM Weather. Lots of speculation but nothing definitive.

Adding to the speculation I suspect XM weather is GFS-based grib data with local processing to display all the arrows and colors.

That means no fronts as we have already noted and I *care* about fronts.

What do you get from imagery? I don't get much except a hint of where there might be a front and a SWAG at whether I'll get rained on.

Since we have expanded from the original question to weather tools in general may I strongly recommend my friend Lee Chesneau's classes in becoming self-sufficient in weather forecasting and routing? See Self-Reliance Weather Courses for Recreational Sailors and Racers « Lee Chesneau's Marine Weather . The three day course is worth every bit of energy you can put into it.


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## Scooter Schneider (Sep 16, 2015)

Looking for a solution to take the audio from the radio into the iPad for weatherfax, Read everything here and had a possible epiphany. 
IK Multimedia | iRig 2 - Guitar interface adapter for iPad
Can't post a link, you will gave to google
I use an iRig to patch my guitar into the iPad. Too much gain distorts bad but at lower inputs, this should work. I'll test later an report my findings.


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## SV Myth (Nov 29, 2015)

*Cheaper Solution*

I have just completed and tested a very simple solution. A 10k potmeter connected to the earphone audio output of the HF receicer. The output of the potmeter via a 1uF capacitor and a two 4.7k resistor divider to the microphone input of the iPad. Works fine, just a couple of $, much easier and cheaper components than a audio transformer.

Don't see the problem, I'm not to afraid about the fact that the ground of the Ipad is connected to the ground of the receiver. Certainly not as long as the iPad is not connected to a charger during reception.

It seems that the resistance on the iPad mic input needs to be in the range between aboit 800 ohm and a about 5 kohm in order to make the iPad believe that a mic is connected.

Hans van der Vliet
Netherlands


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