Play is the best education.
I collect and restore antique vacuum tube electronics (i.e. "boatanchors") and vintage solid-state gear.
Zenithfan over on the Antique Radio Forum is working on an RCA Strato-World 3-BX-671 portable shortwave receiver, and he was having trouble finding PDFs of the manuals. I had collected the RCA service manual, the Riders service info, and the Sams service info from various sites on the internet, so I'm putting them up in my manual archive for him.
The RCA service data is from Brian McCallister's Vintage Radio and Audio Pages. I converted Brian's GIFs to a PDF.
The Riders service info is from Nostalgia Air.
I think the Sams info is from BAMA.
RCA Strato-World 3-BX-671 service data:
The classic method is to use an aluminum cigar tube. I'd been saving these for forty years before finally putting one to use. I scarfed them off my dad, though he didn't smoke cigars so I've no idea how he came by them. He probably scarfed them off a buddy and saved them to make RF probes :-)
This probe is a RF probe for my IM-11 VTVM, using the circuit that's been in the ARRL Handbook for umpty-ump years.
I use a vinyl grommet where the coax enters the tube.
The probe tip is mounted in the plastic cap.
I use H. H. Smith model 200 insulated phone tip plugs as the tips for my homebrew probes.
For cigar tubes, I mount them using the plastic handle of the plug as a nut.
For another approach, I use K & S brass tubing from my local model railroad hobby shop. This probe is for my Knight signal tracer, so it's switchable between a straight-through probe and a demodulating RF probe using a subminiature slide switch mounted on the side of the probe housing.
I used a female BNC connector rather than hard-wiring coax to the probe.
Again, I used a H. H. Smith model 200 insulated phone tip plug as the tip for the probe.
You could mount the probe tip plug and the BNC jack using styrene or ABS tubing from the hobby shop to shim down the diameter of the brass tube, but I elected to fabricate the ends from telescoping sections of brass tubing soldered together. If I had a lathe, I'd have turned them from brass stock; it would be cheaper and easier.
I glued the tip plug in using Walther's Goo. I tapped the other end-piece to match the threads on the BNC jack.
And that's it.
I'm in need of a manual for a Wayne-Kerr B801 VHF admittance bridge. Anyone have a scan they can share, or know where one can be downloaded? I haven't had any luck in finding one.
Update: Richard, G3ZIY, was kind enough to scan his copy of the manual for me. I've made the B801B manual available in my Liberated Manuals section. The manual doesn't have a copyright notice, but I expect it is copyrighted by The Wayne Kerr Company Limited. If they object, I will be happy to remove it.
I had been asking on the Antique Radio Test Equipment forum for a manual for my Krohn-Hite 3202 Variable Filter. Someone later came across my post and asked for copies of any manuals that I had turned up, so I posted them in my Liberated Manuals section.
I somehow ended up with this ancient Micronta R-4002 VOM. It's an interesting very early Radio Shack VOM
I plan to monitor the AC power line voltage in my shack with a Simpson model 59 AC panel meter that I picked up as surplus from someplace or other.
But it's got an oddity - a external 0.0025 µF capacitor hanging off the back of the meter.
The capacitor looks like it's a molded paper type. The Simpson data-sheet for model 59 panel meters mentions that the higher range AC voltmeters (500 volts and above) have an external multiplier, while the lower-range voltmeters have internal multipliers. I wonder if my meter was modified to use a capacitor in place of an internal multiplier resistor.
Inspection of the internals reveals that the capacitor is shunting the multiplier resistance coils. The meter is labeled for "60 & 400 CYCLES". I wonder if originally there was an internal capacitor to compensate for the inductance of the multiplier resistance coils, which failed and was replaced by this external capacitor?
I cut the cap out, leaving a bit of the leads behind in case I need to replace it to make the meter function correctly. I don't want to mess with the solder joints on the precision multiplier resistance coils.
