Maximum range on TDC
 

Has anyone else noticed that the TDC has a maximum range of about 8990 yards? I've spotted a merchant about 20k yards away (according to my cheating WO) on a very clear night and was trying to ballpark guess its actual range with the stadimeter, but it keeps entering "8990" for the range.

What's odd is that the 'range' field on the TDC has FIVE digits, so it seems like it should be able to accept numbers higher than this.

I guess it doesn't matter terribly much, but it pretty well eliminates the use of the stadimeter to make range estimates from far away when trying to plot a target's course and figure out an intercept.

How do you guys plot courses on very-far-away targets and determine your intercept paths? (Assuming you don't have radar, which I currently do not)

nomad_delta

Id make a note of his heading and speed and plot an intercept course.

I have never used the TDC as an aid. Usually I start planning from much much further out.

But how do you get heading and speed when all you can see is a blur on the horizon? (I guess I also should have specified that I'm playing with map contact updates turned off...)

nomad_delta

Using the Watch Officer isn't cheating: It's his friggin' job to tell you bearings and distances.

What you need to do is build yourself a Submarine Attack Course Finder/IS-WAS. Here is the link where you can download it, along with the instructions:
http://www.subsim.com/radioroom/showthread.php?t=106923
Print it off on cardstock and inkjet transparencies, then put it together.

Here is what mine looks like:

Front:
http://img396.imageshack.us/img396/9...ture027rl0.jpg

Back:
http://img396.imageshack.us/img396/8...ture026bb9.jpg


Once you've done that, you can use the SACF/IS-WAS to find the true course and speed of a target given two range/bearing observations. You can also use it to plot an intercept course, and you can use it to find the AOB of the target once you are getting ready to shoot.

I *HIGHLY* recommend using it. It works just as well as doing the calculations manually, and much better than just 'guesstimating'. It's also pretty cheap, less than $10 or $15 US in materials to make several of them.

It also has the advantage of being authentic: It is what real US sub commanders (actually, probably someone in the tracking party) used to determine things like course, speed, and AOB of an enemy vessel.

Nice job on that Puster Mine looks like a 5 year old put it together LOL.

BTW who the hell still uses a straight key ? I bet you only use it to tune the rig :p

BZZZT! Wrong answer. I do 95% CW, and I've only ever used a straight key. Straight keys are the best, because it allows your natural fist to shine through.

I love having a QSO with someone using a vibroplex or a keyer at 20 wpm, then casually mentioning that I'm using a Chinese Army straight key. I can do between 18 and 20 wpm comfortably for a ragchew, and probably 25 or so for a contest type exchange.

Of course, I learned Morse in the Army, and spent 8 hours a day for 4 years copying it (ex 05H10 EW/SIGINT/Morse Interceptor), so I sometimes actually have dreams in CW.

Just for you SteamWake, here is a short video of me using my straight key:

http://www.youtube.com/watch?v=rHM9kWSvGIs

Agreed, but how on earth does the WO figure out exact distance to a target that we haven't even identified yet (and which is too far away for me to have any hope of identifying...)

I guess I also don't like relying upon the WO as my only means of determining distances, 'cause he'll only tell me the range and bearing to the closest target... which means if there happens to be a life boat or something sitting closer he'll keep telling me about that instead. :p

I don't mind having the WO do his job, but I'd at least like to know how he does it so I can do the same myself if I have to.

____

The SACF/IS-WAS looks mighty cool, have been thinking 'bout trying to put together one of those. I don't have an inkjet printer handy though so the transparencies might be a bit of trouble.

For now I've just been using the Nav Map to plot my range/bearing sightings, and then drawing a line through the marks on the map to estimate target course and speed. Only problem with that is that I can't get range values until I'm within stadimeter range, which is apparently ~9000 yards.

nomad_delta

good lord thats an old call Bill, you still in New York ?

KE4JOY here

I can do around 10 to 12 wpm on a straight key but can rip off almost 40 with my paddles ;) .

I can only copy around up to 30wpm anymore. But when I was a kid I could copy 20-30 wpm while watching tv and talking on the phone :p

Yeah, I'm still in NY. My novice call was KB2JII, which was an abomination to send in CW. My call isn't that old, I got it back around 1991 or so. It has such a nice rhythm to it that I've kept it.

By the way, I hadn't warmed up or anything, that was cold, so it isn't as fast as I can go.

I still use a straight key for the same reason I use a flintlock: It's more fun that way.

