Dr. Greg Latta's
Electrical Engineering
and
Amateur Radio Pages

Welcome to my electrical engineering and amateur radio pages.
These are updated on a regular basis so I encourage you to stop back every so often.

Click on one of the links in the table
below or scroll down for more information:
 Receivers  Transmitters  Amplifiers  Accessories  Miscellaneous and Academic
 The AA8V 6x2
Superheterodyne Receiver
 The W8EXI
Wingfoot VFO Exciter
 The AA8V 6AG7
QRP VFO Amplifier
  AA8V Digital VFO
For Vintage Transmitters
 The AA8V Station
 The AA8V
Twinplex Receiver
 The AA8V 6CL6
One-Tube Transmitter
 The AA8V
6146B Amplifier
 Electronic T/R Switching
and the Ameritron QSK-5
  The Workshop at AA8V
   Johnson Viking Ranger
: Restoration and Circuit Descriptions
 The AA8V
Wingfoot 813 Amplifier
 Using the LM-13
Frequency Meter as a VFO
New
 A Study of Secondary Emission
in Vacuum Tubes by Angela Meyers


The AA8V Station
 

The AA8V Station
The AA8V Station

After many requests I have written web pages that will take you on a tour of my amateur radio station. The station features a modern transceiver, a vintage set of Drake Twins from 1965, a vintage station from 1955, and a large amount of homebrew equipment, including a homebrew 6-tube superheterodyne receiver.



Miscellaneous
 

AA8V Workshop
The Workshop at AA8V

I recently had a short time between projects and decided to take you on a photographic tour of my shop. The shop features an electronics shop, metal working machine shop, woodworking shop, photography area, and painting area all packed into a very tight space.



Accessories
 

Digital VFO
AA8V Digital VFO For Vintage Transmitters

One of my most useful projects is a Digital VFO for Vintage Transmitters that I designed and now use with all of my tube and vintage transmitters. The web page greatly expands on my article that was published in the January, 2014 issue of QST magazine. The VFO provides modern frequency stability, digital readout, and operating convenience when using vintage or tube transmitters such as the my 6AG7 one tube amplifier/transmitter, my 6CL6 one-tube transmitter, the Eico 720, and the Johnson Viking Ranger.



Receivers
 
6x2 Superheterodyne Receiver

The AA8V 6x2
Superheterodyne Receiver

My current project has been to finish writing the web pages for the 6x2 Superheterodyne Receiver, a 6 tube superhet receiver for the 80 m and 40 m bands. The receiver is my pride and joy. It features a crystal filter for single signal CW reception, a crystal calibrator, and the ability to receive WWV at 5 MHz. I have finished writing all of the circuit descriptions for the receiver, and am working on the operation and alignment pages.


 
Twinplex Receiver

The AA8V Twinplex Receiver

My most popular web page is perhaps the AA8V Twinplex Receiver. The Twinplex is a one-tube regenerative receiver well within the capabilities of any builder. It has been built by hams and experimenters throughout the world.



Transmitters: Restored Johnson Viking Ranger
 
Ranger Transmitter

The Johnson Viking Ranger

One of my favorite projects was the restoration of a Johnson Viking Ranger. It is now fully restored and working hard on the air, both on CW and AM. It is a classic transmitter and I have taken a lot of time on the web pages to explain in intricate detail the operation of the transmitter. If you go to the schematic diagram page you can click on any section of the schematic diagram and read about that section of the circuit in great detail.



Transmitters: 6AG7/6146B System
 
6AG7 Amplifier

The AA8V 6AG7 QRP VFO Amplifier

The 6AG7 Class A VFO Amplifier can be driven by an analog or digital VFO and can be run by itself as a 3 watt QRP transmitter or it can be used as a buffer to drive the 6146B Amplifier to 60 watts of output on the 80 m - 20 m bands.


 
6146B Amplifier

The AA8V 6146B Amplifier

The AA8V 6146B amplifier is a class AB2 linear amplifier that operates on the 80, 60, 40, 30, 20, 15, and 10m amateur bands. It uses a 6146B tube to produce as much 60W of output when driven by about 1W of input. Either the AA8V 6AG7 VFO Amplifier or the AA8V 6CL6 Transmitter can drive it. It functions just like a larger commercial amplifier. It has bypass circuitry that bypasses the amplifier during receive, and the use of fixed, regulated bias and screen voltages means that it is not necessary to key the amplifier.



Transmitters: Wingfoot System
 
Exciter

The W8EXI Wingfoot VFO Exciter

The 1955 Wingfoot VFO Exciter and modern Wingfoot 813 Amplifier form a complete, late 1950s/early 1960s high power, all tube, VFO transmitting system. The Wingfoot VFO Exciter can run barefoot at 27 watts output or drive the Wingfoot 813 Amplifier to 250 watts output on the 80 m - 20 m bands.


 
Amplifier

The AA8V Wingfoot 813 Amplifier

The 1955 Wingfoot VFO Exciter and modern Wingfoot 813 Amplifier form a complete, late 1950s/early 1960s high power, all tube, VFO transmitting system. The Wingfoot VFO Exciter can run barefoot at 27 watts output or drive the Wingfoot 813 Amplifier to 250 watts output on the 80 m - 20 m bands.



Miscellaneous
 
6CL6 Transmitter

The AA8V 6CL6
One-Tube Transmitter

For crystal control, the 6CL6 One-Tube Transmitter is hard to beat. The transmitter can operate on 80m to 20m and makes a great QRP project. When coupled with the 6146B linear amplifier it makes a fine 60W output transmitter system.


 
QSK-5 Electronic T/R Switch

Electronic T/R Switching
and the Ameritron QSK-5

When I added a new Ameritron AL-572 amplifier to my shack (which I love), I also also purchased the QSK-5PC circuit board for break-in CW. I spent considerable time studying the QSK-5PC on the workbench to understand how it worked, and put everything I learned here on the web under Electronic T/R Switching and the Ameritron QSK-5. Anyone interested in how electronic T/R switching is done will find Electronic T/R Switching and the Ameritron QSK-5 quite useful.



Academic
 
Studio Monitor

Physics 340
Audio Engineering Page

An information page for students at Frostburg State University taking Physics 340, Audio Engineering.


 
Base diagram of 6AU6

A Study of Secondary Emission
and Emission Saturation in Vacuum
Tubes by Angela Meyers

This page is a fascinating study of secondary emission and emission saturation in vacuum tubes. It is the result of work done by Frostburg State University honor student Angela Meyers for her honors thesis. It is a beautiful example of negative resistance.



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Questions, Comments, and E-Mail

LetterIf you have any questions or comments, you can send E-Mail to Dr. Greg Latta at glatta@frostburg.edu

This page is under constant revision. Please check back often.

Thanks for stopping by!