Friday, October 5, 2012
FLIP, FLOP AND...FLOWCHART?
In honor of Tam's link from a post showing examples of logic elements from early computers, here's a link to a site showing a nice dual-triode flip-flop as used in the Burroughs 205. (Plus actual pictures of actual hardware.) Enough of those and you'd have yourself some memory; also an air-conditioning challenge. But wouldn't it be fun?
Saturday, September 15, 2012
MY OWN MINI-PENNYFARTHING
It was inevitable; about as soon as I learned Rideable Bicycle Replicas offered an affordable mini-highweel bicycle, I was determined to own one. 
It arrived last Thursday.
At this writing I have put a couple of miles on it -- also larger grips and a slightly taller and longer seat -- and I can assure you that it's about as much fun as I've had with a bicycle in some years.
There is a definite learning curve; it handles very differently to a modern safety bicycle. But given the 28" front wheel, it doesn't offer the same risks to a new rider as a full-sized "ordinary" bicycle, with a wheel diameter of 38" or more. $189 well spent! (N.B., roll up those dungarees! I only had to catch a bearing-clamp bolt once to figure that out. )
...Rode up to the bicycle store in downtown Broad Ripple, where they were holding a charity event, and learned from another shopper that there was a vintage bicycle show in a nearby town today. Too late to attend today, but I'm realizing this can only lead to membership in The Wheelmen...and eventually a larger pennyfarthing. (Tamara K rode along and observed, "You can't be a wallflower on a bike like that." It does gather attention -- and a lot of questions.)
It arrived last Thursday.At this writing I have put a couple of miles on it -- also larger grips and a slightly taller and longer seat -- and I can assure you that it's about as much fun as I've had with a bicycle in some years.
There is a definite learning curve; it handles very differently to a modern safety bicycle. But given the 28" front wheel, it doesn't offer the same risks to a new rider as a full-sized "ordinary" bicycle, with a wheel diameter of 38" or more. $189 well spent! (N.B., roll up those dungarees! I only had to catch a bearing-clamp bolt once to figure that out. )...Rode up to the bicycle store in downtown Broad Ripple, where they were holding a charity event, and learned from another shopper that there was a vintage bicycle show in a nearby town today. Too late to attend today, but I'm realizing this can only lead to membership in The Wheelmen...and eventually a larger pennyfarthing. (Tamara K rode along and observed, "You can't be a wallflower on a bike like that." It does gather attention -- and a lot of questions.)
Tuesday, September 11, 2012
DREAM MOTORBIKE
I saw a photo of what I'm guessing is a Quax 36" modern pennyfarthing with an add-on motor in front of the front fork. (Here, second row down, far left. And do look around the site; Rideable Bicycle Replicas appear to be America's most prolific manufacturer of old-fashioned bicycles and offer plenty else besides.)
Neat idea -- but only for an expert, as "header over the front" is the standard failure mode* for a high-wheel "Ordinary" bicycle and adding even more weight up top is a recipe for instability.
Fear not; no less a personage than Sir Arthur Conan Doyle helped back the company with the answer to that problem: The Wall Autowheel a/k/a Smith Motor Wheel in the States, by either name a self-powered wheel that attaches beside the bicycle's rear wheel! I have only ever seen them on modern style "safety" bicycles, but darned if I can find a reason to not try it on an Ordinary. The added weight is all at the very back, where it'd do the most good. In fact, it's been done as recently as 1922 -- scroll almost to the very bottom of the linked "Wall Autowheel" article and there it is!
...Not that it's safe. Or especially street-legal, unless there's an exception for a 118 cc 19-teens gasoline engine. But by golly, you'd be the only one like it on the road.
___________________________
* So much so that it's where the term "header" for a forward fall entered the language. Oh, and "breakneck speed," too.
Neat idea -- but only for an expert, as "header over the front" is the standard failure mode* for a high-wheel "Ordinary" bicycle and adding even more weight up top is a recipe for instability.
Fear not; no less a personage than Sir Arthur Conan Doyle helped back the company with the answer to that problem: The Wall Autowheel a/k/a Smith Motor Wheel in the States, by either name a self-powered wheel that attaches beside the bicycle's rear wheel! I have only ever seen them on modern style "safety" bicycles, but darned if I can find a reason to not try it on an Ordinary. The added weight is all at the very back, where it'd do the most good. In fact, it's been done as recently as 1922 -- scroll almost to the very bottom of the linked "Wall Autowheel" article and there it is!