I don't want to have a suicide cord in my shop, so I'll have to rig up a safe way to test out the meter. Some time ago I built a little rig with a line cord, fuse, and power switch feeding a 25.2 volt center-tapped transformer connected to binding posts; I used it for checking the calibration on the low ranges of my VTVMs and VOMs. I think I'll add a couple of insulated pin jacks to access the 117 VAC side.
I'm reorganizing the electronics workbench and storage areas, so things are a mess right now.
The part storage shelves.
Parts bins and test equipment storage cabinets.
The right end of the bench, toolbox, and Tek 'scope.
I recently discovered the Antique Radio Forum. I hadn't cared much for web-forums; too insular and too painful to browse to keep up with the new posts. But ARF has two things going for it: a very knowledgeable community, especially in the test equipment area, and a nice mix of photos and text in the posts. The photos really add a lot; they're what's missing from the technical email lists like the qth-boatanchors list.
While reading the ARF test equipment forum, I stumbled on a post from Paul Koby looking for a manual for a Cushman CE-21. I've got one too, also sans manual. I bought it at the Deerchester hamfest back in the '90's for $125. Works fine, but someday it's going to need servicing. So I approached Paul and we agreed to split the cost of purchasing a manual from Manuals Plus; I'd scan it and send him on the original. So I'm liberating the manual; I've placed my scan of it in my local archive here and will pass it on to the other manual sites.
(Hmm, BAMA doesn't take test equipment any more; where's the current canonical repository for liberated test equipment manuals?
I'm particularly interested in older HP test equipment, especially their signal generators. Currently I have examples of
- HP 200A audio signal generator
- HP 200B audio signal generator
- HP 200C audio signal generator
- HP 200D audio signal generator
- HP 200AB audio signal generator
- HP 200CD audio signal generator
- HP 201CR audio signal generator
- HP 202A low frequency function generator
- HP 206A audio signal generator
- HP 606A RF signal generator
- HP 650A test oscillator
- HP 651B test oscillator (sand-state)
- HP 400AB AC VTVM
- HP 400C AC VTVM
- HP 400D AC VTVM
- HP 400H AC VTVM
- HP 400E AC voltmeter (sand-state)
- HP 410B VTVM
- HP 410C VTVM (hybrid hollow- and sand-state)
- HP 411A RF millivoltmeter
- HP 412A DC VTVM
- HP 425A DC micro volt-ammeter
- HP 427A voltmeter (sand-state)
Items I'd like to add:
- HP 205AG audio generator
- EICO 369 sweep generator
This is my old Voice of Music model 1465-2 AM-FM stereo tuner. All vaccuum tubes. I remember using it to listen to 60's rock on WKTK-FM in Baltimore when I was a teen.
I purchased a new Dual 1219 turntable back in my youth. During my college years, I learned about UPS shipping and insurance when I shipped it home one summer. It arrived with the dust cover smashed, the plinth broken apart, and worst of all, the head-shell broken off the tone arm. My fault for not packing it correctly, and of course UPS wouldn't pay up on the insurance.
I repaired it using super-glue, and it served for light duty for years with occasional re-gluing.
But eventually the glue residue became too thick for further repair. I managed to find a replacement headshell (although it's plastic rather than the original cast magnesium). I'm not sure where I bought it; probably from Garage 'A Records.
I managed to remove the headshell mounting tab from the tone arm without removing the tone arm from the turntable, but I'm sure it's going to need to be removed to install the new headshell and thread the new wire harness into the arm.
I tried to get Audio Lab down in Harvard Square to do the work, but their tech didn't want to attempt it. I downloaded a copy of the manual from the Vinyl Engine, and the instructions for removing the tone arm don't look too difficult.
The lubricants are all gunked up, of course, but the turntable runs its single-play cycle except that the friction plate doesn't move the tone arm. I guess I'm missing the steuerpimpel (guide white). I haven't tried the changer cycle yet; I do have both the 33 1/3 RPM and 45 RPM changer spindles, but I figure I'll wait until I re-lube it before fiddling with the changer cycle.
Anyone have any advice on removing the tone arm and replacing the head-shell, or on cleaning and re-lubricating the works?
