site was formerly http://cool386.tripod.com/index.html
Latest articles: Baird 812 24" Television receiver
Vibrator power supply articles
2" Television Set with 902 cathode ray tube
20W self oscillating transistor inverter
For further pics and information about my projects see also here http://www.flickr.com/photos/13469158@N05/ and my You Tube channel here https://www.youtube.com/channel/UCB8qCNGTrXO1nanG0yDFxeA/
How this site is set up: All the pages are written using Netscape Composer 4.8 which keeps things simple, fast, and Windows 3.1 compatible. It was intially hosted by Bigpond (an Australian ISP), who, provided 10Mb. Once that was used up, I started putting pages on Geocities. In 2009, Bigpond terminated their webhosting (surprising thing to do for the largest ISP in Australia), and Geocities closed down. So, I had to move the entire site to Tripod (a free host) where all seemed well for the next four years until everything was deleted with no warning. I then changed my ISP to iinet who provide 1Gb of space. The site's name comes from a 386DX40 computer still in use.
A bit about me:
An enthusiast for vintage technology and electronics. My technological
interests are based around all the things you see on this site.
I am from the Blue Mountains, about 80km west of Sydney on the east coast of Australia. Learn more here.
CA-2-B15 restoration - (Parts 1,2,3, 4, & 5). Background to the General Electric Monitor Top refrigerator and restoration of a 1934 CA-2-B15.
Monitor Top thermal imaging. See what the human eye cannot see with these thermal images of my CA-2 Monitor Top fridge.
Monitor Top manuals. For 1927 DR machines, 1933-1934 CA machines, Canadian AK models, and 1934-1942 CK/CG/CE/CF/CH/CJ/DK/FBA/LK Monitor Tops, Globe Tops, Liftops, and Flatops. Also contains scans from Nickerson & Collins - Servicing Hermetically Sealed Units, covering DR rebuilding. 1934 Salesman's Bulletin.
CA-1-B15 restoration. After the CA-2-B15, another Monitor Top came into my posession.
Capillary tube conversion for CA Monitor Top. Eliminates troublesome float valves. Also learn about operating on the unit fully charged, and how to extract methyl formate.
Notes on Super Regen receivers. Please read before attempting to construct the following receivers.
6 Transistor Super Regen Receiver. Solid State Superregenerative Receiver. This separately quenched receiver far outperforms other solid state self quenched designs.
4 Transistor Super Regen Receiver. Pocket size VHF receiver as simple as possible while still being practical.
One Tube FM Tuner. From August 1960 Popular Electronics, it uses a 6C4. I constructed this project as closely as I could to the original. Performance left a lot to be desired!
Improved One Tube FM Tuner. In view of the poor performance of the above receiver, I modified the design. Still using a 6C4, it is about the simplest valve receiver for FM.
12AT7 Super Regen Receiver. One valve provides excellent sensitivity and drives headphones to an uncomfortably loud level. Suitable for portable battery operation.
New 12AT7 FM Tuner. An improvement on the Improved One Tube FM Tuner, this incorporates an RF stage.
One Valve FM Receiver with Loudspeaker. Using a single 6DX8, this receiver provides loudspeaker reception of FM stations. UPDATED with improved circuit.
Maxitronix MX801F FM Radio Kit. Three transistor FM receiver needed modifications. Also relevant to the MX901AF and MX901F kits.
Science Fair 28-234 AM/FM Radio Kit. The super regenerative FM receiver in this kit sold by Tandy/Radio Shack is of very poor design and needed modifications to work properly.
VHF receiver with 12V B+. This valve VHF receiver uses 12V for high tension.
Fremodyne Receiver (Parts 1,2, &3). Introduction to the single valve, low cost, FM receiver circuit developed by Hazeltine Laboratories in 1947. It uses a single 12AT7 in a super regenerative superhet circuit and was used in several commercially made AM/FM receivers and FM converters.
Homemade Fremodyne. This is one of my attempts at building a Fremodyne receiver as an FM mantel radio. Sound quality turned out to be quite good with this set.
Solid State Fremodyne. Electronic Australia's article from May 1970 on making a solid state version of the Fremodyne. This is not the full article, but sufficient information is given for experienced constructiors to duplicate the design.
