RAN Technology

Programmable Oscillators - the modern day "rock"


Crystal Replacement 0 Comments 12/06/2018 

Cheaper and more accurate and stable than the old type

Posted By: Robert Nickels (ranickels)

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 crystal makers are facing the reality that demand is a fraction of what it once was and dropping rapidly.  Fifty cent crystals are available - if you are willing to buy 1000 at a time.

What about the guy who needs a crystal to bring an old radio to life, or for a homebrew project?   The modern solulution is the programmable oscillator, which is an integrated crystal and PLL that is one-time programmed to your particular frequency from 1 to 125 MHz.  Frequency stability is +/- 50ppm from -20 to +70 degrees C and these are not just crystals, they're complete oscillators-on-a-chip.   All that's needed to obtain a 5 volt peak-to-peak output signal is power (+5 or 3.3VDC) at 45 mA and ground.   And enable pin makes it easy to turn these devices on off (i.e. keying).    They're available in several packages but the 8 pin DIP is a good choice for most ham projects as it can fit into a space no larger than an old style FT-243 crystal.  

The photo below shows how compact "one rock" using the mini-DIP package can be.   This small form factor is great for testing and since there's an onboard 5 volt regulator, power can be tapped from any convenient low voltage DC source.   In many cases, coupling the oscillator signal to the "hot" side of the old crystal socket as is done here produces good results.


  

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 
   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 
   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 
  

"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 
   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 
  

VERSA-TR Panadaptor Video

Use the VERSA-TR to improve your SDR panadaptor
Category: VERSA-TR Information
An inexpensive SDR like my RANVerter Pi Plus can add a panoramic spectrum and waterfall display to almost any vintage (or modern) radio.    The ability to use the SDR as a 2nd receiver that can be tuned to a different frequency or mode from the main transceiver is a real plus, but annoying feedback and delayed audio will be normally heard through the PC speakers in the transmit mode...  READ MORE
- Robert Nickels (ranickels),  11/27/2018 
   The muting relay on the VERSA-TR can be used to control other devices when RF is present.   An example would be an "On The Air" sign, or to key an amplifier.    One specially-wired cable is required - note that no connection is made to the sleeve, which is usually the ground connection on a TRS plug.  A normally-open set of relay contacts exists between the ...  READ MORE
- Robert Nickels (ranickels),  11/13/2018 

VIEW News Item

Take the Boatanchor Survey!

Let authors and organizers know what you're interested in
VIEW News Item

Announcing the VERSA-TR (as seen in Dec. 2018 QST)

A Versatile T/R solution for SDRs and vintage radios
VIEW News Item

Mike Beachy N8ECR - SK

"If there's a ham radio heaven, they've got a hell of a net control operator"
VIEW News Item

K9QET Update

AM stalwart net control op and all-round good guy needs your thoughts and prayers
VIEW News Item

DX-60 Website Announced

Celebrating the fun of low-power AM

(There are currently no Blogs.)