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Signal Generators
Heathkit IG-5280 Leader LSG-100 |
Two signal generators are mentioned in this page. Heathkit IG-5280 is a transistorized RF signal generator purchased at a flea market for a radio building project; I thought it was just a case and dial and internal components were removed because it was so light. It was found that everything was in there, and worked. Its frequency stability was inadequate for careful servicing so it was soon stowed. Leader LSG-100 is a vacuum tube type, only 2 tubes are used. Its dial is beautiful, but its performance is not enough for the serious servicing. LSG-100 was marketed in the U.S. under the Lafayette brand. |
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Lafayette TE-50 Tube Tester [English] |
This simple tube tester can check the emission performance and short circuit of vacuum tubes. Bought it to check junk tubes in my lab, but then more junk tubes are to be purchased in order to use this tester! A tube user can be now called as a tube mania, when the initial purpose is forgotten... |
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Hewlett-Packard 1200A Oscilloscope |
Having a oscilloscope was indeed a dream of a radio kid.
A quarter centuly later my dream finally became a reality,
when I found a price tag at a flea market; "Scopes: $8 for two" !! One of two units worked nicely, and it helped me a lot. The other unit had a problem; raster did not go rightward. With the aid of working unit, the cause was found to be bad deflection output transistors. Replacing them with surplus transistors regained the nice and stable raster. It revived only for a night, however. Intensity became quite low after several hours of operation. Apparently a register in cathode circuit was damaged. Better to fix it before the working one ceases its life. |
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TRIO CO-1301 Oscilloscope |
This tiny lovely oscilloscope was a low priced kit designed for radio amateurs in Japan back in late 1960s. Its color and style matched to the early Trio (Kenwood) amateur radio transmitters. Obtained from a veteran ham, this unit suffered a raster problem (did not move rightward; somehow similar to my HP-1200A) and unstable operation. Replacing a capacitor cured the raster problem, and replacing the rest of the capacitors brought a stable operation. It works nicely on my bench for monitoring the audio signal. |
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Signal Corp. Code Training Generator Model Unknown |
Purchased at the Santa Rosa amateur club swapmeet, I did not know what this bulky heavy unit was for. It had three vacuum tubes, the panel carried a "frequency" knob, a "volume" knob, a "key" terminal and a speaker. It must be a CW transceiver or some sort, but there wasn't an antenna terminal. Following the operating instruction attached to the panel, I found this was merely a Morse code training generator! |
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Sony SLV-FX5 VHS Hi-Fi Video Deck [English] |
Some Japanese TV programs are tranmitted with bilingual audio.
Viewers can choose Japanese or English (or original audio of foreign movies), for example.
One day my Toshiba VCR failed so I unpacked and plugged my Victor VCR which was stowed since I left the U.S.
It received all the air channels nicely, but it did not have bilingual audio capability. The next week I got a broken VCR from my family. Its tape deck had a problem, but tuner worked fine. By combining with those two VCRs, my requirement was fulfilled. But ... broken deck? Okay, try to fix it. |
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BayNetworks BayStack Model 50 10BASE-T Ethernet Hub |
In 1998, Ethernet equipment became quite affordable, so I connected PCs in my home. For further convenience I added another 10BASE-T hub in my lab. Price of this hub, made by BayNetworks, was cheaper than unknown brand one. It worked just fine and I was happy with it. The next morning I found no indicator lit on the hub. Quick check pointed out that its AC adapter failed. Brutely opening the case of the AC adapter, it was immediately obvious that the soldering at the power transformer loosened. Perhaps this was the reason of the cheap price at a surplus shop. Okay it's not a big deal. Let's enjoy building a power supply. |
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Pioneer SE-550D Stereo Headphones |
This Pioneer stereo headphones have been my friend for these 10 years, but their ear pads wore out after heavy use.
I bought a new set made by other big name manufacturer, but it disappointed me.
It did not sound naturally, loose fit, squeaking headband - even thouth the price tag was the highest at the consumer electronics shop.
It was just a crap.
So I decided to buy a new Pioneer.
Visiting their web site, wrote my recent experience with another make's product and applause to my SE-550D.
Unexpected feedback from Pioneer came, that they still carry new ear pads as spare parts which I immediatelty ordered.
Price of these parts was such that a low price new set could be purchased, but it was much clever way of spending money.
Now I again enjoy SE-550D. |
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Leader LCG-381 Color Bar Pattern Generator |
The recycle shop owner did not have any idea what this was and he okayed immediately when I offered a price.
This color bar pattern generator was for servicing color TV sets and has 12 vacuum tubes.
Salvaging parts was my intention but it might be fun to watch a color pattern generated by 12 tubes...
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Heathkit IT-18 Transistor Tester |
As a non-educated radio kid, I cannot design a radio receiver from a scratch because
I don't fully understand how transistors work.
Feeling a need of experimenting transistors, I purchased this tester.
Simple equipment such as DC hFE can be easily homebuilt, but the price of this kit was much cheaper than purchasing parts.
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Nissyo Kogyo NP-101 DC Power Supply |
While I was in the U.S. mom disposed most of the equipments I used when I was a radio kid.
Somehow this small regulated DC power supply survived,
and now is one of the oldest equipments still living with me.
This time a severe distortion in the output voltage observed,
so I opened the case and drew a schematic diagram,
and started to investigate to find nothing was wrong....
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Too Trivial for a Page |
Collection of misc repairs and attempts too trivial.
Don't excpect anything here.....
Just like the other pages in this website,
this is for our memorandum purpose.
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