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

E-mail: Jack.Smith@cliftonlaboratories.com

This page documents comments on the Z90 and Z91.

Greg, W8WWV's comments are based on a prototype unit, but the main differences between the prototypes and the release version are mechanical. The performance specifications differ only slightly.

All other comments are based on the production version kits.

My comments are in blue text, set off by square brackets [].

As of 11 November 2006, I believe the only two constructed Z90s are those built by Stan, W5EWA and Bob, K7HBG, although I know at least one other builder has made it through Stage 4.

As of 22 November 2006, I Matt, KC0UKK, reports his Z90 as finished and working, and Doug, N6TQS, finished his a week or so before that, bringing the total number of working Z90's to four.
 

Mike has sent me two CD-ROMs worth of photos of his Z90 assembly. Here's one showing his shack with the Z90 in place.
 

Jack:

I am pleased to tell you that Z90 Serial# 1xxx is alive and well, fully assembled in its cabinet. I also installed the 4915 KHz Filter in the rear panel of my Z90 as shown by Doug N6TQS in one of your Construction Updates.

During construction everything checked out perfectly at each step along the way with one small exception: the pre-calibration current draw check on page 58 gave me readings that were slightly higher than you specified; however, my power supply puts out 13.8 volts (rather than the 13.5 volts specified in the manual) and that may have been the reason. In any event my higher-than-expected readings were: 384mA, 402mA, and 480 MA respectively. I decided that was close enough and forged ahead.

[The current readings in the manual are approximate, and are sensitive to the exact power supply voltage. The main thing to look for is gross deviation from the readings.]

Other than the small anomaly noted above everything checks out perfectly. I have been able to write my call sign into the Z90 memory, calibrate the internal oscillator against my frequency counter, and run the filter alignment routine. I have also hooked the Z90 up to my Elecraft K2 and observed signals pretty much as expected, although I can’t say that I know exactly what I am doing, or what I should be seeing, at this point.

In addition, the Z90 Control Program works as expected except in two small regards:

• I loaded down the revised Z90 08Nov2006 update and installed the three unzipped files into my C\Program Files\Z90-Control directory.
   
• The Z90 Control Program runs as expected and the 4914 KHz IF Center Frequency has been replaced with 4915 KHz selection.
   
• I cannot get the Help file to open. It gives me a “Navigation to the webpage was canceled” error message. The Z90.chm file is in the same directory as the Z90 Control Program file. I also get the same error if I try to open the Z90.chm file directly from Internet Explorer (I am using IE version 7, by the way).
   
• Another small glitch is that the COM port default has been lost somewhere along the way. I have to enter it each time I start the Z90 Control Program. Is there any way to reset it as the default without reinstalling the program, or can I reinstall the program without losing the 3 new replacement files?

[I have since provided Mike a new installation file with all the necessary files collected in one package which fixed the software glitches Mike experienced. I've also placed the complete installation file on the Software update page should anyone else experience this problem.]

During construction I took quite a few high resolution photographs at the end of each step. I have far too many to send to you via e-mail, but I could put them on a CD and send them to you if you have any use for them.

I’ll be “tinkering” with my setup over the next couple of weeks and will let you know how everything is going, but so far everything is working wonderfully! Thank you again for a great kit! I can’t wait to see what you come up with next…

[I'm working on several things, and I hope to have at least one of these projects ready for testing in a couple of months.]

73 de Mike W2PY

Jack: Z91 number 1010 is alive and well!

 Finished it without any problems, due to your excellent manual and meticulous parts packaging. I really enjoyed building it. Running it on my K2 and experimenting with the settings. What do you use for setting on your K2?

[I find Span = 50 KHz, RBW = 1 KHz, Vid Avg = 1 and skip factor = "Norm" works well for me.]

Missing only one TenTec black sheet metal screw and one of them is very poorly coated and doesn't match. Would it be possible to procure a pair?

