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Mike from Brisbane
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Location: Brisbane, QLD
Member since 7 May 2018
Member #: 2245
Postcount: 5
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Hi all, I'm a new member here. In my youth, I built a number of radios, a logic plug-board, CRO, and a few robot-like contraptions. I built several computers, including a TTL serial computer of my own design, and even co-wrote the 2650 Disk Operating System. I converted a cocktail Asteroids video game to run a Flight Simulator program, converted a DecWriter terminal from 300 to 600 baud, and other computer projects.
For this forum, the main projects of interest would be my three radios.
The first was an amplified crystal set. An uncle of mine, recently deceased, worked in the hearing aid industry, and made me a DIY kit for an amplified crystal set. He went to a lot of trouble, e.g. soldering washers to a germanium diode to make it easy for a ~eight year old to assemble. That Christmas present established my love of electronics, and I'm forever grateful for that thoughtful gift.
Next was a three transistor regenerative receiver. I have no photos or parts from this, which is the subject of a separate post in the Special Projects forum. Apart from the three germanium transistors, the 3" speaker, aluminium chassis, and 276P battery, I don't remember much about it. I think it had just passable performance. I recall I used a linear pot for the volume control, so the volume didn't change much for the last 90% of the travel. I didn't figure out how to poke the coil wires down to the pins of the plug-in coil formers, so I used flying wires from the pins, over the rim of the coil former, and back down to the coils. No doubt, this contributed to a lack of stability.
My third radio was the EA-160 communications receiver. Again, I didn't get the need for proper "dress" of the RF stages, so it didn't perform very well either. At least the original Electronics Australia article (December 1970) is available, though I don't have my original copy any more. It's difficult to know what you will find valuable in future, and therefore need not to throw away. But of course if you keep too much (and I tend to do a lot of that, too), then you have too much clutter.
Sometime amongst this, the family console radio, which had been intermittently failing, died altogether, and I got to pull it apart. I'm interested in photos and a schematic of that as well. It might have been the one on the right of this photo:
http://watvhistory.com/wp/wp-content/uploads/2011/10/WHF34.jpg
It used side-contact valves, probably including an EM1 magic eye. I recall a large green resistor under the chassis, with (I think) an adjustable tap. I'm pretty sure it was a Philips brand; my family is from Holland and of course the side contact valves were likely made in Eindhoven, Netherlands. I seem to recall that the valves had odd (to me) designations, like "EK2". Many of the valves had "hips" and were frosted. I think several were red frosted. There were only three knobs, although the centre one had two functions, one of which was to change bands. I do have one photo, which I'll attempt to get uploaded. It also features me at age two or so.
Finally, the other family radio was a brown bakelite mantel set. It was high up, out of the reach of young fingers, and I remember my mother used it regularly to listen to "Blue Hills" on 4GR (?) at one o'clock every day. I can't remember much about this set, except perhaps the somewhat distinctive knobs, which were large (perhaps 60 mm diameter), knurled, flat, and slightly domed. I'm resigned to never finding any details on this set, as I have so little to go on, and there were so many similar models made.
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6763
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Welcome to V-R. Many of us here grew up building EA projects (some date back to RTV&H projects). I don't know what specifically got me interested in electronics, although my parents told me I was pulling apart jug cords, etc, as soon as I could use a screwdriver.
It used side-contact valves ... Many of the valves had "hips" and were frosted. I think several were red frosted
That's the P type base, beloved of Philips:
https://www.radiomuseum.org/tubes/tube_ek2.html
There are schematics available today for many sets. Consoles can be more difficult to identify than mantels, but someone here may call out the one in the photo.
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