Don, W6QS has been doing an excellent job in the proceedings and development of the printed circuit board (PCB) that is the heart of our microwave receiver and transmitter! This PCB incorporates some very nifty features!

You may recall that in our last announcement we listed some of the design intent for this project. Since that time Don and his trusty CAD PC (that's Computer Aided Design - Printed Circuit) "work station" have laid out a board that will do wondrous things! It contains:

1) Plug in provision for the 10.7 MHz. Intermediate Frequency (I.F.) filter.

This allows either the hand built component filter (that is used with the 30 MHz. I.F. microwave application) to be fabricated on a "DIP" (Dual Inline Pin) "header". Or for either of the 6 KHz. "narrow band" operations, this header would be substituted by an appropriate filter from Murata company. The narrow band applications are of course intended for 1 KHz. FM deviation modulation on 29 MHz. or 50 MHz. This feature should allow the narrow band receiver to be competitive against a Single Sideband (SSB) receiver in its DX performance. This circuit arrangement provides some 70 Decibels of cascaded noise limiting, a quadrature detector receiver. When such a receiver is demodulating a 1 KHz. deviation voice or MCW signal from a companion transmitter, the DX potential should be phenomenal!

By the way, we do have a companion 6 or 10 Meter transmitter in the works! It will be of a similar size PCB as the receiver, and will operate from 12 Volts DC.

2) Another feature of this PCB that Don has laid out is for an "onboard" FM modulator.

This modulator is used for the companion GunnPlexer that is utilized in the microwave application. The modulator is not included "onboard" the PCB of other manufacturers boards, nor on the similar kit projects that have recently been written about in the VHF/UHF/SHF oriented clubs newsletters! This feature provides nominal FM voice, or Modulated Continuous Wave (MCW) iCW code operation. This should prove to be a real handy feature!

3) The PCB also provides for "proto-typing" other circuits "onboard" the PCB!

This was done primarily to efficiently use any extra circuit board area or "real- estate" that would otherwise have been left as blank unusable circuit board. It does offer some interesting possibilities for the experimenter that might want to add or build a few extra features into his or her particular unit. There is enough circuit space to accommodate a few Integrated Circuits (IC's) chips, or about twice that number of discreet transistors.

4) The PCB also provides for a "Log Driven" signal "S-meter", and also a "Tuning Meter".

The "S" meter will of course be handy for those who want to do actual DX signal assessments, or maybe microwave or other antenna tests, and the "Tuning Meter" essentially allows you to be certain that you are centered within the modulation bandwidth of another stations transmitted signal. Both meters will of course allow you to assess the "symmetricity" of such a modulated signal. It almost makes the unit a piece of test equipment or signal analyzer!

Well, thats just about it! I'm sure though there are other features for which I have simply not placed enough emphasis! Things like the onboard audio amplifier and other handy features. All of these things will I'm certain come to their own light of interest as the number of people grow that will use this PCB for different Ham Radio applications. I hope that as the units start to proliferate the Ham Community, that we can build sort of a "users club". For those of you who may be familiar with such activities, they have really helped to push the development of various radio, computer, or other electronics devices!

It is for this kind of feedback, and just plain fun, that we have thought to make the unit capable of two channel operation. On 10 Meters with one crystal controlled channel at 29.600 MHz. (which is the National Simplex CALLING Frequency) and a second channel at 29.500 MHz. (which is a common "chat" frequency, after you have hooked up with someone on 29.6) there is great potential for many many DX friends on 10 Meter FM. Some will be using different of the 100 Watt HF transceivers that are now prolific on this mode. Hopefully many others will be using our combined FM receiver that Don has designed, and its companion transmitter that was designed by Wil, AA6DD. I will have more on the transmitter as it reaches the prototyping stage!

This same operational scheme that I mentioned above could also be used on 6 Meters, when the PCB is assembled for use on that band. On 6 however, there is even greater potential for some fun experimentation!

This is true because of both the nature of this band, and also because of the nationwide acceptance of its "Band Plan". The units will be 2 channel capable, just like the 10 Meter band assembly. The first channel will be 50.300 MHz. This is a frequency that has gained wide use and popularity, largely spurred on by AA6DD. I would make the following recommendation for the second frequency channel, depending on your desires for the radio's use.

If you are oriented to just finding other folks either locally, or even DX, to just chat with, I would crystal the transmitter/receiver second channel on 50.360 MHz. This places you in a generally good spot to get off the more frequently used 50.300 "quasi calling or activities channel", and it also puts you up in the "War Powers Act" frequency area of FCC Part 97 Subpart E. If however you have a bent or passion for some "Computerized DX'ing", you could put the second channel up at 50.620 MHz., which is the "Experimental Packet Channel".

All baud rates are acceptable for use by convention on this frequency. Of course their is a legal mandate not to exceed the prescribed modulation bandwidth for use on this band of frequencies. This though would allow for baud rates as fast as 9600 baud, or as slow as 300 baud. So, if you have an old TNC that is gathering dust, you could use it here and seek out folks running the same slower baud rates. If you have either a 1200, or preferably 9600 baud rate capable TNC, you can really do some interesting stuff!

Look at my article on our web page on 6 Meter antennas! You will find that I have eluded to, and halfway designed a scheme for a fully computer controlled DX station on 6 Meters. This is a providential time for such activity! Six Meter band "Sporadic E Layer" DX has been really great, and we still are climbing up to the peak of the 11 year Sun Spot Cycle. In about a year or so 6 Meter F Layer DX should really be hopping! You could be the first on your block to have your computer qualify for a "WAS" (Worked All States) award on 50 MHz. (which by the way is a very prized certificate), or maybe your computer might be able to Work All Continents!

The last of this news release is not as positive as the previous announcements. We have had some financial setbacks with some of the group funding for this project. We had one check bounce, that turned out costing us money, and some of the previous participants it seems have lost interest. Our original intent was to turn out a commercial quality FR-4 .062 inch thickness PCB. We may have to produce the first prototypes of a thinner smaller cost overhead fabrication. This will ultimately make more work and effort for those who have remained dedicated to this project from the start! It may also make for some anomalies in our qualification testing that would otherwise have not occurred.

I would like to keep the original plan for a commercial quality board intact. The intent at the level of the qualification board would be for FR-4, .062 thickness, tin over bare copper. The next true production board would then be THIS SAME BOARD, except that it would have a solder mask and silk-screen component layout on the board. Those earlier participants and their present day resolve will dictate whether we are able to do this or not!

We have amassed quite a few more Gunnplexers so that everyone who was first interested should be able to get one. Remember that per our original plans everyone who completed a working I.F. board would get a GunnPlexer essentially for free, until they run out. At this point in time we have a list of these original participants, and their relative contribution or deficit. We can only achieve our intended goal if we do this as a cohesive group!