Tnx, Mike

[I sent Mike two replacement screws yesterday.]
 

Jack, I started working on the Z90 on Sunday, December 3rd and finished today. [Saturday, December 9th.]

No problems with the Z90, and only an inadequately soldered AD8007 pin on the Z10000 kept it from working the first time - it works great!.

Both the front and back panels look fine to me - do not send replacements.

Thank you for a great kit building experience.

73, Randy - K4YYX
 

Hi Jack, The Z90 went together just as slick as can be. I READ and followed the very complete instructions and everything powered up as expected. I do have a decent counter and DVM, calibration went smoothly. I could obtain signal generator output past 70 Mhz under computer control. The mechanical parts fit perfectly and I will be proud to add the Z90 to my shack. I must yet build the buffer amps and install them but I don't expect any problems. My only headache was not of your making. The computer would only communicate via one com port, although it showed three were available.

[Although you can generate an output frequency well above 60 MHz, the amplitude rolls off rather rapidly above 60 MHz, as the 7th order 60 MHz low pass filter takes effect. But, there may still be instances where a weaker signal above 60 MHz can be used.]

One question, I see you had an software update. Do I need to install it or is the software provided on the included disk the most current.

[The software on the disk is current as of the date of shipping, or within a few days of shipping, as I usually make up several disks at a time from the then-current Z90 firmware and Z90-Control software. So far updates fall into the category of small fixes or changes and may or may not be installed as you desire, based on the description of the specific changes. For example, the on-line help in Z90-Control, released on 09 November 2006 may be useful. And, the most recent firmware release, version 606, released 27 November 2006, significantly improves the user's interaction with the soft keys when in signal generator mode, or when setting custom IF or custom span parameters. But, the original software is stable and works, so whether these updates are worth installing is up to the user.]

Also do you have a users group? Thanks again for a great project and tool.

[No user group, but if someone wishes to start one, be my guest. Also, any Z90 owner that wishes to post a review on the Eham.net board is more than welcome to. As the Z90 developer, I can't do that, but if you like your Z90, why not let the world know about it? And, a second production run of Z90 kits is dependent upon a sufficient number of prospective purchasers letting me know of their interest.]

Respectfully, Walt KE8BQ

Glenn, VK4TZL, provides a photo of his Z91 and comments on using it with his K12 and  transverters. The computer is running Z90-Control. Glenn notes:

I re ran the Calibration process after a day or two's operation and I did have a 16hz error. All checks after the third calibration run look very good and the Z91 is immensely useful on the 144 Mhz Band for spotting stations around my operating frequency.

The rest of the build went fine, Jack, the Z90 is up and running. I've completed the interim alignments, everything is rock solid; no drift, no variations, looking really good.

I didn't remove the paint on these panels (though, except for some 'orange peel' they look acceptable) so I'll wait and do the final calibration after the new panels are installed.

Meantime, I'll get started on the K2 IF buffer and while doing that, I'll run some two tone SSB tests on my K2 and all four of my transceivers (I've wanted to do that since I first built them last year).

Anyway, the Z90 Digital Panadapter is a keeper! I'm very pleased with the kit and I'm sure I'll be equally pleased with the product.
 

Hi Jack,

Kit arrived today, two days late on promised delivery, but I'm sure the
delay was with our Customs. Just for your information, no problem.

Kit has just now passed the Checkout after Stage 2X..all OK.

I'll advise as it progresses. Most impressed wit the whole thing...as good
as my Elecraft experience !

73

Glenn
VK4TZL

Hi Jack,

My Z-90 arrived this afternoon and the first surprise was the weight of the package when the postman handed me the box. Of course I almost lost several fingers in my rush to open the box and was impressed with the care with which everything was packaged. A quick scan of the manual and I was further impressed with its content and detail. It's obvious that many untold hours have been devoted to bringing this project to life. My only complaint is the cost of renting a small gorilla to open the Z-90 and cabinet boxes. I had considered using my chain saw but reason prevailed and I settled for the gorilla. After I read the manual several times I will start construction. Looks like a great project and a fine tool.