...Not that it's safe. Or especially street-legal, unless there's an exception for a 118 cc 19-teens gasoline engine. But by golly, you'd be the only one like it on the road.
___________________________
* So much so that it's where the term "header" for a forward fall entered the language. Oh, and "breakneck speed," too.
Thursday, August 30, 2012
VACUUM-TUBE COMEBACK?
And in computers, yet? That's the report, though they're not going to look very much like the 6SN7s in Grandpa's flip-flops; nuvistors would look like skyscrapers beside them. Still and all, tubes. Who would've thought?
Sunday, July 22, 2012
CALLSIGN NABD, USS INDIANAPOLIS, CA-35
She was torpedoed in the Pacific 30 July, 1945, after delivering an atom bomb to Tinian. Of 1,196 crew, some 900 made it into the shark-infested water. Despite sending a distress call, the sinking went unnoticed for five days. Only 317 men survived. It remains one of the worst U. S. naval disasters.
The USS Indianapolis Memorial is here in Indianapolis, and a room of the Indiana War Memorial Museum is dedicated to the ship. Just around the corner in the War Memorial, volunteers have recreated the ship's "Radio Central," piece by piece.
11 of the 41 radiomen were among the survivors.
The original installation is gone with the ship, but the equipment was quite standardized. "Was" being the operational word, as much of it has become quite scarce. The old receivers were uncommonly good -- and uncommonly heavy; the transmitters were even more so, on both counts.
So simply collecting the equipment is a huge accomplishment. But the volunteers are committed to more than mere static display -- they're getting the old gear running!
Entry is very much like stepping into a busy radio room -- CW in the background (including "SOS SOS de NABD...") and recorded talk about the gear plays at several positions.
Visitors walk down a narrow aisle between transmitters and the test bench before coming to the row of operating positions. Left:
Center:
Right:
Ship's radio rooms are a pretty fair match for the ideal ham shack, too, though I don't suppose very many of the guys copy traffic on a "mill" these days. (And I wonder if there might not be a few southpaws on the crew -- or did the Navy train ops to send left-handed?)
The transmitters cover from low frequencies all the way into VHF, with "big rigs" into the upper HF range.
The big transmitters are right there where you can get a good look.
The TBS low VHF transmitter-receiver they've been getting into operating condition is kept far enough away to keep curious fingers safe. You can just see the side of it in the right-side image of the operating positions -- the acronym for this is sometimes (and unofficially) translated "Talk Between Ships" and sure enough, my Dad's 1946 Introduction to Radio Equipment, NAVPERS 10172* says it was "designed to provide short-range communications between surface craft such as task forces or convoys." Interestingly, the book covers operation of just about every receiver and transmitter in the USS Indianapolis Radio Room exhibit.
It's a fascinating installation. It includes a couple of Amateur Radio operating positions, at the Supervisor and Test desks, operating as WW2IND:
The more modern ham gear is kept out of sight when not in use, but pipe that shiny green SP-600! I'll be back -- the museum is not very far from where I work and they tell me volunteers are present many mornings and all day most Thursdays.
________________________________
* This book was my first exposure to the technical side of radio, and does a pretty good job of covering basic theory before moving on to specific equipment. The Naval Reserve, when they learned my father worked for RCA, was determined to make him a radioman...until realizing he didn't know International Morse code. Rather than run a reservist through radio-op school, they set him to toting bags of powder in a gun turret. Which is, if you ask me, one more reason to learn CW! Why'd they think Dad would be a radioman? Have a close look at the photos and you'll see a discreet RCA "meatball" on an awful lot of Navy comms gear; RCA and radio were just about synonyms, as far as the Navy was concerned. There are only two non-RCA receivers on the entire NABD operating bench shown above, in fact -- can you ID them?
The USS Indianapolis Memorial is here in Indianapolis, and a room of the Indiana War Memorial Museum is dedicated to the ship. Just around the corner in the War Memorial, volunteers have recreated the ship's "Radio Central," piece by piece.
