Archive for the ‘Receiver’ Category:

2018-06-24 Antennas Loopstick Vs Spider Web

From FB group Building Transistor Radios Jim Glover You asked about performance. There are factors unrelated to either type that affect the performance, one being the type of wire used. If Litz wire is used it has lower losses, and therefore higher Q than solid wire. Same holds true for silver plated wire at HFs.

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2018-05-13 My First Transistor Radio

From FB group Vintage Transistor Radios OMG, that was so long ago, I could never sort out which one. See, I was born with a soldering iron in my hand, and I fixed so many radios, I could never remember which one was one that I had. Most of the electronics I was given were

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2018-04-22 Ferrite Loopstick Basics

From FB group Building Transistor Radios Then there is the loopstick. It is deliberately made long and thin to capture the RF magnetic fields. The frequencies that loopsticks are better at capturing are those that require long antennas that would be impractical. So the AM broadcast band is where loopsticks do their best. The loopstick’s

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2018-03-28 Wideband RF Amp In Royal 500s

From FB group Ferrite Loopstick Antenna Experimenters Some experimenters in another group looked at schematics and saw that some radios with a RF amplifier between the loopstick and the converter used a third section on the variable capacitor to tune the RF amplifier. This is good, but it makes the variable capacitor more expensive and

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2018-03-26 Reflex Receiver, 2 Transistor

For FB group Building Transistor Radios Darrell Darby (Schematic below) What amazes me is the collector load resistor for the earphone stage is 100k. That’s more than ten times higher than usual, and it’s okay because the crystal earplug is very sensitive. I would squeeze a bit more gain out of it by removing the

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2018-03-02 One Transistor AM Radio

FB group Building Transistor Radios In JF1OZL’s voluminous archive I found his version of a MW receiver.  It is labeled [2] …. MW-RADIO (see link).  He used a long wire antenna, and an IF transformer with the ceramic capacitor removed for the tuning coil.  He also said to use a ferrite loopstick, which is what

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2018-01-09 Regenerative Radios Are Too Difficult

For FB group Building Transistor Radios Bob Johansen After building several of the regenerative receivers, I think I figured out the reason why regens are so difficult.  The circuit has to do so much with very few parts.  If one part value is changed to improve one thing, it adversely affects something else.  The tickler

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2017-12-30 Zenith Royal 755LK

I tried to to post this to the FB group Vintage Transistor Radios, but the FB app crashed and I lost several lines of my typing.  Makes me angry! The radio was not making any sound.  I removed the chassis from the case.  I found the ‘battery saver’ slide switch had been forced apart.  I

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2017-12-16 Olympic 860 Radio Capacitor Replacement 

I was the only bidder on a lot of three radios, one of them is an Olympic model 860 AM transistor radio.  This radio uses four AA cells for a total of 6 volts DC. Overall the radio is in good condition – no chips or cracks.  I powered it up and if I turned

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2017-12-15  Royal 500 Capacitors Replaced

From FB group Electronics Hobbyists, regarding the Zenith Royal 500 radios. Clyde Hendrickson  There are two 50 uF, 10V electrolytic capacitors under the battery holder.  Replace them with 47 uF, 10 or 16 volts. There is also a smaller capacitor next to the other, it might be a 3 uF, or a 16 uF, 10V.

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