Simplified Fremodyne. How much further can the Hazeltine circuit be simplified? This receiver was the test.
Howard 474. Commercially made example of a Fremodyne receiver.
Meck FM Converter. Fremodyne tuner made to be used with the audio section of an existing AM receiver. The safety issues with this set were a bit of a surprise.
Gilfillan 68F. Another commercially made mantel radio using the Fremodyne circuit for FM reception.
Sentinel 315W. The third type of AM/FM mantel radio I've acquired with a Fremodyne circuit. This one had seen a rather careless attempt at restoration.
Heathkit FM Converter. The Heathkit FM1 was a kit version of the Fremodyne circuit.
Olympic 7-532W & 7-532V. Another mantel radio with Fremodyne FM receiver.
Perco FM Tuner. Another kit version of the Fremodyne.
Pulse Counting Receiver. Hi Fi quality, high sensitivity, and only one tuned circuit. Popular in the UK but virtually unknown elsewhere.
Solid State Pulse Counting Receiver. Notes on building a solid state pulse counting FM receiver. This is not a final design.
TDA7000 FM Receiver. Philips IC makes a simple FM receiver with no ceramic filters or IF transformers. Detailed application notes give an interesting insight into this excellent IC, and its offspring, the TDA7010T, TDA7021T and TDA7088T. As well as my own construction attempts, I also take a look at a commercially made receiver.
Tiny Tim II My construction of this regenerative receiver from Radio & Hobbies, April 1943. An excellent little three valve set that drives a loudspeaker.
1J6 Receiver.A battery operated one valve regenerative receiver using a 1J6 or 19 twin triode.
Thames and Kosmos "Radio Ace".This reproduction valve radio isn't exactly a kit despite being sold thus. Despite so many retaillers selling it, there is little technical info on the internet, so I've fixed that. Performance was substandard and required modifications to turn it into something that was useable. Also see the Links further down the page for more on this set.
Automatic Regeneration Control. Make your regenerative receiver as easy to use a superhet! Ideal for non technical uses
Valve Receiver with Automatic Regeneration. Based on the Radio & Hobbies "Three Band Two" this receiver has automatic regeneration control.
ZN414 AM Receiver IC. Notes on this well known TRF receiver IC, and its clones; MK484, YS414, TA7642, LMF501T. Ideal for construction of miniature radios requiring only 1.5V to operate.
Four Valve TRF Receiver. This MW receiver uses four modern TV valves and provides hi-fi sound with its infinite impedance detector. Updated with cascode RF amplifier.
12V Superhet Receiver. This project was built to disprove the fact valves need high voltages. It uses ordinary mains type valves with 12V high tension. Performance is excellent.
Emerson CF255. Two valve TRF receiver from 1939 was said to be the world's smallest practical radio.
Gakken Vacuum Tube Radio kits. Modern valve radio kits from Japan using battery valves. One is a variometer tuned reflex receiver, the other is a 3 valve regenerative circuit.
Detrola 297 Car Radio. Unusual U.S. made car radio from 1940. Very compact one unit construction.
Xmas Box Mantel. Three valve regenerative TRF receiver described in Radio & Hobbies, December 1950.
Minivox Mantel Receiver. From Radio & Hobbies, December 1947, was this three valve regenerative receiver project.
Baird 812. This ex Radio Rentals set uses the Thorn R2M chassis, based on the British Thorn 1500. NEW ARTICLE.
2" TV set. This two inch set uses a 902-P1 cathode ray tube displaying pictures from a DVB-T receiver or other video source. NEW ARTICLE.
Ekco TCX-298 21" 1957 model with doors.
Hiring out vintage TV sets. Unfortunate experiences in hiring out vintage TV sets. The golden rule is don't!
VHF-UHF Fan Aerial. This 1950's design also known as a "Conical" provides excellent results in the 21st century.
Ekco TX-287. 17" model from 1957.
Vertical Blocking Oscillator Transformer Replacement. Are you sick of unreliable blocking oscillator transformers and can never get good locking and linearity? Eliminate the nasty transformer forever with these circuits.
Digital TV and your Vintage Television. Do not worry about analog TV being turned off. You can still use your valve VHF black and white TV sets with the digital transmissions.
