Thursday, May 28, 2015

Receiving and Decoding WeFAX (Weather Facsimile) Transmissions

Another "new" project popped up yesterday on the Iowa during our monthly Radio Guys meeting. Our guy who's rebuilding the CEC (Combat Engaement Center for the civvies) brought up the fact that eventually the Meterology Office on the Bridge Deck will be included on the tour route, and wouldn't it be nice to have a working weather fax on display.

This came up because I was explaining the PC, interface, and software I installed for the Amateur Radio Group to use, and showing how it's used to decode "digital" transmissions.

The most popular digital mode on the Ham bands is called PSK31, and is a narrow-band method of sending text, so you can have a keyboard-to-keyboard chat with another Ham.

The software I like to use is call "FLDIGI", and runs on Linux, Mac, and Windows. The nice thing about it is that it comes with software modems to decode literally DOZENS of digital transmissions.

There's nothing showing in the screenshot below as I don't have a radio hooked up to my Linux box right now, but I've mentioned FLDIGI before in other posts.

Here's a Windoze screenshot of FLDIGI receiving a weather report. The Signal-to-Noise ratio of this frequency is worse than the weather map, which explains the "snowy" image, and lack of correct side-to-side sync. This can be corrected in the program after the broadcast is recorded.

For a webapge giving the "Sights-and-Sounds" of the digital modes, head on over here. There are many other digital modes used, and this is just a small sample of them.

SO.....after the meeting yesterday, I looked up some wefax frequencies, and tuned in the Pt. Reyes Station Coast Guard broadcast, and tried to decode it. I'm not sure what was wrong, but we weren't able to decode an image. Since I've never tried that mode before, I suspect it might be operator error, and left it at that.

This morning I fired up my Windoze PC and my Flex 5000, and tuned in the same station. To my surprise, and using the defaults in the program, I was able to receive the image shown below.

This has me scratching my head, so I'll have to spend some time on the Iowa by meyself to see what's not configured correctly.

Tuesday, May 26, 2015

"Barn Find" P-51 Mustang from Torrance, CA Up For Auction

Interesting story on this one. It appears to have been bought by a man in Playa Del Rey (up by LAX) in 1973, and stored at Torrance (Zamperini Field, TOA) in a hangar, and work started on it. The man passed away in 2004 without really getting much done on it, and it went to his wife, who passed away in 2012.

The attorneys for the estate are now putting it on the auction block, and it's come to light as a 1970's era, unrestored warbird.

Read more about it here, and here, and here, and more here.

Monday, May 25, 2015

Memorial Day on the Battleship Iowa

We had food trucks, radio and TV stations, Talking Heads and Politicians, military vehicles and a fly-by, live music, fun and games for the kiddies, and thousands of people.

But most importanly, we had Vets.

We had Vets from WWII, Korea, Viet Nam, Desert Shield/Desert Storm, Enduring Freedom, and all the other battles, named and un-named, that have happened since December 7th, 1941.

We had Sailors, Soldiers, Airmen, Marines, Coast Guardsmen, Enlsted and Officers, and others.....

And we thanked them all.....

And thank you all for your service, wherever, whenever, and whatever it was.

God Bless You all.......

Saturday, May 23, 2015

Wednesday, May 20, 2015

300k Page Hits.....

Which aint diddly squat compared to some of you, but then my writing eloquence can't hold a candle to most of you.

I'm just glad I've met everybody here, and we consider ourselves friends.

Friday, May 15, 2015

US Navy/Marine Corps MARS Program To End

"MARS" in this case means "Military Auxiliary Radio System", a radio network of non-military stations (Hams) allowed to communicate on military frequencies.

I was encouraged to join the MARS network, but the requirements for actually operating on-the-air are pretty stringent as to the amount of time required, so I declined the invitation.

MARS station have very unique callsigns, as in the case of the Battleship Iowa, NNN0CIA. No idea how we managed the "CIA" suffix, but it always gets a chuckle when radio people visit the Comm Center on the Iowa.

Besides handling routine traffic such as "Health and Welfare" messages, the MARS network is also a complete stand-alone emergency radio network with direct connection to the US Military. And the MARS stations get activated for the Armed Forces Day Cross-Band Test, which allows Amateur radio operators to communicate directly with the military radio stations by transmitting in the Amateur Radio bands, while listening outside the Amateur bands to the military frequencies.

We also have a MARS digipeater for the MARS packet radio network (yes, packet is still alive!) that get excellent coverage due to the antenna being on the top of the ship which gives an unobstructed radio view of the coast line from Santa Barbara to San Diego.

Back in 2009 the Navy/Marine Corps segment of MARS was almost shut down, but a change from "Affiliated" to "Auxiliary" status saved the money, and the Navy/Marine Corps segment of the program.

