These are scans of the specifications for most of the Motorola HEP line of replacement transistors. Germanium and Silicon. Pages 10, 11, 12.
Archive for the ‘Electronic Components’ Category:
2020-03-10 Simple AM Band Antenna Tuning Coil 240 Microhenrys
The standard ferrite antenna loopstick for a 365 pF tuning capacitor has an inductance of about 230 microhenrys. This in combination with the tuning capacitor tunes across the full AM broadcast band. It’s useful to be able to wind your own inductor so it can be used for an antenna coil, a trap to attenuate
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2020-02-21
I found that 100 uH was a good all around value for these solar garden light circuits. But at the time I made these around 2009 the 5252 4 legged chip was uncommon and almost all the garden lights used 2 discrete transistors. I don’t know why they started using the 4 legged 5252 –
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LED Indoor Motion Sensing Lights – Decrease On Time
I bought two of these motion sensing LED lights for my hallway. They have a rechargeable cell that is charged through a micro USB port. To see one inside watch big Clive’s YouTube video – the ebay link to buy them is in his description. The charge lasts for more than a week with frequent
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2020-02-08 60 LED Solar Lights Stopped Working – Dead Diode!
From FB group electronics hobbyists Over the holidays I installed two solar 60 LED lights I bought on eBay. They stopped working just a few weeks after. I finally got up on the ladder and took them down to see why they died. Well, spit! The solar panel is plugged into the jack on the
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2020-01-23 DIY Variable Capacitor 90 to 3400 pF
The beginning isn’t clear about how it looks. First, scroll to end and look at the photo. https://www.randombio.com/capacitor.html
2020-01-20 Costs of Radio Assemblies and Parts
From FB group Vintage Transistor Radios A thought occured. Do you think that Motorola may have had a lot of parts for tube sets and they decided to use them up by putting a transistor chassis in them? If you break down a radio into its assemblies and/or parts, which of them has the highest
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2019-01-15 Zenith Royal 200 Conversion to Silicon
I’m thinking of pulling up the end of the 100 ohm and looping the lead a few times through the ferrite bead. If that still doesn’t stop the ringing, I’m thinking about replacing the bead with an RF choke. Every time the ringing is reduced the reception gets better. I checked to see if I
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2020-01-10 Corrosion and Damage On Diode Leads
This photo is a detector diode that was broken during replacing the electrolytic capacitors. The lead on the top was twisted, apparently putting stress on the glass package. I replaced it with a 1N270 germanium diode. comment from fb group Vintage Transistor Radios Did you notice that the leads are magnetic? They stick to the
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2020-01-08 Sorting Transistors Compared to Picking Fruit
I started thinking about how the makers of transistors sort the different grades of transistors as they’re manufactured. I thought that a reasonable analogy would be similar to how a farmer might sort the fruit he harvests. Here’s what I came up with.The farmer starts with the fruit his workers have gathered. The fruit is
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