"Crystal Plugs"

Crystal Replacement 0 Comments 09/01/2020

DIY version by "RAN Crystals"

Posted By: Robert Nickels (ranickels)

Crystal sockets were popular for pluging in ... crystals, of all things! But they were also used for other purposes, such as the antenna relay connection on some EF Johnson transmitters. If you want to connect a VFO to a transmitter with just a crystal socket, for example, you're going to have to either carve up an old FT-243 type crystal or if you want to outboard a synthesizer to a Drake radio or use that Johnson antenna relay connection, that takes the smaller pin version, like the HC-6/U crystal used.

I got tired of having to cobble up something so I made my own. Brass tubing and wire provides the correct fit and a small PC board hold it all together and provides a way to attach a cable, either soldered or to screw terminals.

My novice crystals came from a place that sold surplus crystals that many remember: JAN crystals. So it was only natural that my crystal plug bear the "RAN Crystals" name.

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Large size pins

Small size

Small size pins

EF Johnson Transmitter Sales

How many did they sell?
Category: Vintage Ham Radio

EFJ transmitter sales data from former employees.... READ MORE

- Robert Nickels (ranickels), 09/16/2020

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Category: Vintage Ham Radio

Like most hams, I remembered seeing the FPM-200 at an astronomical price in the 1962 Allied Radio catalog and wondering just how rich would a person have to be to own one? For my 11 year old self, such things may as well have been on another planet, but well...things change.I'd seen only one FPM-200 sold (to a guy ahead of me at a hamfest) and in the pre-eBay era most rare ra... READ MORE

- Robert Nickels (ranickels), 09/12/2020

why 50 ohms?

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Category: Technical

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- Robert Nickels (ranickels), 09/06/2020

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Category: Historic

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- Robert Nickels (ranickels), 08/14/2020

Multi Products Model CM-1 Conelrad Monitor (Motorola DS9660)

another obscure Elmac returns to the air
Category: Vintage Ham Radio

Bob Heil's favorite radio is the Moseley CM-1 which the developer, John Clemmons, told Carl Moseley stood for Clemens Manufacturing number 1. "No", Mr. Moseley said, "That stands for Carl Moseley number 1!"As that may be, there's yet another CM-1 receiver and it was made by the Multi Products Company of Oak Park, Michigan.As wikipedia states: "CON... READ MORE

- Robert Nickels (ranickels), 08/13/2020

All Band Inexpensive 40 Watt Transmitter

a great "first homebrew xmtr" project
Category: Vintage Ham Radio

Jay Miller KK5IM recently wrote an article in Electric Radio magazine about fulfilling his dream of building a homebrew "AM Kilowatt" transmitter (375 watts output by today's standards). His crystal-controlled exciter that drive the 813 was based on his Novice transmitter, which was built by his grand-uncle back in the 1960s when Novice class hams were l... READ MORE

- Robert Nickels (ranickels), 07/09/2020

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Previously undocumented phenomenon
Category: Technical

Micro SDR innovator Guido PE1NNZ has implemented polar modulation using an Arduino MCU and a class E PA. For more informartion on this fascinating project, join the discussion group at https://groups.io/g/ucxInitially, Guido's design implemented the polar or EER modulation scheme using modifications to the QCX CW transceiver hardware in the traditional way as described by Leonard K... READ MORE

- Robert Nickels (ranickels), 06/20/2020

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- Robert Nickels (ranickels), 06/06/2020

Class E Notes

the result of experiments with high efficiency class E amplifiers
Category: Technical

There is a lot of misunderstanding about how a Class E amplifier works. As the result of studying the literature and experimenting, I thought I'd share what I have learned over the past several years. Below is an example of a test amplifier I used to optimize my 2 watt wspr transmitter boards. It can be visualized as two circuits - the... READ MORE

- Robert Nickels (ranickels), 06/06/2020