I'm interested in shortware, mediumwave, and longwave radio listening and DXing.
I've been interested in electronics since I discovered Alfred P. Morgan's Boys' First Book of Radio and Electronics, Boys' Second Book of Radio and Electronics, and Boys' Third Book of Radio and Electronics in the Harford Hills Elementary School library. They were next to the books on rocketry, so I started in on them after finishing all the books in the rockets and missiles section.
Remember George O. Smith's short SF stories set on the Venus Equilateral Relay Station? I never came across them as a kid, but later in life I've enjoyed them. The electrical engineering and communications engineering elements ring true.
An avocation as well as my vocation.
I'm interested in the history of computing. I have a few interesting examples: a Technico 9900 single board computer using the TI 9900 16-bit processor (my first computer) and a Wicat 2000 system running Unix V7.
Some notable computer collections in museums:
Computer History Museum in Mountain View
Deutches Museum in Munich, Germany
I've been collecting some random vintage Macs and have a software collection dating back to 1986. Except for IP networking (which is the killer app), Mac OS 7.6 and its apps have OS X beat all hollow. Especially the travesty that passes for the Finder these days.
I started in model rocketry in 1963 when I was eight years old. Estes Industries had an ad in the back of "Boy's Life" magazine for a starter kit: 75¢ bought you an Estes Streak, two 1/2A6-4 rocket engines (1/2A.8-4 back then; thrust measurements were in English pounds-force rather than today's metric Newtons), and a sheet on how to construct a launch pad and launch controller. I think it might have included a launch switch (a piece of spring brass and a couple of brass screws mounted on a chunk of Masonite). My dad got a length of 1/8 inch welding rod for the launch rod and we stuck it in a chunk of 2 x 8 wood for the launch pad.
I couldn't believe that a real rocket was something I could afford. I vividly remember taping my three quarters to the letter, and anxiously awaiting my shipment via the USPS.
I must have brushed on ten coats of Testor's enamel on that Streak. All that extra mass didn't slow it down, though. We launched it from our backyard and it lived up to its name - we never saw it again.
I love model railroading. I like the big ones too, but the technical and artistic challenge of creating a miniature railroad has always captured my imagination, sharpened my design skills, and taught me much technology and craft.
I cajoled my Dad into taking me down to Lloyd's Hobby Shop in downtown Baltimore and purchasing a Mantua locomotive kit. We selected a 2-8-2 Mikado freight engine. I never got the thing running as riveting the running gear was beyond my seven year old abilities, but it came with a wonderful gift: a six month free subscription to Model Railroader magazine. This was at the beginning of the Linn Westcott era, where he led the hobby into transistorized electronics with the series of TAT throttles and Twin-T detectors and new structural designs based on his L-girder construction.
One of my best photos from our trip to England and Paris back in 2007. It was taken lookup upward from the west leg of the Eiffel Tower at dusk.
Film is dead: Kodachrome 25 is gone, Sue and I have got shoeboxes full of 4x6 snapshot prints that we'll never organize, review, nor share. It's past time to ditch the old film cameras. I've already donated the darkroom equipment to the Littleton High School; surprisingly, the students seem to enjoy film-based B&W art photography.
I came across this old LP record from my mom and dad's collection. It's a recording of the 1962 Christmas Music Program by the combined choirs of Hiss Methodist Church, Baltimore, Md, Prof. Martin R. Rice, Conductor, Edwin Yearley, Organist, and Faith Presbyterian Church, Baltimore, Md., Wilfred B. Hathaway, Ph. D., Dir. of Music. My parents were members of the Hiss choir and "Mr. Ed" Yearley, the organist, was my god-father.
From my childhood I remember my Dad setting up his new Voice of Music Model 722 reel-to-reel tape recorder at Hiss Methodist Church to make the master tape for this pressing. I don't know the details of the rest of the production, but I assume that the Hiss Methodist Church and Faith Presbyterian Church arranged to have the recording pressed and distributed to interested church-members. I think this Christmas music program must have taken a good deal of effort to put together; it sounds wonderful.