Well, this time it's for real. From The ARRL Letter:

US Navy-Marine Corps MARS Program to End:
The US Department of Defense is phasing out the US Navy-Marine Corps Military Auxiliary Radio System (MARS) program. Its operational mission will transition to the other MARS service branches by the end of September. MARS volunteers are Amateur Radio operators who provide auxiliary or emergency communications to local, national, and international emergency and safety organizations, as an adjunct to normal communications.
"The intent of the transition is to best align the program to support national mission requirements," the announcement said. Chris Jensen of Naval Computer and Telecommunications Area Master Station Atlantic (NCTAMS LANT) told ARRL that the Navy no longer has any service-specific requirements for Navy-Marine Corps MARS and is working within DoD to transition the program into Army and Air Force MARS by September 30.
The announcement encouraged current Navy-Marine Corps MARS members and clubs to submit applications to the US Army MARS or US Air Force MARS programs as soon as possible.
"The US Navy greatly appreciates the thousands of MARS volunteers, past and present, who have been integral to the success of MARS," the announcement concluded.
An individual very familiar with the MARS program said the change was not unexpected and came to a head as the US Strategic Command embraced Army MARS as the lead branch for contingency communication and Air Force MARS began partnering with the US Army program on the operations side.
"The Army and Air Force MARS branches have an obvious role in providing contingency communications for the 50 states," said the individual, who preferred not to be identified by name. "Members are everywhere 'on the ground,' and experience in Afghanistan and Iraq has proven the tactical usefulness of HF on land. There was no similar role for the landlocked membership of Navy-Marine Corps MARS."
He said the MARS program can use all the volunteers it can attract. Read more

The Army and Air Force segments will continue to exist and operate, but "Navy MARS" and "Marine MARS" will be gone forever as of 30 September.

We'll probably be assigned a new callsign for the Iowa, and the digipeater will get reprogrammed, but it's good that at least a portion of MARS will continue to exist.

Wednesday, May 6, 2015

Battleship Iowa Transmitter Progress **We're Getting There!**

Well, good news!

I took my accurate, calibrated, LP-100A Digital Vector RF Wattmeter in today, and we re-ran the tests on the transmitters today using the LP-100A rather than the built-in panel meters.

We also wanted to make sure each exciter was outputting its 100 milliwatts (+20dBm) of rated power.

First, a little background....

The Iowa originally had 11 transmitters; 10 on shock mounts in a racked arrangement, two high and 5 wide, "odd" units on the top, and the "even" units below them, with #11 sitting by itself at the far left end of the rack mounts.

Numbers 2 and 8 were missing from the ship when she came out of the reserve fleet, leaving us with nine units. Three of the nine were stripped of usable parts in the PA (Power Amplifier) assemblies, leaving us with six more-or-less intact units. We might be able to "mix-and-match"  the three partially stripped ones to make a seventh unit, or just keep them "As Is", or as a possible source of "spares", as we really don't have any reason in the world to have seven functioning transmitters!

Originally the "need" was to have two, fully function transmitters, one being the primary unit, and the other being it's back-up, for "Special Event" use, such as the Military/Amateur Crossband Event, or perhaps Museum Ships Weekend.

As of today, two of the units has an exciter with 100mW (+20dBm) or more (+23dBm) of drive power, and one exciter is low on output, only doing 50 mW (+17dBm).

The two with the "good" exciters easily exceeded 1200 Watts output ( ! ), while the one with the "low" exciter did about 800 Watts output.

This is significantly different that what the panel meters read, by a factor of 2 to 3!

And we have another transmitter that appears to be good, as far as the PA Plate Voltage and Current go, but with a dead exciter that only puts out about .5dBm, a little over a milliwatt.

And it took quite a load off us as to trying to figure out where the "missing" RF Power was going. It wasn't "missing", it just wasn't being measured!

And on the Ham Radio side, I installed, and got operational, a Signalink USB interface box on our Kenwood TS-850 HF radio. As soon as I finish my homebrew soundcard interface, we'll have two stations capable of digital operation on such modes as SSTV, PSK31, RTTY, and other modes.

Sunday, May 3, 2015

Panoramic Views of Battleship Iowa Internal Spaces

These have been updated again, with some new areas to virtually explore.

I've seen most of these spaces, and the photography is excellent. These panoramas are actually better than viewing them in person, as the lighting is much better.

It's still quite a thrill to actually visit these spaces, but the panoramas bring out more detail than you'd normally notice, and you can spend as long as you want looking at things.

Battleship Iowa Panoramic Views

Supras and Stereos.....

 The repairs on the Fisher RS-2010 are proceeding, but a bit slower than I expected. The failed transistor is an obsolete part number, so I ...