Best Regards,

Walt, KE8BQ
 

I've just finished opening all three packages and the inner boxes.  What a  nice packing job.  Everything appears to be in excellent condition and ready for assembly into a nifty Z90. 

Normally, at this point I would begin a component-by-component sort and detailed inventory, placing all of the parts into a large multi-divided plastic box that I generally use for this purpose, checking off each part on the bill of materials.  However, the meticulous way you've divided and packaged the Z90 parts, in close congruence with the assembly manual, makes this step appear unnecessary.  So, instead, I've just been browsing through the numerous highly detailed parts envelopes, examining the "Droppsies" bag and the "Long Term Running Spares" box (what a neat way to package those parts) and thinking that I might begin construction this weekend, if I can get a couple of work-related chores completed first. 

On examining the parts, I did have one question: When I examined the DDS Module I noted that all of the solder joints appear dull and grainy, not bright, smooth, and shiny as I would have expected them to be.  It occurs to me that this board might have been assembled using lead-free solder.  Is that the case?  If so, I have to tell you that I don't find it very attractive, as compared to a nice bright and shiny lead-based soldered board.  I guess I'm just old fashioned.

[The DDS modules were assembled by Mike, WA6OWU, of Kit Builders using lead-free solder and no-clean flux, in keeping with his normal practice. The higher heat required for lead-free solder also discolors the pads. I have tested all DDS boards and found no failures, so this is a purely cosmetic issue that seems to be a by-product of the type of solder used. For Z90 assembly, I strongly recommend standard eutectic tin/lead solder, or, even better, tin/lead/silver (2%) solder. JRS]

Upon examination, all parts of the kit, including all of the electronic components, the circuit boards, the cabinetry and other metal work, the cables and other miscellaneous parts, and the manuals are first rate.  I am very pleased with the Z90 kit, and can't wait to begin construction. 

Finally, thank you so much for your inquiry regarding my receipt of the kit. You sure know how to impress your customers and fans! 

PS:  The Serial Number Tags ("Built by W2PY") are also a nice touch.  You don't miss many details.

Jack,

 The kits arrived today, everything is in great shape.  I've looked
over the manual, opened all the boxes and I must say how impressed I
am with the all the little details you've put into your product.

The parts bags are all labeled, the LCD display is boxed separately,
the manual with full dividers, double boxed shipping, photos,
schematics, tips, explanations, etc.  If I have any trouble, it'll be
because I'm sleep walking and not paying attention.

Looks like a great project, Jack, you've already exceeded my
expectations.


Matt

Greg, W8WWV, has used the Z90 prototype exhibited at the Dayton Hamvention, and an early version of the universal interface buffer amplifier.

Greg connected the Z90 with his DSW-II 40 meter band QRP transceiver.
 

[The buffer amplifier has two purposes. First, to provide a non-disturbing connection to the receiver's IF, and second to provide a small amount of gain (12 dB maximum) if necessary. The buffer amplifier's gain should be set so that the SpectraScan shows the receiver's noise on a quiet band. It's important not to use any more gain in the buffer amplifier than absolutely necessary, as extra gain degrades the SpectraScan's useful dynamic range.]

[The top photo is 7 KHz span, and shows detail with a relatively narrow width (each graticule division is 700 Hz). The bottom photo shows maximum span, 200 KHz.]

"With the 7 KHz span, it's possible to get a good look at the AM signal. With the wider span, it's more of a general signal detector, much like the ICOM radio bandscopes."

"I've been fooling around with the span for the most part. It is very reminiscent of the ICOM bandscope on my 750PRO radio, except that when you crank down the span you get a much more detailed view with the Z90, since there are a whole lot more pixels available."

"Anyway, seems to work great, and that buffer amp with 12 VDC supply is pretty much perfect."