11 of the 41 radiomen were among the survivors.
The original installation is gone with the ship, but the equipment was quite standardized. "Was" being the operational word, as much of it has become quite scarce. The old receivers were uncommonly good -- and uncommonly heavy; the transmitters were even more so, on both counts.
So simply collecting the equipment is a huge accomplishment. But the volunteers are committed to more than mere static display -- they're getting the old gear running!
Entry is very much like stepping into a busy radio room -- CW in the background (including "SOS SOS de NABD...") and recorded talk about the gear plays at several positions.
Visitors walk down a narrow aisle between transmitters and the test bench before coming to the row of operating positions. Left:
Center:
Right:
Ship's radio rooms are a pretty fair match for the ideal ham shack, too, though I don't suppose very many of the guys copy traffic on a "mill" these days. (And I wonder if there might not be a few southpaws on the crew -- or did the Navy train ops to send left-handed?)The transmitters cover from low frequencies all the way into VHF, with "big rigs" into the upper HF range.
The big transmitters are right there where you can get a good look.
The TBS low VHF transmitter-receiver they've been getting into operating condition is kept far enough away to keep curious fingers safe. You can just see the side of it in the right-side image of the operating positions -- the acronym for this is sometimes (and unofficially) translated "Talk Between Ships" and sure enough, my Dad's 1946 Introduction to Radio Equipment, NAVPERS 10172* says it was "designed to provide short-range communications between surface craft such as task forces or convoys." Interestingly, the book covers operation of just about every receiver and transmitter in the USS Indianapolis Radio Room exhibit.It's a fascinating installation. It includes a couple of Amateur Radio operating positions, at the Supervisor and Test desks, operating as WW2IND:
The more modern ham gear is kept out of sight when not in use, but pipe that shiny green SP-600! I'll be back -- the museum is not very far from where I work and they tell me volunteers are present many mornings and all day most Thursdays.________________________________
* This book was my first exposure to the technical side of radio, and does a pretty good job of covering basic theory before moving on to specific equipment. The Naval Reserve, when they learned my father worked for RCA, was determined to make him a radioman...until realizing he didn't know International Morse code. Rather than run a reservist through radio-op school, they set him to toting bags of powder in a gun turret. Which is, if you ask me, one more reason to learn CW! Why'd they think Dad would be a radioman? Have a close look at the photos and you'll see a discreet RCA "meatball" on an awful lot of Navy comms gear; RCA and radio were just about synonyms, as far as the Navy was concerned. There are only two non-RCA receivers on the entire NABD operating bench shown above, in fact -- can you ID them?
Thursday, July 19, 2012
BEESWAX
It's your beeswax -- or it should be.
I was reminded of this useful substance just yesterday, when making some changes to the short end of my 40 Windom. I added a cleat for the line holding the feedpoint insulator and a screweye and a cleat for the far end of the short section, both of them in different 7'-tall 4X4 fence posts.
It's still dreadfully hot, so I was cheating, using a battery-powered drill to predrill for and drive the screws. Spinning home the first 2" #10 woodscrew, I found it was taking excessive torque. The driver bit was "camming out" of the screw head, to the detriment of both.
What to do, what to do... Then I remembered the bar of beeswax in the kitchen, purchased for just this problem. With a generous amount of the wax scrubbed into the screw threads, they sank almost too easily. Even driving the 5/16" screweye with a heavy screwdriver through the loop, it went in fast and easy.
Some old texts suggest using bar soap to lubricate screws, but soap will draw moisture and rust the screw. Beeswax is just the ticket -- it works nicely on saw blades, too. Best to store it tightly wrapped up in waxed paper, to keep it from drying out.
(Note to myself: I need to tie actual cleat hitches in the lines! Multiple figure-8s will do for awhile but a real knot is better.)
I was reminded of this useful substance just yesterday, when making some changes to the short end of my 40 Windom. I added a cleat for the line holding the feedpoint insulator and a screweye and a cleat for the far end of the short section, both of them in different 7'-tall 4X4 fence posts.It's still dreadfully hot, so I was cheating, using a battery-powered drill to predrill for and drive the screws. Spinning home the first 2" #10 woodscrew, I found it was taking excessive torque. The driver bit was "camming out" of the screw head, to the detriment of both.
