Slow Progress on the 10HGz WFM Project.

 The past few weeks I have been working a bit on the modulator for the 10GHz HB100 module. The modulator worked, but I needed to build it up on some prototype PCBs and that is almost there. A CW (audio) generator is under way, and then it needs to go into a box, so it can be operated portable.

I may also make myself a test TX ("beacon") with the HB100 and just a CW audio generator. I think I have found some directions where I can test the TX on top of a 12m telescopic fibreglass mast and then walk on road and path to test the path for (near) line-of-sight propagation. First tests will be in the garden, of course, with a max range of about 35m ;)

Then I will have to take some walks, I suspect that I have found a possible distance of about 600m, and maybe one of about 1.6km. 

This will all be using the HB100 with the built-in dual patch antenna on the PCB, and the LNB just with the integrated feed horn. Not a lot of gain, but some people have claimed the range of such a simple arrangement to be 8, maybe 15km. The distance to a fellow amateur who is interested in participating is less than 10km, and we suspect that we could possibly make a line-of-sight contact from garden to garden.

Initially I just build a single TX and RX, but having made one set it is not too difficult to make another.

For longer distances some improved antennas or higher power is needed for WFM contacts.

I hope to be able to make the first one-way tests in my garden this week end, and hope for some decent weather to make the tests on longer distances.

I will need the weather to be dry and not too windy for these experiments, as the HB100 module(s) need to be in the open air, or at least with very low loss material in front of the patch antennas.

Now we start the idea box:

Improved antennas can be the following:

- mounting the HB100 and the LNB (or just the LNB) on a dish. Not easily portable if I need to up a steep road to a hilltop, or up a narrow staircase to a watch tower or the like. Also, for the dish a tripod is needed, and it should not be too flimsy.

- The second option involves more work: Horn antennas. In this case both the HB100 and the LNB need to be "connected" to horn antennas. For this some coax-to-waveguide transitions are needed. I have one.

It may be possible to "glue" a horn antenna in front of the LNB. I will have to test how efficient that will be.

The HB100 *could* be mounted inside a "horn". I do not know how efficient that will be, so modifying a HB100 with a connector/coax to the coax/WG transition.

- The other option for keeping the size/bulk of the equipment low also involves more work: Going narrow band. This could be NBFM as we use it on 2m and 70cm, or it could be a CW transmitter, to keep it as simple as possible. Both would likely involve generating a much lower frequency, and using frequency multipliers to get to 10GHz. Much more complex electronically, but still relatively simple mechanical construction.

We shall see what we will do, but first some short range tests will be done, likely this autumn.