I've digitized the LP to AIFF, Apple mp4, and mp3 files. I've been sending CD's to other members of the Hiss choir with whom I am still in touch. I'd like to get in touch with Prof. Rice's family and Mr. Hathaway's family; I imagine they would appreciate a copy of this music. I intend to send the original LP to the United Methodist Historical Society at the Lovely Lane United Methodist Church in Baltimore.
|Side 1||Label||[ tiff image ]|
|Track 1:||Break Forth, O Beauteous Heavenly Light||Bach||[ m4a | mp3 | aif ]|
|Track 2:||Beside thy cradle here I stand||Bach||[ m4a | mp3 | aif ]|
|Track 3:||Hark! A thrilling voice is sounding||Thiman||[ m4a | mp3 | aif ]|
|Track 4:||Unto Us a Boy is Born||[ m4a | mp3 | aif ]|
|Track 5:||Let our gladness have no end||Carol||[ m4a | mp3 | aif ]|
|Track 6:||The Friendly Beasts||12th C. Carol||[ m4a | mp3 | aif ]|
|Side 2||Label||[ tiff image ]|
|Track 7:||Cantata - The Crib||Martin Shaw||[ m4a | mp3 | aif ]|
|L. Alan Evans,||Baritone|
|Edwin G. Yearley,||Organist|
|Track 8:||Glory to God||Bortniansky||[ m4a | mp3 | aif ]|
|Track 9:||Fragment of Organ Interlude||[ m4a | mp3 | aif ]|
Sue picked out a great DVD from NetFlix: 3 Idiots. We had a great time watching it last night. It's an epic plot, but the engaging thing for nerdy me was that the plot revolves around three students at the Imperial College of Engineering. Four stars!
I acquired this C-3 capacitor checker along a with some other test equipment from the old Linear Electronics in Waltham, MA. They all were marked with "Dr. Ch. Allemand's" sticker and were set up for 230 VAC. I guess Dr. Allemand immigrated from Germany and brought along some gear from his lab. Anyway, this C-3 is unusual in that it doesn't have a dual-primary transformer. The manual includes a sheet on wiring a dual-primary export transformer, but the unit contains a single-primary 230 volt transformer.
Surprisingly the unit has a stock US-style line cord and plug.
The unit is well-built, presumably by Dr. Allemand. The components appear to be stock. The capacitors need to be replaced; the paper caps are almost certainly leaky, and the eye tube has a flutter that I think is probably due to excessive hum due to bad electrolytic filter caps.
The external cosmetics are fair. There are some splatters of white latex paint. (Why does white paint alway spill near the stockpile of electronic goodies?) The front panel shows some mottling. I'd try some auto rubbing compound to try to revive the paint finish.
I also have the original manual with fold-out schematic and wiring diagram for this unit.
I'm half-tempted to replace the transformer with a US-version or mount a 120-to-240 volt transformer inside it, but this unit really belongs back in Europe or somewhere else with 230 volt power. The shipping cost would be horrendous, though. It weighs about 2 kilograms. What to do, what to do?
Anyone want it for $40 plus my actual shipping cost?
This is a nice little 20,000 ohms per volt VOM from Radio Shack. Unfortunately the shaft of the range switch broke, so I'm selling it for parts. Asking $8 plus shipping. Maybe it can help repair another copy. The cosmetic condition is very good. Complete with owners manual and original box. No probes, though; I used them to make HV discharge sticks. The meter has pin jacks, not banana jacks.
You can see that the wiper of the range switch broke off from the shaft. I tried heat-welding the Delrin back together but it didn't have enough strength to handle the spring tension from the wiper.
I've also liberated the manual for download, in case anyone needs a copy.
To do: sell this boatanchor to someone who wants to tinker with it. I've decided to restore the beast; it's one heck of a lot of TTL, apparently including some HP custom chips, but I need a good counter and this one's sitting here in my shop ...