…in which a student is asked how to find out the height of a building with a barometer. The teacher, of course, expects the student to measure the air pressure at the top and bottom and do some calculations to come up with the height, but the student takes a more direct route and offers the barometer to the superintendent if he’ll tell him how tall the building is.

I was trying to find out the frequency of Jeffrey’s watch radio, and I was just about to send a note to the ARRL Technical Information Service to ask for advice on how to do it, when I decided to try a more direct approach. I called the manufacturer’s toll free Customer Service line; someone picked up the phone on the second ring and answered my question immediately: the radios are on 49MHz (which is the same band as baby monitors and old cordless phones use). This explains why there’s so much interference and why we weren’t able to interoperate with FRS radios — I guess the reference to “FRS Technology” means that they use FM. Kudos to
DSI Toys for being responsive, but I wouldn’t recommend the radios for use farther than you can shout — but they certainly look cool. I’m considering wearing one of them to work and seeing if Security says anything about my having an antenna on my wrist.

Memory revisited

I had to print another sheet of pictures tonight, so I made the measurements that Jeremy and I had been discussing last week.

The big jumps in “unused physical memory” correspond to images being loaded and unloaded, and the brief heavy CPU usage is an image being loaded. Interestingly, the swapfile-in-use doesn’t change much, though the swapfile size gets increased substantially when the image is loaded.

It sure looks as though Thumbs Plus Pro expands the image from the 5.6 MB JPEG on disk (as scanned originally at 600×600) to something on the order of 96MB in memory — and that, plus the usual Windows overhead, forces significant swapping, even with 192MB in the box.

The next machine will have at least 256MB — but I’m still in no hurry; today’s Merc suggested that prices may drop further early next year. And if it takes me ten minutes to print a sheet of pictures twice a year, well, I can probably cope.

Besides, I visited the local Ham Radio Outlet today and some of the ham gear looks awfully interesting, if I could just figure out what to do about an antenna.

Then after we got home, Jeffrey dug out an MST3K classic, Space Mutiny. Miss it if you can.

And finally, we watched the end of The Towering Inferno after dinner. I want to find the Second City parody and watch it — I think the acting was better!

FRS Technology, eh?

The wrist radios I got Jeffrey for Hanukkah claim to use “FRS Technology”. Our friends had bought their daughters two FRS handy-talkies for Christmas, so when we got together last night, we tried to make the wrist radio talk to the handy-talkies — no dice. I tried all 14 FRS channels, and the two units couldn’t hear one another (that’s not strictly true — the wrist radio detected but couldn’t make any sense of the FRS radio; the FRS radio couldn’t tell that the wrist radio was in the room). I’m going to have to find some way of telling what frequency the wrist radio actually uses. I did find some Web ads for the radio, claiming a 100-foot range — as I said yesterday, about as far as we could yell!