Clifton Laboratories 7236 Clifton Road  Clifton VA 20124 tel: (703) 830 0368 fax: (703) 830 0711

E-mail: Jack.Smith@cliftonlaboratories.com

The Z100 is a flexible, microcontroller-based tuning aid for CW and RTTY and other digital modes. It displays the audio spectrum (either a 600 Hz or 1200 Hz range) horizontally, with the brightness of the LED being proportional to how frequently that audio frequency appears. The center frequency of this range is adjustable from 400 Hz to 3 KHz and may be saved in memory (up to 16 center frequency settings).

The Z100 may be used with any transceiver or receiver, as it only requires power (+12V) and audio connections.

The Z100 addresses the problem many newcomers to CW operation experience (and it helps even if you have been licensed for 46 years like I am)—have you correctly tuned in a station so that your transmit frequency matches his transmit frequency. In the days of separate transmitters and receivers, you accomplished this task by placing your transmitter into "spot" position and adjusting the VFO so that its pitch matched the station you were listening to on the receiver. This process is known as "zero beating" from the concept that you would hear a beat note between the desired station and your transmitter's spotting signal. As the two frequencies approached each other, the beat note drops in frequency. When the two frequencies exactly match, the beat note frequency is zero Hz.

If you are not zero beat with the other station, then something call "leapfrogging" can occur, where each station adjusts his transceiver frequency incorrectly and the QSO gradually moves up or down the band with each readjustment.

With transceivers largely replacing separate transmitters and receivers, one cannot zero beat in the same fashion. A variety of aids are available for correct tuning, including Elecraft's solution of injecting a tone into the audio chain—you then tune so that the two tones match. The Z100 provides a fast, visual representation of which direction you must tune for zero beat, and how far you must tune to establish that condition.

The display has 24 light emitting diodes, or LEDs. When connected to your transceiver or receiver audio output, each LED is associated with a range of frequencies either 25 or 50 Hz wide, depending on an option switch setting. The frequency corresponding to the center of the LED bar is user settable, and up to 16 settings may be saved and recalled.

When the received audio equals the set center frequency, the center LEDs (green) illuminate. If you are tuned high, LEDs to the right of center are illuminated, proportional to how far off tune you are. Likewise if you are low in frequency; except in this case the LEDs illuminated are to the left of center.

To use the Z100, you perform a one-time calibration, setting the Z100's center frequency to match your transceiver's sidetone or spotting offset. Thereafter, you tune your transceiver so that when receiving CW, key down periods illuminate both green LEDs approximately equally.  That's it--you are then on-frequency.

And, the Z100 may be used for digital modes as well.

Other digital modes may be tuned using the Z100, not just RTTY.
 

The Z100 prices (all in US$) are:

The Z100 includes the following:

• All parts, including programmed PIC microcontroller
• Double sided, solder-masked and silk screened printed circuit board
• Enclosure, with holes cut
• 3.5mm stereo phone jack cable 6 ft (nearly 2 meters)
• Power cable with molded power connector
• Printed manual

To purchase a Z100, mail a check or money order for the price of the goods plus shipping. The payment information is:

Checks / money orders payable to Clifton Laboratories
mail to:
Jack Smith d/b/a Clifton Laboratories
7236 Clifton Road
Clifton, VA 20124-1802

If you wish to order a Z100 via PayPal, you can compute the amount due (the kit plus shipping) and send the amount via PayPal (with your contact information, and shipping address) to orders@cliftonlaboratories.com. I've verified this link is working and receives PayPal payments.

If you have any questions concerning the Z100 or how to purchase it, you may drop me an E-mail at orders@cliftonlaboratories.com, or call at the telephone number at the top of this page.

Error in PayPal address -- I had a typographical error in the PayPal link on my Z100 page from the time it was posted on 07 May 2007 until 0600 EST 08 May 2007. It's now fixed, but if you sent an order via that address during that period, please cancel it and resubmit to the correct address: orders@cliftonlaboratories.com.

It's now working and my apologies to anyone inconvenienced by my error.

The first kits went out 14 May 2007. Kits are normally shipped within a day or two of payment receipt, absent unusual events, such as Dayton or vacation.

The Z100's microcontroller measures the audio input frequency a couple hundred times a second. The measured frequency is fitted into the appropriate 25 (or 50) Hz wide bin and the LED associated with that particular bin is illuminated.

