Best Price on icom 802and/or pactor 4

[avid]

Originally Posted by socaldmax

I like to have a backup system for everything, so an $8 USB RTL receiver and free software is a cheap way to get satellite images that look a lot better than GRIB files.

I did some searching and haven't found the USB RTL receiver you mentioned. Would you mind providing a link? Thanks

[ka4wja]

socaldmax,
While there is nothing wrong with POES APT satellite images...
NOAA - National Oceanic and Atmospheric Administration - Satellites

Originally Posted by socaldmax

I don't own a boat yet, but I'd use every bit of weather info at my disposal to guide me.

Most places you'll end up sailing/cruising, you're going to want a synoptic chart, a forecast / forecast chart / etc. rather than just a real-time satellite image...
Now, yes there are some real remote locales where a POES APT image is the best you're going to get (unless you have internet access), but these are NOT the typical cruising grounds, nor along the regular shipping/cruising routes...
PLEASE understand the limitations of the 137mhz APT images..


Not to mention that receiving live 137mhz APT images on-board (while very do-able) is not as easy as it is on-land or even in-port, at anchor, at the dock, etc...
Yes, much improvement has been made over the years (rec design, LNA's, etc. as well as the satellites themselves) and it has gotten much easier, but it still is not as easy at sea as you may like it to be...




FWIW, I started playing with/using the 137mhz APT images > 30 years ago....and in the early-to-mid-80's did the RF engineering end of a private/univ study of the practical/economic use of the 1691mhz GOES images and data...I built the antennas and LNA...we had just gotten a 80286 machine to run it in real-time unattended, when we were given an 80386 machine to do the processing.....and well...the project head went on sabbatical....(meaning no more money to pay me, etc.) and then I got busy with other stuff and never went back to work with them....but it was fun!!!
(we even broadcast our live images on a friend's 439mhz ATV transmitter, and had live sat images in the county emerg op center, provided by that guy's ATV system....hey, it was the early 80's, before the internet and Wi-Fi, etc.!!!)

The reason I mention all of this is simply to point out that real-time APT images are nice to have, but are a far cry from a long-tern forecast chart, especially one that covers 1000's of miles of ocean/coastline/etc. rather than just 100's of miles....

Besides, I'd rather have some real synoptic charts and forecasts, drawn in B&W, by trained/experienced ocean meteorologists...than a fancy color image any day....
But, that's just me...




Fair winds...

John
s/v Annie Laurie

[ka4wja]

Simon,
I'm not sure where your cruising grounds are....but assuming you're near Aus / NZ, Singapore, Pacific or Indian Ocean, etc...you should have excellent wefax charts (synoptic charts and forecasts, drawn by Aus Met Office professionals), transmitted from VMC and VMW...and ZKLF in NZ... (as well as Singapore, Thailand, Honolulu, etc.) all for FREE....and not require any PACTOR modem at all....

Originally Posted by SimonV

I would love one of the new pactors, mine is a pac lle without the 3 upgrade. But will next year. Pac 2 can be had for around $500. The biggest reason and my most used is for grib files admittedly l only get 10kb files which are fine, but for a $100 upgrade to a 3 you get 30kb grib files.

Are you not using wefax charts at all???
You mention GRIB's, but no mention of the professional drawn charts and forecasts available to you for FREE via wefax...


Just curious??


Fair winds...

John
s/v Annie Laurie

[SimonV]

Originally Posted by ka4wja

Simon,
I'm not sure where your cruising grounds are....but assuming you're near Aus / NZ, Singapore, Pacific or Indian Ocean, etc...you should have excellent wefax charts (synoptic charts and forecasts, drawn by Aus Met Office professionals), transmitted from VMC and VMW...and ZKLF in NZ... (as well as Singapore, Thailand, Honolulu, etc.) all for FREE....and not require any PACTOR modem at all....Are you not using wefax charts at all???
You mention GRIB's, but no mention of the professional drawn charts and forecasts available to you for FREE via wefax...


Just curious??


Fair winds...

John
s/v Annie Laurie

Hi Annie, yes I have used the wefax but i found it less useful. I find Grib files eiser to work with. It may be just the way I was taught.

Sent from my GT-N7105T using Cruisers Sailing Forum mobile app

[socaldmax]

Originally Posted by avid

I did some searching and haven't found the USB RTL receiver you mentioned. Would you mind providing a link? Thanks

Here's one for $8.47, free shipping.
W3LE Software Radio USB DVB T RTL2832U R820T Support SDR Digital TV Receiver New | eBay


Here's one for $8.49, free shipping.
VE4A Software Radio USB DVB T RTL2832U R820T Support SDR Digital TV Receiver New | eBay

Then there's a whole slew of them for $8.72 with free shipping. I usually buy from the vendor with the highest feedback rating and fastest shipping if there are so many of them in the same price range.