How my WO gets the range isn't my problem, as long as he gets it.;) Also, I know this is true in SHIII, not sure about SHIV, but the range the WO gives you isn't exact, it is in 100 meter increments, so there is always some 'slop' in those measurements.

If you need a rational, consider that the guy is an experienced officer, and remember that the human eye in real life can probably resolve details better than you could put on a computer screen.

If you only build the backside of the SACF, you don't need the transparencies. However, if you take the files on a memory stick or diskette to the local Staples or other office supply place, they can print them there on cardstock, transparency, or whatever, and even laminate them for you (which I recommend that you do).

Since I have a printer at home, and had cardstock already to print my QSL cards, all I had to get were some transparencies and some self-stick lamination.

I recommend that you build one as soon as you can. It makes interception and actually hitting the target much easier.

Just to encourage others, and to keep this vaguely on topic, here are some of the submarines I've contacted over the years:


The USS Requin, SS-481:
http://img511.imageshack.us/img511/7...ture035wq4.jpg

USS Clamagore, SS-343:
http://img266.imageshack.us/img266/6...ture036yx4.jpg

USS Ling, SS-297:
http://img49.imageshack.us/img49/7094/picture037zj4.jpg

USS Silversides, SS-236:
http://img232.imageshack.us/img232/5...ture038tb4.jpg

USS Cobia, SS-245:
http://img45.imageshack.us/img45/8513/picture039om2.jpg

USS Batfish, SS-310:
http://img45.imageshack.us/img45/5784/picture040vp3.jpg

USS Cod, SS-224:
http://img47.imageshack.us/img47/5504/picture041sl4.jpg

USS Becuna, SS-319:
http://img527.imageshack.us/img527/8...ture043tk3.jpg


I've also got the USS Growler, and U-505. I was disappointed in the U-505 card, though, because no where does it say that the contact was with the U-505 (that QSO was done while the boat was still outside). If you are going to do a special event, you should have QSL's that reflect that.


I've got a bunch of ship QSL's also, including the USS Yorktown CV-10 (WA4USN), USS New Jersey BB-62 (NJ2BB), USS Wisconsin BB-64 (N4WIS), USS North Carolina BB-55 (NI4BK), USS Missouri (KH6BB), USS Texas (NA5DV), USS Salem CA139 (K1USN), USS Indianapolis Memorial (W9IND), USS Kidd DD-661 (W5KID), USS Slater DE-766 (WW2DEM), USCGC Taney WHEC-37 (WB3AAL), USCGC McLane WMEC-146 (W8BXS), SS American Victory (W4AVM), CSS Acadia (VE0MMA), SS City of Milwaukee (K8GWW), LS Huron (K8HLM), and the LS Ambrose (W2AQ).

Those are just the ones I have cards for. I've contacted the USS Cavalla, and sent them a card, but never received on back. Likewise with the LST-325.

http://www.usstorsk.org/radio/nk3st.htm


Contact the submarine I volunteer on. USS Torsk. Link above.

Wow thats an impressive collection !

Ive never even heard (that Im aware of) these contacts.

Some special events I gather.

Were most of these in HF ? what bands ?

I'd have to look back, but I swear I've contacted the Torsk before.

OK, I just checked my logbooks, and I apparently haven't. It's not that uncommon, unfortunately. Whenever there is a special event, most stations get on 20 Meters. The Torsk is a little close to me to make contact on 20, 40 Meters would be better.

My dilemma is that I am too far away from these boats to visit them in person, and when they get on the air, I'm too close to get them on 20 Meters which is where they all seem to hang out.

There are several boats I'd love to contact, including the Albacore in NH, the Lionfish in MA, the Nautilus in CT, and the Russian sub in RI, but they never seem to get on 80 or 40 Meters to give us 'local' guys a chance!

Oh, and for you SteamWake, you just missed Museum Ships on the Air. You can check http://www.nj2bb.org to keep an eye for the one next year. They also have a 'Submarines on the Air' event every Spring, and sometimes in the Fall. Join the "Submarine Veterans Amateur Radio Association (SVARA)" Yahoo group to find out more. I'm a member, even though I was in the Army.

By the way, if you use VOAAREA and VOACAP for propagation predictions, I have a geo file with the locations of all the museum submarines that get activated if you would like a copy.

The biggest thrill I get is when they actually use the old transmitters for these events. It's a real connection to history to work them that way.