Rapid Plotter and PPI radar
 

I've heard lots of rumblings about the radar being broken. I've been in a "Sugar" boat from day one, so I didn't pay much attention to the squal breeze.

Today I was assigned to a Sargo class and finally got the opportunity to try out the radar on a target about 555 nm east of Honshu (Just in A/C range).

The PPI picked up a single contact off our port bow, so I order CC and came to new heading 272T.

Here's what the PPI picked up:

http://img76.imageshack.us/img76/2478/ppibj9.th.jpg

First thing I noticed was the "happy face"...no big deal; but, more importantly, no compass bearings or range increments....still, no big deal.

I happen to have one of, Kim Ronhoff's Rapid Plotters from my SH1 days, so I plucked it out of the desk drawer and laid it on the face of my paused radar screen to obtain Br 011 Relative.

http://img76.imageshack.us/img76/445...tterkp3.th.jpg

It's seen some action over the years and has been 'round the horn, as they say.

Warning: math.

Next thing I noticed was the face of the PPI measured 5 cm diameter on my computer flatscreen display. All I'm interested in was the radius of 2.5 cm.

Next I took a pair of dividers and spanned from the center of target blip to the center of the "O" scope. (Yes, I was careful with the points of the dividers) It measured 1.4 cm.

Ratio and proportion to determine range. 2.5 : 40,000 : : 1.4 : 22,400.

Since the, Ronhoff, Mk 8 Plotter is calibrated in 1, 2, 5, & 10 min. tracks, I timed the plot for 5 min. and replotted, see below. The Plotter is D/L able from the Pacific Thunder Campaign, I highly recommend it.

http://img79.imageshack.us/img79/399/plot1pq9.th.jpg

I then switch over to the A-scope radar and confirmed my ranges.