VERSA-TR Layout and Connector Locations

VERSA-TR Information 0 Comments 11/11/2018

Posted By: Robert Nickels (ranickels)

For reference - click image to enlarge

Harlan Andersson, computer pioneer and co-founder of Digital Equipment Corp.

A native of my town, Freeport IL
Category: Historic

The following obituary appeared in the Freeport Journal-Standard on Febr. 9, 2019. I attended a lecture by Mr. Anderson in the late 1990s after moving to Freeport and working for Honeywell where despite being a supplier to DEC, few realized the local connection existed to the founder of what once was the second-largest computer company in the world. Mr. Anderso... READ MORE

- Robert Nickels (ranickels), 02/09/2019

The Case of the Phantom Voltage

“When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.”
Category: Technical

A Heathkit HW-12 gave me a troubleshooting challenge the likes of which I've not seen before - or even heard of!A few days ago the transmitter wouldn't produce output, and in checking voltages and I measured -75 volts on the ALC line which should be -20. But it corrected itself and I figured it must have been a solder splash or something that cleared by itself. That theor... READ MORE

- Robert Nickels (ranickels), 02/08/2019

The Solvay Conference, 1927

The Smartest Photograph Ever Take
Category: Historic

The Solvay Conference, founded by the Belgian industrialist Ernest Solvay in 1912, was considered a turning point in the world of physics. Located in Brussels, the conferences were devoted to outstanding preeminent open problems in both physics and chemistry. The most famous conference was the October 1927 Fifth Solvay International Conference on Electrons and Photons, where the world’s most... READ MORE

- Robert Nickels (ranickels), 12/27/2018

Heathkit Singlebanders...cheapest SSB radio made? Or just one of the best?

Slightly insane about singlebanders...
Category: Vintage Ham Radio

Put yourself in 1963...A stamp was a nickel, bread was 22 cents a loaf, and you could buy 3 gallons of gas for a buck. The average wage in the US was $84 a week. If you were a ham, you might have been able to build and trade your way up to a really nice AM/CW station - maybe a Valiant or DX-100 transmitter with an NC-300 or HQ-170 receiver - a huge improvement over the S-38 you s... READ MORE

- Robert Nickels (ranickels), 12/17/2018

Astro...Don Stoner's legacy

How many of these rare transceivers have you seen?
Category: Vintage Ham Radio

A recent post on the Cubic-Astro mail reflector noted the similarities between the rare CIR Astro 200 and the much more common Cubic Astro 150 transceivers. And therein lies an interesting story...I have done a little research on the CIR Astro 200, and the commenter was right - it is the progenitor of the Astro line we are much more familiar with as a result of Swan (already owne... READ MORE

- Robert Nickels (ranickels), 12/09/2018

The DX-60 Family

what hath Benton Harbor wrought?
Category: Vintage Ham Radio

When an engineer at Heathkit in 1962 turned his attention to designing a replacement for the somewhat flawed DX-40 novice transmitter, little would he have expected the DX-60 to remain in the Heathkit catalog for 14 years. From the new solid-state power supply to the streamlined apeperance and dependable performace, the new transmitter was instantly popular with novices who had t... READ MORE

- Robert Nickels (ranickels), 12/09/2018

Four Channel Oscillator board

One board, up to four frequencies
Category: Crystal Replacement

Epson programmable oscillators are a good substitute for quartz crystals in many applications, but they're a bit different to use. First, they are active devices that require DC power, typically 5 volts at 45mA. Second, like all ICs they are easily damaged by static and voltages that exceed the design limits. Finally they are in DIP packates that are i... READ MORE

- Robert Nickels (ranickels), 12/08/2018

Programmable Oscillators - the modern day "rock"

Cheaper and more accurate and stable than the old type
Category: Crystal Replacement

With the demise of International Crystal in 2018, hams and experimenters lost the last US-based source of affordable one-off custom crystals. (And the definition of "affordable" ended up over $30 each). Sure there are some offshore sources but the reality is, manufacturing one crystal to a specific frequency is not simple or inexpensive, and all crysta... READ MORE

- Robert Nickels (ranickels), 12/06/2018

"A Pair of 6V6s"

What more does one need to hear good audio?
Category: Vintage Audio

The first audio amplififer I made (that worked) used a single 6V6 to amplify the output of a regenerative receiver. Ever since they've been my idea of what a good audio tube should be and with a big speaker mounted on a piece of plywood, a 6V6 will produce "room filling volume" as the magazine articles fo the day said. But as my music tastes grew acousti... READ MORE

- Robert Nickels (ranickels), 12/03/2018

Does the VERSA-TR protect my receiver while transmitting?

An important question - and the answer is YES!
Category: VERSA-TR Information

My primary aim when desiging the VERSA-TR was low power transmitters, and to protect the receiver from potentially damaging voltages when transmitting. 100 watts into 50 ohms is a +50dBm signal. I'd measured the attenuation at the receiver connector in the labe at -60 to -70 dB (depending on frequency), which means that should result in -10 to -20dB at the receiver, which should be ... READ MORE

- Robert Nickels (ranickels), 11/29/2018