Philips PM5544 Test Pattern generator. Are you missing the test pattern that SBS used to broadcast? Here's how I've regained it without paying $1000's. A digital box that plays .jpg files is the answer.
Airline 7" TV set. A rebadged Sentinel 400TV sold by Montgomery Ward under their in house brand. Read how I restored and converted this 1949 model electrostatic deflection American TV set for use in Australia.
Using foreign TV sets in Australia. Brought an American , UK, or European TV set into Australia? Here's how to modify it for the local standards.
Background to TV in the U.S. Brief description of the development of television in the U.S, with examples of first generation electronic TV sets.
Circuit diagrams and parts for vintage TV sets. I do not sell parts. Please go to High Country Service Data for diagrams and manuals.
The incandescent light bulb ban and how to defy it. Do you feel you shouldn't be dictated to as to what kind of light bulbs you use?
The origins of the Australian plug and other electrical trivia. Few would be aware the Australian plug is actually a U.S design.
Jaycar AA-0474 Valve Amplifier (1). It looked nice and the price was right, but this Chinese vacuum tube amplifier turned out to be a fake. Please read this if you have any intention of buying a new valve amplifier, especially one made in China.
Jaycar AA-0474 Valve Amplifier (2). The Jaycar amplifier is rebuilt as a true valve amplifier.
The 6CM5 valve for Audio use. Australia's most popular TV line output pentode, also known as EL36, undergoes some experiments to test its viability for audio amplifiers, particularly in single ended class A. If the link doesn't work, go here. For a push pull design producing 17W, see the link below.
6BM8 Amplifier. A simple but good quality audio amplifier using the 6BM8/ECL82 valve. Capable of a couple of watts. Information on using 100V PA line transformers as valve output transformers.
Simple Valve Amplifier circuits. A collection of economical low power amplifier designs using common low cost valves.
60W Inverter. This vibrator inverter provides 240V AC at 60W from a 12V DC supply. UPDATED
Ferrocart Vibrator Application Notes. Some notes on the design of vibrator power supplies as used in car radios, inverters, etc. Includes Ferrocart type numbers. These were made by Astor and mainly used in their car radios. UPDATED
Oak MSP Vibrator Notes. Information on the MSP/Oak/AWA vibrators used by AWA, Ferris and others.UPDATED
Servicing Vibrator Power Supplies. A description of vibrator supplies and the associated waveforms. UPDATED
Battery Eliminator for Valve radios. Provides A+, B+ and C- for battery valve sets.
Rohde & Schwarz NBU Inverter 12V to 220V 35W vibrator inverter. NEW ARTICLE
Transistor Inverter. Simple but practical, this self oscillating
inverter provides 240V at 20W from 12V. NEW ARTICLE
Vintage Inverters - U.S. manufactured:
DuMont 75W Inverter. DuMont Vibrator Power Pack model 2625 provides 115V at 75W from 6 or 12V DC. NEW ARTICLE
Cornell Dubilier "Powercon" Inverter. This 115V vibrator inverter provides 39W. NEW ARTICLE
Terado Trav-electric SR Inverter. 6V to 110V 35W vibrator inverter. NEW ARTICLE
Terado Super 50-127 Inverter. 12V to 110V 75W vibrator inverter. NEW ARTICLE
All State Inverter Sears rebadge of a Terado 12V to 110V 40W inverter. NEW ARTICLE
Terado Satellite 50-138-3 Inverter 12V to 110W 75W inverter for portable TV use. NEW ARTICLE
Terado Electra 50-167 Inverter. 12V to 110V 42W vibrator inverter comes in a gift box. NEW ARTICLE
Low Power AM Transmitter. This "phono oscillator" design transmits over a suprising distance and uses only two valves.
AM/FM Tuner/Amplifier. First use of my 6CM5 audio output stage design along with a superregenerative detector for FM and regenerative detector for AM.
Ericofon installation notes. To clear up facts about this trendy Ericsson telephone, as well as killing off the myth that these telephones do not contain a ringer.
Line Cord Resistor replacements. Relevant to equipment using series heater valves. Options for dropper replacements and how to calculate their value. Examines diode and capacitor dropper circuits.
Reproduction Line Cord Resistor. How to make a new line cord resistor for your American AC/DC radio that is completely authentic and requires no modifications.