What to do, what to do... Then I remembered the bar of beeswax in the kitchen, purchased for just this problem. With a generous amount of the wax scrubbed into the screw threads, they sank almost too easily. Even driving the 5/16" screweye with a heavy screwdriver through the loop, it went in fast and easy.
Some old texts suggest using bar soap to lubricate screws, but soap will draw moisture and rust the screw. Beeswax is just the ticket -- it works nicely on saw blades, too. Best to store it tightly wrapped up in waxed paper, to keep it from drying out.
(Note to myself: I need to tie actual cleat hitches in the lines! Multiple figure-8s will do for awhile but a real knot is better.)
Wednesday, July 18, 2012
MINIATURE SOLDERING IRON REVIEW
One of these days, I'll do a big soldering-iron round-up, everything from the big American Beauty 100 and 75W irons though the nice Hakko and Weller midsize irons down to the tiniest.
One of the very smallest irons in my toolbox, I haven't found since I moved: Wahl used to make a corded, variable-temperature miniature iron that I count among the finest ever built. I purchased a similar Far Eastern iron some years ago at the Dayton Hamvention, only to discover it doesn't get hot enough to actually solder with.
I needed a replacement miniature iron. The Radio Society of Great Britain talks up Antex brand irons in their Handbook and they do look good; I've found RSGB to be an impartial reviewer, and when I realized the Antex G/3U 18W miniature iron (that may be an older model number but you can still buy 'em over here) listed on Amazon and elsewhere, I decided to find out for myself.
I used it to build a Vectronics audio filter kit.* It worked very well. I was concerned that the tips slid on a little too loosely; but it gets plenty hot, plenty fast, and the tip stays in place. Like the Wahl, tips go over the heating element rather than inside. It's claimed to enable better heat transfer; it certainly makes for less iron in the way of the work.
The one shown here has a chisel tip, about 1/16" wide. The kit was through-hole ICs, with 0.10" being the closest spacing and there was no need for anything smaller.
The grip stays cool and the assembly is a good size and balance. It does require a heavy stand, as it weighs so little that if it's not securely held, the cord can drag it around! The Hako stand shown here is not a good choice -- the kind that surrounds the iron with a coiled spring-looking holder would be best. But that's my only complaint. G/3U is a good iron for small work. They're listing for just over $28, last I checked.
______________________________________
* Which shipped with the wrong value resistors for one of the critical frequency-determining positions, 2X for three filter sections. Off by a factor of 10. Oops! But the right resistors are a dime apiece, and that gets fancy 2% metal-film types, so it's not a big deal.
One of the very smallest irons in my toolbox, I haven't found since I moved: Wahl used to make a corded, variable-temperature miniature iron that I count among the finest ever built. I purchased a similar Far Eastern iron some years ago at the Dayton Hamvention, only to discover it doesn't get hot enough to actually solder with.
I needed a replacement miniature iron. The Radio Society of Great Britain talks up Antex brand irons in their Handbook and they do look good; I've found RSGB to be an impartial reviewer, and when I realized the Antex G/3U 18W miniature iron (that may be an older model number but you can still buy 'em over here) listed on Amazon and elsewhere, I decided to find out for myself.
I used it to build a Vectronics audio filter kit.* It worked very well. I was concerned that the tips slid on a little too loosely; but it gets plenty hot, plenty fast, and the tip stays in place. Like the Wahl, tips go over the heating element rather than inside. It's claimed to enable better heat transfer; it certainly makes for less iron in the way of the work.The one shown here has a chisel tip, about 1/16" wide. The kit was through-hole ICs, with 0.10" being the closest spacing and there was no need for anything smaller.
The grip stays cool and the assembly is a good size and balance. It does require a heavy stand, as it weighs so little that if it's not securely held, the cord can drag it around! The Hako stand shown here is not a good choice -- the kind that surrounds the iron with a coiled spring-looking holder would be best. But that's my only complaint. G/3U is a good iron for small work. They're listing for just over $28, last I checked.
______________________________________
* Which shipped with the wrong value resistors for one of the critical frequency-determining positions, 2X for three filter sections. Off by a factor of 10. Oops! But the right resistors are a dime apiece, and that gets fancy 2% metal-film types, so it's not a big deal.
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