Persistence of vision causes the LEDs to present brightness to the human eye that is proportional to the number of times that particular frequency bin is "hit" by the measured frequency.

Part of the audio processing involves an audio limiter, to convert the linear input to logic levels that are usable by the Z100's microcontroller. As with all limiters, very weak signals may show more noise than signal due to capture not occurring.

A maximum of 16 center frequencies may be saved to memory and recalled. Or, the Z100 may be operated in variable mode, where the center frequency is set via a potentiometer. The memory and control switches and potentiometer are accessible from the bottom of the enclosure.
 

The complete Z100 manual is available by clicking here, or via the Documents page. The schematic diagram is available by clicking here.

You may also contact Clifton Laboratories by E-mail or telephone at the addresses shown at the top of this page.
 

There is nothing complicated about the kit. All parts are through-hole and the printed circuit board is silk screened and solder masked. This kit is appropriate for beginners.

My experience and that of two prototype volunteer builders is that assembly time is about 2.5 to 3.5 hours.

The most difficult part of assembly is mechanical—aligning the LEDs and shim strips so that they look uniform when the kit is completed. This requires you to work carefully and slowly when mounting the LEDs.

Experienced builders may ask why the Z100 uses individual LEDs instead of bar strips of 10 LEDs. The answer is both mechanical (it changes the entire form factor towards a tall, thin shape) and design preference, as the desired red-yellow-green-yellow-red arrangement is not possible with bar modules.
 

The Z100's operation is software driven. Since the software is embedded in a microcontroller, this is often called "firmware." The firmware is written in BASIC, using the excellent Swordfish compiler.

Mechanique, the developer of Swordfish, has a free Special Edition compiler (Swordfish SE) available for download at http://www.sfcompiler.co.uk/swordfish/download/index.html.

The Z100's firmware is small enough to fit within Swordfish SE. This allows you to customize the firmware to your liking. I hope it encourages you to work on other PIC projects with Swordfish.

In addition to the free Swordfish SE compiler, you will need a logic-to-USB adapter cable. The Z100 is intended to be programmed with the FTDI TTL-232R USB to TTL Serial Coverter Cable (5V I/O), available from Mouser Electronics for $20.00, part number 626-DLP-TTL-232R.

Note using these tools require the Z100’s PIC to have pre-installed boot-loader firmware compatible with Swordfish’s Loader utility. The PIC that comes with the Z100 kit has this boot-loader in place, but a PIC purchased elsewhere will not. Of course, other programmers are available and the HEX code produced by Swordfish SE may be programmed into a suitable PIC via other programmers.

The Z100's firmware source code is available by clicking the following links.

Release 1.0 code is here
Release 2.1 code is here

This code is provided for the use by Z100 owners in maintaining and modifying their Z100's and for general educational purposes. No other use of the source code is permitted.

Release 2.1 adds the single frequency "PLL-type" display mode, as well as a few other changes.

For obvious reasons, Clifton Laboratories cannot support Z100’s operating with modified code.

Additional details on modifying the Z100's firmware is contained in the Operating Manual, available by clicking here.

There are several ways you can update your Z100 to the new firmware:

1. If you have purchased the programming cable (available from Mouser Electronics for $20.00, part number 626-DLP-TTL-232R) you can download the free Swordfish SE compiler and compile and load the new release 2.1 firmware. This process is covered in more detail at Section 5 "Programming the Z100" of the Z100's Operating Manual. The free Swordfish SE compiler can be downloaded at http://www.sfcompiler.co.uk/swordfish/download/index.html. The Z100 code, version 2.1 source code can be found here or via my Software page.
2. I will program the new firmware into your PIC and return it to you. Remove the 18F2620 PIC from your Z100 and mail it to me at the address shown at the top of this page, along with $3.00 for return postage, and I'll put the new code into your PIC. If you can't be without your Z100 for the week or so it will take for back and forth mailing, I'll send you a programmed 18F2620. When you receive it, return your current 18F2620 to me, along with $3.00 for postage.
3. If you have access to a PIC programmer, drop me an E-mail message and I'll send you a HEX file of the new code.
4. If you want to keep your old 18F2620 PIC, I'll sell you a new one, programmed with version 2.1 for $15, including shipping.

The Z100 started, like all my projects using a PIC with a Basic Micro development board and outboard hardware.

Yes, there a page for that. Click here for the page.