There are actually 2 different chips used in USB RTLs, the RT2832U with R820T or the e4000. I believe the R820T can go down to 24 MHz vice 50 MHz for the e4000, but the e4000 is a little more sensitive and goes up to 1800 MHz. Doublecheck the freq. range before you buy.

I spent a lot more on the antenna and cabling, about $50 for the discone antenna, and $50 ea for 2 50' sections of LMR400 cable.

[socaldmax]

Originally Posted by ka4wja

socaldmax,
While there is nothing wrong with POES APT satellite images...
NOAA - National Oceanic and Atmospheric Administration - Satellites Most places you'll end up sailing/cruising, you're going to want a synoptic chart, a forecast / forecast chart / etc. rather than just a real-time satellite image...
Now, yes there are some real remote locales where a POES APT image is the best you're going to get (unless you have internet access), but these are NOT the typical cruising grounds, nor along the regular shipping/cruising routes...
PLEASE understand the limitations of the 137mhz APT images..


Not to mention that receiving live 137mhz APT images on-board (while very do-able) is not as easy as it is on-land or even in-port, at anchor, at the dock, etc...
Yes, much improvement has been made over the years (rec design, LNA's, etc. as well as the satellites themselves) and it has gotten much easier, but it still is not as easy at sea as you may like it to be...




FWIW, I started playing with/using the 137mhz APT images > 30 years ago....and in the early-to-mid-80's did the RF engineering end of a private/univ study of the practical/economic use of the 1691mhz GOES images and data...I built the antennas and LNA...we had just gotten a 80286 machine to run it in real-time unattended, when we were given an 80386 machine to do the processing.....and well...the project head went on sabbatical....(meaning no more money to pay me, etc.) and then I got busy with other stuff and never went back to work with them....but it was fun!!!
(we even broadcast our live images on a friend's 439mhz ATV transmitter, and had live sat images in the county emerg op center, provided by that guy's ATV system....hey, it was the early 80's, before the internet and Wi-Fi, etc.!!!)

The reason I mention all of this is simply to point out that real-time APT images are nice to have, but are a far cry from a long-tern forecast chart, especially one that covers 1000's of miles of ocean/coastline/etc. rather than just 100's of miles....

Besides, I'd rather have some real synoptic charts and forecasts, drawn in B&W, by trained/experienced ocean meteorologists...than a fancy color image any day....
But, that's just me...




Fair winds...

John
s/v Annie Laurie

Thanks for clarifying! I don't have any experience yet with which is more useful, just trying to show more options but of course that can confuse matters!

[ka4wja]

Again, my apologies for the continued thread drift!!

Anyone that wants more info on 137mhz APT Images (POES Satellite Images), there is a LOT of info out there....both here on Cruiser's Forum and on the internet in general...
Do a search here, and you'll find a LOT....
Just be aware that for 99.9% of sailors/cruisers it is not a substitute for synoptic charts, etc...inexpensive ($100 - $200) 137mhz receivers have been available for many years now, and the antennas are cheap/easy to DIY, but so far their use provides limited info and NO forecasts....now with even lower costs and easier software, etc. we may see more folks playing with these new dongles...)





socal, no worries here....APT is cool!!

Originally Posted by socaldmax

Thanks for clarifying! I don't have any experience yet with which is more useful, just trying to show more options but of course that can confuse matters!

But, I would like to clarify something else here...antennas, etc...

Originally Posted by socaldmax

about $50 for the discone antenna, and $50 ea for 2 50' sections of LMR400 cable.

For most consumer users of 137mhz APT, a VERY simple (and almost impossible to screw-up) "turnstile" antenna (aka "crossed dipoles") works very well, with a fair good pattern and no deep nulls....it can be built by anyone that can use a hacksaw, or wire cutters, and a tape measure...
Yes, a quadrifilar helix antenna is better / has a cleaner pattern...but is not the easiest antenna for the DIY layperson to build...and can be a pain to make strong enough to mount permanently...

But, a "discone" is actually not a good choice for 137mhz APT reception....
A discone is a VERY wide-band antenna (typical vhf discones can cover from 100mhz - 1000mhz), but they are very inefficient antennas (actually negative gain compared to a dipole or vertical whip) and as they are vertical antennas, they have a null directly overhead (meaning as a satellite moves directly over you, say above 70* in elevation, the signal drops rather than getting stronger..)
Yes, they work....even a wire coat-hanger will work....it's just not a very good choice for this application...
(btw, a discone IS a good antenna to use with wideband scanning receivers, and/or some of these vhf/uhf receiver dongles, WHEN listening/monitoring TERRESTRIAL signals...)