Service Tips: An ever increasing list of faults and their repairs for various electronic items.
Solar/Wind installation Installation of a domestic 12V solar and wind powered lighting plant.
Solar water heater Installation and connection of an Evacuated Tube collector panel to an existing electric water heater.
Test run in my 1926 Model T, October 2002.
6V Turn Signal Flasher. 6 volt electronic flasher design with user adjustable flash rate, and low current wiring to the indicator switch. This design is not affected by supply voltage.
Improved Radio for the Model T Ford. Three valve vibrator powered car radio for the Model T. This design uses the 12AT7 super regenerative circuit.
Running coils without the magneto. Improve ignition system performance in cars where the 6V battery is the only power source.
Fun Projects Voltage Regulator. Ever wondered how this accessory voltage regulator works? Wonder no more as this article explains all.
Know Your Coils. Rebuilding and adjusting Model T Ford ignition coils.
6 to 12V converter. Powering 12V appliances in your 6V Model T.
6 or 12V? Examines the often asked questions about using 12V in a Model T.
Electronic Coil Tester. This allows Ford coils to be adjusted correctly without multiple sparking.
Model T thermal imaging. See what's really happening with your model T.
Trek Y bikes The Shrine of the Trek Y bike.
Trek Y5. The first Y bike in my collection. Top of the range 1997 alloy model.
Trek YSL200 mountain bike The Y Superlite was the top of the range OCLV model.
Trek Y33 (1998). The fourth to be added to the collection.
Trek Y33 (1996). This is the bike featured in Popular Mechanics July 1996, and the fifth in my collection.
Trek Y22 (1995). The latest Y bike acquisition; this is probably the most common model, and also the earliest of the Y bikes.
Trek 3900 (2006). My first hardtail was a bargain I couldn't say no to.
Use Google Translate if sites are not in your preferred language.
Monitor Top Refrigerator
Forum. All things to do with General Electric Monitor Top Refrigerators,
including repair advice.
Low Tech FM receivers. FM receiver enthusiast, Andy Mitz has this comprehensive site covering things FM. There are similiar simple FM receivers to what I've presented here, and also an interesting database of commercially made FM receivers.
Model T Ford Club of America. This site has everything you need to know, and an excellent discussion forum.
Nostalgia Air. Source of circuit diagrams for US valve radios. PDF's of Riders manuals. Have found all known Fremodyne sets here.
Trek Y Bikes. My Yahoo group dedicated to Trek's brilliant mountain bike design of the mid 1990's.
Classic Radio Gallery. A good collection of U.S valve radios for sale. This is where my Meck FM converter came from.
Phil's Valve Radio Site. Some interesting homemade receivers and amplifiers. For those wanting a solid state version of the Pulse Counting FM Receiver, this is worth a look.
GE Monitor Top Fridges. My Yahoo group for General Electric's famous monitor top fridge which went into production in 1927. This was the first fridge to use a sealed compressor. This group now inactive due to Yahoo changes.
Savoy Hill. Source of service manuals/circuit diagrams for vintage UK equipment. Was able to get my Ekco TC140 manual here. Excellent personal service, and you can use PayPal.
Sams Photofacts. Known to most U.S technicians/restorers, this company is the place to go for circuits and service manuals for audio/radio/TV gear sold in the U.S. Expensive, but this is where you'll get them and they deal with vintage stuff.
Die Basteleke. This German site authored by Mr. B. Kainka is full of interesting projects, including those with valves operating at low voltage. Its author has written some excellent books, and has designed some of the Kosmos electronic kits (such as the Kosmos Radiomann / Radio Ace).
Children's science radio. For those who like building transistor radios, this Japanese site is full of interesting designs. Many are based around the popular 1960's reflex circuit. Good site if you're into germanium transistors.
Japanese links. A few days worth of browsing here. More Japanese designs using valves and solid state. Eventually, you'll stumble upon the guy who not only likes making pocket radios with valves, but modifies transistor radios to use valves instead of transistors.
Ban Incandescent Lamps? This site looks at what's really involved in forcing everyone to use CFL's instead of incandescent bulbs.
American Radio History. If you like reading old electronics magazines, most issues of the well known U.S magazines have been scanned here.