I hope this helps..

John
s/v Annie Laurie

[ka4wja]

Simon,
No worries here...we all have our own preferences...
But, my name is John.... ("Annie Laurie" is the name of my boat...)
I just wanted everyone here to be aware that GRIB's are raw computer data model...versus wefax charts actually being drawn by a human being...

Originally Posted by SimonV

Hi Annie, yes I have used the wefax but i found it less useful. I find Grib files eiser to work with. It may be just the way I was taught.

Most cruisers who use GRIB's only get one computer model run, for the area they desire....and for the specific timeframe they desire....and this is just that....ONE model run, for just that area, for just those times....
And, it is all just the raw model data...

A wefax chart is prepared by a trained, experienced marine meteorologist, showing the weather that is there, and what their expertise tells them what weather WILL be there in the future (a forecast)...
Yes, they do use the computer models to determine the forecasts, but they use plenty of other data as well....and of course their own experience and expertise....


Weather forecasting is a science, but it is not an exact science!!!
And nobody gets it right 100% of the time....but for me, I rather like the fact that the US NWS/NOAA meteorologists actually sign their name to their forecasts, and they do internal grading/peer reviews, which further hones their skills by making the "competition" viewable by the public...
I'm not who is the best in each office, but I do know that if they can't cut it, they don't last long in the Ocean Prediction Center and the Tropical Prediction Center...


Sorry I'm digressing....

fair winds..

John
s/v Annie Laurie

[sdrformariners]

Sorry socaldmax your info here is plain wrong.

A discone will be near useless for APT images, period.
You need a dedicated weather satellite antenna, I've written free instructions plus tested suitable types, check here:

Weather Satellites - Antennas

Assuming you have a laptop on board, a weather satellite system can be had for less than 20 dollars, will be reliable and easy to install.

For reception-only for wefax images any SSB-enabled portable radio will do the job.
An RTL SDR plus an upconverter plus an antenna is around 80 dollars, you get wefax, APT satellites plus continous coverage from 1.5 to 1400 MHz, for reception-only you can not beat that.

[ullar]

Originally Posted by sdrformariners

Sorry socaldmax your info here is plain wrong.

A discone will be near useless for APT images, period.
You need a dedicated weather satellite antenna, I've written free instructions plus tested suitable types, check here:

Weather Satellites - Antennas

Assuming you have a laptop on board, a weather satellite system can be had for less than 20 dollars, will be reliable and easy to install.

For reception-only for wefax images any SSB-enabled portable radio will do the job.
An RTL SDR plus an upconverter plus an antenna is around 80 dollars, you get wefax, APT satellites plus continous coverage from 1.5 to 1400 MHz, for reception-only you can not beat that.

Can't open that link. Is it just me?

[karabil]

Thanks for your info John,
We will be blue watering again so no mobile network or wifi for pretty long stretches.
We had sail mail set up on our last boat and found it worked well across the Pacific, although it was a pactor 1 or 2 (8 years ago) so slow but steady. We have sold that boat but the setup is still going strong.

[socaldmax]

Originally Posted by sdrformariners

Sorry socaldmax your info here is plain wrong.

A discone will be near useless for APT images, period.
You need a dedicated weather satellite antenna, I've written free instructions plus tested suitable types, check here:

Weather Satellites - Antennas

Assuming you have a laptop on board, a weather satellite system can be had for less than 20 dollars, will be reliable and easy to install.

For reception-only for wefax images any SSB-enabled portable radio will do the job.
An RTL SDR plus an upconverter plus an antenna is around 80 dollars, you get wefax, APT satellites plus continous coverage from 1.5 to 1400 MHz, for reception-only you can not beat that.

I never said I was going to use the discone for sat reception. I merely stated that I paid more for the discone and the LMR400 cabling than I paid for the RTL dongles. I simply have not built my QFH antenna yet.

Anything else is an assumption on your part.

But thanks for touting your website!

[socaldmax]

Originally Posted by ullar

Can't open that link. Is it just me?

No, it's not you. Somehow, the link got modified.

[sdrformariners]

Originally Posted by socaldmax

But thanks for touting your website!

Cause it is written for exactly this purpose - explain how to make a weather sat antenna :-)
And please do not be offended, from the fact that you use LMR-400 you probably know what you're doing

the actual link to it is here: Software Defined Radio for Mariners: Weather Satellites - Antennas

It's free and written for mariners. You're best off with a turnstile, and as noted, besides the eye candy factor it might not be the best weather info.

Cheers,

Akos